جستجوی مقالات مرتبط با کلیدواژه « بیواتانول » در نشریات گروه « فنی و مهندسی »

Every year various types of agricultural plants are cultivated for the purpose of human nutrition, industrial applications and also livestock feed in the world. Unfortunately, a huge amount of these plants is converted to waste mostly due to sub-standard harvesting and planting, incorrect pests and processing. In this investigation, the potential of waste generated from date in Khuzestan province as an agricultural hub of Iran has been discussed. Almost 10 to 15% of the produced date in the word is turned into waste, mostly depending on the cultivated area, which has a great potential for the production of biofuels. Based on the results obtained in this study, annual potential of Khuzestan Province is about 313 thousand tons of date leaves and 49 thousand tons date seeds, of which about 31 million liters of bioethanol can be produced from palm leaf waste and around about 5 thousand tons of biodiesel could be obtained. Results indicated that the province's production potential from date fruit waste was 0.26 million liters of biobutanol, 1.01 million liters of bioethanol, 1.71 million cubic meters of biogas and 0.71 million cubic meters of biohydrogen. The results for biofuel generated from date waste show promising alternatives fuel additives which could have a positive impact on the environment due to reduction in pollution mostly generated from using fissile based fuel in the province.

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.

Fossil fuels are the main sources of energy consumption, however, they raised concerns over their decreasing supply and heavy environmental impacts such as air pollution, greenhouse gases production, and global warming. Biofuels are renewable energy sources which produce much lower contamination and might be appropriate alternatives for fossil fuels. In this regard, micro-algal based fuels are important due to their high growth rate. They can be cultivated in arid areas, and utilize saltwater in small amounts. In addition, microalgae have higher carbon dioxide fixation rates in contrast to the terrestrial plants. Biodiesel and bioethanol are the most common algal biofuels which are appropriate alternatives to traditional diesel oil. Biodiesels are known as "neutral carbon" because their carbon dioxide emission to the air is significantly low. Optimizing the algal cultivation factors, in addition to improvements in harvesting and processing methods will result in a maximum yield of biofuel primary compounds such as lipids and sugars. The extracted oil from algae is used directly as a liquid fuel, and the remaining biomass is converted into bioethanol and biogas by anaerobic digestion/fermentation or used as fertilizer or animal feed. This review analyses different methods used for algal culture and biofuel production in recent years

Bioethanol is a second generation biofuel that has recently received attention due to limited fossil fuel resources and air pollution cause of fossil fuels. In this study production of bioethanol from lignocellulosic material of corn fiber in a membrane bioreactor was investigated. Acid pretreatment was used to increase the fraction of cellulose to 41%. The strain of saccharomyces cerevisiae was used as yeast. In most previous works the experimens have been performed in batch systems, whereas in this study simultaneous saccharification and fermentation (SSF) were performed in a continuous ultrafilteration membrane reactor, where the product is removed to prevent the inhibitory effect of the product on bioethanol production yield and enzyme deactivation. Experimental design and optimization was carried out by Design Expert software. The optimum conditions were determined to be: temperature (38.5°C), agitation speed (631.2 rpm) and surfactant concentration (0.08%v/v). Under these conditions the predicted ethanol yield was 87.8% and the actual experimental value was 84.2%.

In this study, spray behavior of bio-ethanol as a regenerative fuel that reduces emissions such as NOX and CO is investigated in a combustion chamber and compared to its different blends with gasoline. For this purpose, microscopic and macroscopic spray characteristics and also evaporated fuel mass after the injection are modeled and investigated using Fire 2013. It is concluded by increasing bio-ethanol content in the fuel, evaporated fuel mass, spray cone angle, spray area and sauter mean diameter increases, however spray tip penetration remains roughly constant. Increase of injection pressure, decreases spray cone angle and suater mean diameter and increases evaporated fuel mass, spray area and spray tip penetration. If the energy content and time of injection of bio-ethanol and gasoline be equivalent the results vary significantly compared to previous cases. In this case bio-ethanol has a longer spray tip penetration and spray area, higher fuel mass evaporated and smaller spray cone angle and sauter mean diameter compared to gasoline. The increased spray tip penetration and spray area in this case may lead to piston impingement and bore wetting resulting increased hydrocarbon emissions and decreasing engine efficiency.