Co-pyrolysis product analysis of coffee husk and LDPE plastic mixture

The main energy source in Indonesia is fossil fuels, but this energy source has a detrimental impact on the environment such as global warming. One solution to reduce fossil fuel consumption is to use alternative energy sources derived from biomass. Coffee husks are one of the biomass that is abundantly available and has the potential as an alternative energy. To optimize coffee husk waste as an alternative fuel, it is mixed with low-density polyethylene (LDPE) plastic which has a high calorific value, thereby improving the quality of the mixed product. In this research, the slow pyrolysis method without a condenser was used with a temperature of 600 oC, a grain size of 60 mesh, with variations in the treatment of raw coffee husks without the addition of LDPE plastic, the addition of 25% LDPE, and the addition of 50% LDPE plastic. Pyrolysis without the addition of LDPE obtained a yield of 35.9% solid material, 19.9% liquid, and 44.2% gas. Pyrolysis results with the addition of 25% LDPE obtained solid yield of 28%, liquid 21.1%, and gas as much as 50.9%. Meanwhile, the addition of 50% LDPE obtained a solid yield of 19.6%, liquid 42.4%, and gas as much as 38.1%.