Obed M. Ali

Review of the effects of additives on biodiesel properties, performance, and emission features

As a renewable, sustainable and alternative fuel for compression ignition engines, biodiesel is widely accepted as comparable fuel to diesel in compression ignition engines. This is due to several factors like decreasing the dependence on imported petroleum; providing a market for the excess production of vegetable oils and animal fats; using renewable and biodegradable fuels; reducing global warming due to its closed carbon cycle by CO2 recycling; increasing lubricity; and reducing substantially the exhaust emissions of carbon monoxide, unburned hydrocarbons, and particulate emissions from diesel engines. However, there is a major drawback in the use of biodiesel as low heating value and NOX tends to be higher. On the other hand, its relatively poor low-temperature flow properties are a characteristic of biodiesel which limits its application. Here, fuel additives become indispensable tools not only to decrease these drawbacks but also to produce specified products that meet the international and regional standards. This article is a literature review of the effect of different additives on biodiesel properties, performance, and emission characteristics. The researches published by different journals are cited preferentially. From these researches, the effect of biodiesel additives on fuel cold flow properties, engine power, fuel economy and emissions including regulated and non-regulated emissions, and the corresponding effect factors were surveyed and analyzed in detail. Varying results of improvement in cold flow properties have been obtained by using different additives. Similarly, different additives were used by different researchers to improve the performance of a compression ignition engine and its emissions. This review was taken up to identify the various additives used to improve the cold flow properties of biodiesels and improve the performance of a diesel engine and its emissions while using additive blended biodiesels. The review concludes that the additive usage in biodiesel is inseparable both for improving the cold flow properties and for better engine performance and emission control. Further research is needed to develop biodiesel specific additives.

Improving Engine Performance and Low Temperature Properties of Blended Palm Biodiesel Using Additives. A Review

After the oil crisis in 1973, renewable sources of energy are gianing more interest due to multiplicity feedstocks and lower pollution compared with fossil fuels. Wide agricultural lands through the world are not fully benefited. Therefore, farming should include the production of non-food products which are suitable to weather conditions of these lands. This leads to the production of biodiesels as renewable fuel for the domestic energy market, to reduce the dependence on fossil fuels. Biodiesel have gained a large interest of researches during the last few decades, the major reason to find an alternative fuel, is the increasing worry about the greenhouse gas effects and environmental regulations. Blended palm biodiesel with ordinary diesel fuel have been approved as a fuel for compression ignition engines without any modification. Palm biodiesel application is relatively limited to its poor cold flow properties characteristics. Many experimental studies are conducted to evaluate the influence of using different additives with Palm Oil Methyl Ester (POME) biodiesel/diesel blends on fuel properties (viscosity, cold properties, anticorrosiveness, cetane number, heat content, volatility) and engine performance. This article provides a literature survey on the effect of different additives to improve the fuel properties of palm biodiesel and engine performance. The review shows that the additive usage in palm biodiesel is accompanying for improving the cold flow properties and better engine performance as well emission regulation.

Characterization of Blended Biodiesel Fuel Properties with Small Portion of Butanol as a Fuel Additive

The increasing energy demand challenge, in addition to the crises of mineral oils depletion that becoming a very serious topic. As the main fuel used in energy production for all scopes of life now is the fossil fuels, there is an urgent need to find out an alternative fuel to fulfill the energy demand of the world. The feasibility of biodiesel production from palm oil was investigated with respect to its fuel properties and blending characteristics with petroleum diesel. Though biodiesel can replace diesel satisfactorily, problems related to fuel properties persist. In this study an oxygenated additive butanol (BU) was added to palm oil biodiesel (POME)-diesel blend B50 (50% POME + 50% diesel) in the ratios of 1%, 3%, 5% and 7% and tested for their properties improvement. The results showed slight improvement in acid value, significant viscosity and density. Maximum decrease in pour point by 6 °C at 5% butanol, on the other hand maximum decrease in energy contenent about 11% at 7% butanol compare to blended fuel B50.

