**1. Introduction**

242 Sustainable Growth and Applications in Renewable Energy Sources

Pengmei Lv, Zhenhong Y., Longlong M.(2007). Hydrogen-rich gas production from biomass

Pinto Filomena, Franco Carlos, Rui Neto Andre, Tavares C., Dias M., Gulyurtlu I., Cabrita I.

Ramirez J. J., Martinez J. D., Petro S. L. (2007). Basic design of a fluidized bed gasifier for rice

Tavasoli Ahmad, Ahangari Masoumeh G., Soni Chirayu, Dalai Ajay K. (2009). Production of

Wan Ab Karim Ghani, W. A; Moghadam, R.; Salleh, M.; Alias, A. (2009). Air Gasification of

W.A.W.A.K, Ghani, A.B. Alias, R.M. Savory and K.R. Cliffe (2009). Co-combustion of

Xiao R., Jin B., Zhou H., Zhong Z., Zhang M. (2007). Air gasification of polypropylene plastic

Zanzi R., Sjostrom K., Bjornbom E. (2002). Rapid pyrolysis of agricultural residues at high

*Management,* Vol.29, No.2 (February 2009), pp. 767-773, ISSN 0956035X. Worasuwannarak N., Sonobe T., Tanthapanichakoon, W. (2007). Pyrolysis behaviors of rice

*Pyrolysis*. Vol.78, No. 2 (March 2007), pp. 265-271, ISSN 01652370.

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(2003). Effect of experimental conditions on co-gasification of coal, biomass and plastics wastes with air/steam mixtures in a fluidized bed system. *Fuel*, Vol.82, No.

husk on pilot scale. *Latin American Applied Research*, Vol.37, pp. 299-306, ISSN

hydrogen and syngas via gasification of the corn and wheat dry distiller grains (DDGS) in a fixed-bed micro reactor. *Fuel Processing Technology*, Vol.90, No. 4 (April

Agricultural Waste in a Fluidized Bed Gasifier: Hydrogen Production Performance.

Agricultural Waste with Coal in a 10 kW Fluidised Bed Combustor, *Journal of Waste* 

straw, rice husk, and corncob by TG-MS technique. *Journal of Analytical and Applied* 

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Energy production for industrial and domestic purpose has primarily been based upon the combustion of fossil fuels, such as oil and coal and it has been reported that these resources are finite and pose significant environmental impact from their combustion (Carraretto et al., 2004; Abdulkareem & Odigure, 2002; Odigure & Abdulkareem, 2001). It has been predicted that coal will be a viable energy resource for 90-200years, while the world oil supply is reaching its peak due to over dependence on oil consumption (Odigure et al., 2003). This was blame on the inability of energy sector to balance the oil supply with the increasing demand by various sectors including domestic consumption (Abdulkareem, 2005). Like any other commodity, fossil fuel price is also influence by shortage or oversupply and it has been reported that the change in demand as well as supply by the OPEC and non OPEC nations will greatly affects the price of the oil for many years (Abdulkareem, 2005). In other to meet up with the energy demand worldwide, government and oil sector embarks on the programme of new oil discoveries, and it has been reported that searching for new oil is a loss to the companies. For instance, about ten major oil companies spent \$8 billion on searching for new oil; results of their search only produce commercial discoveries of oil worth approximately \$4 billion. Consequently, the oil companies now consider searching for new oil not economical and unable to replace their rapidly depleting resources (Abdulkareem & Odigure, 2006; Abdulkareem & Odigure, 2010; Ahmmad et al., 2011; Udaeta et al., 2007). Apart from the price instability of the fossil fuel which is the major sources of energy, environmental pollution is also a major problem emanated from over dependence on fossil fuel. Combustion of fossil fuel is harmful to human health and the environment, and there is an increasing campaign for cleaner burning

Extraction and Optimization of Oil from

role in the production of biodiesel (Ayhan, 2008).

Moringa Oleifera Seed as an Alternative Feedstock for the Production of Biodiesel 245

 modification (Agarwal and Das, 2001). Biodiesel is therefore, produced by the process known as transesterification, which is a chemical reaction for conversion of oil to biodiesel (El-Sabagh et al., 2011; Adeniyi et al., 2007). In this process the oil is chemically reacted with alcohol like methanol or ethanol in the presence of catalyst like sodium hydroxide or potasium hydroxide. After the chemical reaction, various components of the oil break down to form new compounds known as triglycerides. The triglycerides are converted into alkyl esters, which is the chemical name of biodiesel. If methanol is used in the chemical reaction, methyl esters are formed, while when ethanol is used, ethyl esters are formed. Both of these compounds are biodiesel fuels with different chemical combination (Silas, 2008). While the glycerin, that has been separated during transesterification process is released as a byproduct of the chemical reaction. Glycerin will either sink to the bottom of reaction vessel or come to the surface depending on its phase. It can be easily separated by the centrifuges. This whole process is called transesterification. The feedstock (oil) therefore play a major

