Chemical Processing Technology Articles

Hydrogenation is a billion-dollar industry. Hydrogenating means to add hydrogen to something. According to Haldor Topsoe, hydrogenation comprises 48% of total hydrogen consumption, 44% of which is for hydrocracking and hydrotreating in refineries , and 4% for hydrogenation of unsaturated hydrocarbons (including hardening of edible oil) and of aromatics, hydrogenation of aldehydes and ketones (for instance oxo-products), and hydrogenation of nitrobezene (for manufacture of aniline).   Hydrocracking & Hydrotreating Industrially, hydrotreating and hydrocracking are performed in down flow ‘trickle bed reactors’, where the gas and the liquid feed are sent concurrently through a fixed bed plug flow reactor. Although the flow pattern in the reactor can be reasonably approximated, the observed kinetics in such a trickle bed reactor are quite often affected by minor unplanned oscillations in the flow. How the gas and liquid collide and mix together affects the end product characteristics, so industrial reactor simulation models require that these phenomena be accounted for. Instrumentation, coupled with advance simulation software, is integrated so that operators can keep track of the mass flow of each chemical, interphase mass change, and heat transport in the trickle bed reactors.   Food Industry Hydrogenated fat is usually a substitute to butter fats. High costs of butter fat and its poor storage stability led to using hydrogenated fats and oil. The unsaturated fatty acid content of triglycerides is changed by hydrogenation into hydrogenated oils by the saturating of their carbon double bonds (C=C) and converting them to single carbon bonds (C-C) in the presence of catalyst, usually Nickel. Hydrogenation accomplishes two things: 1) It increases the melting point of the oil or fat. 2) Resistance to oxidation and flavor deterioration. Hydrogenation process depends on several parameters: type of catalyst, pressure, speed of agitation, and temperature. Unsaturated food oil is pumped in a pressure vessel called an hydrogenator. This must be equipped for good agitation, for heating and cooling, and with suitable openings for oil, hydrogen, and sampling. Vacuum is applied on the headspace and heating started. Vacuum prevents oxidation of oil when heated. Catalyst is weighed into a catalyst mix tank, slurried with a small amount of oil, and when the reaction temperature is reached the catalyst is pumped into the reactor, mixed and then hydrogen is added to the desired pressure. Hydrogenators allow the hydrogen to accumulate in the headspace above the oil with recirculation provided by vortex action of the agitator. During hydrogenation, water is circulated through the cooling coils to counteract the heat of reaction since hydrogenation is an exothermic reaction, and later for cooling prior to filtration. After cooling, the nickel catalyst is then removed from the hydrogenated fat by filtration.   Chemical & Pharma Synthesis Aniline is produced by the hydrogenation of nitrobenzene. Nitrobenzene is fed with hydrogen into a tubular plug-flow reactor containing a noble metal (i.e. platinum) catalyst supported on carbon. The hydrogenation is carried out in the liquid phase. The majority of the aniline produced globally is utilized in the manufacture of methylene diphenyl diisocyanate (MDI). To make MDI you react aniline with phosgene, in a process called Phosgenation. Phosgene is made by reacting carbon monoxide with chlorine, and like the hydrogen used in the hydrogenation process, the carbon monoxide used to make phosgene comes from a steam-methane reformer (SMR). In the Pharma industry, the hydrogenation process is particularly useful in the production of chiral and commonly hydrogenators are used, providing organic compounds like R-3-Quinuclidinol (C7H13NO) used in the manufacture of intermediates used in APIs (activated pharmaceutical ingredients).   Conclusion The hydrogenation market brings in over billions of dollars in revenue each year. For this reason, people buy and sell used hydrogenation equipment, and since this equipment is useful across multiple applications, hydrogenation equipment such as hydrogenators hold their value in the second-hand market. Please find our inventory of hydrogenators below:   https://www.phxequip.com/plants-subcategory.49.0/hydrogenation-plants.aspx

Thermoplastics are a class of polymers, that with the application of heat, can be softened and melted, and can be processed either in the heat-softened state (e.g. by thermoforming) or in the liquid state (e.g. by extrusion and injection molding). Over 70% of the plastics used in the world are thermoplastics, and the two most commonly used thermoplastics are both olefins, compound made up of hydrogen and carbon that contains one or more pairs of carbon atoms linked by a double bond. These two olefins are polyethylene and polypropylene.   Polyethylene Polyethylene is a tough, light, flexible synthetic resin made by polymerizing ethylene, chiefly used for plastic bags, food containers, and other packaging. It may be of low density or high density depending upon the process used in its manufacturing. It is resistant to moisture and most of the chemicals. It can be heat sealed and is flexible at room temperature (and low temperature), and in additional to its material properties, its low cost contributes to the popularity and high demand of the material. Major Applications • Low-density polyethylene (LDPE), recyclable plastic no. 4, is flexible and is used in the production of squeeze bottles, milk jug caps, and retail store bags.• Medium-density polyethylene (MDPE) is used for sacks, gas pipes, fittings, and packaging film.• High-density polyethylene (HDPE), recyclable plastic no. 2, is commonly used as milk jugs, liquid laundry detergent bottles, outdoor furniture, margarine tubs, grocery bags, drinking water distribution systems, and water drainage pipes. • Ultra-high-molecular-weight polyethylene (UHMWPE) is tough and resistant to chemicals. It is used to manufacture moving machine parts, bearings, gears, artificial joints, and bulletproof vests. Production Process Polyethylene is made by the polymerization of ethylene, which is the reacting of ethylene molecules together to form a chain of ethylene molecules. The two primary feedstocks for ethylene production are naphtha and natural gas liquids (ethane, propane, butane). Natural gas liquids are used in countries like the United States where natural gas is abundant, and naphtha is used commonly in Asia where producers have access to cheap byproduct naphtha. Ethane is a major bottleneck chemical, so many refineries have furnaces to take the over-abundance of ethane and convert it into the more valuable ethylene.The first step in the production of ethylene is to take the feedstock and crack it into ethylene in a furnace. This process is called pyrolysis. Also called steam cracking, pyrolysis is the thermal cracking of petroleum hydrocarbons with steam. The production process for the two most common types of polyethylene: low-density polyethylene and high-density polyethylene, will be described below. Low-density polyethylene (LDPE) is made from ethylene gas under extremely high pressures (up to about 3,500 bar, or 50,000 psi) and high temperatures (up to about 350 °C [660 °F]) in the presence of oxide initiators, which results in a polymer structure with both short and long branches. Because the branches prevent the polyethylene molecules from packing closely together in stiff, hard crystalline formations, LDPE is a very flexible material. Its melting point is approximately 110 °C (230 °F). Principal uses are in packaging film, trash and grocery bags, agricultural mulch, wire and cable insulation, squeeze bottles, toys, and housewares. High-density polyethylene (HDPE), on the other hand, is manufactured at low temperatures and pressures, using metallocene and Ziegler-Natta catalysts or activated chromium oxide (also known as a Phillips catalyst). The lack of branches in its structure allows the polymer chains to pack tightly, resulting in a highly crystalline, dense material of high strength and moderate stiffness. With a melting point more than 20 °C (36 °F) higher than LDPE, it can withstand repeated exposure to 120 °C (250 °F) for sterilization. Products include blow-molded bottles for milk and household cleaners; blow-extruded grocery bags, construction film, and agricultural mulch; and injection-molded pails, caps, appliance housings, and toys. Major Technology Providers Ethylene Plants: KBR; Technip; Linde; Shaw, Stone & Webster; and Lummus. Polyethylene Plants: Sasol; Formosa Plastics; Ineos; and Odebrecht.   Polypropylene Polypropylene, recyclable plastic no. 5, is useful for a plethora of products such as microwave and dishwasher-safe plastic containers, reusable plastic food containers, sanitary pad lining and casing, diaper lining, carpets, ropes, plastic moldings, piping systems, filters for gases and liquids, car batteries, and insulation for electrical cables. Polypropylene sheets are used for stationery folders and packaging and clear storage bins. In medicine, it is used in hernia treatment and to make heat-resistant medical equipment. Although relatively inert, it is vulnerable to ultraviolet radiation and can degrade in direct sunlight. Polypropylene is not as impact-resistant as the polyethylenes (HDPE, LDPE). It is also somewhat permeable to highly volatile gases and liquids. Production Process Traditional productions methods are the naphtha steam cracking process and propane dehydrogenation. The naphtha steam cracking process is very similar to the steam cracking process of natural gas liquids; while propane dehydrogenation is a very different process that involves mixing fresh propane feed is with recycled propane and optionally also with recycled hydrogen gas and is fed into a heater to be heated to over 540°C (1000°F) and then enters usually three or four reactors. The propylene-rich reactor effluent is compressed, dried and sent to a cryogenic separator where hydrogen is recovered. The olefin stream then goes to an ethylene column where light-ends are removed prior to the propane-propylene splitter where propylene is recovered. Unconverted feedstock is recycled and combined with the fresh feed.Propylene could also be generated in FCC (fluid catalytic cracking) units but its yield is relatively low. Another approach is to integrate the propylene production process into refinery or petrochemical plants, and use lower value chemicals made in the process, for the catalytic cracking of mixed C4 olefins (olefins with 4 carbon atoms) and higher carbon olefins. Major Technology Providers Propylene Plants: Lummus Technology; Servomex; Honeywell UOP; and Mitsubishi Chemical. Polypropylene Plants: LyondellBasell; Borealis; Chisso; Grace; Mitsui Petrochemical; Krupp Uhde; Linde; Yarsintez/Snamprogetti; Novolen Technologies; Rexene; and Sumitomo Chemical.   Conclusion Demand for thermoplastics exceeds billions of dollars globally, and the two most common originate from hydrocarbons from refineries such as naptha, ethane, propane, and butane. If you already have a refinery, or access to cheap feedstock, or, for example, as a by-product from another chemical plant -- the return on investment of a used thermoplastics plant can be less than 3 years depending on the particulars of your local/global economic positioning and utility costs. Please find a link to our ethylene plants on offer below: https://www.phxequip.com/plants-subcategory.36.0/ethylene-plants.aspx

