Microwave assisted coal conversion

This work presents initial results for small scale microwave assisted, low temperature and low pressure conversion of coal to heavy hydrocarbons (pyrolysis oils) in the presence of methane. These heavy hydrocarbons can subsequently be upgraded to liquid transportation fuels, including gasoline, jet, and diesel. Benchmark testing was performed to establish a baseline for the conventional method of pyrolysis oils production from coal. A microwave reactor for experimental demonstration was designed and built. Methane was added directly to the coal in the reactor, where the microwave energy was applied. Testing with Pittsburgh-8 coal has shown that the maximum oils yield under microwave and methane conditions was higher than 40%, representing more than a 100% increase in oils yield compared to benchmark testing. Test results also demonstrated that under microwave and methane conditions the oils yield from Black Thunder coal increased by almost four times reaching 25% at ∼800 °C. Analysis of char collected in microwave testing has shown that the carbon content in char was ∼80%, making char a valuable fuel.