In-bed sulphur capture during pressurized fluidized-bed hydroretorting of Eastern oil shales

Abstract

The Institute of Gas Technology is developing a pressurized fluidized-bed hydroretorting (PFH) process for the production of oil from Eastern oil shales. The sulphur present in the Eastern oil shales is converted to H 2S during hydroretorting. A solid sorbent (limestone or siderite) may be added to the PFH reactor with the oil shale to achieve in-bed desulphurization. The effects of operating conditions on the effectiveness of in-bed sulphur capture with limestone and siderite have been investigated. Reactivities of a limestone and a siderite toward H 2S were determined in experiments conducted in an ambient pressure thermogravimetric analyser. These tests were conducted in the temperature range of 480–565 °C using solid sorbents with an average particle diameter of 0.018 cm (−60 + 100 mesh). The results of thermogravimetric analysis tests indicate that both limestone and siderite should be capable of capturing a significant fraction of H 2S produced in the PFH reactor. Batch PFH tests have been conducted to determine the extent of H 2S removal with in-bed sorbents. The results of these tests confirm that a significant fraction of H 2S produced in the PFH reactor can be removed with in-bed sorbents.