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Ethanol and palm oil biodiesel blended with diesel fuel have the potential to reduce greenhouse gas emissions, such as carbon dioxide (CO2), and can gradually decrease dependence on fossil fuels. However, the combustion products from these fuels, such as oxides of nitrogen (NOx), total hydrocarbons (THC) and particulate matter (PM), require to be examined and any beneficial or detrimental effect to the environment needs to be assessed. This study investigates the hydrocarbon selective catalyst reduction (HC-SCR) activities by the effect of combustion using renewable fuels (biodiesel-ethanol-diesel) blends and the effect of hydrogen addition to the catalyst, with the various diesel engine operating conditions. Lower values rate of heat released were recorded as the ethanol fraction increases, resulting in trade-off where, lower NOx was produced while greater concentration of carbon monoxide (CO) and THC was measured in the exhaust. Consequently, increasing the THC/NOx promoting the NOx reduction activity (up to 43%). Additionally, the HC-SCR performance was greatly heightened when hydrogen was added into the catalyst and able to improve the NOx reduction activity up to 73%. The experiment demonstrated plausible alternatives to improve the HC-SCR performance through the aids from fuel blends and hydrogen addition.

Diesel particulate matter (DPM) and oxides of nitrogen (NOx) are the emissions from diesel engines (compression ignition engines) of the most concern and are currently strictly regulated. In this work, we present an alternative diesel emission control technique to assist in further emission reduction. An experiment-oriented study on diesel engine emission abatement using low-power, low-frequency, high-voltage discharge (HVD) treatment was carried out in a laboratory-scale reactor with whole diesel engine exhaust gas. A dielectric barrier discharge (DBD) reactor was used in direct contact with diesel exhaust gas at atmospheric temperature with an input energy density between 200 and 400 J/L. An investigation of the direct effect of the high-voltage discharge reactor on the diesel exhaust gas treatment was carried out to characterize both diesel particle and gaseous emissions. The proposed HVD system demonstrated up to 95% particulate matter reduction by mass or 64% reduction by number, and 63% reduction of the diesel soot particle geometrical mean diameter by HVD-generated O3 oxidation. Thermogravimetric analysis revealed the significant change in the diesel soot compositions and oxidation characteristics. HVD-treated particulate matter demonstrated a lower reactivity in comparison to untreated soot. Gas composition analysis indicated the generation of free radicals (e, O, OH, O3, and N) by the HVD system, as mainly indicated by the increase of the NO2/NO ratio and concentration of CO and O2. The pattern of CO2 reduction while CO and O2 increased indicated the dissociation of CO2 by HVD. Free radicals generated by HVD directly affected DeNO, DeNOx, NO2/NO ratio, and CO and CO2 selectivities.

With the aim of designing an onboard hydrogen production system for automotive applications, this work numerically obtained in-depth knowledge of the catalytic partial oxidation of ethanol (ECPOX)....

To produce hydrogen for automotive exhaust gas aftertreatment systems, the catalytic partial oxidation of ethanol over a platinum–rhodium catalyst supported on alumina is examined via experimental ...

To enable passive regeneration of a diesel particulate filter (DPF), this work seeks to study the potential of silver and ceria for the catalytic oxidation of diesel particulate matter (PM). Different contents of silver and ceria supported on alumina and silver loaded on ceria are synthesised by the incipient wetness impregnation method. The catalysts are characterised via XRD, SEM, and EDX. Catalytic PM oxidation performance for different PM/catalyst weight ratios and contact conditions is examined by using TGA. Removal of light soluble organic fraction (SOF) occurs between 110 and 350 °C through the vaporisation process. For the PM/catalyst weight ratio of 1/5, the silver compositions do not improve the depletion of light SOF but promote the combustion of both heavy SOF and soot, and the enhancement increases with silver content. For 16 wt% of silver supported on alumina, the PM/catalyst weight ratio of 1/20, and tight contact, oxidative activity is improved throughout the temperature window for light and heavy SOF and soot. The silver catalyst shows good stability for five runs. Active oxygen adspecies generated by ceria are different from those produced by silver. Enhanced performance for light SOF oxidation at a relatively low temperature is obtained using pure ceria. With the addition of alumina into ceria, light SOF removal ability of ceria is negatively affected. The positive effect on heavy SOF and soot reduction gained from the presence of silver is suppressed when ceria is mixed with silver.

The full potential of hydrogen for internal combustion engines is considered as an alternative fuel because hydrogen can be improved the engine performance and enhanced aftertreatment activities. This study is an investigation of the hydrogen production via partial oxidation reforming process (POx). This type of partial oxidation reforming process involves an on-board generation of hydrogen containing the gas by direct catalyst interaction of palm oil biodiesel (B7) fuel with the engine exhaust gas. The reformate (i.e. H2-rich gas) will be produced and introduced continuously into the engine as reformate exhaust gas recirculation (REGR) which it can be enhanced engine performance with low exhaust gas emission. The aim of this work is the design of a fuel reforming system with simulated the real exhaust gas in order to examine the effect of oxygen concentration, hydrocarbon concentration (B7) and space velocity (SV) (i.e. 13,000 and 16,000 h-1) on reforming catalyst. The result found that the reforming catalyst can produce up to 11% hydrogen production that significant benefit can be derived from the use of onboard hydrogen production in terms of engine performance, aftertreatment system performance and environmental emissions. In additions, the on-board hydrogen production targets optimization are required to enhance the engine performance and aftertreatment activities in reducing diesel exhaust gas emissions.

