Coal gasification performance

One advantage of modem coal gasification combined cycle systems is excellent environmental performance. Not only are regulatory standards met, but emissions and effluents are well below accepted levels (13,16,28). 

This paper touches on the chemistry of coal gasification and liquefaction comments on the current status of conversion processes and the influence of coal properties on coal performance in such processes and examines the contributions which coal conversion could make towards attainment of Canadian energy self-sufficiency. Particular attention is directed to a possible role for the medium-btu gas in long-term supply of fuel gas to residential and industrial consumers to linkages between partial conversion and thermal generation of electric energy and to coproduction of certain petrochemicals, fuel gas and liquid hydrocarbons by carbon monoxide hydrogenation. 

SFE and SFE/derivatization for the extraction of phenols from a coal gasification wastewater have been performed by first collecting the wastewater organics on "Empore" C-18 sorbent discs (8). The sorbent discs were first prepared by washing with methanol and water as per the manufacturer s instructions. A 100-mL sample of wastewater was acidified to a pH <2, 4 mL of methanol was added, and the waters were filtered through the sorbent discs. The discs were then placed in a 2.5 mL cell and extracted at 80°C and 500 atm using pure C02, C02 with 1.0 mL methanol modifier placed in the cell, or C02 with 1 mL of 0.1 M TMPA in methanol placed in the cell. (Extractions using methanol modifier and TMPA derivatization were each performed statically for 5 minutes followed by dynamic extraction for 10 minutes.) No attempt was made to dry the discs before SFE. 

The software system, to meet the needs of the 1980 s, has wide flexibility and capabilities. For processes such as coal gasification or coal liquefaction, it can be used to perform steady state material and energy balances, calculate sizes of equipment, and carry out economic evaluations. Its flexibility can allow for the handling of coal or other solids in streams and equipment, and its capabilities allow for the simulation of many different types of process equipment and the calculations of physical properties under widely different conditions. Included in this is the ability to analyze conventional chemical and petroleum processes. Another valuable feature 1s a good preliminary cost estimation capability that permits the comparison of alternative processes on an economically consistent basis at an early stage of development. 

An exergetic analysis of coal gasification has already been performed for individual processes (1, 2). This showed that high exergetic losses may occur in the waste heat section of such a plant. In this article, an attempt is made to determine the influence of the chosen concept and the gasification parameters on the exergy balance by systematic investigation. 

Fischer-Tropsch (FT) technology converts synthesis gas produced by reforming of methane or coal gasification into waxy products. Long alkanes (-CH2 -chains) produced by using FT synthesis are chemically similar to polyethylene. Lubricating oils derived from isomerization of FT waxes are gaining interest due to increased demand for lubricants with the advanced performance and environmental benefits described earlier. 

After performing the coal-gasification step, the reduced In(III)-ferrite reacted with CO2 at 800°C to carry out the C02-reduction step. Significant amount of CO was evolved and the evolution was completed within 30 min. In the XRD pattern of the ferrite after the CO2-... 

Although no coal gasification-based polygeneration plant that coproduces hydrogen and electricity currently exists, the technologies required for such a plant are fairly mature. Many heavy oil-based facilities, which utilize similar technology, have already been in operation. There have been many studies and analysis conducted to evaluate the system performance and economics of such coal-to-hydrogen systems. 

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