Western oil shale conversion using ROPE® process

Western Research Institute (WRI) is continuing to develop the Recycle Oil Pyrolysis and Extraction (ROPE®) process to recover liquid hydrocarbon products from oil shale, tar sand, and other solid hydrocarbonaceous materials. The process consists of three major stepss (1) pyrolyzing the hydrocarbonaceous material at a low temperature (T < 400°C) with recycled product oil, (2) completing the pyrolysis of the residue at a higher temperature (T > 400°C) in the absence of product oil, and (3) combusting the solid residue and pyrolysis gas in an inclined fluidized-bed reactor to produce process heat. Many conventional processes, such as the Paraho and Union processes, do not use oil shale fines (particles smaller than 1.27 cm in diameter). The amount of shale discarded as fines from these processes can be as high as 20% of the total oil ahale mined. Research conducted to date suggests that the ROPE® process can significantly improve the overall oil recovery from western oil shale by processing the oil shale fines typically discarded by conventional processes. Also, if the oil shale fines are co-processed with shale oil used as the heavy recycle oil, a better quality oil will be produced that can be blended with the original shale oil to make an overall product that is more acceptable to the refineries and easier to pipeline. Results from tests conducted in a 2-inch process development unit (PDU) and a 6-inch bench-scale unit (BSU) with western oil shale demonstrated a maximum oil yield at temperatures between 700 and 750°F (371 and 399°C). Test results also suggest that the ROPE® process has a strong potential for recovering oil from oil shale fines, upgrading shale oil, and separating high-nitrogen-content oil for use as an asphalt additive.