In this article, we will show that a steam methane reformer (SMR) is critical in the production processes of hydrogen, ammonia, and methanol; as all three use the raw syngas produced by an SMR upstream in their synthesis.   Syngas Production In what is called steam methane reforming, high-temperature steam (700°C–1,000°C) is used to produce raw syngas from a methane source, typically natural gas. Using a steam methane reformer (SMR), methane reacts with steam under 3–25 bar of pressure in the presence of a catalyst to produce hydrogen, carbon monoxide, and a relatively small amount of carbon dioxide. The resulting gas mixture is called synthesis gas, or syngas for short; and is the raw ingredient in hydrogen production, ammonia synthesis, and methanol synthesis.   Hydrogen Production Subsequently, in what is called the "water-gas shift reaction," raw syngas and steam are reacted using a catalyst to produce carbon dioxide and more hydrogen. In a final process step called "pressure-swing adsorption," carbon dioxide and other impurities are removed from the gas stream, leaving essentially pure hydrogen.   Ammonia Synthesis Ammonia is produced at an industrial scale through the synthesis of nitrogen and hydrogen in an ammonia synthesis loop in what is called the Haber-Bosch process. The hydrogen and nitrogen are mixed at a 3:1 ratio. In most processes the reaction takes place on an iron catalyst. The reaction pressure is normally in the range of 150 to 250 bar‚ and temperatures are in the range of 350°C to 550°C. Generally speaking, an ammonia plant will have feed purification, a primary and secondary SMR, water-shift converter, carbon dioxide removal, methanation, and finally an ammonia synthesis section. For a more in-depth view, please find our ammonia article below: https://www.phxequip.com/resource-detail.56/ammonia-production-technologies.aspx   Methanol Synthesis                    Methanol is produced by reacting carbon monoxide and carbon dioxide with hydrogen using a methanol synthesis loop. It processes raw syngas made from a SMR and gas recycled from the secondary reformer in the presence of a zinc / copper catalyst. The partially reformed gas stream from the primary reformer is sent to the secondary reformer where it is reacted with oxygen and most of the remaining methane converted to synthesis gas, which is called recycle gas and is sent back to the primary reformer for processing. A standard methanol plant consists of the following process section: feed purification, steam reforming, syngas compression, methanol synthesis (conversion/reaction) and methanol distillation. Please find a more detailed explanation of methanol production in our article below: https://www.phxequip.com/resource-detail.16/the-3-phases-of-large-scale-methanol-production.aspx   Conclusion Syngas is a key feedstock in the production of hydrogen, ammonia, and methanol. Almost all of this syngas is produced by a steam-methane reformer (SMR), so regardless if you’re planning to build a hydrogen, ammonia, or methanol plants -- SMRs are the heart of the facility. Furthermore, due to the inherent similarities between ammonia synthesis loops, and methanol synthesis loops, engineering firms have successfully converted ammonia plants into methanol plants, and methanol plants into ammonia plants. So, there are multiple path to save on capital costs by purchasing a used plant.   Link to Syngas/Hydrogen Plants: https://www.phxequip.com/plants-subcategory.140.0/hydrogen-hyco-syngas-plants.aspx Link to Ammonia Plants: https://www.phxequip.com/plants-subcategory.140.0/hydrogen-hyco-syngas-plants.aspx Link to Methanol Plants: https://www.phxequip.com/plants-subcategory.55.0/methanol-plants.aspx  

Discussion on Types of Air Separation Plants Introduction: From the mass production of steel to the manufacture of sophisticated micro-chips and semi-conductors by leading technology firms, air separation plants – and specifically access to the right volume and purity of oxygen and nitrogen – are critical to the successful operations of a variety of manufacturing and engineering businesses. Oxygen and nitrogen can be extracted from atmospheric air using both cryogenic and non-cryogenic air separation processes. So how can chemical engineers choose between the two processes and what does each involve? Non-cryogenic air separation is ideal for lower-volume processes where cost efficiency is key and lesser purity acceptable. Typically, purities of 85–95% oxygen purity and up to 99.999% nitrogen purity can be achievable and cost effective using a non-cryogenic process. By contrast, cryogenic air separation suits (ASU) a high-volume process where purities of around 99.5% O2 and parts per billion oxygen in nitrogen may be required, or very high-volume processes that would require many non-cryogenic air separators to achieve the required output. Ultimately, each situation is different and any approach should be tailored and bespoke to requirements, with the focus firmly on achieving the best return on investment. Process Differences: In both cryogenic and non-cryogenic processes, the air is compressed and the heat of compression is removed. Sometimes further cooling is achieved via shell-and-tube exchangers or direct contact aftercoolers using both cooling water and chilled water. Downstream of air cooling, the two methods of production differ significantly. For cryogenic plant, to ensure safety and facilitate an efficient process, it is critical that contaminants such as CO2, water vapor and heavy hydrocarbons are removed from the air. This is achieved using temperature swing adsorption (TSA). The adsorber vessels contain beds of activated alumina and molecular sieves. They operate cyclically, alternating between adsorption and regeneration, achieved with dry waste gas. Some of the lighter hydrocarbons pass through the TSA and into the cold box where their concentration is monitored and controlled. In the non-cryogenic process, hydrocarbons, moisture and particulates are removed using carbon towers, filters and mist eliminators. The process gas then enters a pressure swing adsorption twin-bed system using a carbon molecular sieve which separates oxygen and CO2 from the air. Different adsorbents attract certain gases more strongly than others. For example, in nitrogen production, oxygen is preferentially adsorbed on the bed while a nitrogen-rich stream is recovered as product. Exhaust gases are vented to atmosphere.  Other technologies such as membranes are used to produce typically 95–99.5% nitrogen in typical volumes of 25 tons per day (tpd). Vacuum swing adsorption is an alternative means of low-purity oxygen production for markets such as glass, wastewater treatment, cement production, bio-fuels, metals production, pulp and paper and steel.  The range of oxygen production varies from 5–500 tpd. Cryogenic Air Separation: Cryogenic air separation units (ASUs) then take the air through another cycle of treatment to extract gases of a higher purity of volumes in excess of 4,000 tpd per ASU. This involves air liquefaction and distillation. The boiling points of pure gases are -183°C for oxygen and -196°C for nitrogen at atmospheric pressure. By compressing the air, heat integration within the cold box is allowed and nitrogen is condensed against boiling oxygen in the low-pressure column reboiler. Cycle selection is dependent on product purity, range of products and whether gas or liquid products are required. Choosing the optimal configuration is vital to minimizing capital and operating costs. The cold box contains distillation columns operating at a range of pressures. The clean air stream is cooled in a main heat exchanger (MHE) before flowing to a high-pressure column, with a fraction of the cooled air expanded to provide refrigeration to the plant. Alternative means of refrigeration may be employed; for example, liquid nitrogen (LIN) injection. In the high-pressure column, the liquid from the bottom of the column becomes enriched with oxygen, while the vapor passing up to the top of the column steadily increases in nitrogen purity. Gaseous nitrogen product is taken from the top of the high-pressure column. The vapor at the top of the column is then fed to the low-pressure column reboiler where it is condensed. A portion of the condensed nitrogen returns to the high-pressure column as reflux, and at this point a stream of condensed nitrogen may be sent to storage as LIN product. Within the low-pressure column, oxygen is withdrawn as a liquid from the sump. It may be pumped as a liquid when high pressure gaseous oxygen is required. A low-pressure waste stream may be obtained from the column, warmed in the MHE and used for TSA regeneration. Furthermore, pure argon may be produced by withdrawing a feed stream from an optimal location and processing in a separate distillation column system. Making the Choice: Both cryogenic and non-cryogenic air separation processes have their advantages dependent on the specified volume and purity. Employing the right approach and the most appropriate cycles is critical if chemical engineers are to ensure air separation plants operate at maximum efficiency, and the highest levels of safety. While ambient processes may be simpler but sometimes less efficient than cryogenic technology, they offer more flexibility for batch processing, with short startup and shutdown times and considerably less equipment. In contrast, air separation units have multiple design options which allow the whole range of atmospheric gases to be recovered. Major Air Separation Plant Producers Cryogenic Air-Separation: Air Products and Chemicals, Enerflex Ltd., Gas Engineering LLC, Linde AG, Messer Group GmbH, Taiyo Nippon Sanso Corporation, Inc., Technex Limited, and Universal Industrial Gases. Non-cryogenic Air-Separation: Air Products and Chemicals, Generon, Kuraray Chemical, On-Site Gas Systems, Parker Hannifin, and Proton Onsite.  

