**2. Biofuels**

Biofuels are energy sources that are produced from biomass—the living matter of plants or organic waste. Biofuel comprises of liquid or gaseous fuels used basically for the transport sector, which are primarily produced from biomass. They include ethanol, methanol, biodiesel, hydrogen and methane, respectively. Liquid biofuels to fuel vehicles, engines while gaseous fuels cells for electricity generation. An estimated 54 billion litres of biofuels was recorded in 2007 as a result of increased world production and these gains meant biofuels accounted for 1.5% of global supply of liquid fuels, up 0.25 % from the previous year [5]. First generation biofuels include two main types:


The transesterification of vegetable oils has been widely known and employed since the 19th century. In fact, the process currently in use for making biofuels from biomass still follows former protocols and the feedstock utilized for their preparation remain very similar. Peanut, hemp and corn oil and animal tallow conventionally used for biodiesel have been partially replaced by soybean; rapeseed, recycled oil while forest wastes, trees and sugarcane are used for bioethanol. According to Luque et al. [7], the history of biofuels is however more political and economic than technological. In the 18th century, Rudolph Diesel firstly demonstrated using peanut oil as diesel for his compression ignition engine at a world exhibition in Paris. These particular vegetable oils were employed as fuels in diesel engine before engine altera‐ tions were made, enabling the use of currently known diesel fuel. Biofuels were believed to would offer a solution to fuel issues in the transportation industry not only by Diesel but also by Henry Ford who was convinced that renewable resources were essential to the success of future automobile designs to be run with ethanol. During the World War II, countries engaged in the war utilized biomass fuels in their machines and despite their use during this time, biofuels have remained inconsequential due to the discovery of fossil fuels and a concrete petrol-based industry that made the world very dependent on petroleum. The potential of

biofuels reappeared in public awareness, brought back by various bioenergy programs established in Brazil in 1975 and international organizations such as the International Energy Agency (IEA) Bioenergy, established in 1978 by the organization for Economic Co-operation and Development (OECD), which aimed to expand bioenergy research, development and implementation between countries that have related national programs. The United Nations (UN) International Biofuels Forum is constituted by a number of countries including Brazil, China, India, the United States, and European Union along with South Africa, which is the only country from the African continent. The United States, Brazil, France, Sweden and Germany are world leaders in biofuel development and consumption. The worldwide advancement of the biofuels industry, however, over the recent years has mostly been triggered by a global crisis produced by the increased use of fossil fuels, resulting in limitation of supply, previously high inflationary prices and negative environmental impact. However, towards 2008, interest in biofuels underwent a huge surge largely accredited to the compulsion towards mandatory fuel blends in Europe and other developed nations [8]. Sub-Saharan Africa's biofuel production potential was emphasized by several research studies, which drove the intense interest for African biofuel investments [9–11] and stimulated international investors to acquire large regions of land for feedstock plantations in sub-Saharan Africa [12– 14]. The environmental and social sustainability of biofuels has been under extensive scientific scrutiny with initiatives emerging to develop guidelines for sustainable production according to the communiqué of the Roundtable on Sustainable Biofuels [15,16] with regards the market regulations from consumer countries and producer countries (e.g. South Africa and Mozam‐ bique) [17]. According to Mwakasonda, Southern Africa possesses largely untapped potential of biofuels in the world [18] with biodiesel development in sub-Saharan Africa still regarded to be in its initial stages. This has initiated deliberations and discussion among policy makers, development practitioners and other stakeholders to foster the development of biofuels in Africa. Bio-fuels are considered as a source of foreign exchange especially for oil-deprived countries via the development and use of locally produced renewable fuel, reduction of demand for imported petroleum, boosting of local agriculture production and additional markets and revenue to farmers, leading consequently to the increase of some rural people's purchasing powers and quality of life, beneficial environmental impact through the use of organic municipal solid waste materials to generate a higher value end-product, reduced level of carbon dioxide emitted by motor engines and subsequent preservation of the atmosphere [19]. It is worthy of mention that despite these benefits, biofuels/biodiesel production in sub-Saharan Africa has met with challenges and caused some unforeseen problems. For example, in several African countries, the biofuel policy priorities at national level revolved around energy security and rural development as well as attempts to take advantage of carbon finance where available. Despite policy and investors interest, several early biofuel ventures collapsed. According to research studies carried, there is evidence to suggest that lack of proper agro‐ nomic knowledge, lack of appropriate institutions to regulate nascent biofuel sector, investor caution, lack of market development and a growing understanding of the potential environ‐ mental and socio-economic impacts has left poor local communities poor or even poorer [20]. Studies have also shown that poverty outcomes are directly related to the loss of access of local

primary energy consumption has been increasing steadily to about 24% [3]. While liquid fuels remain the largest source of energy, fossil fuels are expected to meet much of the global energy required for sustainable development. Predictable high world oil prices in the nearest future, though prices are currently very low, may lead many energy users to shift from liquid fuels when feasible will make a way for renewable energy sources [4]. Among the many possible resources, biodiesel has received the most attention as a promising substitute for conventional

