Preliminary Design of a Bagasse Based Firm Power Plant for a Sugar Factory

Abstract

This paper analysis the performance of the bagasse cogeneration power plant at Mumias Sugar Company in Kenya and recommends the development of a dual fuel cogeneration power plant. The main challenge facing bagasse cogeneration power plants is the intermittence of bagasse fuel supply and hence unreliability of the power plant as a grid connected power plant which leads to penalties and other related sanctions from the utility company. The study reviews the performance of an existing bagasse cogeneration power plant that uses bagasse alone as a fuel and seeks to improve its performance by conversion to a coal-bagasse cogeneration plant which is a firm power plant that utilizes bagasse and an alternative fuel in production of heat and electricity. The performance analysis showed a serious decline in availability and revenue from the power plant mainly due to unsteady supply of sugar cane leading heavy penalties from the electric utility for failure to meet contracted targets which led to the collapse of the entire sugar factory. In this study, a technical and economic viability was done to determine the performance of the current and proposed in technical and economic terms. Since it is cost effective as shown by the analysis, the study recommends that a dual fuel firm power plant will ensure the plant operates even when there is no sugarcane bagasse hence avoiding downtown due to sugar factory unavailability but will require significant investment in new and more efficient equipment for the boiler and fuel system. A simple analysis shows a payback of 4.05 years for the proposed plant. This will eliminate penalties and increase revenue, efficiency and profitability of the cogeneration plant and the entire sugar factory.Abbreviations: Cogen: Cogeneration, ESP: Electrostatic precipitator, mt: metric tons, h: specific enthalpy, ppa: power purchase agreement; ssf: specific steam consumption