Methanol plant/process

In 1968 a new methanol carbonylation process using rhodium promoted with iodide as catalyst was introduced by a modest letter (35). This catalyst possessed remarkable activity and selectivity for conversion to acetic acid. Nearly quantitative yields based on methanol were obtained at atmospheric pressure and a plant was built and operated in 1970 at Texas City, Tex. The effect on the world market has been exceptional (36). 

The cmde product from the gasifier contains CO2 and H2S, which must be removed before the gas can be used to produce chemicals. The Rectisol process is used to remove these contaminants from the gas. This is accompHshed by scmbbing the product with cold methanol which dissolves the CO2 and H2S and lets the H2 and CO pass through the scmbber. The H2S is sent to a Claus sulfur plant where over 99.7% of the sulfur in the coal feed is recovered in the form of elemental sulfur. A portion of the clean H2 and CO are separated in a cryogenic distillation process. The main product from the cryogenic distillation is a purified CO stream for use in the acetic anhydride process. The remaining CO and hydrogen are used in the methanol plant. 

The chemical complex includes the methanol plant, methyl acetate plant, and acetic anhydride plant. The methanol plant uses the Lurgi process for hydrogenation of CO over a copper-based catalyst. The plant is capable of producing 165,000 t/yr of methanol. The methyl acetate plant converts this methanol, purchased methanol, and recovered acetic acid from other Eastman processes into approximately 440,000 t/yr of methyl acetate. 

The high cost of coal handling and preparation and treatment of effluents, compounded by continuing low prices for cmde oil and natural gas, has precluded significant exploitation of coal as a feedstock for methanol. A small amount of methanol is made from coal in South Africa for local strategic reasons. Tennessee Eastman operates a 195,000-t/yr methanol plant in Tennessee based on the Texaco coal gasification process to make the methyl acetate intermediate for acetic anhydride production (15). 

Eastman Chemical Company has operated a coal-to-methanol plant in Kingsport, Tennessee, since 1983. Two Texaco gasifiers (one is a backup) process 34 Mg/h (37 US ton/h) of coal to synthesis gas. The synthesis gas is converted to methanol by use of ICl methanol technology. Methanol is an intermediate for producing methyl acetate and acetic acid. The plant produces about 225 Gg/a (250,000 US ton/a) of acetic anhydride. As part of the DOE Clean Coal Technology Program, Air Products and Cnemicals, Inc., and Eastman Chemic Company are constructing a 9.8-Mg/h (260-US ton/d) slurry-phase reactor for the conversion of synthesis gas to methanol and dimethyl... 

Catalyst improvements allow methanol plants and plants using the Oxo process for aldehyde production to operate at lower pressures. The process also has a higher yield and produces a better quality product (Dale, 1987). 

The German Lurgi Company and Linde A. G. developed the Rectisol process to use methanol to sweeten natural gas. Due to the high vapor pressure of methanol this process is usually operated at temperatures of -30 to -100°F. It has been applied to the purification of gas 1 plants and in coal gasification plants, but is not used commonlv natural gas streams. 

SAQ 4.15 Use the data in the Resource Material to answer the following question. It is 1977. The bacterial SCP from methanol plant referred to in Table 4.9 does not produce protein at a price that competes with soya protein. By how much would the cost of methanol have to fall in order that the protein from such a plant can be produced competitively with soya protein You can assume i) that the SCP processes referred to in Tables 4.7 and 4.9 to 4.15 are of 2 x 10s tons annual capacity, ii) that yield on methanol is 0.5kg biomass per kg methanol, iii) bacterial SCP contains 60% protein. 

Small but environrrientallyjnendly. The Chemical Engineer, March 1993 Huge increases in technology in the past distributed manufacturing in small-scale plants miniaturization of processes domestic methanol plant point-of-sale chlorine simpler and cheaper plants economy of plant manufacture process control and automation start-up and shut-down sensor demand [145],... 

Methanol oxidation, 12 214 Methanol plant reformers, 16 303 Methanol processes. See also Methanol-to-entries... 

In 1996, BP Chemicals announced a new methanol carbonylation process, Cativa , based upon a promoted iridium/iodide catalyst which now operates on a number of plants worldwide [61-69]. Promoters, which enhance the catalytic activity, are key to the success of the iridium-based process. The mechanistic aspects of iridium-catalysed carbonylation and the role of promoters are discussed in the following sections. 

Since 1923, methanol has been made commercially from synthesis gas, the route that provides most of the methanol today. The plants are oEten found adjacent to or integrated with ammonia plants for several reasons. The technologies and hardware are similar, and the methanol plant can use the CO2 made in the Haber ammonia process. In this case, the route to methanol is to react the CO2 with methane and steam over a nickel catalyst to give additional CO and H2 and then proceed to combine these to make methanol ... 