The urea production uses CO2 gas and liquid ammonia as raw materials supplied from an Ammonia plant. This article will divide urea production into six sections: 1) Synthesis & HP Recovery; 2) MP Purification & Recovery; 3) LP Purification & Recovery, 4) Vacuum Concentration; 5) Condensate treatment; and 6) Prilling.   SYNTHESIS AND HIGH PRESSURE (HP) RECOVERY In addition to the HP machinery required to feed ammonia and carbon dioxide and to recycle ammonium carbamate solution, this section includes: the reactor where urea is formed; the stripper necessary to strip out as vapors, from the urea solution leaving the reactor, a large amount of ammonia and carbon dioxide not converted to urea in the reactor; the carbamate condenser that condenses these vapors; the ejector that recycles the ammonium carbamate solution to the reactor. In this equipment the pressures are of a similar level, 150 bar, while the temperatures of the outlet solutions are 188, 205 and 155°C for the reactor, the stripper and the carbamate condenser, respectively. Inside the reactor a matching number of trays of a very simple design are installed to improve the conversion. Under these conditions 62-64% (conversion) of the total CO2 entering the reactor is converted to urea. The total carbon dioxide conversion in the HP section (or loop) is 85-90%. All the equipment in this section, the heaviest of the urea plant, is installed at ground level, thus providing a horizontal layout with all the relevant benefits. The stripper and the hydrolyzer in the waste water section are the only two items of equipment in the plant that consume medium pressure steam. The amount of steam consumed in the stripper is practically completely recovered in the carbamate condenser: its pressure is lower but still sufficient to be used in the urea plant itself. The quantity of oxygen introduced into the plant as air is 0.25% vol of the fresh feeding carbon dioxide. This minimum amount guarantees, at the same time, excellent equipment passivation and the absence of explosive mixtures where the “inerts” are released from the plant into the atmosphere after practically all the ammonia contained therein has been washed. Thanks to the proper choice of the materials in contact with the process fluids and to the presence of excess ammonia, it is possible, during unscheduled shutdowns lasting only a few days, to bottle-in the high-pressure synthesis loop by operating a few valves, thus keeping all the process solutions inside the loop. In this way obvious pollution and start-up problems are completely averted. All kinds of machinery (reciprocating and centrifugal) is utilized according to local conditions.   MEDIUM PRESSURE (MP) PURIFICATION AND RECOVERY The purpose of this section is to partially strip out the reactants, ammonia and carbon dioxide from the urea solution and, after their condensation in water, to recycle the obtained solution to the reactor, together with the ammonia and carbon dioxide aqueous solution resulting from the downstream sections of the plant. The ammonia excess is separated in this section and recycled to the reactor separately. A distillation column is provided for this purpose. The operating pressure is 17 bar g. A particular feature is included in this section. Ammonia and carbon dioxide are partially condensed in the shell of a preheater within the vacuum section, thus recovering some energy in the form of 200 kg of steam per ton of urea, with an investment cost that, even in existing plants, has a pay-back time of less than two years. Another particular characteristic of the MP section is the washing of the so-called inerts (CO, H2 and CH4 contained mainly in the carbon dioxide and the passivation air). For the complete abatement of the ammonia contained in the inerts, in completely safe conditions with regard to explosions, The inerts are washed with water after the addition of a quantity of flammable gas, as for example natural gas, in such an amount that after the ammonia has been eliminated, the composition of the inerts is out of the explosive field due to the excess of flammable gas. The washed inerts are sent to a burner together with the natural gas. It should be emphasized that the presence of the MP section provides great plant flexibility, which can be operated over a wide range of NH3/CO2 ratios, with excess ammonia present in the urea stream from the stripper being recovered and condensed by the MP section.   LOW PRESSURE (LP) PURIFICATION AND RECOVERY Further stripping of ammonia and carbon dioxide is made in the LP section, operating at 3.5 bar g. The vapors, containing ammonia and carbon dioxide, are condensed and recycled to the reactor via the MP section. An appropriately sized tank is provided in this section to collect all the solutions from the plant when it is shut down for long time. Therefore, in no circumstances are solutions discharged from the plant.   VACUUM CONCENTRATION The urea solution leaving the LP section is about 70% b.w. and contains small quantities of ammonia and carbon dioxide. The final concentration of the urea solution (99.8% b.w.) is made under vacuum in two steps at 0.3 and 0.03 bar abs. for the prilled product, and in one or two steps for the granular product, according to the granulation technology chosen. An important feature of this section is the preconcentration of the urea solution to about 86% b.w. The necessary heat is provided by partial condensation of the vapors (ammonia and carbon dioxide essentially) from the MP section evaporator. A simple solution has been found to the problem of lump formation in the second vacuum separator: lump formation is prevented by wetting the internal walls of the separator by means of a small recycle of molten urea.   PROCESS CONDENSATE TREATMENT This stage discharges a large amount of process water with 1 ppm of urea and 1 ppm of ammonia lowers specific consumption of ammonia and reutilizes process water as boiler feedwater). All possible and convenient heat recoveries are generally introduced into this section in order to minimize energy consumption.   FINISHING: PRILLING Prilling is the easiest technology to manufacture solid urea with commercially valid chemical and physical characteristics. Molten urea (99.8% b.w.) is sprayed at the top of the prilling tower, at a height of 55-80 m, according to climatic conditions; at the bottom, essentially spheroidal urea particles, namely prills, are collected and sufficiently cooled in order to be sent to storage or directly to the bagging section without screening, coating or any other treatment. A rising draught of air inside the prilling tower is the cooling medium that removes the solidification heat and cools the prills.   MAJOR TECHNOLOGY LICENSORS There are multiple technology licensors with proprietary plant designs and features. The main urea process licensors are Snamprogetti, Urea Casale, Kellogg and Stamicarbon.   COST AND UTILITIES OF AN UREA PLANT A new plant constructed in Azerbaijan in 2018 by Samsung Engineering, with licensing in place with Haldor Topsoe for the production of ammonia and Stambicarbon for the production of urea, produces 1,200 tons of ammonia and, subsequently, 2,000 tons of urea per day. The plant will consume 25-26 MW of electricity per hour. The urea plant will require 1.3 million cubic meters of natural gas per day for operation at full capacity. The cost of the project is 770-780 million euros.

