ABSTRACT
This chapter describes the design and economic analysis of a lignite refinery and a biogasification process. Although none of the cases analyzed produced revenues sufficient to achieve a 15% return on investment at prevailing economic conditions and level of technical development, one of the lignite refinery cases produced a positive cash flow of $32 million per year. Therefore, the lignite refinery is favored over biogasification alone. Lignite is in abundance in Texas, but since it is composed of nearly 50% moisture and ash, it is not adaptable for the same uses as bituminous coal. The chemical structure of lignite is composed of aromatic clusters and oxygen groups. These oxygen groups are more prevalent in lignite than in higher-ranked coals, and it is the bonds between the carbon and oxygen molecules that break down under alkaline hydrolysis, thereby producing water-soluble organic acids.
