THERMAL CONVERSION OF PALM KERNEL SHELL AND MESOCARP FRUIT FIBRE INTO FUEL
Palm Oil processing yields a considerable quantity of palm kernel shell (PKS) and mesocarp fruit fiber (MFF). This has been predominantly used as fuel through direct combustion which is inefficient and polluting. Better grade fuel could be derived through torrefaction. The objectives of the work therefore was to determine the optimum parameters for the conversion of palm kernel shell (PKS) and mesocarp fruit fiber (MFF) to high grade fuel via torrefaction. Samples of PKS and MFF were torrefied with a temperature range of 200°C to 350°C at the step of 30°C. The torrefied product yield were determined by weighing, proximate, ultimate analysis of the torrefied product were determined using A.O.A.C. method. The higher heating value was calculated using Dulong Petit. Percentage torrefied product decreases as the reaction temperature increases, from 71.70% to 56.32% for 200°C to 350°C. The higher heating value ranges from 8607.6MJ/Kg to 9510.4MJ/Kg for 200°C to 350°C respectively. Palm kernel shell has higher heating value when compared with mesocarp fruit fiber. PKS at 350°C had the highest value for HHV palm kernel shell and mesocarp fruit fibre torrefied.
Energy exists in different forms, all of which measure the ability of an object or system to do work on another object or system. Energy is fundamental to the survival of people, it is used in different areas of life such as; source of light and also for powering our vehicles, trains, planes, and rockets, machinery and tractor on the farm. The different forms of energy includes; electrical, fossil fuels with quite a number of availability in the form of coal, oil and natural gasses; hydro and energy, nuclear and wind energy. The United States of America analyses the rate of depletion done to the ozone layer as a result of wide use of fossil fuel which serves as the bulk of energy in use and discovered that the rate of depletion has greatly increased. This was due to the harmful elements released after the burning of petroleum fuels as stated by Mark,(2005).
These harmful chemical released to the atmosphere which cause changes in atmospheric condition, human health deterioration serves as point of the challenges to look into an alternative source of energy. However, increasing population and development of the third world countries caused an increased in the demand for traditional fuel which is a common type known as biomass energy. Biomass energy is another form of renewable energy source and it is derived from living or dead organisms like plants, waste and alcohol mostly. The major sources of biomass include; waste materials from industrial processes, waste material from pulping industries and municipal waste. When energy is extracted from alcohol or from the fiber present in the corn, it is known as ethanol fuel. This ethanol fuel is really helpful in providing fuel to the cars and farm tractors. Biomass energy can also be sourced from various kinds of agricultural processed refuse like polar, willow, hem, corn, miscanthus, sugar cane, spice trees, eucalyptus, switch grass and sorghum. The mentioned sources of biomass energy have one or more effect on the living organism, human and the living environment. Some of the effect which includes deforestation, competition with food materials and other industrial usage which is a result of more demand for such product, hence the need for research into a less competitive products in term of the environment and the inhabiting organism which will reduce the use of other mentioned in term of their economic and industrial demand. Hence the need for the choice of palm kernel shell and mesocarp fruit fiber.
The conversion of biomass into useful energy can produce heat and electricity. This includes: thermal conversion, biochemical method, and mechanical methods of conversion. The mechanical method of conversion involves compressing the materials together which is known as briquetting while biochemical method of conversion entails biological activities such as fermentation, aerobic activities on the materials and the introduction of micro organism on the material. This method of conversion works better for non- lignocellulosic.
The thermal method of conversion involves the use of heat, which include; direct combustion, gasification, pyrolysis, torrefaction (2015). Direct combustion ways of conversion is done in the presence of oxygen to produce heat, light and particulate, which can pose hazardous substances to the health of the user. Gasification process converts biomass completely to combustible gases as stated by Mark, (2005). However this process is good for on-site. Pyrolysis which occurs at temperature range of temperature range of 400°C to 800°C in the absence of Oxygen (Jianghong, 2007). The final products include the liquid, solid and gas, are about 70% efficient. Torrefaction on the other hand is another thermal method of biomass conversion which according to (Jianghong, 2007), has higher conversion efficiency of about 90%. Therefore this work focused on torrefaction. However, from literature available for review little has been done on this method. As a result, there is a need of determining optimum conversion parameters for torrefaction of Palm Kernel Shell(PKS) and Mesocarp Fruit Fiber(MFF).
1.1 Problem Statement
The rate of depletion of the ozone layer been increased due to the harmful or heavy elements released after the burning of petroleum fuels to be precise the invention of chlorofluoro carbon increased the rate of depletion. The increasing population and development of the third world countries caused an increase in the demand for traditional fuel. The fast rate of forest destruction (deforestation) and low rate of replacement (aforestation) has simultaneously rescued the availability of firewood. Due to the over dependence of developing countries on firewood, deforestation has set in, which makes a country like Nigeria cost approximately 464 square miles of forest each year to these human activities.
A quest for cleaner fuel in the developed country also lead to a series of research into what and what can be used to generate heat without having to burn fossil fuel. Hence the need for a less industrial and food competing materials which is the palm kernel shell and Mesocarp fruit fiber.
The objectives of this work therefore include;
i. Conversion of Palm Kernel Shell and Mesocarp Fruit Fiber samples to fuel at reaction temperature of 200°C to 350°C at the step of 30°C.
ii. Determination of effect of reaction temperature on torrefied products.
iii. Determination of combustion characteristics such as; Volatile Content, Nitrogen, Carbon, Oxygen, Sulphur, Fixed carbon, Moisture Content, Hydrogen Content Ash Content.
Biomass, hydroelectric, power and solar power are the most important sources of renewable energy while petroleum product as the major non renewable energy used in Nigeria today. Petroleum production in its own part is expensive and the price increases at interval, during exploration and use it also has environmental hazards. firewood usage on a perennial bases leads to deforestation, solar power is expensive to install and cheap to maintain but there should be consideration for less sunny days during which less or No power is produced. Therefore, there is need for the production of less smoky fuel using palm kernel shell and Mesocarp fruit fiber.