Competition between Ammonia technology suppliers is quite fierce. Three technology licensors — KBR (Kellogg Brown and Root), Haldor Topsøe, and ThyssenKrupp Industrial Solutions (TKIS) — currently dominate the market. Ammonia Casale, which offers an axial-radial catalyst bed design, is a market leader in revamps of existing plants. Most of the ammonia plants recently designed by KBR utilize its Purifier process, which combines low-severity reforming in the primary reformer, a liquid N2 wash purifier downstream of the methanator to remove impurities and adjust the H2:N2 ratio, a proprietary waste-heat boiler design, a unitized chiller, and a horizontal ammonia synthesis converter. Depending on the configuration of the plant, energy consumption can be as low as 28 GJ/m.t. Because the secondary reformer uses excess air, the primary reformer can be smaller than in conventional designs. The cryogenic purifier, which consists of an expander, condenser, feed/effluent exchanger, and rectifier column, removes impurities such as CO, CH4, and argon from the synthesis gas while adjusting the H2:N2 ratio of the makeup gas in the ammonia loop to the optimum level. The ammonia concentration exiting the low-pressure-drop horizontal converter is 20–21%, which reduces energy requirements for the recycle compressor. The syngas generation section (or front end) of a Haldor Topsøe-designed plant is quite traditional with the exception of its proprietary side-fired reformer, which uses radiant burners to supply heat for the reforming reaction. Haldor Topsøe also offers a proprietary iron-based synthesis catalyst, radial-flow converters consisting of one, two, or three beds, and a proprietary bayonet-tube waste-heat boiler. More recent developments include the S-300 and S-350 converter designs. The S-300 converter is a three-bed radial-flow configuration with internal heat exchangers, while the S-350 design combines an S-300 converter with an S-50 single-bed design with waste-heat recovery between converters to maximize ammonia conversion. ThyssenKrupp offers a conventional plant with a unique secondary reformer design, a proprietary waste-heat boiler, radial-flow converters, and a dual-pressure ammonia synthesis loop. Today, a production rate of 3,300 m.t./day can be achieved using the TKIS dual-pressure process. ThyssenKrupp’s dual-pressure synthesis loop design features a once-through reactor between syngas compressors. The Linde Ammonia Concept (LAC) is an established technology process scheme with over 25 years of operating experience in plants with capacities from 200 m.t./day to over 1,750 m.t./day. The LAC process scheme replaces the costly and complex front end of a conventional ammonia plant with two well-proven, reliable process units: a) production of ultra-high-purity hydrogen from a steam-methane reformer with PSA purification; b) production of ultra-high-purity nitrogen by a cryogenic nitrogen generation unit, also known as an air separation unit (ASU). Also featured is a pressure-swing adsorption unit for high-purity hydrogen production and an air separation unit for high-purity nitrogen production. Ammonia Casale’s plant design has a production rate of 2,000 m.t./day. One of the key features of this design is axial-radial technology in the catalyst bed. In an axial-radial catalyst bed, most of the synthesis gas passes through the catalyst bed in a radial direction, creating a very low pressure drop. The rest of the gas passes down through a top layer of catalyst in an axial direction, eliminating the need for a top cover on the catalyst bed. Casale’s axial-radial catalyst bed technology is used in both high-temperature and low-temperature shift converters, as well as in the synthesis converter. Ammonia Casale’s process employs a catalyst bed that harnesses axial-radial technology, which has a lower pressure drop and higher efficiency than standard catalyst beds. Ammonia from coal The basic processing units in a coal-based ammonia plant are the ASU for the separation of O2 and N2 from air, the gasifier, the sour gas shift (SGS) unit, the acid gas removal unit (AGRU), and the ammonia synthesis unit. Oxygen from the ASU is fed to the gasifier to convert coal into synthesis gas (H2, CO, CO2) and CH4. There are many gasifier designs, but most modern gasifiers are based on fluidized beds that operate above atmospheric pressure and have the ability to utilize different coal feeds. Depending on the design, CO levels of 30–60% by volume may be produced. After gasification, any particulate matter in the synthesis gas is removed and steam is added to the SGS unit. The SGS process typically utilizes a cobalt and molybdenum (CoMo) catalyst specially designed for operation in a sulfur environment. After reducing the CO concentration in the synthesis gas to less than 1 vol%, the syngas is fed to an AGRU, where a chilled methanol scrubbing solution (e.g., Rectisol) removes CO2 and sulfur from the synthesis gas. The CO2 overhead is either vented or fed to a urea plant. The sulfur outlet stream is fed to a sulfur recover unit (SRU). Syngas that passes through the AGRU is typically purified by one of two methods: a) a nitrogen wash unit to remove residual CO and CH4 from the syngas before it is fed to the synthesis loop; b) a PSA system for CO and CH4 removal. Cost of Ammonia Plants There have been several recent cases of greenfield new ammonia plants that have taken 36 to 48 months for mechanical completion and have cost in the billions. While full cost reports are not in, the expected final costs are in the $1,500 to $2,200 per annualized ton range (Total capital cost divided by the expected total annual tons). A recent used plant for relocation project was a 1,000 ton per day Kellogg Design that was removed, relocated, rebuilt and upgraded. This project was in the range of $500 million and took 25 months to mechanically complete from the groundbreaking (after an environmental permit was issued). The ground breaking occurred in December 2013 and the first drop of ammonia was in April 2016. The full costs were less than $1,100 per annualized ton.

INTRODUCTION TO PET PRODUCTION PET may be produced from ethylene glycol and either dimethyl terephthalate (DMT) or terephthalic acid. High purity is required of all raw materials. In either case, the first step of the reaction is the formation of a prepolymer, bis-hydroxyethyl terephthalate (bis-HET). Subsequent polymerization of this material (with the removal of ethylene glycol) forms the polymeric polyethylene terephthalate. The extent of polymerization (apparent from the molecular weight of the polymer) is a function of the polymerization conditions and significantly affects the properties of the resin that is produced. Until the mid-1960s, DMT had been the preferred feedstock for PET manufacture, partly because the ester could generally be made in purer form than the acid. With the development of high-purity terephthalic acid processes, notably by Amoco, the free acid gained acceptance and is now the preferred feedstock. The use of high purity terephthalic acid (purified terephthalic acid - PTA) eliminates the need to recover or recycle methanol and has the added advantage that esterification to the prepolymer is considerably more rapid than the transesterification reaction, which is the first step when starting from DMT. The conventional PET process consists of two discrete plant sections; the melt phase reaction to lower intrinsic viscosity product that is suitable for textile applications, but not for bottle grade and other high molecular weight applications. That lower intrinsic viscosity material is then further polymerized to bottle-grade intrinsic viscosity in a solid-state polymerization section. Note that intrinsic viscosity (as well as molecular weight) indicates the degree of polymerization, which in turn is the main factor in setting the properties of PET. COMMERCIAL ANALYSIS Fiber producers have for some time been converting older plants to PET bottle grade production by adding SSP capacity, in order to escape the more difficult market conditions in the fibers industry. This is still ongoing in certain areas, although the amount of remaining capacity that could be converted to competitive PET resin capacity is minimal relative to the amount of new capacity expected. RESOURCE LINKS Phoenix Equipment sells used PET and PTA plants that are immediately available for purchase and relocation. Buying a used plant can save you significant capital and drastically shorten the time required to build or expand manufacturing operations.

Falling feedstock prices, greater efficiency, and an increased worldwide demand as more economies emerge all present lucrative opportunities for the conversion of natural gas to liquid synthetic crude oil. That’s because much of the world’s natural gas – up to one-third by many estimates – are located in remote deposits. Liquefaction of natural gas makes it more economical to transport via tanker or pipeline and to store for future refinement and use. Small, onsite gas-to-liquid (GTL) plants will make tapping these “stranded gas” deposits profitable. Natural gas has proven the best feedstock for creating crude oil alternatives through the industry standard Fischer-Tropsch process, topping coal in purity, handling, and ease in conversion to syngas, which is required for efficient conversion to synthetic crude.   GTL Plant Benefits The synthetic oil GTL plants produce is virtually interchangeable with conventional oil, both as refined transportation fuels and petrochemicals. Technological breakthroughs in catalyst design and reactor engineering, as well as more efficient chemical processes, have reduced start-up and operating costs to the point where they are becoming competitive. GTL is becoming more attractive for a number of reasons: Ecology – The GTL process creates more homogeneous mixtures, with less sulfur, nitrogen, and aromatics, making combustion more consistent and complete, so carbon emissions are reduced. Supply – Natural gas, the preferred GTL feedstock, is plentiful compared to oil and coal. Developed and emerging economies can use technology to literally fuel their growth. Feedstock Cost – The abundance of localized stranded gas pockets around the world and the greater accessibility of shale gas in the United States has helped keep the cost of natural gas low. The ability to transform natural gas into higher-value fuels for transportation has generated significant interest in monetizing natural gas. Low feedstock costs now can offset many of the higher startup and operating costs associated with GTL plants. National Security – Exploiting natural gas to produce the inputs needed to manufacture oil-based products can reduce dependence on oil imports that can be withheld as a diplomatic, negotiating, or strategic weapon. Industry Outlook While significant challenges remain in order to maximize production efficiencies, revenues, and profits, investors in gas-to-liquid processing have the potential to get in on the ground floor of a lucrative industry. Major players such as Shell and Exxon-Mobil are investing heavily in GTL technologies that eventually will bring improved efficiencies, lower costs, and develop markets. These markets are expected to become ever more segmented, as countries strive to: Develop domestic industries Reduce dependence on imports Build industrial and transportation infrastructures Create jobs Gas-to-Liquid Processing As mentioned above, the conversion of natural gas into liquid petroleum products involves the Fischer-Tropsch (FT) synthesis, but the first part of the conversion involves the production of syngas through a reformer that converts natural gas to base reactants. Synthetic gas, “syngas” is a mixture of hydrogen and carbon monoxide produced by the high-temperature reaction between the methane in natural gas and steam. It is commonly used in the production of ammonia. In step two, the FT process converts syngas to synthetic hydrocarbon in the form of paraffins. The final step, called “upgrading,” injects more hydrogen into the waxy, long-chain paraffins under mild hydrocracking conditions. The hydrogen breaks the chains into diesel, kerosene, naphtha, and other valuable products while removing impurities such as olefins.   Gas-to-Liquid Plant from Phoenix Phoenix Equipment offers used GTL and syngas processing equipment for startup and expanding operations. Phoenix recently acquired a complete 7 million standard cubic feet per day (18,500 normal cubic meters per hour) plant offering turnkey entry into the industry. Built-in 2016 and operational as a demonstration plant for only a few months, this Hydro-Chem (now Linde) manufacturing facility is immediately available for purchase. The ready-to-commission plant includes two reforming units, feed heater and superheater, desulfurizer, steam generators and drums, and more. The equipment provides all you need to produce syngas from natural gas or biomass and then convert it to naphtha and diesel with the Fischer-Tropsch process. For more information view the plant liquidation, call Phoenix Equipment at (732) 442-6990, or contact our sales team and we would be happy to assist you.

