Techno Study of “Waste to Electric” with Woodchip Pellet Feedstock Through Multi-Stage Gasification in Dual Fuel Diesel Engine

Abstract The increasing demand for energy in various sectors means that energy sources can no longer depend on fossil energy sources, the number of which is decreasing. The decline in fossil energy supply has increased the development of environmentally friendly renewable energy sources, such as biomass. The biomass raw material used is woodchips which has the characteristics of water content 8.4%, volatile solid 74.19%, ash content 1.34%, carbon content 16.07%, hydrogen content 0.0479%, nitrogen 0.4372%, carbon monoxide 0.1701%, methane 0.049%, oxygen 0.1622% and a heating value of 3,907 Kcal/kg. Processing biomass into syngas is carried out through a gasification process. Gasification is the process of converting woodchips into syngas in the form of a gas phase using a three-stage gasification method. Furthermore, the syngas is used as fuel in a dual-fuel diesel engine combined with biodiesel fuel. In this research, a 5 kW diesel engine was used as an experimental tool to determine the performance produced by a dual-fuel diesel engine when dual fuel is injected, namely biodiesel and syngas. The gasifier used in the gasification process of woodchips biomass raw materials has the best water ratio characteristics between the pyrolysis, oxidation and reduction zones, namely 1:7:2. The results of tests that have been carried out with an air ratio setting of 1:7:2 can produce the best diesel engine performance with a stable engine speed value of 3000 rpm and the average voltage at each change in load is 250 volts. Load variations for dual-fuel diesel engine testing are carried out from a load of 0 watts to a load of 4,500 watts. With an increase of every 500 watts. The syngas injection method from the gasifier into the combustion chamber uses 1 variation value, namely full opening (100%). Testing with 100% syngas valve opening resulted in higher average values of engine temperature, exhaust gas temperature and oil temperature compared to other openings. Apart from that, the test results of a 5000-watt engine with dual fuel mode (biodiesel and syngas) were scaled up when applied to the Kolaka PLTD engine which has a capacity of 529 kW. From the calculation results, the value of the savings for using diesel fuel on a 529 kW PLTD engine is Rp. 225,900,975 per month. The initial investment cost is IDR. 1,279,068,380. Meanwhile, the annual income is Rp. 2,445,374,002 assuming Capacity Factor (CF 70%). So the Break Event Point (BEP) value is less than 2 years. Apart from that, a decrease in decarbonization value was also produced by utilizing syngas from woodchip biomass as fuel in a dual-fuel engine with a capacity of 529 kW, resulting in 21.25 tonnes of CO2/year or Rp. 637,431.2