Biodiesel as an alternative sources of energy, can be produced from biological or biomass material including corn, cellulose, sugar cane, edible oils such as vegetable oil, soybean, palm oil etc. Biodiesel Fuel can also be produced from a variety of non edible oil including rapeseed, mustard flax, sunflower, canola, hemp, Jatropha and waste vegetable oils (Aghan, 2005; Adeniyi et al., 2007; Helwani et al., 2009; Hossain and Boyce, 2009; Abdulkareem et al., 2010). This fuel sources are said to reduce engine wear and produce less harmful emissions. In different part of the world, depending on availability, biodiesel has been produced from different plants. This was first done as an academic exercise, but today commercialization of this production process and product is on-going. For instance Freedman et al, (1984) reported the use of fish oil, soy oil, rape seed oil, cotton seed oil, sun flower, safflower, peanut and line seed oil for the production of methyl esters. According to Barminas et al, (2001) categories of suitable agricultural products for bio-fuel production include seeds, nuts, fruits, leaves, and root and stem etc. It has also been reported that algae farming provide yields 4-5 times more biodiesel per acre than crops like soybeans, but the technology of producing biodiesel from algae is very expensive hence the possibility of achieving commercialization of biodiesel from algae might not happen any moment soon. The European standard specification EN 14214 in 2004, therefore defined biodiesel as fatty acid methyl esters (FAME) from any kind of feedstock (Canakci, 2007; Chhetri *et al*., 2008; Refaat *et al*., 2008). Therefore, from an economic point of view; the production of biodiesel is very feedstock sensitive. The cost of biodiesel has been estimated based on assumption regarding production volume, feedstock and chemical technology (Canakci and van Gerpen, 2001; Zhang *et al*., 2003b; Kulkarni and Dalai, 2006) and feedstock cost comprises a very substantial portion of overall biodiesel cost. Though, the production from various feed stocks had been investigated, however, each of the feedstock has its own problems. For instance, the production of biofuel from waste oil has been described to be economical and readily available, however the inherent difficulties of processing and gathering remain the major factor that militate against its usage as a feedstock in the production of biodiesel (Whang et al 2003(a&b)). Edible sources like soybeans, sunflower seeds and cotton seeds etc. which are easily available and can be gathered and processed easily need to be closely monitored and controlled in other not to create larger global problems of deforestation, hunger and poverty while trying to solve the problem of energy crises. Critics of biofuel fear that the uses of food (edible oil) as a feed feedstock in the production of biodiesel could result into food crisis. It has been reported that to produce 5% of the total diesel consumption in United State of America

fuel in order to safeguard the environment and protect man from the inhalation of genotoxic substances (Perez-Roa et al., 2006; Adeniyi et al., 2007; Abdulkareem et al., 2010). For instance, the exhaust from petroleum products, especially diesel is known to be toxic and carcinogenous in nature, since they contain polycyclic aromatic hydrocarbons (Ahmmad et al., 2011). Though, there is no energy source that is completely environmentally safe, hence it is important to use the available energy sources wisely to minimize environmental hazard and optimize the efficiency with which it is produced (Bernard & Wolfgang, 2009; Abdulkareem et al., 2011). The environmental impacts of using fossil fuel and other nonrenewable fuels, such as coal and uranium, present a major obstacle to the continued use of such resources to meet our energy needs. The conventional petroleum-based fuels such as gasoline or diesel, as well as natural gas and coal, all contain carbon. When these fuels are burnt, their carbon recombines with oxygen from the air to form carbon dioxide which is the primary greenhouse gas that causes global warming. In the same vein, combustion of fossil fuels at the high temperature and pressures reached inside an internal combustion engine (what powers most vehicles) or in an electric power plant produces other toxic emissions (Abdulkareem et al., 2011). Carbon monoxide, oxides of nitrogen, oxides of sulphur, volatile organic chemicals, and fine particles are all components of air pollution attributable to the refining and combustion of fossil fuels. When released into the atmosphere, many of these compounds cause acid rain or react with sunlight to create ground level smog. Vast ecosystem damage, increase lung disease and cancer are the ultimate price inhabitant pay for consuming these fossil fuels (Abdulkareem & Odigure, 2006). The concern for price instability due to over dependence on the fossil and increasingly awareness on the environmental impact of combustion of fossil fuel have called for the alternative source of energy and proper utilization of existing energy sources. Biofuel which is described as the natural and renewable domestic fuel are now considered promising and economical alternative and sustainable energy sources (Shireen & Debabrate, 2008; Khunrong et al., 2011; Eevere et al., 2011). Biodiesel made from vegetable oil, has been reported to burns clearly, which result in a significant reduction for the types of pollutants that contribute to smog and global warming. Some of the advantages of the biodiesel over the fossil fuel diesel include cost of production, it has been reported that once the technology of biofuel is readily available, the cost of biofuel will be much less than that of fossil fuel (Ahmmad et al., 2011; Durosoy et al., 2011). This was blame on the fact that increases in word population will lead to an increment in demand for oil which will results in increase in price beyond the expectation level (Nashawi et al., 2010). While fossil fuel is described as limited resources since it is produce from a specific material, biofuel can be manufactured from a variety of material (Vera & Langlois, 2007). Other problem associated with fossil fuel is the nonbiodegradability; the situation that makes it difficult to clean when spillage is experienced. While the biofuel are easily biodegradable and safer to handle than the fossil fuel, this makes spill of biofuel to be less hazardous and less expensive to clean up. Biodiesel also had a high flash point which makes it less explosive at moderate temperature, hence biodiesel is safer to transport and store (Hamamci et al., 2011). There is also wide spread of efforts to investigate an economical additives that can be blended with biodiesel to enhace its application in a colder climates which is the major detractor at moment. On the suitability of the biodiesel in a diesel engine, it has been reported that the first diesel engine which was invented by Rudolf Diesel in 1892, was originally designed to run on unrefined biodiesel.This provide an indiaction that diesel engine can easily adapt to biofuel with little

