Exergoeconomic evaluation of a banana waste pyrolysis plant for biofuel production

Abstract

Health and environmental problems arise in the world due to gases produced during the combustion of fossil fuels. This problem has focused on researching the production of renewable fuels from biomass. One type of biomass is the waste produced during banana cultivation. In this industry, for every ton of banana harvested, there are on average four tons of waste that also pollute the environment. This paper aims to evaluate the economic and exergetic viability of a banana waste pyrolysis plant in Colombia. The plant processes were simulated in Aspen Plus®, which resolved the material and energy balance. The yield of products was validated with experimental results from literature, where differences could be attributed to biomass composition and reactor type. The results obtained revealed yields of 40.20%, 24.75% and 35.07% from bio-oil, char and gas respectively. Additionally, economic and exergy data were combined for an exergy costing method to carry out the exergoeconomic analysis. The overall exergy efficiency of the plant was 61.76%. The highest exergy destruction is located in the dryer and the pyrolysis reactor, which accounts for 35.84% and 32.96%. The combustion chamber has the highest exergy destruction cost (180.19 $/h) and a low value of the exergoeconomic factor (5.96%), indicating that an improvement of the equipment is required, even if it means an increase in investment cost. The study reveals that the analysis made demonstrates the potential of bio-oil production from banana waste, and the possibility of using gaseous products in a combined heat and power plant. The novelty of this paper is the methodology that can be applied to design of energy generation projects, supported by process simulators, combining economic and exergetic analysis, which are useful in developing countries.