Effects of Biodiesel Saturation Degrees on NOx Emission and FTIR Spectroscopy

The Fourier Transform Infrared (FTIR) spectroscopic characteristics of biodiesel produced from vegetable oils with different saturation degree was investigated in this study. Unsaturation degree, usually determined by the Iodine Value (IV) indicates the sum of double bonds, triple bonds and/or rings. In this work, biodiesels were produced by canola oil, palm oil and coconut oil that have saturation degree of 7.0 wt%. 45.6 wt% and 81.5 wt%, respectively. Biodiesel blends of B10, B15 and B20 were tested in a direct injection diesel engine and the NOx emissions were measured with a flue gas analyser. The NOx emission was increased in all biodiesel cases, where the NOx emission seems to be proportional with the biodiesel unsaturation degree. The FTIR spectroscopy of each biodiesel was analysed with FTIR spectrometer. Each biodiesel produced different FTIR spectroscopy characteristics and the double bond of C=O was the most abundant in highly unsaturated canola oil methyl ester which suggested that FTIR spectroscopy can be suitable to analyse biodiesel characteristics

Effects of Biodiesel Saturation Degrees on NOx Emission and FTIR Spectroscopy

The Fourier Transform Infrared (FTIR) spectroscopic characteristics of biodiesel produced from vegetable oils with different saturation degree was investigated in this study. Unsaturation degree, usually determined by the Iodine Value (IV) indicates the sum of double bonds, triple bonds and/or rings. In this work, biodiesels were produced by canola oil, palm oil and coconut oil that have saturation degree of 7.0 wt%. 45.6 wt% and 81.5 wt%, respectively. Biodiesel blends of B10, B15 and B20 were tested in a direct injection diesel engine and the NOx emissions were measured with a flue gas analyser. The NOx emission was increased in all biodiesel cases, where the NOx emission seems to be proportional with the biodiesel unsaturation degree. The FTIR spectroscopy of each biodiesel was analysed with FTIR spectrometer. Each biodiesel produced different FTIR spectroscopy characteristics and the double bond of C=O was the most abundant in highly unsaturated canola oil methyl ester which suggested that FTIR spectroscopy can be suitable to analyse biodiesel characteristics

Biodiesel unsaturation degree effects on diesel engine NOx emissions and cotton wick flame temperature

As compared with conventional diesel fuel, biodiesel has better lubricity and lower particulate matter (PM) emissions however nitrogen oxides (NOx) emissions generally increase in biodiesel-fuelled diesel engine. Strict regulation on NOx emissions is being implemented in current Euro 6 standard and it is expected to be tighter in next standard, thus increase of NOx cannot be accepted. In this study, biodiesel unsaturation degree effects on NOx emissions are investigated. Canola, palm and coconut oils are selected as the feedstock based on their unsaturation degree. Biodiesel blends of B20 were used to fuel a single cylinder diesel engine and exhaust emissions were sampled directly at exhaust tailpipe with a flue gas analyser. Biodiesel flame temperature was measured from a cotton wick burned in simple atmospheric conditions using a thermocouple. Fourier transform infrared (FTIR) spectrometer was also used to identify the functional groups presence in the biodiesel blends. Oxygen content in biodiesel may promote complete combustion as the NOx emissions and flame temperatures were increased while the carbon monoxide (CO) emissions were decreased for all biodiesel blends. It is interesting to note that the NOx emissions and flame temperatures were directly proportional with biodiesel unsaturation degree. It might be suggested that apart from excess oxygen and free radical formation, higher NOx emissions can also be caused by the elevated flame temperatures due to the presence of double bonds in unsaturated biodiesel

Biodiesel unsaturation degree effects on diesel engine NOx emissions and cotton wick flame temperature

