Design and simulation of a biomass combustion cogeneration unit for sustainable energy and reduced carbon emissions

Abstract

Biomass combustion is a sustainable energy solution that reduces dependency on fossil fuels while minimising carbon emissions. This study aims to design and simulate a biomass combustion cogeneration unit to replace diesel combustion in industries. This study follows a systematic approach to designing and simulating a biomass combustion cogeneration unit. Data collection was conducted from the current diesel-based system to understand operational parameters. Elemental and laboratory analyses were performed to determine the calorific values of Rubber-wood chips and Gliricidia sawdust, which are utilised as renewable fuel sources. The biomass combustion system was designed and simulated using EBSILON software, by designing a 2.5 MW power and 2 MW generated system, which enabled a detailed modelling of thermodynamic processes and system efficiency. The analysis of electrical efficiency and Combined Heat and Power (CHP) efficiency reveals variation based on the fuel types used in the combustion unit. The simulation results indicate the mass flow rates for diesel, Gliricidia sawdust, and Rubber-woodchips were 0.17 kg s−1, 0.3042 kg s−1, and 0.3003 kg s−1, respectively. CHP efficiency was highest for diesel at 75.40%, followed closely by Rubber-wood chips at 74.94%, and Gliricidia sawdust at 73.97%. Among tested fuels, diesel showed the highest nonrenewable CO2 emission of 0.4954 kg s−1, while Gliricidia 0.4411 kg s−1 and rubber wood 0.1647 kg s−1 emitted renewable carbon-neutral CO2. These findings suggest that although diesel provides the highest electrical and CHP efficiency, rubber woodchips and Gliricidia sawdust are near alternatives. The study demonstrates that biomass combustion reduces emissions, enhances economic feasibility by cutting diesel reliance, and optimises energy efficiency, showing viability for sustainable operations.