2. Sustainable Biofuel from Edible Sources Bangladesh produces vegetable oils at a small amount compared to the world production. But, these vegetable oils are successfully used to harvest biofuel in Bangladesh. Soybean oil, waste cooking oil, mustard oil, coconut oil, sesame oil and mosna oil are used as edible sources of biofuel.
3. Sustainable Bio-Fuel from Non-Edible Sources In Bangladesh, the production of these non-edible sources of biodiesel is less in amount compared to the other developed countries. These sources do not create conflict with food which is the most important advantage. Castor oil, rice bran oil, Jatropha curcas oil, karanja oil, cottonseed oil, micro-algae oil, rubber seed oil, neem oil and linseed oil are used as non-edible sources of biodiesel in Bangladesh. A brief description of the characteristics and potentialities of these biofuel sources are shown in Figure 4. Table 3 demonstrates the potentialities of different biofuel sources. Rice bran oil production capacity is comparatively higher than the other sources. On the other hand, Jatropha curcas soil production capacity is low. The fertile land of Bangladesh is suitable to produce the sources contained demonstrates the availability of raw materials and estimated biodiesel production from RBO. The maximum biodiesel generation capacity is 0.9 wt% e amount of biodiesel production is 1 million metric ton which is half of the annual diesel demand. The biodiesel generation from RBO not only mitigates the diesel demand but also ensures an ecological environment. Furthermore, the RBO biodiesel supports the economy and protects the development of the entire financial situation. Karanja is another non-edible potential biofuel source. Table 4 shows the potentialities of different portions of Karanja seeds with their quantities and other characteristics such as calorific value, energy content etc. The products of Karanja seed are fuelwood, bio-oil, glycerin, seed cake and pond cover can be used as the raw materials of biofuel production. Among the following Karanja products stated at Table 4, the potentiality of pond cover, seed cake and fuelwood are higher than the other products. On the other hand, glycerin is produced in small amounts from Karanja seed and biofuel production capacity is lower.
4. Biofuel from Biomass Resources Definitely, biomass is a prospective source of energy in Bangladesh. At present, Bangladesh is the seventh greatest congested state in earth and biomass offers 73% of the entire energy [35]. In Bangladesh, most of the biomass resources are obtained from rural areas like wood, cow dung, and different types of agricultural waste products which are generally used in cooking purposes in countryside areas. Nowadays, different countries all over the world are trying to use biomass resources for producing renewable energy like biodiesel. If the entire biomass resources can be properly utilized, 50 exajoule renewable energy may be produced per annum. The production of energy from biomass suggests a numeral benefit not only the price of biomass remainders is low but also the energy translation effectiveness is extraordinarily compared with other fossil fuel-based production methods [37]. Generally, energy is harnessed from biomass resources as biofuel.
4. Biofuel from Biomass Resources Definitely, biomass is a prospective source of energy in Bangladesh. At present, Bangladesh is the seventh greatest congested state in earth and biomass offers 73% of the entire energy [35]. In Bangladesh, most of the biomass resources are obtained from rural areas like wood, cow dung, and different types of agricultural waste products which are generally used in cooking purposes in countryside areas. Nowadays, different countries all over the world are trying to use biomass resources for producing renewable energy like biodiesel. If the entire biomass resources can be properly utilized, 50 exajoule renewable energy may be produced per annum [36]. The production of energy from biomass suggests a numeral benefit not only the price of biomass remainders is low but also the energy translation effectiveness is extraordinarily compared with other fossil fuel-based production methods. Generally, energy is harnessed from biomass resources as biofuel.
5. Physical and Chemical Properties of Biodiesel Physical as well as chemical characteristics of the produced biodiesel containing kinematic viscosity, cetane number, cloud point, flash point, heating value, and pour point are offered in Table 5. Engine effectiveness, as well as emision, considerably depend on the dissimilar biodiesel characteristics, biochemical and fatty acid configuration. The assessment of these characteristics with conventional diesel exhibited that FFA content, kinematic viscosity, and density values of the biodiesel is comparatively greater than conventional diesel. The flashpoint of biodiesel remained 1780C, which is an extraordinary value that has the advantage of greater security than conventional diesel for transportation prospects. In addition to that, the biodiesel’s cloud point and pour point, remained significantly greater than conventional diesel. Therefore, biodiesel is less appropriate to be utilized in winter. The heating value of biodiesel was found to be 36.25 MJ/kg which is lesser than the diesel standard because of the presence of oxygen in biodiesel. The cetane number of biodiesel is 53.7 which is not only greater than conventional diesel fuels but also indicates a small ignition delay.
6. Biofuel Emission Characteristics Nabi and Nazmul Hoque, analyzed the production of biodiesel from linseed oil and the corresponding engine performance. They found that the engine thermal efficiency was similar to the conventional diesel fuel but with 1% to 2% lower performance due to higher viscosity, low volatility, and high density of the biodiesel. Roy examined the prospects of biodiesel in DI diesel engines and found that the exhaust emission was lower in the case of B100. It (B100) also reduced the emission of CO and particulate materials, but B20 increased the NOx emission slightly. Roy revealed that for B20, the brake thermal efficiency was almost similar or slightly lesser in no-load or low-load situations and without the Exhaust Gas Recirculation (EGR) system CO emission was higher whereas NOx emission was lower. They recommended that B20 with 10% EGR, results in better performance for a diesel engine and reduces NOX greatly.