Manufacturers use synthesis gas, or “syngas” for fuel to produce electricity and as feedstock for production of industrial chemicals such as ammonia, methanol, and other hydrogen-rich compounds. Once isolated and purified, hydrogen from syngas is a major component in petrochemicals and oil refining. Syngas itself is a mixture primarily of hydrogen and carbon monoxide, created through the gasification of hydrocarbons in natural gas, coal, petroleum, biomass, and other feedstocks. Virtually all the hydrogen produced in the United States is produced from methane. And the cheapest, most available source of methane is natural gas.   Steam Methane Reforming Steam methane reforming (SMR) accounts for about 95 percent of the industrial hydrogen produced domestically and about half the world’s production. The process begins with the introduction of superheated (1,300 to 1,800 degrees Fahrenheit) steam and natural gas into an array of vertically hanging tubes filled with nickel catalyst. As the mixture flows through the tubes, which are heated externally (the reaction is endothermic), the methane in the natural gas reacts with the water vapor to produce hydrogen and carbon monoxide: CH4 + H2O < ——– > 3H2 + CO Ensuring the feed mixture contains excess steam ensures the maximum production of hydrogen. Plentiful steam also enables the consumption of as much methane as possible. Methane in the product is an impurity and must be stripped from the gas later in the process. Nearly complete conversion of methane has the added benefit of preventing creation of elemental carbon, which can deposit on and foul the catalyst. At present, the most widely used and cheapest method for hydrogen production is the steam reforming of methane (natural gas). This method includes about half of the world hydrogen production, and hydrogen price is about US$ 7 / GJ. Below listed are several well-known companies which provide process technology and engineering of syngas / hydrogen production on the basis of steam reforming. The number in parenthesis shows the units installed worldwide approximately.   Foster Wheeler (100) Lurgi (30) Linde (120) KBR (100) Uhde (60) Praxair (140) Haldor Topsoe (40) Technip (240) CB&I (175)   Water-Gas Shift Reaction Another reason for incorporating relatively more steam than methane in the mixture is to encourage a secondary reaction for the recovery of additional hydrogen. In this process, the mixture passes through another set of tubes of iron-chromium catalyst in a fixed-bed reactor where the molecules in the water vapor are split into oxygen and hydrogen. The hydrogen is collected along with that produced in the SMR process. The oxygen bonds with the carbon monoxide from SMR to make carbon dioxide. CO + H2O < ——– > CO2 + H2 Unlike the primary reaction, the water-gas shift reaction is exothermic, and the energy produced can be captured to partially fuel the steam-heating required in SMR. Pressure Swing Adsorption While steam methane reforming and water-gas shift reactions are quite efficient, complete reaction of methane is impossible because the reactions are subject to thermal equilibrium. This leaves some unreacted methane along with the carbon dioxide from the final product, some unreacted carbon monoxide, water vapor, and other contaminants in the gas mixture. As many operations require virtually pure hydrogen, the pressure swing adsorption process removes these contaminants. This is accomplished by pumping the mixture through cylinders filled with specially treated beads to which the unwanted gasses adhere. Once the pristine hydrogen is pumped out of the cylinders, pressure can be lowered, releasing the contaminants from the beads. They then can be flushed from the chamber. Numerous hydrogen PSA units have been installed worldwide. Leading technology licensors include:   KBR Air Products & Chemicals Linde Praxair UOP Lurgi   Conclusion A modern syngas / hydrogen plant typically has capacity range from 5 MMSCFD to 200 MMSCFD. For a 90 MMSCFD plant, the capital cost to build such a plant is estimated at approximately US$ 55 million nowadays. Average hydrogen production cost is US$ 1.60 per 1,000 standard cubic feet, or US$ 53 million per year to operate a plant of this capacity. This estimate is based on the following utility consumption. Utilities consumption per 1,000 ft3 of contained hydrogen:   Natural gas feed, million Btu LHV 317 Natural gas fuel, million Btu LHV 126 HP export steam, lbs 90 Boiler feedwater, lbs 120 Power, kWh 52 Cooling water, gal 8   Low-cost feedstock and efficient conversion of hydrogen makes steam methane reforming from natural gas the most widely used process for syngas production. Phoenix Equipment sells used hydrogen and syngas plants, and hydrogen purification components that are immediately available for purchase and relocation. Buying a used plant can save you significant capital and drastically shorten the time required to build or expand manufacturing operations.

The manufacturing of nitric acid for use in fertilizers, plastics, dyes, textiles, and other industrial products, has evolved to three industry-standard processes. They all produce acid with 60-68% concentration, and each uses essentially the same nitric acid plant design. The choice between medium- and high-pressure mono and dual-pressure production process often comes down to financial considerations and owner priorities. Nitric Acid Production Technology While nitric acid plant technology has made production more efficient and environmental controls more effective, the process remains the same: Ammonia combustion in the presence of hot air and a platinum/rhodium catalyst creates nitric oxide (NO). Oxidation of the NO creates nitrogen dioxide (NO2). The NO is cooled and compressed as it travels to the absorption tower. The cooling process creates nitrogen dioxide and produces heat, which is recycled for use in other plant operations. Absorption of the NO2 in water creates nitric acid (HNO3). This dilute solution dissolves in the remaining water. The reaction also forms small quantities of NO, which combine with ambient oxygen to reform NO2 and continue the reaction. Modern nitric acid plants are designed to carry out the three chemical processes in a variety of ways, considering initial investment costs, space constraints, feedstock cost, and other factors. The oxidation reaction is more efficient under medium pressure, while the absorption and ultimate production of nitric acid solution works better under high pressure. As a result, three distinct processes have been developed for carrying out the various reactions.   1. Mono Medium Pressure Process Using an uncooled radial compressor to deliver air at 4 to 5 bar abs or an axial flow compressor (5 to 6 bar abs) a nitric acid plant can produce up to 700 tons of nitric acid per day (maximum 65 percent concentration) using a single ammonia combustion unit and a single absorption tower. Production can be increased to 1,000 tons per day with the addition of a second absorption tower. Because the oxidation of nitric oxide into nitrogen dioxide occurs more quickly at lower temperatures, nitric acid plants using mono medium are more efficient than their high-pressure counterparts at this portion of the production process. And because the reaction is exothermic, the mono-medium setup’s ability to maximize energy recovery helps offset operating costs. The compressor can be driven by reusing steam captured during nitric acid production. Or, if steam can be exported for credits, the compressor can be driven by electric motor so all generated steam can be collected for export. 2. Mono High Pressure Process While medium-pressure nitric acid plants optimize the second critical chemical reaction, raising the pressure to 8 to 12 bars enhances the final step. The higher pressure “forces” the nitrogen dioxide (and dinitrogen tetraoxide, which is also produced in the oxidation phase) gas into water. Manufacturers seeking a quick capital often take advantage of this nitric acid plant technology, as a single absorption tower is sufficient to produce up to 1,000 tons of nitric acid per day. The higher pressure also means the burner unit, piping, and other equipment can be made smaller so the plant occupies a more compact footprint, making the initial capital investment less and the road to profitability shorter. 3. Dual Pressure Process As might be surmised, the dual pressure process uses two different pressures during nitric acid production. It uses medium pressure for the compressed air used in ammonia combustion, then compresses to high pressure to optimize absorption. An attempt to capitalize on the best of both mono processes, the dual pressure process can realize up to 1,500 tons per day of nitric acid (up to 70% or higher concentration) with one ammonia combustion and process gas cooler unit installed. Additional units can be added to increase capacity. The lower oxidation pressure also takes less of a toll on the catalyst – a major savings, considering the cost of platinum. Varying the pressure not only extends catalyst life, but also keeps the nitric acid concentration low as it exits the condenser, fostering its absorption into water. Which is the Best Nitric Acid Production Process? All three processes have their place in nitric acid plant design, depending on strategic goals and other factors. Initial investment in medium- and high-pressure mono process plants are generally lower than those required for dual-pressure facilities. Variable costs, however, can run higher, requiring slightly larger quantities of ammonia and taking a greater toll on the catalyst. As a result, mono –pressure nitric acid technology is more prevalent in smaller (900 tons per day and less) plants. Most experts consider the dual-pressure process the best available technology, and most new high-capacity nitric acid plants are designed for dual pressure. Because both technologies are incorporated, a higher initial investment is required, but the greater capacity and lower operating costs help recoup the investment more quickly. Typical Consumption Figures of Modern Nitric Acid Plants The following chart is the comparison of typical consumption figures for steam turbine driven and inline compressor set nitric acid plants, per ton of nitric acid (100%), with NOx content in the tail gas of less than 50 ppm. Plant Type Medium Pressure Process High Pressure Process Dual Pressure Process Operating Pressure (abs.) 5.8 bar 10.0 bar 4.6 / 12.0 bar Ammonia 284 kg 286 kg 282 kg Electricity 9.0 KWH 13.0 KWH 8.5 KWH Platinum, Primary Losses 0.15 g 0.26 g 0.13 g Platinum losses after recovery 0.04 g 0.08 g 0.03 g Cooling water (Δt = 10 k), including water for steam turbine condenser 100 t 130 t 105 t Process Water 0.3 t 0.3 t 0.3 t LP heating steam, 8 bar, saturated 0.05 t 0.20 t 0.05 t HP excess steam, 40 bar, 450 ºC 0.76 t 0.55 t 0.65 t Energy Recovery and Tail Gas Treatment Whichever technology a nitric acid plant uses, each reaction in the production process releases energy, which can be recovered and used throughout the plant. For instance, the air used to oxidize the ammonia must be filtered, compressed and heated. It is possible to obtain nearly all the energy required for these processes by extracting heat from tail gasses. Nitric acid plants must treat the NO, N2O, and NO2 gasses produced throughout the manufacturing process. Both are greenhouse gasses and can do great harm to the environment if not properly neutralized. A variety of technologies exist to make these waste gasses less harmful including: Heating them in the presence of a catalyst to convert NOx to nitrogen Installing additional absorption trays (or a complete additional absorption tower) Cooling weak acid within the absorption tower Attaching molecular sieves to contact tail gasses to return NO for another pass through the absorber Use of liquid alkali, carbonates, or potassium permanganate (wet scrubbers) to pull NO from tail gas to form nitrate salts Leading Technology Licensors Weatherly, a company of Chematur Engineering Group of Sweden; ESPINDESA, a company of Técnicas Reunidas of Spain; Borealis of Austria; Uhde (now ThyssenKrupp Industrial Solutions) of Germany; MECS Technology of USA; KBR of USA; Technip of France. Planning to start or expand a nitric acid plant? Phoenix Equipment buys and sells complete nitric acid plants. Take a look at our current nitric acid plant inventory or if you can’t find what you need, contact us today and one of our plant experts can assist you in finding exactly what you need, no matter which nitric acid production process you are looking for.

