Optimization of biomass to bioenergy supply chain with tri-generation and district heating and cooling network systems

Abstract

Bismil district of Diyarbakir (Turkey) is a region where agricultural activities are very common. About 60% of the terrain is irrigable. Cotton and corn are mostly grown in these irrigable lands. Given the bioenergy incentive provided by the Republic of Turkey and the extensiveness of agricultural lands in Turkey, energy production from cotton and corn residues in the tri-generation facility through gasification conversion technology seems like a quite profitable investment. In this study, a mixed-integer linear programming model, which optimizes the numbers, locations, and capacities of the tri-generation facility/s, was developed and empirically solved. The model tries to maximize the net present value of the potential investment by comparing the trade-offs between the raw material/end-product transportation costs, facility/s, and pipeline installation costs. Electricity and heating/cooling energy were sold to the government and settlements through the closest interconnected lines and pipelines, respectively. In this study, electricity, the heating/cooling energy and the fertilizer (biochar) sale were considered for the calculation of annual revenue, while transportation of raw materials and heating/cooling energy, losses during heat transfer and electricity transmission, operation and maintenance costs of facilities and pipelines were considered for the calculation of annual expenses. Initial investment cost includes facility, pipeline, and electricity transmission installation costs. The model proposes one facility with an installed power of approximately 35 MW which met cooling energy demand of 3 settlements, both cooling and heat energy demand of 2 settlements. The net present value of the investment is almost 338 million EUR and the repayment period is 1.3 years.