High BTU

High Heat- Value Gas. High heat-value (high Btu) gas (7) has a heating value usually in excess of 33.5 MJ/m (900 Btu/fT). This is the gaseous fuel that is often referred to as substitute or synthetic natural gas (SNG), or pipeline-quaHty gas. It consists predominantiy of methane and is compatible with natural gas insofar as it may be mixed with, or substituted for, natural gas. 

For the methanation reaction in the process of converting coal to a high Btu gas, various catalyst compositions were evaluated in order to determine the optimum type catalyst. From this study, a series of catalysts were developed for studying the effect of nickel content on catalyst activity. This series included both silica- and alumina-based catalysts, and the nickel content was varied (Table I). 

On the basis of this past work and ongoing experiments, we feel that the liquid-phase methanation process promises to become an economic, reliable, and versatile means of converting synthesis gas mixtures to high Btu gas. Chem Systems believes that this technology is a key step in the transformation of fossil feeds into pipeline gas, and we look forward to its successful application in commercial coal gasification plants. 

Bakhshi, N.N., Dalai, A.K, and Srinivas, S.T. (1999). Conversion of Various Biomass-derived Chars to Hydrogen/High Btu Gas by Gasification with Steam, Proceedings of the 4th Biomass Conference of the Americas, Oakland, CA, August 29-September 2, 1999. pp. 985-990. 

Srinivas, S.T., Dalai, A.K., and Bakhshi, N.N. (1998). Potential of Producing Hydrogen and High Btu Gas from Steam Gasification of Biomass-derived Chars, Canadian Society for Chemical Engineering Conference, London, Canada, 4-7 Oct CONF-981052(ISBN 0-920804-32-2). 

Atkins, W.T. and Takach, H.J. "Problems Associated with Controlling Sulfur Emissions from High-BTU Coal Gasification Plants, Interim Report," C.F. Braun Co., Alhambra, CA, FE-2240-13. 

Good fuel economy and heating value Higher-density fuel has more potential heating value or BTU per volume than lower density fuel. High-BTU fuel has a greater concentration of aromatic compounds per fuel volume than low-BTU fuel. 

A search of the recent literature indicates identifiable plans for 19 high Btu coal gasification, 10 medium and low Btu gas, and 15 liquefaction projects. These range from laboratory scale, through seeking funds for feasibility studies, to the construction of commercial scale demonstration plants. The implied coal input in Table V is based on extrapolations to commercial size of those projects which are sufficiently advanced to provide data on input and/or output, site, and time frame. Other projects may be included later but they could not make a contribution before the mid-1990 s. 

Combustible Reaction Moles Pounds Heat ol combustion (High) Btu pound of fuel... 

Pilot plant and demonstration plant scale projects include the SYNTHANE process, the Hygas process, and the Bigas process among others. See W. P. Haynes and A. J. Forney, High BTU Gas from Coal Status and Prospects, Tech. Rep. PERC/IC-76-1. U.S.E.R. D.A. Office of Public Affairs, 1976. 

The C. F. Braun papers have been presented to summarize the results of studies which they have reported in detail in DOE reports. Their studies are the only ones that are available to the public which present economics for multiple high Btu gas processes on a consistent basis by one organization. But one must be careful in using the information in the papers to note the dates and the caveats. 

For a so-called "advanced process of flash hydropyrolysis, (14), a paper by Rockwell International and Cities Service Research and Development reported a 1977 minimum high Btu gas price of 2.36/MMBtu from western subbituminous coal using "AGA/ERDA cost guidelines" with utility financing under conditions yielding significant quantities of by-product BTX liquids. For details, reference was made to contractual reports. 

Finally, a number of options exist for the production of high-Btu gas by hydrocarbonization and hydropyrolysis processes. 

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