fuel in order to safeguard the environment and protect man from the inhalation of genotoxic substances (Perez-Roa et al., 2006; Adeniyi et al., 2007; Abdulkareem et al., 2010). For instance, the exhaust from petroleum products, especially diesel is known to be toxic and carcinogenous in nature, since they contain polycyclic aromatic hydrocarbons (Ahmmad et al., 2011). Though, there is no energy source that is completely environmentally safe, hence it is important to use the available energy sources wisely to minimize environmental hazard and optimize the efficiency with which it is produced (Bernard & Wolfgang, 2009; Abdulkareem et al., 2011). The environmental impacts of using fossil fuel and other nonrenewable fuels, such as coal and uranium, present a major obstacle to the continued use of such resources to meet our energy needs. The conventional petroleum-based fuels such as gasoline or diesel, as well as natural gas and coal, all contain carbon. When these fuels are burnt, their carbon recombines with oxygen from the air to form carbon dioxide which is the primary greenhouse gas that causes global warming. In the same vein, combustion of fossil fuels at the high temperature and pressures reached inside an internal combustion engine (what powers most vehicles) or in an electric power plant produces other toxic emissions (Abdulkareem et al., 2011). Carbon monoxide, oxides of nitrogen, oxides of sulphur, volatile organic chemicals, and fine particles are all components of air pollution attributable to the refining and combustion of fossil fuels. When released into the atmosphere, many of these compounds cause acid rain or react with sunlight to create ground level smog. Vast ecosystem damage, increase lung disease and cancer are the ultimate price inhabitant pay for consuming these fossil fuels (Abdulkareem & Odigure, 2006). The concern for price instability due to over dependence on the fossil and increasingly awareness on the environmental impact of combustion of fossil fuel have called for the alternative source of energy and proper utilization of existing energy sources. Biofuel which is described as the natural and renewable domestic fuel are now considered promising and economical alternative and sustainable energy sources (Shireen & Debabrate, 2008; Khunrong et al., 2011; Eevere et al., 2011). Biodiesel made from vegetable oil, has been reported to burns clearly, which result in a significant reduction for the types of pollutants that contribute to smog and global warming. Some of the advantages of the biodiesel over the fossil fuel diesel include cost of production, it has been reported that once the technology of biofuel is readily available, the cost of biofuel will be much less than that of fossil fuel (Ahmmad et al., 2011; Durosoy et al., 2011). This was blame on the fact that increases in word population will lead to an increment in demand for oil which will results in increase in price beyond the expectation level (Nashawi et al., 2010). While fossil fuel is described as limited resources since it is produce from a specific material, biofuel can be manufactured from a variety of material (Vera & Langlois, 2007). Other problem associated with fossil fuel is the nonbiodegradability; the situation that makes it difficult to clean when spillage is experienced. While the biofuel are easily biodegradable and safer to handle than the fossil fuel, this makes spill of biofuel to be less hazardous and less expensive to clean up. Biodiesel also had a high flash point which makes it less explosive at moderate temperature, hence biodiesel is safer to transport and store (Hamamci et al., 2011). There is also wide spread of efforts to investigate an economical additives that can be blended with biodiesel to enhace its application in a colder climates which is the major detractor at moment. On the suitability of the biodiesel in a diesel engine, it has been reported that the first diesel engine which was invented by Rudolf Diesel in 1892, was originally designed to run on unrefined biodiesel.This provide an indiaction that diesel engine can easily adapt to biofuel with little

 modification (Agarwal and Das, 2001). Biodiesel is therefore, produced by the process known as transesterification, which is a chemical reaction for conversion of oil to biodiesel (El-Sabagh et al., 2011; Adeniyi et al., 2007). In this process the oil is chemically reacted with alcohol like methanol or ethanol in the presence of catalyst like sodium hydroxide or potasium hydroxide. After the chemical reaction, various components of the oil break down to form new compounds known as triglycerides. The triglycerides are converted into alkyl esters, which is the chemical name of biodiesel. If methanol is used in the chemical reaction, methyl esters are formed, while when ethanol is used, ethyl esters are formed. Both of these compounds are biodiesel fuels with different chemical combination (Silas, 2008). While the glycerin, that has been separated during transesterification process is released as a byproduct of the chemical reaction. Glycerin will either sink to the bottom of reaction vessel or come to the surface depending on its phase. It can be easily separated by the centrifuges. This whole process is called transesterification. The feedstock (oil) therefore play a major role in the production of biodiesel (Ayhan, 2008).

