Synthesize an Optimum Combined Heat and Power (CHP) System for Sago Industry via Mathematical Approach

摘要

Sago palm is labeled as a perfect crop for sustainable agriculture due to its ability to cultivate in most soil condition, and it can boost high starch productivity while using little resources for cultivation. The main product that can be extracted from sago palm is sago starch. However, during the extraction process, large amount of sago biomass is generated per ton of starch such as sago barks, sago fibres and sago wastewater. These sago biomass contain solid lignin structures making sago biomass suitable for combustion for renewable energy production. However, in current industrial practices, these sago biomass are not being recovered. Instead, untreated sago fibres and sago wastewater are disposed into river while sago barks are used as flooring material in the surrounding of sago mills. Hence, it is important to utilities these sago biomass by sustainable conversion into clean energy. This paper presents a mathematical optimization approach to synthesize an optimum Combined Heat and Power (CHP) system for sago industry based on technical, economic and environmental aspects. This novel approach helps the industry players in decision making in selecting the location of pre-treatment process, type of transportation, location of CHP (centralized or decentralized) and the configuration of CHP. To achieve the objective, a generic superstructure is first developed. Based on the generic superstructure, the approach can be developed by formulating a series of generic equations which covers mass balance, cost and profit computation, and carbon footprint calculation. Fuzzy-based optimization approach is adopted to trade-off the conflicting objective (maximize profit and minimize CFP) to obtain the optimum pathway. A sago-based CHP system case study in Sarawak, Malaysia is solved to illustrate the proposed approach. Based on the optimized results, a total of 1586.26 MW per year of bioelectricity can be generated with an estimated net profit of MYR 5.25 million per year an