Techno-economic, environmental, and heat integration of palm empty fruit bunch upgrading for power generation

The palm empty fruit bunch (PEFB) is a residue from oil pressing. As a renewable energy source, it is expected to achieve high-yield bio-oils, low gas content, and low char content. In this work, a comprehensive pyrolysis process model, bio-oil upgrading plant, and electric power generation were simulated simultaneously. This work applied the pyrolysis kinetic reaction model at 500 degrees C based on 1,000 tons/day of PEFB. The results showed that suitable validation with the existing published work, in that 1 kg/s of PEFB could produce 0.21 kg/s of gas, 0.67 kg/s of bio-oil, and 0.11 kg/s char. Implementing a heat exchanger network (HEN) improves the minimum capital cost implication and maximum heat recovery compared to the non-heat exchanger network (non-HEN) design. Therefore, HEN implementation shows a cost reduction of 57.46%, with a feasibility study performed by estimating the equipment size and cost. The economic assumptions are estimated to be 10% of the annual discount rate for 20 years. According to an economic analysis of the HEN, the net present value, internal rate of return and payback duration are $20,086,830.26, 28.40%, and 5.62 years, respectively. In comparison, the non-HEN design shows $12,966,333.26, 27.55%, and 5.77 years, respectively. Furthermore, the environmental-economic analysis shows that the non-HEN design and HEN design indicate global warming at midpoints of 281,677 and 263,330-ton carbon dioxide equivalent (CO2 eq.)/year. The non-HEN design has a higher midpoint and endpoint than the HEN design. (C) 2021 The Authors. Published by Elsevier Inc. on behalf of International Energy Initiative.

Automated summary

This study presents a simultaneous simulation of a comprehensive pyrolysis process, bio-oil upgrading, and electric power generation using empty palm fruit bunches (PEFB) as feedstock. The results show that implementing a heat exchanger network (HEN) design can reduce costs and improve heat recovery. Economic analysis demonstrates that HEN implementation leads to higher net present value, internal rate of return, and payback duration.