Biodiesel as an alternative sources of energy, can be produced from biological or biomass material including corn, cellulose, sugar cane, edible oils such as vegetable oil, soybean, palm oil etc. Biodiesel Fuel can also be produced from a variety of non edible oil including rapeseed, mustard flax, sunflower, canola, hemp, Jatropha and waste vegetable oils (Aghan, 2005; Adeniyi et al., 2007; Helwani et al., 2009; Hossain and Boyce, 2009; Abdulkareem et al., 2010). This fuel sources are said to reduce engine wear and produce less harmful emissions. In different part of the world, depending on availability, biodiesel has been produced from different plants. This was first done as an academic exercise, but today commercialization of this production process and product is on-going. For instance Freedman et al, (1984) reported the use of fish oil, soy oil, rape seed oil, cotton seed oil, sun flower, safflower, peanut and line seed oil for the production of methyl esters. According to Barminas et al, (2001) categories of suitable agricultural products for bio-fuel production include seeds, nuts, fruits, leaves, and root and stem etc. It has also been reported that algae farming provide yields 4-5 times more biodiesel per acre than crops like soybeans, but the technology of producing biodiesel from algae is very expensive hence the possibility of achieving commercialization of biodiesel from algae might not happen any moment soon. The European standard specification EN 14214 in 2004, therefore defined biodiesel as fatty acid methyl esters (FAME) from any kind of feedstock (Canakci, 2007; Chhetri *et al*., 2008; Refaat *et al*., 2008). Therefore, from an economic point of view; the production of biodiesel is very feedstock sensitive. The cost of biodiesel has been estimated based on assumption regarding production volume, feedstock and chemical technology (Canakci and van Gerpen, 2001; Zhang *et al*., 2003b; Kulkarni and Dalai, 2006) and feedstock cost comprises a very substantial portion of overall biodiesel cost. Though, the production from various feed stocks had been investigated, however, each of the feedstock has its own problems. For instance, the production of biofuel from waste oil has been described to be economical and readily available, however the inherent difficulties of processing and gathering remain the major factor that militate against its usage as a feedstock in the production of biodiesel (Whang et al 2003(a&b)). Edible sources like soybeans, sunflower seeds and cotton seeds etc. which are easily available and can be gathered and processed easily need to be closely monitored and controlled in other not to create larger global problems of deforestation, hunger and poverty while trying to solve the problem of energy crises. Critics of biofuel fear that the uses of food (edible oil) as a feed feedstock in the production of biodiesel could result into food crisis. It has been reported that to produce 5% of the total diesel consumption in United State of America

Extraction and Optimization of Oil from

Eaves, 2007).

method.

Moringa Oleifera Seed as an Alternative Feedstock for the Production of Biodiesel 247

distribution of energy supplies among countries has led to significant vulnerabilities. It has been reported that energy security resulted into the political instability of several energy producing countries, the manipulation of energy supplies, the competition over energy sources, attacks on supply infrastructure, as well as accidents, natural disasters, the funding to foreign dictators, rising terrorism, and dominant countries reliance to the foreign oil supply (Wesley, 2007). The world wide over dependence on the oil and the peaking limits of oil production, it is obvious that economics and societies will begin to feel the decline in the resources that we have dependent upon. Hence, the issue of energy security has become one of the leading issues in the world today as oil and other resources have become as vital to the world's people. The looming end of the era of cheap oil is going to put the energy security of most industrialized countries in jeopardy and the same is true in the case of food since many of the imports which are not sustainable even at this very moment, may become far too expensive to afford. It is therefore, important that both of these issues are extremely

Food security is probably on a more serious level than energy security even though both have to be considered side by side. The high prices of food today are mostly driven by elevating demand due to rapid population growth among other conventional factors such as urbanization and industrialization, economic growth and food consumption, and land use changes and water scarcity (Khan *et al*., 2009). Today there are almost 219,000 additional people to feed at the global table every night, this unfortunate scenario is the consequenc of the current competition between food and energy. Most developed nations are now converting food products into energy sources, for instance, the United States is now converting massive quantities of grains into fuel for cars, even with increasing grain consumption. This massive capacity to convert grain into fuel means that the price of grain is now tied to the price of oil. The same phenomenon is also happening in Brazil, where distills ethanol from sugar cane, ranks second in production after the United States, while the European Union's goal of getting 10 percent of its transport energy from renewable, mostly biofuel, by 2020 is also diverting land from food crops (Eaves and

Principles of optimization find applications in the fields of science, engineering, and business. Optimization is therefore concerned with selecting the best among the entire set by efficient quantitative methods (Onifade, 2002). It has been reported that the recent development in chemical and process engineering industry has undergone significant changes during the past few years due to the increased cost of energy, increasingly stringent environmental regulations, and global competition in product pricing and quality (Onifade, 2002). One of the most important engineering tools for addressing these issues is optimization of the technique involved. Effective optimization techniques are now available in software for personal computers, a capability that did not exist some years ago. To achieve effective application of optimization in the chemical and process industries, there is the need for proper understanding of both the theory and application by engineers and scientists who find optimization as the decision making process which is the exasperating and difficult. In this present study, optimization technique is employ to determine the best conditions at which oil can be extracted from moringa oleifera seed by solvent extraction

serious and need to be dealt with and addressed immediately.

