Condensates from coal processing

Correlation of Vapor-Liquid Equilibria of Aqueous Condensates from Coal Processing... 

Od condensed from the released volatdes from the second stage is filtered and catalyticady hydrotreated at high pressure to produce a synthetic cmde od. Medium heat-content gas produced after the removal of H2S and CO2 is suitable as clean fuel. The pyrolysis gas produced, however, is insufficient to provide the fuel requirement for the total plant. Residual char, 50—60% of the feed coal, has a heating value and sulfur content about the same as feed coal, and its utilisation may thus largely dictate process utdity. 

Sasol Fischer-Tropsch Process. 1-Propanol is one of the products from Sasol s Fischer-Tropsch process (7). Coal (qv) is gasified ia Lurgi reactors to produce synthesis gas (H2/CO). After separation from gas Hquids and purification, the synthesis gas is fed iato the Sasol Synthol plant where it is entrained with a powdered iron-based catalyst within the fluid-bed reactors. The exothermic Fischer-Tropsch reaction produces a mixture of hydrocarbons (qv) and oxygenates. The condensation products from the process consist of hydrocarbon Hquids and an aqueous stream that contains a mixture of ketones (qv) and alcohols. The ketones and alcohols are recovered and most of the alcohols are used for the blending of high octane gasoline. Some of the alcohol streams are further purified by distillation to yield pure 1-propanol and ethanol ia a multiunit plant, which has a total capacity of 25,000-30,000 t/yr (see Coal conversion processes, gasification). 

The supercritical fluid extraction (SFE) is a process in which a highly compressed gas (fluid) is brought into contact with a relatively non-volatile solid or liquid at temperatures at or slightly above the critical temperature of the solvent. Under such conditions, the condensed phase will begin to volatize, which is interpreted as the supercritical fluid phase (Vayisoglu et al., 1996). The SFE is one of the best methods to obtain hqnid fuels from coals. The SFE extraction is carried out in an autoclave at above the critical temperature and the pressure of the solvent. The yield of soluble material increases with increasing pressure (Paul and Wise, 1971). 

Pyridine and its derivatives are technically-important fine chemicals. Their isolation from coal tar is decreasing, whereas their manufacture by synthetic methods has increased rapidly. The classical pathways to pyridine have been discussed by Abramovitch (74HC14-1-4). Many of them rely on the reaction of aldehydes or ketones with ammonia in the vapor phase. However, the condensation processes used suffer from unsatisfactory selectivity. Using soluble organocobalt catalysts of the type [YCoL] allows pyridine and a wide range of 2-substituted derivatives to be prepared selectively and in one step from acetylene and the appropriate cyano compound [Eq.(l)]. 

The most advanced two-stage process involves close coupled operation with a disposable slurry catalyst (typically iron and/or molybdenum) added with the feed coal and an integrated hydrotreater to treat the distillate condensed from the gaseous phase from the... 

There is water vapour in the air, as can be seen on a cold day when it condenses out of the air of a room onto the window panes of a house (unless they are double or triple glazed), or are even seen as we breathe out. Water vapour comes from any process of burning a hydrocarbon in oxygen, and that includes us as we burn up glucose in our bodies to produce energy plus the waste gases of C02 and H20. Our metabolic processes also produce water and water vapour, which we exhale in our breath. Plants do a similar thing. Cars, when they burn petrol, and power stations as they burn oil, gas or coal all produce water vapour. 

In 1825, Faraday isolated benzene from a liquid condensed by compressing oil gas. Benzene was first synthesized by Mitscherlich in 1833 by distilling benzoic acid with lime. Benzene was first commercially recovered from light oil derived from coal tar in 1849 and from petroleum in 1941 (IARC 1982a). Several years after the end of World War II, the rapidly expanding chemical industry created an increased demand for benzene that the coal carbonization industry could not fulfill. To meet this demand, benzene was produced by the petroleum and petrochemical industries by recovery from reformat and liquid by-products of the ethylene manufacturing process (Purcell 1978). 

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