Sustainable supply of electricity is crucial to comfortable living in homes and attaining economic development in any country. Despite being blessed with enormous green and non-green energy resources, Nigeria has been in a quandary about adequate generation and supply of electricity. The electricity crisis has, over the years, had significant adverse impact on the nation's socio-economic and technological development as well as standard of living of its citizens. This paper examines the problems in the electricity sector and the energy potential of green energy resources in Nigeria. The study reveals that the major source of electricity generation (natural gas) and mode of electricity transmission (a single national grid) in the country have been and are still being constrained by myriad of challenges, hence, the inability of the power sector to satisfy the electricity yearnings of Nigerians till date. The study also reveals that about 1182.375GWh of energy per day could be obtained from green energy resources in Nigeria and the provision of this quantity of energy through decentralized off-grid energy solutions would significantly increase electricity availability as well as accessibility in the country.

This study focused on the design and testing of a downdraft gasifier. The gasifier design was based on a combination of the Imbert and stratified models with some modifications. Sizing of the gasifier was done using empirical relations and some experimental data relating to specific gas generation rate, biomass flow rate, throat diameter and reduction zone diameter etc. The thermal capacity of the gasifier was set at 5 kW. A cyclone separator, an air-cooling unit and a filter unit (containing wood shavings) were coupled to the gasifier's reactor to purify the produced syngas. The gasifier system was tested in a forced draught mode using air as the gasifying medium. The feedstock conversion rate of the gasifier was 1.25kg/hr for wood chunks (10-70mm) and 2.1kg/hr for wood shavings (2-5mm). The syngas produced for both types of wood residues burnt with stable blue flames, indicating minimal tar percentage in the syngas. This signifies that the produced syngas can be safely utilized not only for cooking but also in internal combustion engines to generate electricity.

Abstract-

The design engineer is daily confronted with the need for materials to meet design requirements of strength, stiffness, toughness, wear-resistance, corrosion-resistance, high-temperature operation and so on. Steel is the most versatile material and can be made into various forms, types or grades and possesses diverse mechanical properties that made it suitable for different uses. Through the study of the metallurgy of steel, steels are standardized into groups according to their composition, characteristics and uses derived from the types, sizes and dispersion of micro-constituents. The knowledge of the various standards and their equivalence relationships are the tools for choice of steel for design and for the development of new grades of steel.

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