Abstract: Production of ammonia by the sequence of steam hydrocarbon primary reforming, secondary reforming with air, carbon monoxide shift conversion, carbon oxides removal and catalytic ammonia synthesis is improved by using oxygen-enriched air at secondary reforming and/or by operating the reforming steps so that 5-15% by carbon atoms of the starting hydrocarbon is not reformed but is purged from the synthesis. The oxygen enriched air can be the by-product of a simple air separation plant producing nitrogen, and the nitrogen can be used to aid start-up or shut-down of the process or to keep the process plant in a hot stand-by condition.

Abstract: Carbon dioxide is removed from a raw gas containing hydrogen, carbon dioxide, and intermediate boiling gas, e.g. nitrogen, to give a gas suitable for use as a synthesis gas by a wet carbon dioxide removal process, and the resultant carbon dioxide depleted gas is subjected to pressure swing adsorption (PSA) to remove some, or all, of the intermediate boiling gas and the bulk of any residual carbon dioxide. The PSA waste gas is used to strip the absorbent liquid in the regeneration of the latter in the wet carbon dioxide removal process.The process is of particular utility in the manufacture of ammonia synthesis gas from a raw gas containing an excess of nitrogen, particularly as prepared by primary/secondary reforming/shift of a carbonaceous feedstock with partial bypass of the primary reforming stage.

Abstract: A moist hydrogen stream is dried by cooling to below the dewpoint of water and separating water, drying further over a regenerable solid absorbent, separating a part stream of dried gas and using it to regenerate water-loaded absorbent, and recycling the resulting moist regeneration gas stream into the moist hydrogen stream upstream of the water separation step. If the starting moist hydrogen stream is produced by shift, CO.sub.2 -removal and methanation the recycled gas is preferably introduced between CO.sub.2 removal and methanation. If it is produced from unreacted methanol synthesis gas the recycled gas is preferably introduced upstream of methanol synthesis.

Abstract: In a methanol production process comprising synthesis gas generation, catalytic synthesis, recovery of crude methanol and purification by distillation, organic compounds of higher boiling point than methanol (the so-called "fusel oil" stream) are contacted in liquid form with a gaseous stream to be fed to synthesis gas generation, whereby to convert those compounds to synthesis gas. When an alkali is added to the crude methanol before distillation the contacting step permits utilisation of the organic compounds in the fusel oil, leaving an alkali compounds solution, which is withdrawn.

Abstract: In an ammonia production process a hydrocarbon steam mixture (16) is preheated (18, 24) and reacted in an adiabatic catalyst bed (22, 26), the resulting methane-containing gas is reacted (30) with air (32) to introduce more than 1 N.sub.2 per 3H.sub.2 and purified (44, 48, 54) the purified gas is passed to ammonia synthesis (66) in admixture with a hydrogen-rich stream (82) separated at 80 from reacted synthesis gas, and the rate of flow of that stream is controlled so that the H.sub.2 :N.sub.2 ratio of the gas entering the synthesis catalyst is in the range 1.0 to 2.5. Preferably methane is purged at 86 to the extent of 5-15% of the hydrocarbon feedstock.

Abstract: A process for producing methanol and ammonia by generating nitrogen-containing synthesis gas, reacting the carbon oxides and hydrogen incompletely to methanol and passing the unreacted gas to ammonia synthesis, is characterized by carrying out the methanol synthesis in a first, steam-free, stage and in a second stage in the presence of sufficient steam to convert to carbon dioxide substantially all the carbon monoxide not converted to methanol. Methanol can be taken from the systhesis stage as part of the product or can be recycled to that stage, thus limiting its methanol output.

Abstract: In a process in which, after product recovery, an off-gas containing hydrogen and/or carbon monoxide is produced, energy economy is improved by reacting the off-gas in a fuel cell. The resulting electricity is preferably used for driving small machines in the process. The process is especially useful for producing methanol from natural gas feedstock and then includes the steps of methanating the off-gas and letting it down in an engine before passing it to a fuel cell.

Abstract: An ammonia production process comprises steam hydrocarbon primary reforming, air secondary reforming, carbon monoxide hift, carbon oxides removal, ammonia synthesis and discarding of non-reactive gases and is made more economical in energy consumption by using excess air in secondary reforming and treating the synthesis gas to separate a hydrogen-enriched stream and returning that stream to the synthesis. Preferably the synthesis gas after carbon moxides removal is compressed if at all by no more than 50% and consequently the process can be carried out in a plant having a gas circulator but no compressor. Preferably synthesis is at a pressure in the range 40-80 bar abs. and at an outlet temperature in the range 350.degree.-430.degree. C. over a catalyst containing iron, cobalt and promoting compounds. Recovery of the hydrogen-enriched stream is preferably from a side stream of synthesis gas.

Abstract: In a process for producing a hydrogen containing gas by reacting steam with a feedstock to give a gas at a temperature of at least 350.degree. C., generating high pressure steam by heat exchange with such a gas, letting down the steam in an expansion engine of the pass-out type and using engine exhaust steam as process feed, an improvement in energy economy is achieved by bringing the engine exhaust steam into heat exchange with water and contacting the resulting hot water with a gaseous or vaporised feed to the process. The steam exhausted from the engine is preferably at a pressure lower than that at which the steam-using process step is generated. The process is especially useful in ammonia production by way of steam hydrocarbon reforming at an unconventionally high pressure in the range 40-80 bar abs, followed by synthesis at a pressure not more than 50% higher.