A propylene splitter is a large distillation column used in the petrochemical industry to separate propylene (C3H6) from propane (C3H8). It is also called C3 splitter. Both propylene and propane are hydrocarbons with similar molecular weights and boiling points, but they serve very different purposes and have distinct chemical properties. The main goal of a propylene splitter is to produce high-purity propylene, which is an essential raw material for the production of polypropylene and other chemical products. The splitter relies on fractional distillation, where a feed mixture containing both propane and propylene enters the column. Through heating and distillation, propane and propylene separate based on their boiling points. Propylene splitters are typically very tall, as the height helps achieve the desired separation purity through multiple trays or packing sections. Several technologies are used to enhance the efficiency of propylene splitters, making the process more economical and energy-efficient due to the high energy demands involved. Some of the main technologies include: 1. Heat-Integrated Distillation Description: This method integrates heat exchangers within the distillation process to recycle energy, reducing overall heating and cooling requirements. Types: Dividing-Wall Columns (DWC): Uses a physical partition to enable more efficient separation in a single column instead of two. Heat-Pump Assisted Distillation: A compressor is used to increase the energy of vapor leaving the column, which is then used to reheat the bottom, reducing reboiler duty. Benefits: Reduces energy costs significantly and minimizes the number of columns required for the same separation. 2. Membrane Separation Description: Utilizes specialized membranes that selectively allow either propylene or propane to permeate, separating them based on molecular size and structure differences. Benefits: Although not a full replacement for distillation, membrane separation can reduce the load on the distillation column, leading to energy and cost savings. Limitations: Membranes are often sensitive to fouling and might not achieve the ultra-high purity levels needed for some applications, so they are typically used as a pre-separation step. 3. Adsorptive Separation Description: Uses materials like zeolites or metal-organic frameworks (MOFs) that selectively adsorb propylene over propane. Benefits: Offers high selectivity, can be effective for certain applications, and is an alternative to thermal distillation. Limitations: Adsorbent materials can be costly and may require periodic regeneration, which adds complexity to the operation. 4. Cryogenic Distillation Description: Uses low temperatures to exploit the slight difference in boiling points between propane and propylene. Benefits: Achieves very high purity for both propane and propylene. Limitations: Extremely energy-intensive due to the need for refrigeration at very low temperatures. 5. Hybrid Systems Description: Combines multiple methods, such as membranes with distillation or adsorption with heat integration, to maximize efficiency and flexibility. Benefits: Provides higher separation efficiency, flexibility in operations, and potential energy savings. The following is an example of an advanced technology utilized in real production. Distillation Process by Linde Engineering Linde Engineering uses advanced distillation technologies in its propylene splitter systems to enhance the separation efficiency of propane and propylene. One of their notable setups includes a multi-column process involving a dryer, a stripper, and a splitter, designed to maximize purity while reducing energy consumption. These systems can process both refinery-grade and chemical-grade propylene, with specific feed trays in the splitter column to optimize feed entry points based on quality. Additional purification steps, including regenerative treatment, help achieve high-purity propylene essential for downstream applications like polypropylene production. By leveraging proprietary designs and equipment like efficient trays and packing materials, Linde Engineering's technology improves separation efficiency in large-scale operations, offering more stable and energy-efficient production compared to traditional single-column splitters. This approach ensures that propylene purity levels can reach up to 98.25%, while propane is effectively removed and sent for other uses or storage. For large-scale industrial applications, this high-efficiency distillation method can be crucial for minimizing operating costs and maximizing product purity?

Formaldehyde is a main raw material for manufacturing value-added chemicals and adhesives used in wood products such as particleboard and plywood. Colorless but odiferous and flammable, formaldehyde is a key component in melamine, urea-formaldehyde, and phenolic resins that have strong bonding and heat resistance qualities. Formaldehyde also is a potent preservative with uses in sterilization and embalming. Commercial producers typically use two methods to manufacture formaldehyde at scale: 1) Oxidation-dehydrogenation using a silver catalyst to achieve either the complete or partial conversion of methanol; and 2) the FORMOX process, which directly oxidizes methanol using metal oxide catalysts. In most cases, production targets a 37% aqueous solution (called formalin), but manufacturers may market concentrations as high as 57%. The solution is usually transported with methanol added to prevent polymer precipitation. Solutions that do not include methane stabilizers can avoid precipitation only when kept at 86 degrees Fahrenheit or higher. The advantage is lower shipping costs, as the higher concentrations can be diluted to the desired 37% saturation at the destination.   FORMOX: Formaldehyde Production Using Metal Oxide Catalysts Conducted in a controlled reactor environment at around 500 to 900 degrees Fahrenheit, converts nearly all the methanol feedstock into formaldehyde and water: 2 CH3OH + O2 → 2 CH2O + 2 H2O  This high efficiency – 98% or higher conversion – reduces waste and requires less of the expensive starter material than the silver catalyst process to achieve the same volume of formaldehyde. FORMOX introduces feedstock containing lower methane concentrations than the surrounding steam and the steam and air to ensure a stable reaction and eliminate the possibility of explosion. The process creates highly purified formaldehyde containing only trace amounts of carbon monoxide, dimethyl ether, carbon dioxide, and formic acid byproducts. The reaction works by injecting vaporized methanol, air (and sometimes tail gases from previous cycles) over the iron oxide catalyst inside the reactor. As the methanol reacts with oxygen inside the tank, transfer fluid captures the heat generated and uses it to boil water and create steam for powering other industrial processes. Meanwhile the gases – mostly newly converted formaldehyde travel to an absorption chamber, where they condense and are absorbed into water fed into the chamber. An anion exchange reduces the formic acid content of the aqueous solution, the resulting product may contain up to 55% formaldehyde by weight, depending on the quantity of water introduced into the absorption chamber.   Formaldehyde Production Using Silver-catalyzed Methanol Heating the feed stock to approximately 700 degrees Celsius increases the rate and equilibrium of the endothermic dehydrogenation reaction sufficiently to convert 97% to 98% of the methanol. After cooling to shut down undesirable side reactions, the vaporous mixture enters an absorption column, which elutes the formaldehyde to 40-55% formaldehyde by weight, with small amounts of aqueous methanol and formic acid (created from excess oxygen present during formaldehyde production). Requiring reactor temperatures of 1,100 degrees Fahrenheit and above, this process converts some of the methane in the same manner as the FORMOX process above, but also simply extracts hydrogen from the methane feedstock to product formaldehyde through a different, anaerobic reaction: CH3OH → CH2O + H2  This direct dehydration is less efficient than FORMOX, so it demands more methane to be fed into the reactor in order to return similar concentrations and volumes of the finished formaldehyde. So, why would manufactures use silver rather than the more efficient metal oxide catalyzation reaction? Despite higher methanol feedstock consumption, silver-catalyst formaldehyde production can deliver lower-cost products than iron oxide operations. This cost savings may offset efficiency losses, especially for smaller plants that can obtain methane cheaply to convert it in one of two subprocesses:    (Nearly) Complete Conversion With conversion as high as 98%, this process begins by heating the feedstock to approximately 1,200 degrees Fahrenheit to optimize the rate and equilibrium of the endothermic dehydrogenation reaction. Conversion occurs at a much lower temperature, however, and creates trace elements of carbon monoxide, carbon dioxide, hydrogen, and water along with the formaldehyde. Rapid cooling shuts off potential side reactions that can cause the formaldehyde to deteriorate. Absorbed into water, the formaldehyde creates a 40 to 55% aqueous solution, which also contains tiny amounts of methanol and formic acid, which are formed using the excess oxygen not used in the formaldehyde reaction. Incomplete Conversion and Distillate Recovery  The reactor heats the methane-containing feedstock to approximately 1,300 degrees Fahrenheit to forestall any unwanted secondary reactions. The reaction uses the oxygen in the chamber to convert 77 to 87% of the methane. Once cooled and absorbed into water, the solution contains about 43% formaldehyde, along with the 13 to 23% unconverted methane, formic acid, and other byproducts. Equipment removes the methanol and recirculates it into future conversion cycles. The next step is to further remain the solution to reduce the formic acid content, boosting its formaldehyde concentration to as much as 55% and its yield to around 90%. Comparing and Contrasting Methods and Applications As noted, manufacturers may choose FORMOX to capture formaldehyde reaction efficiencies or they may choose silver catalyzation to take advantage of lower operating costs. Plant operators should consider several other variables in deciding which process makes sense in their situation:   Plant Capacity – For low-capacity facilities, producing up to 5,000 tons per year of formalin, the silver process is more economical. This process is less technical and requires fewer upfront costs, making it an attractive option for smaller operations. Larger plants producing up to 100,000 tons per year, however, likely should use the iron oxide catalyst process. Although this process requires higher capital expenditure on technology, the added capacity helps to offset these costs. The larger scale allows for greater economies of scale, improving the overall efficiency and profitability of the operation. Ultra-large operations may become inefficient due to excessively large gas conducts required for the metal oxide process. These producers should consider splitting production among medium-sized units that can capture all the metal oxide catalyzation efficiencies. Catalyst Cost: Silver catalysts must only last a few months, but because they can be fully regenerated, their overall cost is less than iron oxide catalysts that can last for over a year, but whose salvage value is limited to their molybdenum contents. Tail Gas Processing: The silver process generates tail gases containing approximately 20% combustion-facilitating hydrogen. Combustion creates steam and burns off carbon monoxide and other environmentally harmful organic compounds. Conversely, the tail gas produced in the iron oxide process is not flammable due to its low dimethyl ether, carbon monoxide, methanol, and formaldehyde content. Burning these gasses can only be accomplished by using a catalytic incinerator or adding fuel, making the process more complicated and costly. Steam Generation: The metal oxide process produces sufficient steam heat that manufacturers can export and use to power other processes, potentially providing energy efficiency and cost savings. Methanol rectification fully consumes the little steam generated in the silver-catalyst operation. Sometimes, the steam produced is insufficient and the reaction can only be completed by adding more. Product Purity: Metal oxide catalytic production yields formaldehyde with significantly less formic acid, heavy metals and unreacted methanol, and other impurities compared to the silver process. Industries increasingly require formaldehyde solutions with zero methanol and concentrated (up to a 4:1 formaldehyde to water ratio), urea-stabilized solutions, which can only be made in metal oxide-catalyst operations.    Phoenix Equipment stocks a full range of formaldehyde production equipment to help manufacturers start or scale operations. Whether you need reactors, absorption towers, boilers, evaporators, or a fully operational plant, we can help you get up and running in a fraction of the time and cost of buying new equipment. If you don’t see what you want on our website, contact our experts. We engage with suppliers and motivated sellers around the world and would be happy to put the word out.  

