The report gives results of an evaluation of: (1) the relationship of the combustion characteristics of hydrothermally treated (HTT) coals to environmental emissions, boiler design, and interchangeability of solid fuels produced by the Hydrothermal Coal Process (HCP) with raw coals currently being used as the source of energy; and (2) the conversion of solubilized coal to terephthalic acid. Results indicate that the HTT coals are clean solid fuels that, in many instances, can be burned with little or no sulfur emissions. Flue gas SO2 concentrations were well below Federal Sulfur Emission Standards for New Sources. The HTT coal was found to burn as well as or better than raw coal. Trace metals emissions should be significantly reduced because of the lower concentrations in HTT coals. Therefore, the use of HTT coal in conventional boilers and furnaces should reduce environmental pollution. HTT coals appear to be more suitable for firing in wet-bottom than in dry-bottom furnaces because of potential fouling and slagging associated with their alkali content. However, additives may possibly be used to reduce fouling and slagging. The coal solubilized during desulfurization can be converted to terephthalic acid by the oxidation-Henkel reaction. However, low yields suggest that this approach may not be economical.

Contract no. 68-02-2119. Program element no. EHE623A. April 1978. Includes bibliographical references.