Title : Torrefaction and Gasification of Coconut Shells for Electricity Production
Abstract:
Globalization and exponential growth of population demand the development and use of alternative resources to produce electricity, as fossil-based fuels contaminate the environment and are draining. Biomass is a renewable resource that, in addition to sunlight, wind, water, the ocean, and the earth's heat, can support world economic growth. Biomass is a non-fossilized, biodegradable organic material derived from abundant, clean, and carbon-neutral plants, algae, and animals that has the potential to replace fossil fuels as a bioenergy source. Coconut is a biomass resource that is abundant in tropical areas. The Philippines produces 2.2 million tons of coconut shells from 347 million coconut trees that produce 14.7 million tons of nuts every year. Coconut shells considered a waste resource, can be utilized to generate electricity. The purpose of the study was to use coconut shells as a biomass resource to generate power using a gasification process. Methodology: The coconut shells were collected, crushed, torrefied, and fed into the designed and fabricated 1.8-kVA biomass gasification power system (BGPS). The BGPS was run, and its performance was evaluated. Findings: The calorific value of raw coconut shells is 8.55 kWh/kg. After being torrefied at 275°C for 30 minutes, the calorific value climbed to an optimum of 9.55 kWh/kg, implying an increase of 11.70 percent. At the optimal calorific value, the mass yield was 90.10 percent, while the energy density was 111.64 percent, indicating a total energy yield of 100.59 percent. The torrefied coconut shells were heated to 904°C in the gasifier, causing a thermochemical transition that released producer gas resulting in a thermal efficiency of 64.51 percent. The producer gas was converted to synthesis gas using the chiller, filters, and other components, resulting in an overall thermal efficiency of 62.67 percent. The overall energy conversion efficiency of the BGPS was 13.06 percent. Conclusion: Torrefaction improved the calorific value of coconut shells by 11.70 percent, resulting in the energy generation of the BGPS to 1.247 kWh per kilogram. The created BGPS could be expanded in the future to supply electrification in rural and urban areas.