Sulphonation Sulphonation is key to making the sulfates used as key ingredients in soaps and detergents, and manufactured in a process called “Sulphonation”. Production Process Fundamentally, Sulphonation is based on the reaction between a sulphur trioxide stream diluted in air and an organic base. The reaction is carried out in a stainless-steel multi-tube film reactor where the sulphur trioxide stream and the organic base are conveyed in co-current, for a reaction time necessary for a sulphuric group to react with the base and to form an additioned molecule. This molecule has an electrically neutral end (the hydrocarbon chain), which is hydrophobic, and a hydrophilic polar end (the sulphuric group). This dual property is the key behind the detergent behavior of the LABSA (linear alkyl benzene sulphonic acid), and its ability to modify the water surface tension Product quality control Color is a critical property for the commercial value of the sulphonated organic base. Color may be impaired by several factors, including reaction temperature. Since the reaction is fairly exothermal, in order to hold constant temperature, the reactor tube bundle is submerged in circulating cooling water under temperature control. Sulphuric acid content, free oil content, and density are other quantifiable parameters of product quality. Common section of the production process The sulphuric stream production is a common feature of all sulphonation processes. The sulphuric stream is manufactured by a process similar to the sulphuric acid (H2SO4) production. Solid Sulphur is the raw material, usually in pellet form at high purity as produced by the Claus process, which is the partial oxidation of sour gas, any gas such as natural gas with a significant amount of hydrogen sulfide. Sulphur is molten by steam in a jacketed tank, then is pumped to a combustion furnace where is burnt in a large excess of air with formation of sulphur dioxide. It is critical for the sulphur dioxide stream to be cooled down for the next processing step. Conversion and sulphonation The cooled down Sulphur dioxide is then conveyed to a multi-layer catalytic reactor, where sulphur dioxide (SO2) is converted almost completely to sulphur trioxide (SO3). Further cooling and filtration of this stream is required before being reacted with the organic base in the multi-tube film reactor. Under strict control of temperature and of flow rate, the organic base is fed to the sulphonation reactor. Software and hardware enable the operator to carry out the control tasks automatically or flexibly bring such key parameters under manual control. SLES (sulphonated ethoxylated lauryl alcohol) A LESA (type of acid) stream is neutralized in a loop where the reactor output is treated with a caustic soda solution and is subject to a homogenizing process in a dedicated piece of equipment achieving lump-free and stringent homogenization specifications as necessary for its application in the cosmetic industry. A special cooler is used to handle the significant amount of heat developing out of the neutralization reaction; then, for color adjustment, pH adjustment, deareation and product ageing -- additional on-stream equipment and injections are used. Deareation consists in the removal of small air bubbles forming during the various atmospheric processes, in a degasifier working under vacuum, providing a crystal appearance to the SLES paste. 1,4 – Dioxane, eventually produced as an undesired by-product of the sulphonation reaction, can be removed by further optional treatment. Dioxane is stripped out of the paste in a vacuum film evaporator where also deareation occurs simultaneously. AOS (sodium alpha olefin sulfonate) A supplementary treatment is involved in the production of Sodium Alpha Olefin Sulfonate (AOS), named “hydrolysis”, in addition to the neutralization of caustic soda from the acidic reactor output. The neutralized AOS stream is heated up to high temperature, homogenized and aged per proper time specifications ensuring the complete conversion of Sultones to surfactant compounds. After a final cooling, the product is ready for storage or packing. Technology providers: Chemithon Desmet Ballestra Lion Corp Marsina Engineering Mazzoni Meccaniche Modeme Fatty Acid & Glycerin Production Another critical part of the soap supply chain is oleochemical plants. Please find the below link to learn more about fatty acid and glycerin production. https://www.phxequip.com/resource-detail.64/edible-oils-fats-refining-process.aspx Conclusion Proper attention to production parameter is key to the quality of the intermediaries produced in the sulphonation process. It might be best to consult with multiple technology providers to get the results your customers require.

Vinyl chloride is an organochloride with the formula H2C=CHCl that is also called vinyl chloride monomer, VCM or chloroethene. This colorless compound is an important industrial chemical chiefly used to produce the polymer polyvinyl chloride (PVC). Nearly all production of VCM is based on ethylene, which is first reacted with chlorine to make ethylene dichloride (EDC). There are two routes commonly used to make EDC: direct chlorination using pure chlorine and ethylene, and oxychlorination in which the ethylene reacts with chlorine in hydrogen chloride. The EDC is then converted to VCM by thermal cracking and the hydrogen chloride by-product can be recycled to an oxychlorination plant to make more EDC. Many EDC/VCM complexes use an integrated chlorination-oxychlorination process which proceeds in three stages: the chlorination of ethylene in the liquid or vapor phase to make EDC; the thermal cracking of EDC to form VCM and hydrogen chloride; and the oxychlorination of ethylene with recycled hydrogen chloride to make more EDC. VCM is sent through a catalyst-containing reactor where polymerization occurs. Chemicals cause the VCM molecules to react until they link together into Polyvinyl Chloride (PVC). The linking of VCM molecules creates PVC resin – which is where all vinyl compounds begin. The suspension polymerization process is most widely used process to manufacture PVC. First, the raw material VCM is pressurized and liquefied, and then fed into the polymerization reactor, which contains water and suspending agents in advance. Through high-speed agitation within the reactor, small droplets of VCM are obtained. Next, the initiator for polymerization is fed into the reactor, and PVC is produced by reaction under a few bar at 40 - 60° C. PVC obtained through suspension polymerization is suspended in water as particles of 50 - 200μm diameter (in slurry form). Thereafter, the slurry discharged from the polymerization reactor is stripped of residual monomer, dehydrated, dried and the particle size controlled by screening to yield PVC in the form of a white powder. The un-reacted VCM is entirely recovered through the stripping process, and after purification, recycled as raw material for reuse in this process. PVC resin produced via this ‘suspension’ process is referred to within the industry using the abbreviation S-PVC. Emulsion polymerization and bulk polymerization are alternative, much less extensively employed, technologies to manufacture PVC. Emulsion polymerization produces finer resin grades having much smaller particles, which are required by certain applications. This type of resin is sometimes called ‘paste’ PVC and referred to within the industry using the abbreviation P-PVC to distinguish it from S-PVC. PVC comes in two basic forms: rigid (sometimes abbreviated as RPVC) and flexible. The rigid form of PVC is used in construction for pipe and in profile applications such as doors and windows. It is also used for bottles, other non-food packaging, and cards (such as bank or membership cards). It can be made softer and more flexible by the addition of plasticizers, the most widely used being phthalates. In this form, it is also used in plumbing, electrical cable insulation, imitation leather, signage, inflatable products, and many applications where it replaces rubber.   PVC Production Process in China The calcium carbide route used in China involves heating lime and coal-derived coke in an electric furnace at a temperature of 2,000 °C to obtain calcium carbide. Acetylene is generated by the hydrolysis of this calcium carbide. This early part of the process is labor intensive, requires a lot of energy, and generates vast quantities of a watery calcium hydroxide slag. With the use of a catalyst that is usually based on mercuric chloride, the acetylene is then reacted with anhydrous hydrogen chloride to produce vinyl chloride.   Major Technology Providers & Producers EDC/VCM: Ineos Technologies OxyVinyls Tosoh Vinnolit   PVC: Arkema Hanwa Chemical Ineos Technologies Nouryon Vinnolit

