Surface Retorting of Jordanian Oil Shale and Associated CO2 Emissions

In this study, two oil shale samples, from two different deposits in Jordan, have been pyrolysed using a thermogravimetric analyser (TGA). The controlling parameters studied were the final pyrolysis temperature and the influence of the heating rate as well as type of purge gas employed on the process of thermal degradation of the shale sample. It is found that there are two main steps of samples weight loss. The first one is due to conversion of organic matter to oil and gas which occurred within the temperature range of between 250 to 550 °C, while the second step represents weight loss due to carbonate decomposition releasing CO2 and occurred at approximately higher temperature of more than 550 °C for examined samples. In directly heated systems additional quantities of CO2 will be produced due to combustion of residual carbon in order to provide needed heat for the retorting process. Therefore, surface retorting processes aiming to produce crude shale oil from raw oil shale will release higher rates of CO2 emissions to the environment compared with production of conventional or other synthetic fuels.