PRODUCTION OF BIOETHANOL FROM MOLASSES AND EFFLUENT TREATMENT OF SPENT WASH

ABSTRACT

The use of ethanol in fuel blending has long been in use, and this help in controlling gas emissions but cannot be compared to bio-ethanol in control of greenhouse gas emissions. Bio-ethanol is known to adsorb CO₂ they emit; it also improves rural economy. A lot of materials especially starchy crops are used in the production of bio-ethanol. This research work focuses on the production of bio-ethanol from molasses; a waste from sugar cane industries. Bio-ethanol is regarded as one of the most promising fuels from renewable sources. This study also looks at protecting the environment as the effluent of the bio-ethanol production can be treated before discharging to the open field. Four steps are involved in its production; dilution, fermentation, decantation and distillation. The molasses (700ml) was diluted with 300ml of water, after which yeast was added for fermentation process. Other reagents were also added to enhance the fermentation process and production of quality ethanol. The fermented molasses was distilled and to get bio-ethanol, the residue which is the spent wash was treated to reduce its contamination level in order not to affect lives when discharged to the environment. The results from the analysis gave 93.7% ethanol, 78.42^oC boiling point value, 0.8301ml/l density, produced no offensive odour, completely miscible with water. Statistical analysis of untreated and treated spent wash reveals that it is statistically significant with p=0.032. These with other results gotten in this study are within the Nigerian Industrial Standard (NIS) and therefore have proven that molasses (waste) is a good substrate for bio-ethanol production which can be used for so many purposes.

 CHAPTER ONE

1.1       INTRODUCTION

Transportation was one of the greatest challenges for society in the 21 century is to meet the growing demand of energy, heating and industrial processes, and to provide material for the industry in a sustainable way. Ethanol production, however, traces back as far as the days of Noah who was believed to have built himself a vineyard in which he grew grapes that he fermented into some sort of alcoholic beverages. Ethanol an important member of a class of organic compounds with general name ‘Alcohol’. During the early times, ethanol was used as a constituent of alcoholic beverages. With civilization and advancement in science and technology, the benefits derived from ethanol have continued to multiply. These include solvent, germicide, as anti-freeze, fuel and versatile intermediate for other organic chemicals. For these enormous advantages of ethanol, researchers have been geared towards the production of ethanol from various raw materials or feedstock. In addition, the environmental deterioration resulting from the over-consumption of petroleum derived products, especially the transportation fuels, is threatening the sustainability of human society (Bai et al., 2008).The excessive consumption of fossil fuels particularly in large urban areas, has resulted in generation of high levels of pollution during the last few decades. In this scenario, fuel production as one of the renewable sources for the energy industry and the chemical industry may depend on biomass as an alternative source in the near future (Oliveria and Hira, 2009). All petroleum- based fuels can be replaced by renewable biomass fuels such as bio-ethanol, bio-diesel, bio-hydrogen, etc., derived from sugarcane, corn, switch grass, algae, etc (Sarkar et al., 2011).