Life cycle analysis of palm kernel shell gasification for supplying heat to an asphalt mixing plant

The Government of the Republic of Indonesia states that the thermal energy for hot-mixed asphalt production shall be supplied by the direct combustion of fossil fuels in the form of diesel oil, natural gas, or fuel gas from coal gasification which may generate GHG emission. Biomasses are able to substitute the fossil fuels through gasification technology. Gasification converts the biomass using limited air into gaseous fuel containing mainly CO and H2 that are subsequently combusted to produce heat, carbon dioxide, and water. It is obvious that the CO2 is then absorbed by the plants for photosynthesis, maintaining a balanced closed cycle. This study examines the level of global warming potential of this system for supplying heat based on the openLCA v1.9 software. The analysis used a gate-to-gate approach to evaluate scenarios of shell gasification to produce 1 metric tonne of hot-mixed asphalt. The scope covers raw material supply and transportation, palm kernel shell gasification, and products. The evaluation concludes that gasification could potentially reduce CO2 emissions. Environmental impact analysis and interpretation of the results using the openLCA database of Traci 2.1 recommend that greater CO2 emission reduction is possible using palm kernel shell gasification, not only for supplying heat but also for electricity generation to operate all electrical equipments.