As compared with conventional diesel fuel, biodiesel has better lubricity and lower particulate matter (PM) emissions however nitrogen oxides (NOx) emissions generally increase in biodiesel-fuelled diesel engine. Strict regulation on NOx emissions is being implemented in current Euro 6 standard and it is expected to be tighter in next standard, thus increase of NOx cannot be accepted. In this study, biodiesel unsaturation degree effects on NOx emissions are investigated. Canola, palm and coconut oils are selected as the feedstock based on their unsaturation degree. Biodiesel blends of B20 were used to fuel a single cylinder diesel engine and exhaust emissions were sampled directly at exhaust tailpipe with a flue gas analyser. Biodiesel flame temperature was measured from a cotton wick burned in simple atmospheric conditions using a thermocouple. Fourier transform infrared (FTIR) spectrometer was also used to identify the functional groups presence in the biodiesel blends. Oxygen content in biodiesel may promote complete combustion as the NOx emissions and flame temperatures were increased while the carbon monoxide (CO) emissions were decreased for all biodiesel blends. It is interesting to note that the NOx emissions and flame temperatures were directly proportional with biodiesel unsaturation degree. It might be suggested that apart from excess oxygen and free radical formation, higher NOx emissions can also be caused by the elevated flame temperatures due to the presence of double bonds in unsaturated biodiesel

Musculoskeletal analysis of driving fatigue: The influence of seat adjustments

Main causes for discomfort experienced by vehicle drivers during driving were investigated using a rigid-body model originally developed in the AnyBody Modeling System [. The interactions between the human body and the car-seat in various combinations of seat-pan/backrest inclinations and the effect of pedal spring stiffness were analyzed using an inverse dynamics approach. To deal with the muscle redundancy problem, (i.e. the problem with the human-body containing more muscles than necessary to drive its degrees of freedom) a minimum-fatigue criterion [ was utilized. The results show that various seat adjustments (e.g., seat-pan and backrest inclinations) and the pedal spring stiffness have complex influences on the muscle activation and spinal joint forces of the human body. From the results, an optimal adjustment for the car-seat is proposed, i.e. the backrest inclination is 10° and the seat-pan inclination is between 0o to 5 o. This study can in general capture the overall interactions between human body and environment (i.e. the maximum muscle activity and spine forces), which is thought to be the factors of driving fatigue.</jats:p

Detailed Examination on the Enhancement of Heat Release Rate in Inversed-delta-injected Diesel Spray Flame

Diesel engine will remain relevant even in the net-zero carbon society due to its high torque and high thermal efficiency characteristics. Inversed-delta injection rate shaping Diesel spray has been proven to increase Diesel engine thermal efficiency further. Although enhancement of heat release due to large scale vortices growth and development in the unstable inversed-delta-injected Diesel spray flame was observed, its impact on combustion duration reduction is much lesser than anticipated. In this study, apparent heat release rate derived from pressure history will be compared with the simultaneous high-speed images of OH* chemiluminescence and laser Schlieren; all the data were previously acquired in a constant volume combustion chamber CVCC experiment using a TAIZAC (TAndem Injector Zapping ACtivation) injector. MATLAB-based codes were employed for the flow velocity field turbulence intensity and the fuelair mixture spatiotemporal distributions analysis using Flame Imaging Velocimetry (FIV) analysis and Musculus-Kattke 1D model, respectively. Inversed-delta injection rate shaping exhibits enhancement of heat release throughout the diffusion combustion phase compared to that of conventional rectangle injection. Large scale vortices effect seems to be dominant factor in enhancing the heat release and OH* intensity in the inversed-delta injection rate shaping at the earlier stage of diffusion combustion phase. At the later stage, effects of high turbulence intensity coincide with fuel-air mixture availability at the spray tail marks by a larger OH* reacting area seems to be more pronounced in enhancing heat release rate for the inversed-delta injection. Regardless of the detected vortex and fuel-air mixture at the spray tail during the late combustion phase, no apparent OH* signal is observed in both injection cases suggesting that the mixture might be overly lean.</p