Techno-economic evaluations for feasibility of sago-based biorefinery, Part 1: Alternative energy systems

Due to the huge amount of sago biomass generated and discharged to the environment from sago industry without proper treatment, serious environmental impacts are caused. In order to reduce such environmental pollutants, sustainable conversion of biomass into value-added products is of paramount importance. However, up-to-date, sago-based biorefinery, which is a facility that converts sago biomass into value-added products via different conversion technologies, is yet to be implemented in sago industry. Therefore, this pair of articles presents techno-economic evaluation to examine the feasibility of sago-based biorefinery in Malaysia context. This is an essential and necessary initial step to encourage investors to evaluate and invest in sago-based biorefinery. In part 1 of this pair of articles, techno-economic analysis is conducted to examine the feasibility of sago biomass-based combined heat and power (CHP) system. In addition, a systematic generic fuzzy optimisation-based techno-economic evaluation framework is presented in Part 1 to determine the optimum CHP system with consideration of technical, environmental and economic aspects. Following the proposed approach, the optimum CHP system which using normal pressure boiler, generates 472 kW of net electricity from sago barks (10.2 odt/d) with a payback period of 3.51 years, and carbon saving of 5475 kgCO₂/d. Note that in order to achieve the optimum result, making use of current labour from sago starch extraction process (SSEP), and off-site pre-treatment are needed. Besides, sensitivity analysis based on the existence of pre-treatment, variations in feedstock cost, boiler efficiency, and biomass feedstock is also conducted. Part 2 of this pair of articles is to further extend the techno-economic evaluation to examine the feasibility of integrated sago-based bioethanol production and energy systems (Wan et al., 2015a). In this pair of articles, a sago starch processing facility from Sarawak, Malaysia with a starch production capacity of 12 t/d is used for techno-economic evaluations.