Syngas technology is one of a well-known alternative process way to produce valuable chemical products. This research discussed on biomass composition which related to syngas production yield via gasification process. Four type of biomass from wood are selected to be model for the experiment: Neem tree (Azadirachta indica), Cassia tree (Senna siamea), Eucalyptus tree (Eucalyptus melliodora), Mimosa tree (Leucena leucocepphala) were analyzed for proximate and ultimate analysis. The results show the most heating value detected in eucalyptus biomass (19,267.65 kJ/kg), Cassia and Neem wood (17,500 kJ/kg and 17,417 kJ/kg repectively). The high heating value of Eucalyptus wood exhibit higher than that in coal and rice straw (18,840 kJ/kg and 14,826 kJ/kg, in consequence). Nitrogen contains in all biomass show a rarely bit composition (Eucalyptus: 0.2 %, Cassia: 0.17% and Neem: 0.0%). In conclusion, three different kind of wood biomass have a potential to be applied for syngas production as a new biomass for linear heart gasifier in the experiment.

Dry reforming of CH 4 on a platinum-rhodium alumina catalyst is selected to numerically investigate biogas reforming process. Langmuir-Hinshelwood-Hougen-Watson (LHHW) rate expressions for dry reforming and reverse water-gas shift reactions are presented. Activation energies are estimated by combining microkinetics with the theory of unity bond index-quadratic exponential potential (UBI-QEP). Pre-exponential factors are initially obtained by using the transition state theory (TST) and optimised, later, by minimising errors between modelling and experimental data. Adsorption of CH 4 on the catalyst surface is found to be the rate determining step in the range of relatively low temperature (600–770 °C), while at relatively high temperature (770–950 °C) the thermal cracking of adsorbed CH 4 is the rate controlling step. Small effect of reverse water-gas shift reaction results in the ratio of H 2 to CO produced less than unity for all operating conditions. The simulation shows that the dry reforming process proceeds with reaction rate far from equilibrium state. The presented mechanism is capable of predicting the dependence of biogas dry reforming activities (e.g., reactant conversions, product formations, H 2 to CO ratio, and temperature profile inside the catalyst) on operating conditions (e.g., inlet temperature, heat supplied through the catalyst wall, and composition of biogas at inlet).

The aim of this experimental study is to investigate the combustion low-calorific producer gas within porous burner. The small scale downdraft biomass gasification for rural area was performed to produce gaseous fuel. Three types of wood in Thailand were used as raw materials to produce producer gas, i.e. Acacia-mangium, White popinac and Eucalyptus. The low heating values of producer gas were in the range of 3800-4232 kJ.kg-1 that are difficult to burn in conventional burner. Tapered and bilayer porous burners were used to overcome this limitation. The effects of air preheating modes, equivalence ratio and firing rate on thermal structure and pollutant emission were revealed. The results showed that the complete combustion with low emission of low-calorific producer gas was accomplished with low firing rate in the range of 2.8 – 3 kW. Both CO and NOx emission were less than 160 ppm for all of tests. The combustion within tapered porous burner emitted small CO emission nearly zero for all of equivalence ratios. The tar reduction was 99.5% by combustion within porous burner.

The demand of fossil fuel for transportation increases continuously while the fossil fuels resource is limit. Hence, the aim of experimental study is to investigate the effect of compress biogas as the alternative fuels on engine performance and emission in modified SI engine. The engine was modified and replaced fuel metering system to compress biogas system with standard ignition system configuration. The gas engine was operated under various engine speed (1500 - 3000 rpm) and different engine load at 25%, 50% and 75% of maximum load. The result shows that the gas engine fuelled with compressed biogas can enhance engine performance with low exhaust gas emission. Therefore, the utilization of compressed biogas is highly potential for automobile since it reduces the reliance on fossil fuels. In addition, compression biogas can support the growing demand of transportation fuels in the future.

The lean NO X catalyst in reducing Nitrogen Oxide (NO X ) emission is necessary for a modern compression ignition (CI) engine. However, the high operating temperature is the main problem for the catalyst. Thus, the aim of this research is to investigate the hydrocarbon selective catalytic reduction (HC-SCR) in order to reduce nitrogen oxide containing in exhaust gas of a CI engine. The research carries out by using diesel, biodiesel and ethanol at different blending ratio as the fuel. The engine speed is kept constant at 1,500 rpm and the engine loads are varied at 25, 50 and 75 % of maximum engine load. The result shows that when increase of ratio of ethanol affect the increase of HC:NO X . In diesel, biodiesel and ethanol fuel blends at a ratio of 30:20:50 shows the maximum nitrogen reduction with products from HC-SCR can reduced nitrogen oxide up to 22 %. Then increase the amount of hydrogen (approximate 3,000 and 6,000 ppm) in exhaust gas to promote the HC-SCR reaction of nitrogen oxide reduction in low temperature. The effect of hydrogen addition can reduced nitrogen oxide up to 55.26 %.