Pyrolysis of lignites and brown coal catalytically depolymerized with phenol was studied in order to design easy liquefaction or up-grading procedures effective under non-extreme conditions, where the recovery of phenol may be critical. The lignites were solubilized in pyridine very easily at low phenol/lignite ratios, but high ratios were required to induce their solubility in benzene-ethanol or THF. Although THF- and pyridine-soluble (abbreviated as THFS and PS, respectively) fractions exhibited fusibility in their single carbonization to produce grain cokes of optical isotropy, optical anisotropy can be developed by co-carbonization with petroleum pitches, suggesting that these fractions may be suitable as needle or blast furnace coke sources. The heat-treatment of PS with a hydrogen donor made it completely soluble in benzene. The recovery rates of bound phenol in the depolymerized lignite were at highest 57 and 36%, respectively, for the coking and heat-treatment processes, although the formation of alkyl phenols may occur in the heat-treatment.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Fuel Technology
- Energy Engineering and Power Technology