CHAPTER 1
INTRODUCTION
1.1 BACKGROUND OF STUDY
The world today is going green, everyone is thinking about alternative source of energy, the present and most popular form of energy fuel is known for its disadvantageous effect on the ozone layer in the atmosphere. First world countries like the USA, England, Russia and Germany are far ahead searching for alternative source to fuel energy most especially the latter who is the leading country in renewable energy for electricity generation. Developing countries are also looking for ways to go into other sources of energy apart from fossil fuel.For this reason, they have to look around and beyond their immediate environment to create energy.
Biomassareorganicmatterthatisrenewableoverthe course of time.Moresimply,biomassisreservedenergy(Zhang, 2012). Biomass is produced by green plants converting sunlight into plant material through photosynthesis and includes all land and water-based vegetation, as well as all organic wastes. With the principles of biomass, energy from immediate environment like agricultural waste, sawmill/carpentry waste, charcoal can be used to create energy in the form of Briquettes. Briquetting is the process of compaction of residues into a product of higher density than the original raw materials. It is also known as densification. The use of fuel wood for cooking has health implications especially on women and children who are disproportionately exposed to the smoke apart from environmental effects. Women in rural areas frequently with young children carried on their back or staying around them, spend one to six hours each day cooking with fuel wood(Oladeji, 2015). In some areas, the exposure is even higher especially when the cooking is done in an unventilated place or where fuel wood is used for heating of rooms. Generally, biomass smoke contains a large number of pollutants which at varying concentrations pose substantial risk to human health. Agro waste is the most promising energy resource. The decreasing availability of fuel woods has necessitated that efforts be made towards efficient utilization of agricultural wastes. These wastes have acquired considerably importance as fuels for many purposes, for instance, domestic cooking and industrial heating. Some of these agricultural wastes for example, coconut shell, wood pulp and wood waste can be utilized directly as fuels. These waste can be processed in a form whereby they are well compacted and hardened in form that they burn for a longer a time. These processes as earlier stated is called briquetting and it is produced with aid of a briquetting machine.
Briquetting can help in expanding the use of biomass in energy production, since densification improves the volumetric calorific value of a fuel, reduces the cost of transport and can help in improving the fuel situation in rural areas(Hussein et al., 2012). Briquetting is one of several agglomeration techniques which are broadly characterized as densification technologies. Agglomeration of residues is done with the purpose of making them denser for their use in energy production(Wright et al., 2010). The idea of briquetting is to use materials that are not otherwise usable due to a lack of density, compressing them into a solid fuel of aconvenient shape that can be burnt like wood or charcoal(Adekoya, 2007).
The compaction of loose combustible material for fuel-making purposes was a technique used by mostcivilizations in the past(Wilaipon, 2007). Biomass densification, otherwise known as briquetting of agro-residueshas been practiced for many years in several countries. Briquettes were discovered to be an importantsource of energy during the First and Second World Wars for heat and electricity production, using simpletechnologies (Yadong and Henry, 2014). During this period, briquetting of sawdust and other waste materialsbecame widespread in many countries in Europe and America under the impact of fuel shortages. Screwextrusion briquetting technology was invented and developed in Japan in 1945. As of April 1969, there were 638plants in Japan(Grover and Mishra, 2011). The methods used were no more than simple baling or drying.Industrial methods of briquetting dated back to the second part of the 19th century.
Fuel briquettes are essentially a compressed block of organic waste materials used for domestic cooking andheating. The final end product of briquetting process is known as a briquette. Briquettes are made from raw materials that are compacted into a mould. Briquette could be made of different shapes and sizes depending on the mould. The appearance, burning characteristics of briquettes depend on the type of feedstock and the level of compactness and the mould used(El Saeidy, 2004; Wilaipon, 2007). But in general, briquettes have better physical properties and combustion rate than the initial waste. Production of briquette charcoal helps to ease the pressure on the forest reserve, there by solving the deforestation problem.
