Volume 04 Issue 02

Abstract: Biomass is a renewable energy source. Energy can be extracted from biomass through gasification, a thermo-chemicalconversion process. The quantity and quality of the producer gas depend on the operating parameters like temperature, equivalence ratio and steam to biomass ratio. Enhancement of the quantity of hydrogen in producer gas is considered in the present context. A thermodynamic equilibrium model based on Gibbs free energy is developed to represent biomass gasification mathematically. This model is used to study the effect of the operating parameters on various gas yields, especially hydrogen. Air-steam gasification of coconut shell has been illustrated. Further a statistical software package, Design Expert is used to study the effect of parameter interaction on hydrogen yield based on the predictions made by the model. The study reveals that the hydrogen yield increases with increase in temperature and SBR. However, hydrogen yield decreases with increase in ER. A regression equation has also been obtained for hydrogen yield based on the operating parameters.

Abstract: This paper presents the exergy assessment of a simple direct expansion solar assisted heat pump (DX-SAHP) systemunder hot and humid environment conditions. Experiments are performed at Solar Energy Center in National Institute of Technology Calicut, India, located in the southern peninsula of the Indian continent. Experimental set up mainly incudes the hermetically sealed compressor, and an air cooled condenser, a solar collector/evaporator and a thermostatic expansion valve with R22 as the working fluid. The exergy relations for each component of the system and for total system are derived for performance assessment purposes. The results showed that the maximum average exergy destruction observed in the condenser and followed by the solar collector/evaporator, compressor and expansion valve of the system. The obtained result helps for the designer for the optimization of the system components and for the total system.

Abstract: The increased biomass production of microalgae is important for the economic production of biofuel. An efficient and economic production biomass requires the optimum values of cultivation parameters such pH value and concentration of KNO3. In this work, central composite design (CCD) was employed to study the effect of pH and KNO3 for the biomass production of Chlorella pyrenoidosa using Bold Basal Media (BBM). In the first phase, the biomass concentration (g/l) and optical density of C.pyrenoidosa was measured for 16 days and formulated a correlation to find biomass concentration from optical density values. Based on our previous experiments, the biomass concentration of C.pyrenoidosa was affected by parameters such as concentration of KNO3 and pH of the BBM used. In the second phase, these parameters are then optimized using response surface methodology with CCD, in which experiments are performed using 13 combinations of these parameters using Minitab-17 software. The optimum values of concentration of KNO3 and pH were found 0.18 g/l and 8, respectively with an experimental biomass concentration of 1.72 g/l against a predicted value of 1.819 g/l.

Abstract: Biodiesel production from rubber seed oil containing high free fatty acid (FFA 52%) using Candida Antarctica Lipase B (CAL B) as biocatalyst was investigated in the present work. Immobilized CAL B was used as the catalyst. The effect of reaction parameters such as catalyst concentration, type of acyl acceptor, oil to acyl acceptor molar ratio were investigated against biodiesel conversion percentage. The reusability of the catalyst was also studied. Among the two acyl acceptors under study, methanol gave better results in comparison with ethyl acetate. The maximum biodiesel conversion was obtained as 81.23% at an oil to methanol molar ratio of 1:4 and enzyme concentration 10 (w/w) % of oil in a solvent free system. Reused CAL B has also shown good conversion efficiency.

Abstract: Despite having a better performance, mineral oil based lubricants causes serious issues on environment and tamper the harmony of our ecosystem. Moving in a path that can add more to life than burning harmful oils brought the finest environmentalists and tribologists to go in search of promising alternative oils. Vegetable oils are found to be biodegradable and possess good tribological properties but have low thermal-oxidative stability and very poor low temperature fluidity. Therefore selection of vegetable oil as base oil for lubricant is crucial. This paper focus on the tribological study of palm oil methyl ester (POME) extracted from palm oil by the process of alkali esterification. By optimizing the percentage of catalyst (1% KOH) and alcohol (25% methanol), maximum yield of methyl ester was achieved during esterification process. The friction and wear test conducted over crude palm oil and POME shows the domination of crude oil by 52.3% and 12.3% respectively. Removal of glycerol molecules have resulted in drastic fall in viscosity but have improved the flow properties from 23.6ºC to 9ºC thereby extending its application to lower temperatures.

Abstract: Increased numbers of vehicles on road have brought about a severe problem of environment pollution and scarcity of the petroleum fuels in the recent past. Biodiesel is an attractive alternative fuel because of its environmental friendliness, ease in production and replacement potential of petroleum diesel. Biodiesel produced from a wide variety of vegetable oils is expected to supplement diesel fuel. In this work an attempt is made to produce biodiesel from a new feed stock, Avocado fruit and test its feasibility to be used as Diesel engine fuel. The main drawback of biodiesel as an engine fuel is the increased NOx emission and reduced engine performance compared to diesel fuel. Studies shown that addition of nanoparticles on fuel can reduce the NOx emission along with increased engine performance. In this work doped metal oxide nanoadditives (Al2O3 doped with MnO2) were used. SEM imaging was conducted for characterization of the nanopowder. Engine test fuels were prepared by adding nanoparticles to biodiesel blend (B20) at three different concentrations (30, 60 and 90 ppm). The results of engine tests by the addition of nanoparticles showed a noticeable reduction in exhaust emissions and improvement in engine performance.

Abstract: The present work deals with the performance of a single basin single slope solar still using Al2O3 nanofluids. Initially, The experiments are carried out in the single basin single slope solar still with different quantity of water (15kg, 20kg, 25kg) in the basin to find the optimum. Then the experimental works have been conducted using different concentration (0.1%, 0.2% and 0.3%) of Al2O3 nanofluids on volume basis with optimum quantity of water in the basin. It is observed that while using 0.3% concentration of Al2O3 nanofluids produces the maximum distilled water of 3.150 kg/m2 per day. The present work concluded that the use of Al2O3 nanofluids considerably enhance the heat transfer rate and evaporation rate in the single basin single slope solar still, hence the yield is improved.