The Oil Shale Transformation in the Presence of an Acidic BEA Zeolite under Microwave Irradiation

The transformation of an oil shale sample from the Autun Basin in the Massif Central, France, was studied using two different heating strategies: microwave irradiation and conventional heating. Microwave heating was performed using a single-mode cavity operating at a frequency of 2.45 GHz under an inert atmosphere. Heating of the sample generated liquid products of similar composition using either microwave or conventional heating. The yields of liquid products were similar in the two cases, while the overall energy requirements were much lower using microwave irradiation. The influence of water vapor on the oil shale decomposition was also studied under microwave energy. In order to simulate conversion of the organic fraction of the oil shale in the presence of an acidic zeolite catalyst, the oil shale sample was mixed with 5 wt % BEA zeolite and heated under microwave irradiation. It was found that the liquid products yield decreased along with an increase in the amount of coke produced. Gaseous and liquid products recovered showed a tendency for the production of lighter components in the presence of zeolite. The aromatic character of the oils was more important when microwaves were used, especially in the presence of zeolite.