With the rapid development of economy, energy consumption increases gradually every year, and coal slurries are used in various thermal machines, especially in internal combustion engines, in accordance with the global strategy of saving and replacing oil.
In the production of CWS fuel, the ration of raw coal and additives and the relevant process are important for improving the quality and saving the cost.
Pak Song Chol, researcher at the Faculty of Physics, conducted an experimental study to convert coal-water-oil slurry (CWOS) into an alternative fuel (AF) for internal combustion engines by high-voltage discharge (HVD) and dielectric barrier discharge (DBD) plasmas.
He prepared CWOS by adding oil to the coal-water mixture in a relevant ratio. Then, he converted the CWOS to AF by passing high-voltage discharge and DBD plasma with gas emission and liquefaction reactions through it.
The result showed that after HVD and DBD plasma treatments, the CWOS has the average coal size reduced from 12.95 to 8.26㎛, improved dispersibility, less deposits, and calorific value enhanced by 35%.
The plasma-treated CWOS is similar to other liquid fuels in terms of rheological property and calorific value. It is therefore concluded that it can be directly employed to fuel combustion in the internal combustion engines with a little design modification.
The details can be found in his paper “Enhancement of calorific value and dispersion stability of coal-water-oil slurry by discharge plasmas: application of high voltage discharge and dielectric barrier discharge” in “International Journal of Coal Preparation and Utilization” (SCI).