Coal gasification major contaminant

Significant effort is underway in the United States to develop and commercialize coal gasification processes for producing gaseous fuels One of the major obstacles in the development of such a process is the presence of undesirable contaminants in the product gas stream. The major contaminant in coal gasification is hydrogen sulfide (H2S), which is toxic, poisonous to downstream catalysts and extremely corrosive in nature. Control of H2S in the fuel gas to a safe level is therefore essential. The H2S removal requirements are even more critical when the fuel gas is used in combined cycle power generation or in fuel cells. 

Methanol, also called methyl alcohol and once commonly know as wood alcohol, is a clear, volatile liquid mp, -98°C bp, 65°C). Until the early 1900s, the major commercial source of methanol was the destructive distillation (pyrolysis) of wood, a process that yields a product contaminated with allyl alcohol, acetone, and acetic acid. Now methanol is synthesized by the following reaction of hydrogen gas and carbon monoxide, both readily obtained from natural gas or coal gasification ... 

Complex Mixture Extraction. Analytical SFE can also be used for complex mixture sample preparation. Typical examples using hazardous waste samples are described below. Sample A was a soil boring contaminated with coal gasification residuals and sample B was from a waste stream from a treatment facility. The major objective of these studies was to compare the extraction abilities (e.g., amount of material extracted) of three different fluid systems using approximately four-gram aliquots of the samples. The specific fluid systems, the extraction conditions, and the percentage of the total mass of material extracted from each sample are listed in Table II. 

Carbonaceous fuels are used throughout the world as major energy sources. They exist primarily in solid forms, or heavy liquid forms, containing significant process and environmental contaminants compared to cleaner fuels such as natural gas. Coals and biomass fuels are two of the many carbonaceous fuel types that can be effectively processed in fluidized bed reactors, and they are currently of great industrial interest for fluidized bed gasification and combustion. 

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