**1.2 Application of optimization in solvent extraction** 

from biodiesel, will require approximately 60 % of the crop produced in United State, the action consider being unethical by the critics. Despite the wide acceptance of biofuel as alternative energy source to supplement or replace fossil fuel. The latest research and development in the production of biodiesel is aimed at producing the biofuel from non edible oil like Jatropha Curcas, sunflower etc. Employing non edible oil as a feedstock in the production of biodiesel will actually help in solving the strain relationship between the energy sectors and critics of production of biodiesel from edible oil which was considered unethical. This present study is therefore focus on the optimization of extraction of oil from moringa oleifera seed kernel which is non edible oil especially in Nigeria where it is abundantly available, as an alternative feedstock in the production of biodiesel. Moringa Oleifera (Zogale) seed kernel contains about 45% oil by weight. The oil can be use for cosmetic making, lubrication and consumption. Beside its industrial use as a fine lubricant, the fatty acid profile of the oil with its high content of oleic acid make it an oil with potential for further industrial application (Michelle, 1994). Moringa oleifera seeds are available in abudant in Minna and utilizing the oil from the seed to produced biodiesel will not constituite any enviromental hazard.

### **1.1 War of energy and food security**

Food security refers to the availability of food and one's access to it, a household is therefore, considered food-secure when its occupants do not live in hunger or fear of starvation. According to FAO, 2008, food security exists when all people, at all times, have physical, social and economic access to sufficient, safe and nutritious food to meet their dietary needs and food preferences for an active and healthy life. Hence, the stages of food insecurity range from food secure situations to full-scale famine. Generally, the food insecurity can be categorized as either chronic or transitory. In chronic food insecurity situation, the societies exposed to a high degree of vulnerability to famine and hunger. The situation is similar to undernourishment and is related to poverty, which is existing mainly in poor countries (Ayalew, 1988). Many countries experience perpetual food shortages and distribution problems, which resulted in chronic and often widespread hunger amongst significant numbers of people. Worldwide around 852 million people are chronically hungry due to extreme poverty, while up to 2 billion people lack food security intermittently due to varying degrees of poverty (FAO, 2003). According to CNN report (2009), six million children die of hunger every year - 17,000 every day. It has been reported that as of late 2007, export restrictions and panic buying, US Dollar depreciation, (HM Government, 2010) increased farming for use in biofuel (Smith and Edwards, 2011), world oil prices at more than \$100 a barrel (The Monitor's view, 2008), global population growth, (Randerson, 2008) climate change (Vidal, 2007), loss of agricultural land to residential and industrial development (Dancy, 2008) and growing consumer demand in China and India (Walt, 2008) are claimed to have pushed up the price of grains (Brown, 2008). The issue of food security is therefore a complex objective pursued with shelter, safety, health and self-esteem in a world where individual households, face diverse complex and different livelihood opportunities (Smit *et al.,* 1993). Hence, the proper understanding of food security requires explicit recognition of complexity and diversity, and that it necessarily privileges the subjective perceptions of the food insecure themselves (World Bank, 1986).

Energy security is a term used to describe an association between national security and the availability of natural resources for energy consumption. Though, access to cheap energy has become essential to the functioning of modern economies, however, the uneven

from biodiesel, will require approximately 60 % of the crop produced in United State, the action consider being unethical by the critics. Despite the wide acceptance of biofuel as alternative energy source to supplement or replace fossil fuel. The latest research and development in the production of biodiesel is aimed at producing the biofuel from non edible oil like Jatropha Curcas, sunflower etc. Employing non edible oil as a feedstock in the production of biodiesel will actually help in solving the strain relationship between the energy sectors and critics of production of biodiesel from edible oil which was considered unethical. This present study is therefore focus on the optimization of extraction of oil from moringa oleifera seed kernel which is non edible oil especially in Nigeria where it is abundantly available, as an alternative feedstock in the production of biodiesel. Moringa Oleifera (Zogale) seed kernel contains about 45% oil by weight. The oil can be use for cosmetic making, lubrication and consumption. Beside its industrial use as a fine lubricant, the fatty acid profile of the oil with its high content of oleic acid make it an oil with potential for further industrial application (Michelle, 1994). Moringa oleifera seeds are available in abudant in Minna and utilizing the oil from the seed to produced

