Effect of temperature, coal, donor solvent, and hydrogen on short contact time liquefaction yields

Abstract

Ind. Eng. Chem. Prod. Res. Dev. 1985, 2 4 , 641-644 641 noted above, a total yield of single-ring phenols and hydrocarbons of 9.6 w t % would be calculated. This figure compares favorably with the total single-ring phenols' and hydrocarbon yields of less than 2 wt % obtained from pyrolysis alone. Conclusions 1. Preferred products from the hydrodeoxygenation of substituted guaiacols and catechols at temperatures of 250-325 "C were predominantly alkylated phenols and single-ring hydrocarbons, with combined molar yields of up to 0.60 observed. Conversion of these substrates to char was greatly reduced in comparison to pyrolysis alone.2. Hydrocracking of thermally stable biphenyl, diphenylmethane, and phenyl ether interaromatic unit linkages was achieved at temperatures of 280-330 OC during the hydrodeoxygenation of o,o'-biphenol, ohydroxydiphenylmethane, and phenyl ether substrates. Oxygen removal prior to interunit bond cleavage was also observed.3. These model compound results were applied to liquefaction of actual lignins. A 5-fold increase, relative to pyrolysis, in the total yield of single-ring phenols and hydrocarbons was predicted to occur from catalytic liquefaction at milder conditions than those required for pyrolysis. AcknowledgmentWe acknowledge the financial support of the Exxon Teaching Fellowship Program. We thank Drs. John Obst and Roger C. Pettersen of the USDA Forest Products Laboratory, Madison, WI, for providing GC/MS analyses. Registry No. Ligninphenyl ether, 101-84-8. Literature Cited Bredenberg. J. B-son; Ceylan, R. fuel 1983, 62. 342. Bredenberg. J. &son; Huuska, M.; Raty, J.; Korpio, M. J . Cstal. 1982, 77, 242. Connors, W. J.; Johanson, L. N.; Sarkanen, K. V.; Winsiow, P. Holzforschung 1980, 3 4 , 29. Domburg, 0. E.; Sergeeva, V. N.; Kalninsh, A. I. Therm. Anal., Proc. Int. Conf. 3rdThe liquefaction of different coals slurried in Koppers' creosote oil at short contact time (12 min) was studied at different reaction temperatures (300-450 "C). The influence of tetralln and hydrogen on short contact time (SCT) liquefaction ylelds and vehicle Incorporation was monitored. The data support the following concepts: (1) The conversion to tetrahydrofuran (THF) and pentane solubles of the reaction products increased with increasing temperature in all cases.(2) The presence of tetraiin or hydrogen enhanced the conversion to THF and pentane solubles; when both tetralln and hydrogen were present, the effects were additive for conversion to pentane solubles but not additive for conversion to THF solubles. (3) Both high temperature and the presence of a hydrogen source minimized vehicle incorporation into the coal and coal products.