Two stage direct coal gasification to C(2)-C(4) hydrocarbons

The main objective of this work was to study the conversion of coal to C{dollar}sb 2{dollar}-C{dollar}sb 4{dollar} hydrocarbons in a two-stage reactor system. Coal was converted to liquids at 440{dollar}sp {lcub}circ{rcub}{dollar} C in a stirred batch autoclave using tetralin as the hydrogen donor solvent. The liquids produced were separated from the unreacted coal and ash by filtration. The liquids were then fed into a second stage fixed bed reactor containing sulfided Ni-Mo/Al{dollar}sb 2{dollar}O{dollar}sb 3{dollar} and SiO{dollar}sb 2{dollar}-Al{dollar}sb 2{dollar}O{dollar}sb 3{dollar} catalyst. The liquids were hydrocracked on the dual functional catalyst giving high yields of C{dollar}sb 2{dollar}-C{dollar}sb 4{dollar} hydrocarbons. The pressure was 1800 psi and the temperatures were in the range of 425 to 500{dollar}sp {lcub}circ{rcub}{dollar} C. The kinetic parameters of the conversion of coal liquids to gases were determined. The activation energy was determined to be 23.9 Kcal/mol. Cracking reactions involving C-C bonds appear to be rate-controlling.; Coal-derived liquids essentially free of the original hydrogen donor solvent were produced by recycling the liquids produced in the first stage several times. The liquids thus produced were used in the second stage to compare the conversions obtained from coal-derived liquids with those from coal-derived liquids containing the solvent. Coal-derived liquids gave higher conversions and higher rate constant.; Experiments were conducted to study the effectiveness of a hydrogen donor solvent(tetralin) in supercritical phase in controlling agglomeration and adhering tendency of a caking coal. It was observed that supercritical tetralin was as effective as tetralin in liquid phase in controlling agglomeration and adhering tendency.; Pressure fluctuations measurements were made in a fluidized bed reactor while fluidizing sand particles with nitrogen at atmospheric pressure and 500 psi. By Fast Fourier Transform technique, the pressure fluctuation data were converted to Power Spectral Density Function (PSDF). The variation of PSDF with frequency indicated if the bed is fluidizing.