جستجوی مقالات مرتبط با کلیدواژه « Bioethanol » در نشریات گروه « مکانیک »

The general goal of this research is to find the right fuel composition containing bioethanol, gasoline, acetone and n-butanol in order to increase engine performance and reduce engine pollutants and energy production costs. In this research, in order to use sample fuels, a single cylinder engine was coupled with a 5kWh generator. A TDGC2-5kVA type variable resistor and a 1kW heater were used to load the motor. By measuring the power of the motor, the amperage and voltage of the electricity were measured. It should be noted that the engine test was performed at full load (100% load) and a fixed speed of 1500 rpm as the rated speed of the engine. Based on the obtained results, adding n-butanol from 2 to 5% caused a relative decrease and from 5 to 7% caused a relative increase in braking power. The lowest amount of braking power was obtained in the range of combined additives of bioethanol and n-butanol without acetone. The highest amount of braking power was obtained in the highest percentage of n-butanol, acetone and bioethanol additives in the gasoline fuel sample. In this interval, the thermal efficiency was also higher than the control fuel sample and the special braking fuel consumption was also lower than the control fuel sample. The highest amount of nitrogen monoxide emission was relatively in the sample of fuels containing combined additives of bioethanol and n-butanol. The lowest amount of nitrogen monoxide emission occurred in the fuel sample containing the combination of bioethanol and acetone. By adding n-butanol to fuel samples, the emission of nitrogen oxides increased. The results also showed that the effects of these additives can be highly dependent on engine design, operating conditions, and the specific blend ratios used. This research paves the way for several future research directions in the field of alternative fuel additives and spark ignition engines.

The investigation of alternative fuels, such as biodiesel, have been prompted by the detrimental emissions resulting from the combustion of fossil fuels. Undoubtedly, the primary concern in fuel selection lies in the examination of emissions. Hence, the present study aims to examine the performance and environmental life cycle assessment methodologies of a dual fuel diesel engine. Furthermore, a fuel blend is made by combining biodiesel sourced from sunflower oil with varying concentrations of bioethanol (3%, 5%, and 7%) and pure biogas, with a percentage ranging from 50% to 80%. This fuel blend is intended for use in the combustion process. In this study, a total of eight fuel samples were meticulously produced and subsequently examined, alongside diesel fuel which served as the control fuel. The entire life cycle evaluation encompasses several stages, starting with the manufacturing of inputs to the combustion of fuel samples. This includes the extraction of oil from sunflower seeds, the production of biodiesel and bioethanol, as well as the generation of natural gas produced from pure biogas. These processes are regarded as captivating and pioneering topics within the field. The provided samples underwent combustion within a dual fuel engine. The findings indicate that the B5 fuel sample, when combined with a 3% bioethanol additive, demonstrates superior engine performance and reduced exhaust emissions. Furthermore, enhanced conditions were achieved in terms of engine performance and exhaust emissions when operating at the lowest rate of natural gas fractionation, which was 50%. The findings of a thorough life cycle evaluation, which examines the entire process from farm to combustion, indicate that the blend B5E7, consisting of 50% natural gas portion at maximum engine load, demonstrates both environmental friendliness and appropriate performance characteristics.

Nowadays, the production of alternative fuels to fossil fuels is one of the most noticeable issues in dealing with environmental pollution. With the same approach, biodiesel is using to replace fossil diesel fuel. In general, this article examines four generations of biofuel production from different sources and economic comparisons of their production. In this review study of the previous reports, firstly, according to the approach of localizing alternative fuels, we discuss the introduction of microalgae's types, their reproduction process and environmental applications, production of biogas, bioethanol, and biodiesel. Afterward, in particular, the optimal method of producing biodiesel from microalgae is investigated, and eventually, a comparison has been made between biodiesel produced from microalgae and fossil diesel fuel and the ASTM standard of biodiesel. The results of numerous studies have demonstrated that due to the rapid growth of microalgae, high efficiency, and the low cost of their cultivation and production, it is possible to produce about 5000 to 15000 gallons of biodiesel from each hectare of microalgae cultivation; which makes the production of biodiesel from algae allocate a significant position compared to other sources of biodiesel production.