Oleochemical Process Plants: Fatty Acid Production and Glycerin Production The oleochemical manufacturing industry includes the processing of natural oils and fats, both of vegetable and animal origin, into numerous substances, such as: Fatty acids by cleavage (splitting) of the triglycerides molecule into its constituents (i.e. fatty acids and glycerin); Biodiesel, mainly by substitution (transesterification of glycerin with methanol in the triglycerides molecule); and Glycerin by processing glyceric aqueous solutions mainly derived from transesterification and splitting. This article will focus on the production of fatty acids, glycerin (which is a co-product of fatty acid production) and their derivatives. Fatty Acids and their chemical derivatives have a place in almost every aspect of modern living. They are used in shampoos, liquid detergents, fabric softeners, lotions, flavors, fragrances and much more. Fatty Acid Process Plants and Glycerin Process Plants supply a wide range of industrial applications with thousands of end-products mainly in the following fields: Coating & Paints Cosmetics Emulsifiers Lubricants Plasticizers Rubber Chemicals Soap & Detergents Surfactants Textile Chemicals Raw materials for fatty acid plants include soybean oil, palm oil, sunflower see oil, rapeseed oil, cotton oil, olive oil – all vegetable based oils; and animals fats like lard, butter, tallow, fish oil and poultry fat. Feedstocks are typically vary by geography and are determined by local supply and costs. Note: Crude glycerin is typically produced in an oleochemical fatty acid production plant, where fats and/or vegetable oil molecules are split to make fatty acid and a glycerin co-product at a 10:1 ratio. As noted earlier, it is also possible to make glycerin by saponification or in bio-diesel production via transesterification. Whatever the final derivate (ester, salt, alcohol, sulphate, sulphonate, amine, amide, etc.) the intermediate steps always involve the products of fatty acids, as a distilled mixture or as pure fraction: An oleochemical processing facility – aka fatty acid plant and glycerin plant - can be composed of the following processes or sections: Pretreatment Splitting Straight Distillation Heating Systems Fractional Distillation Sweetwater Treatment and Concentration Wet Fractionation Hydrogenation Flaking Glycerin Distillation and Refining Glycerin Recovery   Technology Suppliers: Below is a list of worldwide fatty acid process plant and glycerin process plant technology companies: Andreotti Impianti Desmet Ballestra DVC Process Technologists Fenix Process Technologies Gianazza JJ-Lurgi Lipico Technologies Mectech Process Engineers Muez-Hest Planning to start or expand a fatty acid or glycerin plant? Phoenix Equipment buys and sells complete fatty acid plants, glycerin plants and oleochemical facilities. Take a look at our current fatty acid plant inventory and glycerin plant inventory, or if you can’t find what you need, contact us today and one of our team members can assist you in finding exactly what you need.

Understanding the molecular process of methanol applications has provided us with the opportunity to create practical solutions for its use. Beneficial products such as antifreeze, wastewater treatment, camping and boating stoves, de-staining products, and even acetic acid are all produced using methanol. Among its most prominent applications, methanol has been used to fuel ground transportation vehicles through its production of methyl tert-butyl ether (MTBE), which is most commonly applied as an octane booster in gasoline. Methanol can also be used to produce biodiesel as well as diesel and gasoline for high performance engines. Looking to the future, researchers are studying methanol’s potential for sustainable energy use because of its short half life in groundwater. Whereas benzene can carry a half life of up to 730 days, methanol is considerably biodegradable with a half life of up to only 7 days. Some suggest that there may even be a use for methanol in powering electronic devices such as laptops and cell phones. No matter the intended use of the methanol, there are three distinct stages of methanol production, including: 1. Autothermal Reforming of Natural Gas to Synthesis Gas While methanol can be made from biomass, carbon dioxide plant emissions, and most fossil fuels, natural gas is the by far the most widely used feedstock for its convenience and efficient conversion. The first step in methanol production requires the formation of synthesis gas (“syngas” is a mixture of hydrogen and carbon monoxide gases) from natural gas. Natural gas and steam in a 3:1 ratio are heated to 1,300 to 1,800 degrees Fahrenheit inside nickel catalyst-filled tubes. Methane, natural gas’s primary component, reacts with the water vapor to make syngas: CH4 + H2O à3H2 + CO The exact ratio of hydrogen and carbon monoxide in the product can be controlled through pressure, natural gas composition, steam-to-carbon ratio, and other reactor design and processing variables. The steam methane conversion equation above produces a 2:1 diatomic hydrogen to carbon monoxide ratio. This autothermal reforming of natural gas ratio is perfect for producing both fuel-grade and high-purity methanol outlined in step 2. 2. Methanol Synthesis When exposed to a copper/zinc oxide, aluminum oxide catalyst, single carbon monoxide molecules combine with two diatomic hydrogens to synthesize methanol: CO + 2H2 à CH3OH Any carbon dioxide in the gas mix also reacts with hydrogen for additional methanol production: CO2 + 3H2 à CH3OH + H2O These reactions take place in a low-pressure synthesis loop reactor that allows for maximum recovery of the heat generated, as the three reactions are net exothermic. Use of isothermal reactors also allows for smaller sizes to keep investment and operating costs down. Composition of the catalyst is key, as high-performance and methanol synthesis selectivity are necessary for efficient conversion and long-term operation. The two reactions are net exothermic, and the heat generated can be converted to high-pressure steam for use in other operations in the plant or to generate electricity. Many methanol plants have installed pre-reformers that optimize the natural gas feed for more complete syngas production. The adiabatic conversion transforms higher hydrocarbons in the feed into methane and other lighter compounds such as carbon oxides and hydrogen so the primary reformers can work more efficiently. After treatment by the pre-reformers, the syngas enters a stand-alone, oxygen-fired autothermal reformer composed of a: Burner Combustion zone Catalyst bed in a refractory lined pressure vessel As the burner combusts, the feedstock in the oxygen-rich environment to complete the steam reforming and shift conversion reactions to equilibrium. The synthesis gas produced by ATR is rich in carbon monoxide, resulting in high reactivity of the gas. Removing carbon dioxide or recovering and recycling hydrogen makes it suitable for methanol production. 3. Methanol Purification and Distillation Synthesized methanol and water travel to a two-stage separation and boiler tower for purification and distillation to concentrations of 99.85% by weight or even greater. The product flowing into the vaporizing units typically contains 18% water, as well as alkanes, alcohols and propanol that must be burned off to achieve the required purity (IMPCA or U.S. Grade AA). Topping – First-stage purification is a topping process that removes “light end” impurities with relatively low boiling points. The water/crude methanol mixture is heating in the topping column to a temperature below methanol’s boiling point. “Light end” pounds boil off. Refining – In the second stage, the methanol/water mixture enters a refining column consisting of series of boiling tanks. Methanol boils at a lower temperature than water, so as the first tank is boiled, methanol vapor rises (along with some water steam) into the next tank. The vapor is cooled, then boiled again in each tank. Every iteration of boiling/cooling process extracts the methanol and lesser and lesser quantities of water until the liquid methanol concentration approaches 100%. Phoenix Equipment sells second-hand methanol synthesis loop equipment and turnkey plants immediately available for relocation. Buying used plants and components can save manufacturers significant capital and drastically shorten the time required to build or expand manufacturing operations. Contact us today so we can help you find the processing equipment or plant to suite your needs.