Briquettes have many numerous uses which include both domestic and small industrial cottage applications (Ahmed et al., 2008). They are often used as a development intervention to replace firewood, charcoal, or other solid fuels. This is because with the current fuel shortage and ever rising prices, consumers are looking for affordable alternative fuels and briquettes fill this gap as it can be used for domestic cooking and water heating, heating productive processes as in tobacco curing, firing ceramics and clay wares such as improved cook stoves, fuel for gasifiers to generate electricity and in powering boilers to generate steam.
1.2STATEMENT OF THE PROBLEM
Recycling of waste product is a very good source of income, but unfortunately it is not taken very seriously in this part of the world. Rural communities around Africa generate a lot of agricultural waste. These waste are not properly disposed of and this results in pollution of the atmosphere. In as much as these waste are not well utilised, deforestation is also another issue. Trees are felled for the sole purpose of getting firewood for domestic cooking and other heating purposes. The smoke from the burning of this wood is very hazardous to human health as continuous inhalation may result in lung problems and/or other health problems. It also results in the global change in climatic conditions.
Briquetting technology facilitates the utilization of these biomass residues as a source of renewable energy in contrast to simply disposing of these residues. The end result is creation of jobs for the ever increasing unemployed youths in the society as well as the creation of wealth. In the long run, it tends to promote the economic growth of the country.
1.3 AIM AND OBJECTIVES
1.3.1 AIM
The main aim of this study is to design and construct a standard screw type biomass briquetting machine capable of producing briquettes from biomass.
1.3.2 OBJECTIVES
The specific objectives are to:
- Design a screw type briquetting machine capable of grinding, forming, setting and drying biomass into full briquettes.
- Fabricate a user friendly and cost effective briquette
- Collect sawdust from the local sawmill in the Effurun metropolis and groundnut shell from waste bins located around the school premises and use them to produce quality briquettes.
- Produce durable biomass briquettes within a very short time with little effort.
1.4 SIGNIFICANCE OF THE WORK
Due to the increasing demand of energy and the constant importation of fuel from other countries, the need for optimization of local energy sources should be given much effort. Production and utilization of alternative energy sources such as briquettes can be of help to address the rising energy demands of the country.
As of 2005, Nigeria has the highest rate of deforestation in the world according to the Food and Agriculture Organization of the United Nations (FAO). Deforestation is considered to be one of the contributing factors to global climate change. The effects of these climate change on Nigeria is very clearly seen as we experience heavy rainfall during the wet season and the scorching heat from the sun during the dry season. The thick fumes that is being emitted from the firewood stove is also another cause of global warming, these fumes no matter how little, when combined with other emitted fumes can deplete the ozone layer. This project is therefore important as one of its objectives is to help reduce or completely eradicate deforestation.
This work is also important for the bakery industry in Nigeria as regards the poor state of electricity in the country. Lots of bakery factories especially the foreign ones are closing up in the country due to this issue, but most of the available ones have resorted to the local oven. But as stated earlier, these ovens are not eco-friendly. The use briquettes as an energy source in these bakeries for their baking activities would greatly reduce smoke produced from the local ovens.
Production of briquettes in commercial quantity would also be a form of diversification of the economy, considering the fact that raw materials needed to produce these briquettes are very cheap and can easily be gotten from agricultural wastes majorly in host rural communities. If produced in a larger scale, it could also go as far as creating employment for the youths in the community, through production and sales of briquettes to companies and individuals both in rural and urban settlements.
1.5 SCOPE OF THE WORK
Briquettes produced by this machine will be sold at very low prices to the women selling roasted plantain and beans within the school premises in place of the charcoal they use. This could serve as a source of internally generated revenue for FUPRE.
Before now, biomass wastes are grinded in a grinding machine separately and then transferred manually to the briquetting machine where it is thoroughly mixed and compacted to give the strongly compacted briquettes. This research seeks to improve upon existing briquetting machines, as it proposes the fabrication of a grinder which will be attached to the hopper of the briquetting machine. The grinder will be attached to the hopper of the machine such that, as the biomass wastes is grinded in the grinder, it moves immediately to the briquetting machine by means of a conveyor system where it is compressed to give the strongly compacted briquettes.
The sawdust samples were collected from the local wood market in Effurun. And the groundnut shell samples were collected from waste bins around FUPRE school premises.
The machine can be used for large production of briquettes.
