Energy Recovery Study for Polyethylene and Cotton by Thermal Plasma Degradation

In the present study, the main focus was on plasma pyrolysis and gasification of organic waste, specifically polyethylene and cotton waste and exploring the energy recovery possibilities from the gases obtained after the plasma pyrolysis and gasification. In pyrolysis the gases formed are Syn gas (H2 + CO), CH4, higher hydrocarbons along with soot particles. The waste is disintegrated using thermal plasma (which is generated using graphite plasma torch) in oxygen starved environment (pyrolysis) and also in partial oxidation condition (gasification). Experiments have been carried out by varying pyrolysis chamber temperature from 5000C to 7000C and polyethylene and cotton are fed into the pyrolysis chamber. It has been observed that plasma pyrolysis of polyethylene in the temperature range of 500 to 700 0C yields H2 as main component around 30-40% volume basis along with CO, CO2, CH4, C2H6, C2H4, C2H2 and soot particles whereas pyrolysis of cotton, on the other hand provides less H2 around 15-20 %. However, it has also been observed that in plasma gasification H2, CO, CH4 content in the exhaust gases reduces to some extent (2-5%). The theoretical and experimental energy recovery comparisons have also been carried out.