Results from simulated, modified in-situ retorting in pilot retorts

Data obtained from operating 1.5 m x 0.3 m and 6 m x 0.9 m laboratory retorts to simulate a modified in-situ process are summarized. The effects of feed-gas composition, including addition of steam, shale particle size and bed porosity on retorting rate, temperature maxima and profiles, off-gas composition and oil yield are presented. Inclusions of steam is shown to increase retorting rate, oxygen efficiency and hydrogen content of the off-gas. The heating value of the off-gas is also raised somewhat, but is mainly determined by the C/sub 4//sup +/ content. With a narrow shale particle size range, the experimental data agree well with model calculations based on the underlying physical and chemical processes. The experimental results with a broader range of particle size or large content of fines indicate complexities due to gas flow non-uniformity and oil holdup. The use of intra-retort gas composition and temperature data to detect and help interpret these complexities is demonstrated.