Biofuels are energy sources that are produced from biomass—the living matter of plants or organic waste. Biofuel comprises of liquid or gaseous fuels used basically for the transport sector, which are primarily produced from biomass. They include ethanol, methanol, biodiesel, hydrogen and methane, respectively. Liquid biofuels to fuel vehicles, engines while gaseous fuels cells for electricity generation. An estimated 54 billion litres of biofuels was recorded in 2007 as a result of increased world production and these gains meant biofuels accounted for 1.5% of global supply of liquid fuels, up 0.25 % from the previous year [5]. First generation

**•** Bioethanol produced from plant sugars of biofuel crops, such as sugarcane and maize, which ferments to produce ethanol. The ethanol produced can be further blended with 5–10% gasoline fuel for use in normal cars; however, higher percentages of ethanol are needed for

**•** Biodiesel synthesized from a chemical reaction between triglycerides and an alcohol. The use of triglycerides without any modification directly in modified diesel engines cut biodiesel processing costs and eliminates excessive glycerol by-product from the process. The transesterification of vegetable oils has been widely known and employed since the 19th century. In fact, the process currently in use for making biofuels from biomass still follows former protocols and the feedstock utilized for their preparation remain very similar. Peanut, hemp and corn oil and animal tallow conventionally used for biodiesel have been partially replaced by soybean; rapeseed, recycled oil while forest wastes, trees and sugarcane are used for bioethanol. According to Luque et al. [7], the history of biofuels is however more political and economic than technological. In the 18th century, Rudolph Diesel firstly demonstrated using peanut oil as diesel for his compression ignition engine at a world exhibition in Paris. These particular vegetable oils were employed as fuels in diesel engine before engine altera‐ tions were made, enabling the use of currently known diesel fuel. Biofuels were believed to would offer a solution to fuel issues in the transportation industry not only by Diesel but also by Henry Ford who was convinced that renewable resources were essential to the success of future automobile designs to be run with ethanol. During the World War II, countries engaged in the war utilized biomass fuels in their machines and despite their use during this time, biofuels have remained inconsequential due to the discovery of fossil fuels and a concrete petrol-based industry that made the world very dependent on petroleum. The potential of

petrol-diesel fuel.

40 Biofuels - Status and Perspective

biofuels include two main types:

specially adapted cars [6].

**2. Biofuels**

communities to natural ecosystems implying that that there may be significant linkages between the environmental and socioeconomic performance of biofuel projects [21].

### **2.1. Biodiesel**

Biodiesel presents the following advantages: improved fuel performance, increased lubricity, higher cetane number and flashpoint as compared to fossil-diesel, lower toxicity to living organisms, reduced exhaust emissions, and its versatility for use as fuel [22–25]. It is a local renewable source of energy that reduces importation of energy and affords improved security of energy supply. It is highly biodegradable [26, 27]. It also improves the quality of the environment with less harmful soot generated from the exhaust of vehicles. Biodiesel when mixed with fossil diesel creates a biodiesel blend suitable for diesel engines with minimal modifications as the superior lubricity of biodiesel increases functional engine efficiency; with a low viscosity and lower carbon monoxide emissions [28], biodiesel is user-friendly, non-toxic, and free of sulfur [29] and aromatics [30]. Possessing a high flash point eases storage and the presence of a higher amount of oxygen in biodiesel fuel guarantees the complete combustion of hydrocarbons. The production of biodiesel (methyl esters) from vegetable oils represents an alternative means of producing liquid fuels from biomass, and one which is growing rapidly in commercial importance and relevance due to the fluctuations in petroleum prices and the environmental advantages the process offers. Biodiesel can be produced from a variety of feedstock, vegetable oils, waste cooking oils and animal fats. These oils typically consist of C14– C20 fatty acid triglycerides. In order to produce a fuel that is suitable for use in diesel engines, these triglycerides are usually converted into the respective mono alkyl esters by basecatalyzed transesterification with short chain alcohol, usually methanol.