Abstract: In an ammonia synthesis process at a pressure under 120 bar bas. ammonia is recovered from incompletely reacted synthesis gas by absorption in water. Unreacted synthesis gas is dried preparatory to further reaction by passing it through a charge of regenerable solid absorbent until that charge is loaded with water and switching its flow to a fresh or regenerated charge. The loaded charge is regenerated by passing ammonia-containing reacted synthesis gas through it, the displaced water being separated in the ammonia absorption step. Alternatively or additionally the water content of the unreacted synthesis gas is decreased by contacting it with liquid aqueous ammonia at below 0.degree. C.

Abstract: Disclosed is a process for synthesis of methanol including reacting hydrocarbons with steam to produce carbon oxides and hydrogen which are reacted to form methanol wherein low grade heat sources comprising gases at 150.degree.-300.degree. C. are available. Previously the recovery of heat from such low grade heat sources has been inefficient or inconvenient. According to the invention the heat is recovered by means of an intermediary liquid coolant, which is brought into direct heat exchange with streams to be used in the process. Preferably the liquid is water under pressure and is brought into direct heat exchange with a gas to be fed to the process; by this means 10-30% of the steam can be provided from low grade waste heat.

Abstract: Methanol is produced from a carbon monoxide stream by reacting carbon monoxide with steam in a catalytic shift reaction, removing any excess steam and at least part of the carbon dioxide from the shifted gas, reacting the resulting gas over a copper-containing methanol synthesis catalyst at under 300.degree. C., heat exchanging reacted synthesis gas with water under pressure and bringing the resulting hot water into direct heat exchange with the carbon monoxide stream to provide steam for the shift reaction. In a preferred process the carbon monoxide stream is freed of non-refractory sulphur compounds before the shift stage and the refractory sulphur compounds are converted in the shift stage to H.sub.2 S, which is removed with the carbon dioxide.

Abstract: An exothermic gas phase reaction, especially synthesis of ammonia or methanol, is carried out by passing the reactant gas over a catalyst in a first zone in heat exchange with a coolant and then in a second, adiabatic zone and then passing reacted gas directly to a heat recovery zone. Such a sequence of zones affords a higher output of product and better heat recovery than in many previously used sequences, especially when the heat available from the cooled zone is used to pre-heat reactant gas and the heat removed from the gas leaving the adiabatic zone is used in high-grade recoveries such as high pressure steam generation.

Abstract: An ammonia production process comprising synthesis gas generation and ammonia synthesis with heat recovery in the generation section by steam raising and steam superheating and heat recovery in the synthesis section by steam raising or boiler feed water heating is made more controllable by effecting part of the superheating in the synthesis section, so that a shut-down of the synthesis section results not only in a decrease in steam flow through the superheaters, but also in a decrease in the temperature of the steam fed to them. Thus overheating of the superheaters, a defect of some earlier processes, is avoided. The process is operated with a synthesis pressure under 150, preferably 40-80 bar abs. and preferably synthesis gas generation is based on primary hydrocarbon steam reforming at such a pressure that synthesis gas compression is by under 50%.

Abstract: Purified methanol is produced by distilling a water methanol mixture in (a) a first column from which is taken a product methanol stream at an upper level, weakly aqueous methanol as a side stream and water as bottoms and (b) a second column in which that weakly aqueous methanol is separated into an overhead product stream and aqueous methanol bottoms. The first column may be preceded by a preliminary volatiles-removal column. The process is economical in heat consumption, especially when methanol vapor from the second column is heat-exchanged with the feed or bottoms of the first column.

Abstract: A methanol production process including synthesis gas generation, methanol synthesis and methanol distillation includes an autonomous system in which low pressure steam is raised by heat exchange with a fluid stream at 120.degree.-300.degree. C. in the process, the low pressure steam is used as live steam to heat at least distillation column in the distillation section and bottoms water from a distillation column in that section is used as feed to the autonomous steam system.

Abstract: In a process of reacting a hydrocarbon with steam and/or carbon dioxide in a reaction zone heated by a combustion furnace to give olefins or process gas containing carbon oxides and hydrogen high grade heat is recovered from furnace flue gases and/or process gas whereby to cool such gases to 150-300.degree. C. When the process gas is used in a synthesis of for example methanol or ammonia, gases at 150.degree.-300.degree. C are also produced. Previously the recovery of heat from such low grade heat sources has been inefficient or inconvenient. According to the invention the heat is recovered by means of an intermediary liquid coolant, which is brought into direct heat exchange with streams to be used in the process. Preferably the liquid is water under pressure and is brought into direct heat exchange with a gas to be fed to the process; by this means 10-30% of the steam can be provided from low grade waste heat.

Abstract: In a process for producing methanol by generating methanol synthesis gas, generating high pressure steam by heat exchange with a hot gaseous stream produced in the course of synthesis gas generation, bringing synthesis gas to synthesis gas pressure by means of a compressor powered from an engine in which such high pressure steam is let down, and synthesising methanol over a catalyst at an outlet temperature of under 300.degree. C, thermal efficiency is improved by transferring heat evolved in the synthesis to water maintained under a pressure too high to permit boiling and the resulting hot water is used as feed for the high pressure steam generation. If the methanol synthesis is of the recirculatory type and involves a purge, the purge gas is heated and let down in pressure in an expansion engine.

Abstract: In a process for producing methanol from a gaseous hydrocarbon feedstock, such as natural gas, containing more than the stoichiometric ratio of hydrogen to carbon, the hydrocarbon is subjected to steam reforming to give synthesis gas, the synthesis gas is incompletely reacted over a catalyst to give methanol, methanol is removed from the gas, the unreacted gas is treated to remove carbon monoxide or carbon dioxide from it, and the carbon monoxide or carbon dioxide or both is recycled to the methanol synthesis. By this means the concentration of carbon monoxide or carbon dioxide or both in the gas passing over the synthesis catalyst is kept at a higher level, thus increasing the efficiency of the synthesis and wastage of feedstock is avoided. At the same time a useful high-purity by-product hydrogen stream is produced.