Direct use of vegetable oil and animal fat as alternative fuel in internal combustion engine

Abstract

Gradual depletion of world petroleum reserves and the impact of environmental pollution of increasing exhaust emissions lead to the search for a suitable alternative fuels for diesel engines. The substitution of conventional fuels (gasoline, diesel) by renewable biofuels is considered a potential way to reduce pollution and to support the sustainable development of a country. Direct use of vegetable oil and animal fat is a promising alternative to solve these problems. An exhaustive review of the experiments in this area, carried out by several researchers in last three decades, is presented here. Different problems associated with the direct use of vegetable oil and animal fat and potential solutions from both public and private sectors are discussed. Some engine manufacturers have started to launch full-warranty engines with vegetable oil as fuel. It is expected that the competitive engine market will witness more intense research, resulting in the launch of more vegetable-oil engines with full warranties. The steep rise in food prices in recent years is concerning policy-makers and has raised the old 'food vs fuel' debate. It has been concluded that vegetable oil can probably only substitute small to medium portions of petroleum-based fuel due to future severe land-usage competition from food sector. This calls for intense research initiatives into the production of suitable fuel from non-edible vegetable oil, grown in wasteland. In this regard, genetic engineering may prove to be extremely effective in developing 'designer fuel'.

Characteristics of vegetable oils for use as fuel in stationary diesel engines—Towards specifications for a standard in West Africa

“…These PUFA could polymerize into insoluble particles such as gums, sediments or other deposits under the action of light, high storage temperature, or oxygen [104,107]. However, oxidative stability is closely related to the iodine value [102], which is a global measurement of total SVO unsaturation (see section 5.1.2).…”

Impact of Fischer–Tropsch and biodiesel fuels on trade-offs between pollutant emissions and combustion noise in diesel engines

“…and on the hardware (piston ring sticking) [10,11]. Moreover, due to its higher surface tension and viscosity the cold startability of diesel engines with biodiesel is deteriorated [12]. Some of these effects affect negatively the vaporization process, so that incomplete combustion is induced during the engine start and also an increase of NO x emissions can be noticed [13].…”

Uncertainty Analysis of the Life-Cycle Greenhouse Gas Emissions and Energy Renewability of Biofuels

“…Typical conversion kits include a heat exchanger in which waste heat from the engine is supplied to the oil. This heat source can be supplemented by an electric booster (Mondal et al, 2008). An additional (small) fuel tank for fossil diesel and a three-way valve to switch between the main SVO tank and the small fossil diesel tank complete the package.…”