Food security refers to the availability of food and one's access to it, a household is therefore, considered food-secure when its occupants do not live in hunger or fear of starvation. According to FAO, 2008, food security exists when all people, at all times, have physical, social and economic access to sufficient, safe and nutritious food to meet their dietary needs and food preferences for an active and healthy life. Hence, the stages of food insecurity range from food secure situations to full-scale famine. Generally, the food insecurity can be categorized as either chronic or transitory. In chronic food insecurity situation, the societies exposed to a high degree of vulnerability to famine and hunger. The situation is similar to undernourishment and is related to poverty, which is existing mainly in poor countries (Ayalew, 1988). Many countries experience perpetual food shortages and distribution problems, which resulted in chronic and often widespread hunger amongst significant numbers of people. Worldwide around 852 million people are chronically hungry due to extreme poverty, while up to 2 billion people lack food security intermittently due to varying degrees of poverty (FAO, 2003). According to CNN report (2009), six million children die of hunger every year - 17,000 every day. It has been reported that as of late 2007, export restrictions and panic buying, US Dollar depreciation, (HM Government, 2010) increased farming for use in biofuel (Smith and Edwards, 2011), world oil prices at more than \$100 a barrel (The Monitor's view, 2008), global population growth, (Randerson, 2008) climate change (Vidal, 2007), loss of agricultural land to residential and industrial development (Dancy, 2008) and growing consumer demand in China and India (Walt, 2008) are claimed to have pushed up the price of grains (Brown, 2008). The issue of food security is therefore a complex objective pursued with shelter, safety, health and self-esteem in a world where individual households, face diverse complex and different livelihood opportunities (Smit *et al.,* 1993). Hence, the proper understanding of food security requires explicit recognition of complexity and diversity, and that it necessarily privileges the

subjective perceptions of the food insecure themselves (World Bank, 1986).

Energy security is a term used to describe an association between national security and the availability of natural resources for energy consumption. Though, access to cheap energy has become essential to the functioning of modern economies, however, the uneven

biodiesel will not constituite any enviromental hazard.

**1.1 War of energy and food security** 

distribution of energy supplies among countries has led to significant vulnerabilities. It has been reported that energy security resulted into the political instability of several energy producing countries, the manipulation of energy supplies, the competition over energy sources, attacks on supply infrastructure, as well as accidents, natural disasters, the funding to foreign dictators, rising terrorism, and dominant countries reliance to the foreign oil supply (Wesley, 2007). The world wide over dependence on the oil and the peaking limits of oil production, it is obvious that economics and societies will begin to feel the decline in the resources that we have dependent upon. Hence, the issue of energy security has become one of the leading issues in the world today as oil and other resources have become as vital to the world's people. The looming end of the era of cheap oil is going to put the energy security of most industrialized countries in jeopardy and the same is true in the case of food since many of the imports which are not sustainable even at this very moment, may become far too expensive to afford. It is therefore, important that both of these issues are extremely serious and need to be dealt with and addressed immediately.

Food security is probably on a more serious level than energy security even though both have to be considered side by side. The high prices of food today are mostly driven by elevating demand due to rapid population growth among other conventional factors such as urbanization and industrialization, economic growth and food consumption, and land use changes and water scarcity (Khan *et al*., 2009). Today there are almost 219,000 additional people to feed at the global table every night, this unfortunate scenario is the consequenc of the current competition between food and energy. Most developed nations are now converting food products into energy sources, for instance, the United States is now converting massive quantities of grains into fuel for cars, even with increasing grain consumption. This massive capacity to convert grain into fuel means that the price of grain is now tied to the price of oil. The same phenomenon is also happening in Brazil, where distills ethanol from sugar cane, ranks second in production after the United States, while the European Union's goal of getting 10 percent of its transport energy from renewable, mostly biofuel, by 2020 is also diverting land from food crops (Eaves and Eaves, 2007).

### **1.2 Application of optimization in solvent extraction**

Principles of optimization find applications in the fields of science, engineering, and business. Optimization is therefore concerned with selecting the best among the entire set by efficient quantitative methods (Onifade, 2002). It has been reported that the recent development in chemical and process engineering industry has undergone significant changes during the past few years due to the increased cost of energy, increasingly stringent environmental regulations, and global competition in product pricing and quality (Onifade, 2002). One of the most important engineering tools for addressing these issues is optimization of the technique involved. Effective optimization techniques are now available in software for personal computers, a capability that did not exist some years ago. To achieve effective application of optimization in the chemical and process industries, there is the need for proper understanding of both the theory and application by engineers and scientists who find optimization as the decision making process which is the exasperating and difficult. In this present study, optimization technique is employ to determine the best conditions at which oil can be extracted from moringa oleifera seed by solvent extraction method.

Extraction and Optimization of Oil from

Fig. 2.1. Moringa oleifera tree

*2000*).

vegetable oil.

