ANALYSIS OF ENERGY CHARACTERISTICS OF RICE AND COFFEE HUSKS

ABSTRACT
This work presents a report on the analysis of energy characteristics of rice and coffee husks blend, from rice and coffee husks ash of analytical grade. India has a major agribusiness sector which has achieved remarkable successes over the last three and a half decades. Agricultural waste or residue is made up of organic compounds from organic sources such as rice straw, coffee husks, oil palm empty fruit bunch, sugar cane bagasse, coconut shell, and others. Rice and coffee husk are one example of alternative material that has a great potential. Rice and coffee husks are one of the most commonly available lignocellulosic materials that can be converted to different types of fuels and chemical feedstocks through a variety of thermochemical conversion processes. This husk is used as fuel in the rice mills to generate steam for the parboiling process. This husk contains about 75 % organic volatile matter and the balance 25 % of the weight of this husk is converted into ash during the firing process, is known as rice and coffee husk ash. This hush ash in turn contains around 85 % – 90 % amorphous silica. The moisture content ranged from 8·68 to 10·44%, and the bulk density ranged from 86 to 114 kg/ m3. Basically two major steps were involved in the characterization processes, first was the ashing of rice and coffee husk by a laboratory furnace to obtain a carbon free ash. Secondly, the ash was been digested in a digester for 24 hours, to obtain a viscous, transparent, colourless sodium-silicate solution, In coffee and rice husks blends, substantial reductions of hemicellulose and cellulose peaks were observed. Use of coffee and rice husks blends applying high temperature gasification would reduce the latter’s flammability, while increasing its flame retention characteristics, hence offering opportunities for production of clean syngas in a sustainable manner.

INTRODUCTION
Critical economic and environmental situations of the current days encourage companies and researchers to develop and improve technologies intended to reduce or minimize industrial wastes. As a consequence, much effort has been expended in different areas, including the agricultural production.
With increasing the demand of energy by society, the fossil fuel has been rapidly decreasing as the main source of energy. Thus looking for a renewable energy has became a focus which has attracted lots attention of society. Biomass energy with large range of providers is an ideal renewable one which is generated by massive waste of industries, agriculture and timber each year Tyebkhan G (2002). Among the world’s energy consumption so far, the consumption of biomass energy has occupy 14% of the total energy consumption in the world with the ranking 4th, which is just followed by the consumption of oil, coal, and natural gas. Using abundant renewable source such as corn stalks and rice hull in the north and south of our world could bring plenty of economic rewards and income for enterprises and the common people, which is able to partially or completely replace the coal. On the other hand, biomass sources is a clean and renewable energy with nearly discharging none of CO2, which could be fully made use of and play an important role in environmental protection, ecological balance improvement of living standard of the common people. It is an effective way of using biomass sources that we applied biomass fuel to the fuel of boiler, and biomass boiler has been rapidly developed in recent years.

Historically, humans have harnessed biomass-derived energy since the time when people began burning wood to make fire, D. A. Mwakipesile (2012). Even today, biomass is the only source of fuel for domestic use in many developing countries. Biomass is all biologically-produced matter based in carbon, hydrogen and oxygen. The estimated biomass production in the world is 104.9 petagrams (104.9 * 1015 g) of carbon per year, about half in the ocean and half on land D. A. Mwakipesile (2012).

Burning rice and coffee hush as a fuel substitute in order to generate energy is a useful solution which is used by many industries; however it results in a new waste, named rice and coffee husk ash. This residual ash obtained from the combustion can contain over 60 % of silica and some amount of metallic impurities P. J. Haines (2002). Depending on the burning process, rice and coffee husk ash can contain silica in the amorphous form; therefore, this residue can be considered as a new economically viable raw material to produce detergent Eduard Smulders (2002).

India has a major agribusiness sector which has achieved remarkable successes over the last three and a half decades. Agricultural waste or residue is made up of organic compounds from organic sources such as rice straw, oil palm empty fruit bunch, sugar cane bagasse, coconut shell, and others. Rice and coffee husk is one of the most commonly available lignocellulosic materials that can be converted to different types of fuels and chemical feed stocks through a variety of thermo chemical conversion processes, Eduard Smulders (2002). This husk is used as fuel in the rice mills to generate steam for the parboiling process. This husk contains about 75 % organic volatile matter and the balance 25 % of the weight of this husk is converted into ash during the firing process, is known as rice husk ash. This RHA in turn contains around 85 % – 90 % amorphous silica. The moisture content ranged from 8·68 to 10·44%, and the bulk density ranged from 86 to 114 kg/ m3 J.C.Da Rocha (2010).

Rice and coffee husk is unusually high in ash, which is 92 to 95% silica, highly porous and lightweight, with a very high external surface area. Its absorbent and insulating properties are useful to many industrial applications, such as acting as a strengthening agent in building materials J. Chumee et al. (2008). Rice husks are processed into rectangular shaped particle boards.

1.2 SCOPE OF THE STUDY
The study is focus on the analysis of energy characterization of rice and coffee husk blend in Nigeria. The project will be guided by both objective and analysis of literature review on survey and experimental research conducted on the characterization of rice and coffee husk.