Development of an Integrated Biomass Gasification and Chemical Looping Combustion System for Power Generation with Inherent Carbon Capture in North West Nigeria

Simultaneous power generation, biomass waste valorisation, and carbon dioxide capture represents a negative emissions technology opportunity that is particularly relevant for North West Nigeria, where abundant agricultural biomass residues and limited grid electricity coexist with Nigeria's Paris Agreement decarbonisation commitments. This study conceptualises, models, and optimises an integrated system combining biomass gasification and chemical looping combustion for power generation with inherent CO2 capture, using groundnut shell biomass from Katsina State. An original process systems framework is developed in Aspen Plus to simulate the integrated system comprising a fluidised bed biomass gasifier, chemical looping combustion reactor pair using nickel aluminate oxygen carrier, a syngas conditioning train, a combined cycle power block, and a CO2 compression and purification unit. Original contributions include the derivation of a novel oxygen carrier reduction kinetics model that accounts for sulphur poisoning effects of gasification-derived H2S on nickel-based oxygen carriers, and the development of a multi-objective optimisation framework balancing power output, CO2 capture rate, and biomass-to-energy efficiency using a non-dominated sorting genetic algorithm. Pareto-optimal solutions at the 90% CO2 capture front achieved a biomass-to-electricity efficiency of 32.4% on a lower heating value basis, with specific capital cost of 3,240 USD per kW. Techno-economic analysis projected a levelised cost of electricity of 0.094 USD per kWh with a carbon price of 50 USD per tonne of CO2. The study establishes an original theoretical and systems engineering framework for integrated biomass power with carbon capture in Nigeria. Keywords: chemical looping combustion, biomass gasification, carbon capture, Katsina State, multi-objective optimisation