Moringa Oleifera Seed as an Alternative Feedstock for the Production of Biodiesel 249

The Moringa tree grows mainly in semi-arid tropical and subtropical areas, but grows best in dry sandy soil; it tolerates poor soil, including coastal areas. It is a fast-growing, drought-resistant tree that is native to the southern foothills of the Himalayas, and possibly Africa and the Middle East. The tree has its origin from the Southern Indian State of Tamilnadu. Today, it is widely cultivated in Africa, Central and South America, Sri Lanka, India, Mexico, Malaysia and the Philippines. It grows up to 4m in height and develops to flowering and fruiting within one year of its cultivation. Moringa oleifera is considered as one of the world's most useful trees, this is because almost every part of the tree can be used for food, or has some other beneficial property. Hence it is commonly called the '*Wonder Tree'*. In the tropics, it is used as foliage for livestock. The immature green pods, called "drumsticks" are probably the most valued and widely used part of the tree. They are commonly consumed in India, and are generally prepared in a similar fashion to green beans and have a slight asparagus taste (Rajangam *et al,* 

The Moringa seeds (Figure 2.2) yield 38–45% edible oil (called Ben oil, from the high concentration of Behenic acid contained in the oil) that can be used in cooking, cosmetics and lubrication. Unfortunately, the oil from moringa oleifera seed is not popular edible oil in Nigeria; hence extraction of oil for the purpose of biodiesel production will not pose any food shortage threat which is a major factor against the production of biodiesel from

The process of solvent extraction of oil , includes diffusion of a solvent into oil-bearing cells of vegetable oil seeds resulting in a solution of the oil in solvent. Various solvents can be used for extraction. However, after extensive research and consideration of various factors, such as commercial economics, edibility of the various products obtained from extraction, physical properties of the solvent especially its low boiling point, volatility, toxicity, viscosity etc. Hence, the selection of the equipment for an extraction process is influenced by the factors, which are responsible for limiting the extraction rate. Thus if the diffusion of the solute through the pores of the residual solid is the controlling factors, the material should be of small size so that the distance the solute has to travel is small. On the other hand, if the diffusion of the solute from the surface of the particle to the bulk of the solution is the controlling factor, then a high degree of agitation is required for optimum leaching of the seed, thus particle size, temperature, agitation and solvent are the major factors influencing solvent extraction techniques. These factors are therefore combined during experimental design which resulted into what is described as factorial experimental design for the purpose of optimizing the process and to investigate the interaction between the various factors that influence the rate of extraction.

The method of factorial experimental design forces data to be orthogonal which allows one to determine the relative importance of each input variable and thus to develop a parametric model that includes only the most important variables and effects. It also represents efficient method of experimentation to determine the best operating condition for each variable factor that influences the process. In factorial experimental design, experiments are systematically planned and conducted in such a way that all the variable factors are changed simultaneously rather than one at a time, for the purpose of reducing the number of experiments. Due to the orthogonal nature of a factorial design method, statistical tests are effective in discriminating among the effects of different natural variations such as the unit operations, operators, batches and other environmental factors. The standard factorial design therefore requires 2k tests, where k represents the number of input variables to be investigated. It is also important for the user of factorial design to decide the extent to which each of the variable input should be changed from its original value. To take this decision, the user needs to take into account the sensitivity of the process response to a change in a given input variable, as well as the typical operating range of the process. The experimental design range should therefore be chosen in other to avoid the possibility of the response of the resulting measurements not to generate errors that are far greater than the typical real values. To achieve this in experimental factorial design, variance (ANOVA) or regression analysis can be use to analyzed the experimental results effectively, which is relatively easy to determine the major effect of a variable factor. The factorial design therefore,becomes an important tool in the solvent extraction techniques.

### **2. Moringa oleifera**

Moringa oleifera popularly called Zogale in the northern part of Nigeria is the most widely cultivated variety of the genus Moringa and belong to the family of Moringaceae. Moringa oleifera is a nutritious vegetable tree with a variety of potential uses. The moringa oleifera tree shown in Figure 2.1 is slender with drooping branch that grows to approximately 10 m in height. To maintain the pod and leaves within the arms reach, the tree is normally cut to one meter or less.

The process of solvent extraction of oil , includes diffusion of a solvent into oil-bearing cells of vegetable oil seeds resulting in a solution of the oil in solvent. Various solvents can be used for extraction. However, after extensive research and consideration of various factors, such as commercial economics, edibility of the various products obtained from extraction, physical properties of the solvent especially its low boiling point, volatility, toxicity, viscosity etc. Hence, the selection of the equipment for an extraction process is influenced by the factors, which are responsible for limiting the extraction rate. Thus if the diffusion of the solute through the pores of the residual solid is the controlling factors, the material should be of small size so that the distance the solute has to travel is small. On the other hand, if the diffusion of the solute from the surface of the particle to the bulk of the solution is the controlling factor, then a high degree of agitation is required for optimum leaching of the seed, thus particle size, temperature, agitation and solvent are the major factors influencing solvent extraction techniques. These factors are therefore combined during experimental design which resulted into what is described as factorial experimental design for the purpose of optimizing the process and to investigate the interaction between the various factors that influence the

The method of factorial experimental design forces data to be orthogonal which allows one to determine the relative importance of each input variable and thus to develop a parametric model that includes only the most important variables and effects. It also represents efficient method of experimentation to determine the best operating condition for each variable factor that influences the process. In factorial experimental design, experiments are systematically planned and conducted in such a way that all the variable factors are changed simultaneously rather than one at a time, for the purpose of reducing the number of experiments. Due to the orthogonal nature of a factorial design method, statistical tests are effective in discriminating among the effects of different natural variations such as the unit operations, operators, batches and other environmental factors. The standard factorial design therefore requires 2k tests, where k represents the number of input variables to be investigated. It is also important for the user of factorial design to decide the extent to which each of the variable input should be changed from its original value. To take this decision, the user needs to take into account the sensitivity of the process response to a change in a given input variable, as well as the typical operating range of the process. The experimental design range should therefore be chosen in other to avoid the possibility of the response of the resulting measurements not to generate errors that are far greater than the typical real values. To achieve this in experimental factorial design, variance (ANOVA) or regression analysis can be use to analyzed the experimental results effectively, which is relatively easy to determine the major effect of a variable factor. The factorial design therefore,becomes an

