Enhancing Power Generation Availability In Nigeria Using Combustible Waste As Energy Source For Off- Grid Applications

Abstract

The application of combustible waste as energy source provides an alternative energy option to enhance electrical power generation for off-Grid applications. The integrated alternative energy sources identified are energy stored in metropolitan waste, energy stored in wood residue, and palm kernel residue. The framework studied the available quantities of these energy sources and developed a model to convert the energy options into electrical energy. The generating plant unit comprises Steam Generator, Steam Turbine, Steam Condenser, Pumps and Alternator with their ancillaries. The steam generator, a miniature low pressure externally fuel-fired water tube type consists of boiler, furnace, superheater, air-heater, stack, forced- and induced draught fans. The steam turbine is of the impulse- type whilst the condenser is a surface type. A software was also developed using visual Basic to run the Power Plant Model, the software utilized for the validation of boiler efficiency is Kane International calculator and for steam consumption in turbine whilst Katmar software was used for boiler efficiency. The simulated efficiency is 38.722 % and calculated result is 35.69 % for boiler performance whilst for steam turbine consumption is 3.22 kg/s and 3.123 kg/s. This model is suitable for off- Grid communities that are close to one another. It is recommended that colour coded waste bins be introduced at waste collection centres, incentives to farmers to bring waste to collection centres should be introduced and government should also invest in the production of the plant.

Keywords: Combustible wasteRenewable EnergyOff-Gridsimulationpower plant

Introduction

Energy is required in various forms to do useful work, it is necessary for the continuous improvement in the living standard in any society ( Ral, 2008). Energy sources (Coal, Crude oil, Natural gas, radioactive element) therefore have to be explored, developed and managed to enhance industrial process ( Sharma, 2007). The primary energy sources from which bulk electrical energy is produced in Nigeria are derived from fossil fuel which are limited in reserve, depleting and non-renewable. To sustain the increasing energy demand, the need therefore arises to explore non depleting sources of renewable energy, fuel wood renewable energy reserve is approximately 13,071,464 hectares in Nigeria ( Sambo, 2009) An overview of energy conversion principle is discussed whilst waste to power energy conversion strategy is considered in detail. The controlled combustion of waste in furnace converts the stored energy to produce steam required to drive a steam turbine ( Nag, 2008).

Model OF1.0MW steam power plant

The water tube is designed with inlet feed water at 152 ^oC/5 bar, discharged steam conditions at 300 ^oC/15 bar at turbine inlet with steam flow rate at 3.23Kg/s at 1.06 factor of evaporation and flue gas conditioned at 7.74kgS ^-1/160.8 ^oC at air heater outlet. The surface steam condenser requires 713000.85kg at cooling water per hour for condensate to maintain the exit water temperature at 440 ^oC (see Table 1 ). Model include sizing of firebox, heat exchanger, rating of electric motor drive, pump blower cable and circuit breaker (see Figure 01 , Figure 02 & Figure 03 ).

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Problem Statement

The Electrical power supply in Nigeria is characterized with epileptic Nature, poor power quality, insufficient supply and do not accommodate the off-grid communities. The need arise to make energy available in the off grid settlement. Energy stored in waste has been identified and harnessed in this research.

Research Questions

Does applying combustible waste as energy source could enhance power generation for off- grid utilization?

Purpose of the Study

Research Methods

The methodology adopted in this study is as follow;

Findings

This research is concerned with the development of an innovative technology of waste to energy generation and the following were findings of the study;

Wood waste and saw dust are exposed to direct open air combustion of no economic value and this often causes environmental pollution. When put in use as fuel for energy generation in power plants, it will reduce dependency on crude oil and its allied products and also add value to the waste.

Metropolitan wastes are lumped together with no provision for separation at the collection centre thereby creating challenges in waste disposal mechanism as they always occupy very large space. Putting the waste in use for energy generation will help in reclaiming land and reducing health hazard associated with improper waste disposals.

The existing power generation plants in the country predominantly use fossil fuel which is expensive, depleting and it is not also environmental friendly. A major setback in Energy generation will occur in the event of shortage of this fuel.

Conclusion

A computer software using visual basic was developed to simulate each module of the model; furnace design, superheater design, airheater design, chimney, draft design, and steam turbine to determine boiler efficiency, load factor and steam consumption. The result was validated using two other software kane international engineering calculator for boiler efficiency and steam turbine consumption calculator (katner software) for steam consumption.

Mass of combustible waste required to run the power plant per year with due consideration to the calorific value was estimated.

Acknowledgments

Tertiary Education Trust Fund (Tetfund Nigeria).

References

• Igbinomwanhia, D. I. (2012). Characteristic of Commercial Solid Waste in Benin metropolis Nigeria. Journal of Emerging Trends in Engineering and Applied Science, 3(5), 834-838.
• Nag, P. K. (2008). Power Plant Engineering (Second Edition). New Delhi: Tata-McGraw-Hill Publishing Company Ltd.
• Ral, O. D. (2008). Non-Conventional Energy Sources (Fourth Edition). New Delhi: Khanna Publishers.
• Sambo, A. S. (2009). Strategic Development in Renewable Energy in Nigeria. International Association of Energy Economic.
• Sharma, P. C. (2007). Power Plant Engineering (Eighth Edition). New Delhi: K. Kataria & Son.