Electricity Generation from Wood Sawdust: A Sustainable Approach to Biomass Energy Utilization in Nigeria

With the global demand for electricity growing and the concerns over the environment and the continued problems with power supply reliability in many developing countries increasing the need for sustainable and decentralized energy solutions. Traditional electricity generation methods that are dependent upon fossil fuels also play a significant role in greenhouse gas emissions, air pollution and climate change. Therefore, renewable energy technologies are a critical part of the strategies to achieve sustainable development and carbon emission reduction globally. Biomass energy is a promising option among the total renewable energy resources, because biomass is widely available, carbon neutral, and can be used to convert the organic wastes into useful energy (Demirbas, 2001; McKendry, 2002). Wood sawdust is a by-product of timber processing industries in saw mill and furniture manufacturing factories, which is an abundant biomass resource with little utilization. Sawdust is produced in significant amounts in many developing nations, such as Nigeria, and is often burned in the open or dumped in an unmanaged manner. In such cases, disposal of waste products leads to environmental pollution, emissions of particulate matter into the atmosphere and involves waste management issue in the locality (Basu, 2013). Although it has low carbon content, this biomass residue has good energy potential because of its relatively high calorific value and lignocellulosic composition and therefore can be used for thermochemical energy conversion processes (combustion, gasification and pyrolysis) (Bridgwater, 2003). In this work, the feasibility of producing electricity from wood sawdust through thermochemical conversion technologies is explored focusing on biomass gasification. Gasification is an advanced biomass conversion process that is the partial oxidation of biomass at high temperatures and in a controlled oxygen environment to produce a combustible gas mixture (synthesis gas or syngas). The syngas produced usually contains carbon monoxide (CO), hydrogen (H₂), methane (CH₄) and other gases which can be used to generate essslectricity power through internal combustion engines or gas turbines. (Basu, 2013). Gasification can be more energy efficient than direct combustion technologies, help to lower emissions and provide higher flexibility in decentralised energy systems. The research assesses the physical-chemical characteristics of wood sawdust such as moisture content, calorific value, particle size distribution and ash content, which greatly affect the efficiency of biomass conversion processes. Further, the study covers the system design aspects for small-scale biomass gasification plants, such as feedstock preparation plants, biomass gasifier reactors, gas cleaning plant, and power generation plant. Thermodynamic performance analysis is carried out to estimate the energy conversion efficiency and to see the possibility of generating electricity from sawdust as the main feedstock. For a practical illustration, a case study on sawmill operations in the Edo State of Nigeria in Benin City is presented, where huge amounts of wood residues are produced every day. The analysis shows that the use of sawdust as a source of energy through gasification-based power generation can be a reliable and sustainable decentralized energy supply for local communities, small industries and rural enterprises. The initial evaluation of energy potential indicated that these systems could be used to decrease the use of diesel generators and enhance access to energy in off-grid locations. The results show that electrical conversion efficiency of 20-30% can be realized with gasification technology based on sawdust, depending on the quality of the feedstock, the design of the gasifier and operating conditions. Besides, biomass gasification can also help achieve significant environmental advantages such as decreased open burning of biomass, decreased greenhouse gas emissions, and better waste management. From an economic point of view, availability of low cost biomass feedstock also makes the systems more economically viable for a rural electrification project. The study concludes that the utilization of biomass energy through electricity generation from sawdust is technically feasible, environmentally sustainable and economically attractive in the developing economies. Sawdust power systems could play a part in rural development, enhance energy security, and help boost renewable energy use and sustainable resource management on a global scale.