Influence of Oxygenated Additive on Blended Biodiesel-Diesel Fuel Properties

Diesel fuel is widely used in almost all scopes of life, especially in the transportation sector which accounts for 36% of total energy consumed in 2008 in Malaysia. The transportation sector represents the higher energy consuming sector after industrial sector. As the main fuel used in diesel engine now is the fossil fuels which depleting continually accompanied by increasing consumption and prices day by day. Blended biodiesel fuel is considered as alternatives to current fossilized fuels at a low blending level less than 30% biodiesel. The fuel physical characteristics are among the most important parameter to determine the quality of each fuel. Though biodiesel can replace diesel satisfactorily, problems related to fuel properties persist at high blending ratio. In this study an oxygenated additive diethyl ether (DEE) was added to palm oil biodiesel (POME)-diesel blend B40 (40% vol. POME + 60% vol. diesel) in the ratios of 2%, 4%, 6% and 8% and tested for their properties improvement. These blends were tested for energy content and various fuel properties according to ASTM standards. Qualifying of the effect of additive on palm biodiesel-diesel blended fuel properties can serve the researchers who work on biodiesel fuels to indicate the fuel suitability for diesel engines according to fuel standards. The results showed an improvement in acid value, viscosity and density. The minimum pour point for the blended fuel was-2 °C for B40DE6 compare to 1°C for blended fuel B40, while maximum decrease in energy content for B40DE8 was about 7.36% compare to blended fuel B40.

Influence of 1-Butanol Additives on Palm Biodiesel Fuel Characteristics and Low Temperature Flow Properties

Diesel engines are widely used in almost all professions and cannot be dispensed with in the near future. Now the fossil fuels which are mainly used in diesel engines are depleting continually accompanied by increasing consumption and prices, there is the need to find alternative fuel to fulfil the worlds energy demand. Alternative fuels like biodiesel, are being used as effective alternative for diesel. The feasibility of biodiesel production from palm oil was investigated with respect to its fuel properties. Though biodiesel can replace diesel satisfactorily, problems related to fuel properties persist. In this study an oxygenated additive 1-butanol (BU) was blended with palm oil biodiesel (POME) in the ratios of 1%, 3%, 5% and 7% and tested for their properties improvement. These blends were tested for energy content and various fuel properties according to ASTM standards. Qualifying of the effect of additive on palm biodiesel fuel properties can serve the researchers who work on biodiesel fuels to indicate the fuel suitability for diesel engines according to fuel standards. Blends of BU in POME resulted in an improvement in acid value, viscosity, density and pour point with increasing content of BU in the blend. Further improvement in the pour point temperature of the palm oil methyl esters 1-butanol blends (B-BU) at 7°C can be achieved by adding 7% BU additive to POME, accompanied by 8.07% decrease in energy content of biodiesel.

Experimental Study of Performance and Emissions of Fusel Oil-Diesel Blend in a Single Cylinder Diesel Engine

In order to reduce the dependency on fossil oil energy resources, the using of several energy resources in compression-ignition engine has been the target of attention of researchers. The major renewable alternative combustible species are methanol, biogas, ethanol, biodiesel, and hydrogen. Fusel oil is a by-product of bioethanol production during the fermentation process present one of the new alternative fuels for compression-ignition engine. The aim of this work is to experimentally investigate the effect of fusel oil–diesel blending on performance and emission in single cylinder compression ignition engines. The test achieved under 25 % engine load at five-engine speed 1200 to 2400 rpm with intervals of 300 rpm. The experimental results revealed that the engine indicted power and torque slightly decrease for F20 compared with pure diesel, and the increment was happened in fuel consumption. Although diesel fuel yields, the highest volumetric efficiency and exhaust temperature. Moreover, the results showed CO2 and CO were increased while the NOx emissions decrease with the use F20. All the negative effects that happened in power and torque was because of the water content, low heating value, low cetane number for fusel oil.

Characteristic of blended fuel properties and engine cycle-to-cycle variations with butanol additive

Biodiesel fuel characteristics are one of the most important parameters that limited their application in diesel engines. Though biodiesel-diesel blended fuel can replace diesel satisfactorily at low blending ratios up to 20%, problems related to fuel property persist at high blending ratio. Hence, in the present study, the feasibility of biodiesel-diesel blended fuel B30 was investigated with respect to its properties and engine cyclic variations with increasing butanol additive. The blended fuel with additive were tested experimentally in a diesel engine and the in-cylinder pressure data were collected and analyzed using the coefficient of variation and wavelet power spectrum to evaluate the engine cyclic variations compared to diesel fuel engine test results. The fuel property test results showed slight improvement in density and acid value with significant reduction in viscosity when increasing butanol additive. Furthermore, the blended fuel pour point was reduced to −6 °C at 8% butanol additive. On the other hand, the energy content slightly affected with increasing butanol additive in the blend. From the wavelet power spectrum, it is observed that the short-period oscillations appear intermittently in pure blended fuel, while the long and intermediate-term periodicities tends to appear with increasing additive ratio. Moreover, the spectral power increased with an increase in the additive ratio indicating that the additive has a noticeable effect on increasing the cycle to cycle variation. The coefficient of variation of indicated mean effective pressure for B30 were found to be the lowest and increases with increasing additive ratios. Both the wavelet analysis and coefficient of variation results reveals that blended fuel B30 has engine cyclic variations comparable to diesel fuel with increasing butanol additive up to 4%.