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.