Abstract

Phase I of a joint program to investigate coprocessing of various coals and heavy oil/bitumen resids using HRI's ebullated bed technology was completed in 1986. The program was sponsored by Electric Power Research Institute (EPRI), Ontario Ohio Synthetic Fuels Corporation Ltd. (OOSFC), Alberta Research Council (ARC) and Dyn Corp (formerly Dynalectron Corporation); OOSFC received financial support from the State of Ohio Coal Development Office. The study involved experimental work at the laboratory and the continuous bench scale level as well as economic and commercial evaluations of the process. This report details laboratory work performed by the Alberta Research Council using a 1-litre batch autoclave.

Autoclave reaction conditions were selected in an attempt to simulate those present in an ebullated bed reactor. Thus the coal and oil feedstocks were blended with diluent solvents in a ratio of 1:2. A supported catalyst was added in pellet form at a equal weight ratio to the feedstock pair. Both Alberta sub bituminous and Ohio bituminous coals were tested with an atmospheric bottoms resid derived from Cold Lake heavy oil.

Conversions of both Alberta and Ohio coals exceeded 90% at a variety of operating conditions and coal to oil ratios. For the majority of feedstock ratios, the conversion of the coal plus pitch (524 °C+) portion of the feedstock was greater than was predicted from experiments using either coal or resid alone. Product qualities were superior to those attained using a disposable iron oxide/dimethyldisulphide catalyst.

Introduction

The Province of Alberta has vast reserves of hydrocarbons in the form of gas, heavy oi1, bitumen, and subbituminous coal1. Currently the coal is mined from shallow deposits for use in power generation. The low cost of this coal makes it an attractive feedstock for the production of synthetic liquid fuels. In addition, the subbituminous coal is low in sulfur thus a blended feedstock of coal and bitumen or heavy oi1 would need 1ess treatment for environmental and product quality requirement schemes. The Alberta Research Council has investigated several schemes to produce 1iquid hydracarbon fuels from blended2–3 feedstocks of coal and bitumen, i.e. coprocessing. This present study describes a program which was undertaken to use HRI's ebullated bed technology for the coprocessing of coal and heavy oil.

The program was a joint effort by Electric Power Research Institute (EPRJ), Hydrocarbon Research Inc. (HRI), the Alberta Research Council (ARC) and Ontario-Ohio Synthetic Fuels Corporation (OOSFC). The program tasks were divided between the participants to utilize their individual skills. Thus HRI performed bench unit, microautoclave screening and product characterization tests as well as economic screening. The Research Council contributed hatch autoclave studies and feedstock characterization while OOSFC initiated a commercial planning study. All four parties participated in program planning and technical management. This presentation concentrates on the batch autoclave screening tests performed by Alberta Research Council. The remainder of the program has been reported elsewhere 4–5.

Figure 1 shows a typical arrangement for the HRI ebullated bed technology as applied to coprocessing of coal and heavy oil.

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