ATR is a stand-alone process which combines POX and SR in a single reactor. The ATR process was first developed in the late 1950s by Topsoe, mainly for industrial synthesis gas production in ammonia and methanol plants [27]. 

This process has many similarities to NH3 synthesis. The pressure is not as high for acceptable conversions, and modem methanol plants operate at -250°C at 30-100 atm and produce nearly equilibrium conversions using Cu/ZnO catalysts with unreacted CO and H2 recycled back into the reactor. 

Methanol was first produced commercially in 1830 by the pyrolysis of wood to produce wood alcohol. Almost a century later, a process was developed in Germany by BASF to produce synthetic methanol from coal synthesis gas. The first synthetic methanol plant was introduced by BASF in 1923 and in the United States by DuPont in 1927. In the late 1940s, natural gas replaced coal synthesis gas as the primary feedstock for methanol production. In 1966, ICI announced the development of a copper-based catalyst for use in the low-pressure synthesis of methanol. 

Two versions of the MTG process, one using a fixed bed, the other a fluid bed, have been developed. The fixed-bed process was selected for installation in the New Zealand gas-to-gasoline (GTG) complex, situated on the North Island between the villages of Waitara and Motonui on the Tasman seacoast (60). A simplified block flow diagram of the complex is shown in Figure 6 (61). The plant processes over 3.7 x 106 m3/d(130 x 106 SCF/d) of gas from the offshore Maui field supplemented by gas from the Kapuni field, first to methanol, and thence to 2.3 x 103 m3/d (14,500 bbl/d) of gasoline. Methanol feed to the MTG section is synthesized using the ICI low pressure process (62) in two trains, each with a capacity of 2200 t/d. 

A 1,000 ton/day methanol plant, using a Winkler type gasifier adapted to burn wood chips and to use the ICI process for synthesis, requires the following consumption of ingredients per ton of methanol ... 

Process - Methanol Plant , Krupp-Koppers, Rio de Janeiro, 1976. 

The details of the methanol conversion process and its control are in development. The process itself is described in Dr. George Olah s book titled Beyond Oil and Gas The Methanol Economy, published by Wiley-VCH, and I understand that it is being developed by Universal Oil Products (UOP), which is also developing related process technologies and joint ventures for demonstration and de facto plants. Therefore, it is not certain, but it is likely that the methanol process could mature by the time the solar-hydrogen demonstration plant is completed, and in that case, it could be made part of the total power plant. 

The indirect liquefaction processes include Fischer-Tropsch and coal to methanol. Both processes have operated on a commercial scale. For the past 25 years, a Fischer-Tropsch facility has operated in South Africa. Presently the South Africans are constructing an advanced and larger facility. Coal-to-methanol plants existed in the United States, but were replaced by natural gas-to-methanol facilities because it was more economical to do so. 

The MTG process will soon see its first commercial application in a plant currently being constructed for the New Zealand Synthetic Fuels Corporation Limited. This plant, scheduled for completion in 1985, will produce gasoline from methanol derived from New Zealand natural gas. It will produce some 570,000 tonnes per year (14,000 BPSD) of unleaded gasoline averaging 92 to 94 research octane. This is equivalent to about 1/3 of New Zealand s gasoline consumption. Two 2,200 tonnes per-day methanol plants will provide the feed for the single-train MTG plant. 

JORGE A. CAMPS has BS and MS degrees in Chemical Engineering from Louisiana State University. He worked for five years with Exxon Corporation at various U.S. and overseas locations. He joined Davy Powergas International in 1974 and is now a Principal Process Engineer of Synthesis Gas Processes. His most recent experience was as the Lead Process Engineer for a 2300-STPD methanol plant for SCT in Saudi Arabia. Mr. Camps is also an adjunct Professor of Chemical Engineering at the University of South Florida in Tampa. 

For convenience, the discussion of materials for these various processes is divided into five chapters. Crude units and utilities are discussed in this chapter. FCCs, fluid cokers, delayed cokers, sour water strippers, and sulfur plants are covered in Chapter Two. Desulfurizers, reformers, hydrocrackers, and flue gas are discussed in Chapter Three. Hydrogen plants, methanol plants, ammonia plants, and gas treating are discussed in Chapter Four. Underground piping, pipelines, production equipment, and tankage associated with the refinery industry are covered in Chapter Five. Discussed throughout these chapters are many common environments and equipment (e.g., sour or foul water, distillation, etc.) that appear in the various types of refinery process plants. 

Topsoe supplies a complete range of catalysts that can be used in the methanol plant. Total energy consumption for this process scheme is... 

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