Environmental and socio-economic assessment of wood pellet production from fast growing trees in Thailand

Sufficient quantity of raw materials is a critical factor for wood pellet production. The recommendations from past research on biomass have indicated that the cultivation of fast growing trees should be encouraged in wasteland. Leucaena and Acacia are the popular fast growing trees in Thailand because they are resistant to drought and can grow in low quality soil. Wood from them has a high heating value and entrepreneurs invite farmers to grow these varieties on contract farming for renewable energy. The purpose of this study is to assess the environmental and socio-economic of wood pellet production from Leucaena and Acacia. The environmental impacts were evaluated by cradle to gate life cycle assessment, covering fast growing tree cultivation (sprout preparation, plantation, cutting), transportation and wood pellet production. The ReCiPe2016 Midpoint method (version 1.02) was used to evaluate the environmental impacts of one tonne wood pellet production from Leucaena and Acacia. The indicators of socio-economic considered in this study were the profit from cultivation, economic assessment of wood pellet production (net present value, internal rate of return, payback period, discount payback period and benefit cost ratio) and opportunity of employment. The environmental results showed a better performance of wood pellets made from Leucaena are better than Acacia. The production capacity of 110 tonnes per day of wood pellet factory would return a profit when the price of raw material is less than 1,300 THB per tonne. Finally, Leucaena and Acacia cultivation increase the opportunity of employment at 0.16 and 0.10 person-year per ha, respectively. The wood pellet production increases the opportunity of employment at 0.0019 person-year per tonne. Considering the results of the environmental and socio-economic assessment, Leucaena is seen to be better than Acacia and should be supported as an alternative raw material for wood pellet production.