Concerns about increasing environmental pollution and increasing greenhouse gas emissions from fossil fuels have led researchers to use renewable energy. In this research, the environmental impacts of bioethanol production from potato waste were investigated from the agricultural stage to the production stage of bioethanol (crushing and malt production, enzymatic hydrolysis, fermentation and dehydration). Investigation of environmental impact of the data collection was done using a life cycle assessment method in the form of 15 impact groups and 4 final indicators, and its functional unit was considered to produce 1 kg of bioethanol. The results obtained from the impact groups in two stages of agriculture and bioethanol production showed that the agricultural stage in all the affected groups except the carcinogenicity group had higher values than the stages of bioethanol production (malt production, hydrolysis, fermentation and dewatering). Also the results showed that the highest contribution to creating different impact groups is related to energy consumption of electricity, steel, agricultural machinery, nitrogen, phosphate and direct emission of pollutants from the field and manufactory. The comparison between different environmental endpoints indicator shows that the human health index is 9.90 times higher than ecosystem quality, 1.28 times higher than climate change and 1.48 times higher than that of resources with destructive effects on bioethanol fuel production.

In the current paper, the optimum conditions for bioethanol production from sugars were surveyed. Then the operational condition effect on some physical characteristics of bioethanol fuel was investigated. 27 types of bioethanol samples from sugarcane molasses, sugar beet molasses and sugar cane juice were produced at anaerobic fermentation condition in three different temperature levels of 25 ˚C, 30˚c and 35 ˚C and in three different time levels of 24h, 48 h and 72 h. Then the values of density, kinematic viscosity and flash point were calculated in triplets. The results showed that with increasing the temperature and time processing, the viscosity, density and flashpoint would be decreased. The sugar type had a significant effect on these parameters. The closest value of viscosity to its standard amount was related to sugarcane molasses, producing at 25 ˚C and after 72 h fermentation, which was 1.5174 cSt. The nearest amount of density to its standard value was reported 0.9560 which was attributed to sugarcane juice producing at 35˚C and after 72 hours and for flashpoint it was 24.5 ˚C which belonged to sugarcane juice at 30 ˚C and 72 hours. The most bioethanol concentration was 74 gr.L-1 which was produced from sugarcane juice at 35 c◦ and after 72h.

In this paper, the effect of bioethanol- gasoline fuel blends on exhaust emissions of a four-cylinder spark ignition (SI) engine was investigated experimentally. Pure gasoline fuel was blended with various percentages of bioethanol (0, 20, 40, 60 and 85%), and the HC, CO, CO2 and NOX exhaust emissions were measured at different engine speeds and two throttle valve positions (full throttle and 50% throttle valve).The experimental results showed that as the ratio of bioethanol fuel is increased in the blend, the CO and HC emissions are decreased but CO2 and NOX are increased at two throttle valve positions. Also when the speed of engine was increased, the HC and CO2 emissions were decreased but CO and NOX emissions were increased. The statistical analysis indicated that the effect of bioethanol percentage in fuel blends on emissions at 5% level was significant.

In this paper، a model is described to predict performance parameters and emissions of a spark ignition (SI) engine using genetic programming (GP). To acquire data for training and testing of proposed GP، a four-cylinder engine was fueled with ethanol-gasoline fuel blends. The pure gasoline fuel was blended with various percentages of bioethanol (0، 5، 10، 15 and 20%)، and the engine brake power، the torque and exhaust emissions (CO، HC، CO2 and NOX) were measured at different engine speeds and loads. Experimental results showed that as the ratio of the ethanol fuel was increased in the blend، CO and HC emissions were decreased but the brake power، the torque، CO2 and NOX were increased. Numerous runs were performed with the GP model and the performance of developed equations was evaluated. Optimum models were selected according to statistical criteria of the root mean square error (RMSE) and the coefficient of determination (R2). Simulation results demonstrated that the GP model was a powerful tool to predict engine pollutant emissions.