Catalytic Multi-stage Liquefaction (CMSL)

1996Final ReportPDFTech ReportDOE/PC/92147-T2-VOL.1DE-AC22-93PC92147CatalystsCoal liquefactionIronMolybdenumPlasticsSolid wastesSubbituminous coalBench-Scale ExperimentsCatalytic EffectsCoprocessingEconomic AnalysisSubbituminous CoalSulfationSynthesis GasTables(data)United StatesHydrocarbon Technologies, Inc.Comolli, A. G.Ganguli, P.Karolkiewicz, W. F.Lee, T. L. K.Pradhan, V. R.Popper, G.Smith, T.Stalzer, R. H.Hydrocarbon Technologies, Inc.US Transportation CollectionReported herein are the details and the results of laboratory and bench scale unit experiments that were conducted at Hydrocarbon Technologies, Inc. (HTI), under DOE Contract No. DE-AC22-93PC92147 during the period of October 1, 1992, to December 31, 1995. The program results described herein build on the previous technology base and investigating additional methods to improve the economics of producing transportation fuels from coal. This included purely physical parameters, coal treatment and variation in solvent to coal ratio, the use of syngas to replace part of the hydrogen as the reducing gas, the use of dispersed catalyst in addition to and replacing the supported catalyst, \u2018and the coprocessing of coal with plastic waste material. The overall objective of this program is to produce liquid fuels from direct coal liquefaction at a cost that is competitive with conventional fuels. This report includes the results of an economic assessment of the various process strategies that were evaluated during this program. Hydrocarbon Technologies, Inc. (HTI) has completed a research and development program, originally schedule for 24 months but was extended to 36 months, and which incorporates new concepts and ideas ftom HTI and Pittsburgh Energy and Technology Center, and builds on continuing developments at DOE-sponsored university and private contractor laboratories. These studies were performed in a continuous bench scale unit that is representative of commercial operations. This bench unit is unique in that it can be operated as a single, two, three or four stage reactor system, as an ebullated-bed, back-mixed, plugflow continuous stirred tank reactor, or as a fmed bed system with provisions for interstage sampling in-line hydrotreating, and alternative solid separation systems. The bench scale unit was further modified during the program to include a hot slurry mixing system, an interstage separator, a hydrotreater, and a pretreater. Technical assessment has shown that for coal only operations the cost of equivalent crude oil of $29 per barrel from Black Thunder Mine sub-bituminous coal can be attained, a reduction of $3 per barrel from that for earlier CTSL. Factors resulting in this improvement are: a) interstage removal of vapors which lowered the vapor load in the reactors for a more efficient reactor design; b) lower oil/coal ratio for slurry in feed coal; d) in-line hydrotreating downstream of the second stage reactor. Prospectively substitution of mixed plastics for a portion of the coal fed would reduce the equivalent crude oil cost by as much as $10 per barrel. An equivalent crude oil cost for an operation with 50% plastic as low as $20 per barrel was estimated for a configuration that was not necessarily optimum, which used Mo and Fe additives only with no extrudate catalyst. The direct addition of Synthesis Gas (5044% CO) to the liquefaction reactors in place of high purity hydrogen increased the cost of equivalent crude oil by $0.4-$1.5 per barrel. Page 1 Volume I Catalyst additives, Mo as Molyvan lubricant additive and FeOOH, have the principal effect of increasing coal conversion over that obtained with supported Ni-Mo catalyst, by as much as 5% with sub-bituminous coal. With only dispersed catalysts higher temperatures are required with increased light gas yields which reduced the advantage of lower catalyst concentration. The lowest slurry oil/coal ratio successfully employed was 0.9 kg/kg. When synthesis gas, 7584% CO, was fed to the liquefaction reactor a supported Ni-Mo catalyst was very effective in promoting the shift reaction of Co to HZ, but also converted a large proportion of the CO to CH,. With only catalyst additive, the proportion of CO reacted to H, was only 1/2-2/3 as great, but no CH, was formed. Interstage removal of vapors with sub-bituminous coal conserved H2 by rejecting COZ before it could be converted to CH, by supported catalyst in the second stage. The conservation was greatest with only catalyst additive in the fast stage.79