Moringa oleifera popularly called Zogale in the northern part of Nigeria is the most widely cultivated variety of the genus Moringa and belong to the family of Moringaceae. Moringa oleifera is a nutritious vegetable tree with a variety of potential uses. The moringa oleifera tree shown in Figure 2.1 is slender with drooping branch that grows to approximately 10 m in height. To maintain the pod and leaves within the arms reach, the tree is normally cut to

rate of extraction.

**2. Moringa oleifera** 

one meter or less.

important tool in the solvent extraction techniques.

The Moringa tree grows mainly in semi-arid tropical and subtropical areas, but grows best in dry sandy soil; it tolerates poor soil, including coastal areas. It is a fast-growing, drought-resistant tree that is native to the southern foothills of the Himalayas, and possibly Africa and the Middle East. The tree has its origin from the Southern Indian State of Tamilnadu. Today, it is widely cultivated in Africa, Central and South America, Sri Lanka, India, Mexico, Malaysia and the Philippines. It grows up to 4m in height and develops to flowering and fruiting within one year of its cultivation. Moringa oleifera is considered as one of the world's most useful trees, this is because almost every part of the tree can be used for food, or has some other beneficial property. Hence it is commonly called the '*Wonder Tree'*. In the tropics, it is used as foliage for livestock. The immature green pods, called "drumsticks" are probably the most valued and widely used part of the tree. They are commonly consumed in India, and are generally prepared in a similar fashion to green beans and have a slight asparagus taste (Rajangam *et al, 2000*).

The Moringa seeds (Figure 2.2) yield 38–45% edible oil (called Ben oil, from the high concentration of Behenic acid contained in the oil) that can be used in cooking, cosmetics and lubrication. Unfortunately, the oil from moringa oleifera seed is not popular edible oil in Nigeria; hence extraction of oil for the purpose of biodiesel production will not pose any food shortage threat which is a major factor against the production of biodiesel from vegetable oil.

Extraction and Optimization of Oil from

**3.2 The 2k**

Treatment

Moringa Oleifera Seed as an Alternative Feedstock for the Production of Biodiesel 251

electric oven and distillation column. The moringa oleifera seeds and rice husk used in this

When several factors are of interest in an experiment a factorial method of analysis is used in order to study the effect of individual factor and its interaction with other factors to economize the experimental resources (Azeez, 2005;Zhang and Huang, 2011; Wang et al., 2011). In this study, three factors namely temperature, particle size and resident time are of interest while agitation was kept constant. This gives rise to three-factor factorial experiment; the factors are tested at high and low levels. When three factors are tested at two levels as applicable in this study, it is denoted by 23 factorial; thus there exist eight (23) treatment combinations as shown in Table 3.1. The table indicates how the individual effect and interactions are calculated. It was assumed that A,B and C are the fixed factors where there are 'a' levels of A, 'b' levels of B and 'c' levels of C arranged in the factorial experiment. Generally there will be abc…..n total observations if there are n replicates of the

I I A B C AB AC BC ABC

A + - - - + + + -

B + + - - - - + +

Ab + - + - - + - +

C + - - + + - - +

Ac + + - + - + - -

Bc + - + + - - + -

Abc + + + + + + + +

Consider a three factors experiment, with underlying model as shown in Equation1, before the model equation can be fitted, it is important to conduct some statistical tests such as Gtest, T-test and F-test, which involves calculation of these statistical parameters with the aid of certain formulae shown in Equations 2-4 and compare them with those given in the statistical tables. G-test is used to check if the output has the maximum accuracy of replication. T-test is used to check the significance of regression coefficient, and F-test is used to test for the adequacy of the model. Equations 2-4 represent the formulae to calculate

study were collected in Bosso Estate, Minna, Niger State, Nigeria.

complete experiment. The analysis variance is shown in Table 3.2.

combination Factorial Effect

Table 3.1. Design matrix for a 23 Factorial Design

G-test, T-test and F-test respectively.

 **factorial experimental design** 

Fig. 2.2. Moringa oleifera (a) Dried pods (b) Seed kernel with husks (c) seed kernel without husk

The refined oil is clear, odourless and resists rancidity like any other botanical oil. The seed cake remaining after the oil extraction can be used as fertilizer or as flocculants to treat turbid water. The leaves are highly nutritious, being a significant source of beta-carotene, Vitamin C, protein, iron and potassium; it is consumed mostly among the Hausas in Northern Nigeria. In addition to being used fresh as a substitute for spinach, the leaves are commonly dried and processed into powder and used in soups and sauces.
