Synergistic effects of alcohol-based renewable fuels: fuel properties and emissions

Biodiesel is known to improve the fuel properties of alcohol-diesel blends. However biodiesel is obtained from different feedstock and consequently the composition can be different, with varying fatty acid profiles resulting in different physical and chemical properties and a different response when blended with alcohol-diesel blends. To understand the effect of molecular structure of biodiesel on fuel properties and emissions, the most representative individual fatty acid methyl esters were added to alcohol-diesel blends. The results show that 15% of all methyl esters was enough to avoid phase separation of alcohol-diesel blends and keep the wear scar diameter of the blends below the limitation required by lubricity standards. Short carbon chain length and saturated methyl ester are recommended to improve emissions of alcohol-diesel blends. A comparison between two different alcohols used in the engine tests highlighted that butanol blends were more effective in reducing carbonaceous gas emissions and particulate matter emissions than ethanol blends. Further research on the effect of molecular structure of biodiesel on alcohol-diesel blends was conducted to understand influence of hydroxylated biodiesel which is derived from castor oil. The existence of hydroxyl group in biodiesel considerably improves the lubricity of alcohol-diesel blends. It was also shown to be beneficial in terms of engine-out emissions such as enhancing soot oxidation and reducing activation energy to oxidise soot emissions. To counteract the likely increase in gaseous carbonaceous emissions with alcohol blends, the addition of hydrogen to replace part of the carbon within the liquid fuel was studied. The incorporation of hydrogen and alcohol blends indicates that there was a dramatic reduction in carbon dioxide, unburnt hydrocarbons and particulate matter emissions

Effect of fatty acid composition of methyl and ethyl esters on the lubricity at different humidities

Lubricity of individual fatty acid methyl or ethyl esters and biodiesel fuels has been measured using a high frequency reciprocating rig (HFRR). Tests have been carried out varying the ambient humidity to assess the effect of this parameter on the lubricity of the fuels. The European standard proposes a single humidity correction factor for all the fuels, regardless their composition. It has been proved in this study that this factor is not constant and it depends on the fuel composition. For this reason two different correlations have bee n proposed for the estimation of the humidity correction factor and normalized wear scar as a function of different fuel compositional characteristics. The influence of the water content on the lubricity and the relationship between humidity and water content of the fuel has been studied revealing that the effect of the air humidity is an indirect effect of the hygroscopy of the fuel

Source Contribution of 1,3 Butadiene in the Vicinity of Petrochemical Industrial Area

Emissions and ambient concentrations of 1,3 butadiene released from the synthetic rubber industries in the largest petroleum and petrochemical complex in Thailand were evaluated in this study. The industrial emissions in this analysis were those emitted from process fugitive, combustion stack, flare, and wastewater treatment facility. It was found that wastewater treatment units were the largest emission source among other potential sources. The contribution of emission from wastewater treatment plants were about 92% of total 1,3 butadiene emission. The extent and magnitude of 1,3 butadiene in ambient air were further evaluated through the simulation of AERMOD dispersion model using these emission data together with local meteorological and topographical characteristics. Predicted annual 1,3 butadiene concentrations at every receptor were lower than its ambient air quality standard (< 0.33 μg m-3). Source apportionment analysis was performed with the objective to reveal the contribution of each emission source to the ambient concentrations at each receptor. Analytical results indicated that wastewater treatment units were the major emission source affected to the environmental concentrations of 1,3 butadiene in the study area. Evaluation of the potential adverse health impact of this chemical revealed that there may be a potential carcinogenic risk from inhalation exposure of 1,3 butadiene. Therefore, an effort in controlling emission of 1,3 butadiene should be given the priority to effectively manage the level of this compound in the environment

Performance of Adsorbent from Calcium Carbide Residue to Reduce Exhaust Emissions of Two-wheeler

The performance of calcium carbide residue in reducing two-wheel exhaust emissions has been studied. To perform this experiment, the carbide residue was first converted into adsorbent and then mounted in the exhaust gas line. Two-wheeler used are vehicles commonly used among Indonesian motorcyclists. The test was carried out by varying the adsorbent dimensions and engine transmission. Engine emission tests and adsorbent performance investigations were performed both before and after the exhaust emissions made contact with the adsorbent. The results showed that upon direct contact with the carbide adsorbent, the emission of two-wheeled engines decreased. Carbon-based emissions were reduced significantly in the early stages of the experiment. Moreover, emissions reduction benefits are seen in all adsorbent and transmission engine configurations. The greater the adsorbent's surface area, the better the emission reduction. A significant emissions reduction is also achieved when the first engine transmission condition is applied compared to the neutral transmission. However, the adsorption efficacy declined over time in all research variations. The presence of channels and pores in the adsorbent, and the high temperature attained by the adsorbent, keep improving the adsorbent's adsorption capabilities. However, as saturation increases, the adsorbent's adsorption, and oxidation capability decline