焙烧态水铝钙石催化剂的制备及催化合成生物柴油

分别采用共沉淀法、清洁法制备焙烧态水铝钙石,通过低温N2吸脱附法、CO2-TPD、XRD、DTA和FT-IR表征结构,并将其作为大豆油与甲醇酯交换合成生物柴油的催化剂,探讨制备方法对焙烧态水铝钙石催化合成生物柴油的影响。此外,考察了Ca/Al摩尔比、焙烧温度、甲醇与大豆油摩尔比(醇油比)、催化剂用量和反应时间对酯交换合成生物柴油的影响。结果表明,清洁法制备的焙烧态水铝钙石具有更高的比表面积,强碱中心的表面碱量更大,催化活性更高。当Ca/Al摩尔比为2∶1,焙烧温度为600℃时,制备的Ca2Al O-2-600催化剂的催化活性最高,在醇油比8∶1、催化剂用量3%、反应温度65℃、反应时间4 h的条件下,大豆油转化率达到98. 0%。催化剂经重复使用3次后仍保持较高催化活性。     

Effect of hydroxy gas enrichment on vibration,noise and combustion characteristics of a diesel engine fueled with Foeniculum vulgare oil biodiesel and diesel fuel

Gaseous fuels can be used in diesel engines to improve combustion and obtain more favorable emission. Vibration and noise formation in diesel engines is a rather complex phenomenon which is created during combustion of fuels and leads to a reduction in vehicle comfort. Although there are studies in the literature that examine the noise and vibration of the diesel engine using different biofuels, there is no study that thoroughly examines the effect of combined utilization of Foeniculum vulgare oil biodiesel (FVB) and hydroxy gas (HHO) on vibration, noise and combustion characteristics. Therefore, this study aimed to explore the effects of FVB, a promising biodiesel feedstock, and HHO dual fuel operation on vibration, noise and exhaust emissions of a diesel engine. The vibration, noise and emission data obtained by the use of diesel fuel were taken as a reference and the effects of FVB and HHO mixture utilization on vibration, noise and emission formation were examined. The results show that the total vibration and noise generated by the engine was decreased by the use of FVB. In addition, the utilization of HHO together with biodiesel further reduced the engine vibration and noise according to experimental data. According to exhaust emission formation measurements, the minimum carbon monoxide values were obtained when the engine was fueled with HHO and FVB mixtures. However, CO₂ and NO_X emissions increased with the combination of HHO and FVB usage.     

Influence of cerium oxide additive and aloe vera biodiesel on a CI engine

Diesel is the main source of world transportation due to higher combustion efficiency, compliance, consistency and cost-economy. It is also a major contributor to the world prosperity since it is used extensively. Diesel engine’s emissions are the serious hazard to the world environment and it is measured to be the major causes of air pollution. The demand in biofuels for years created a scope for aloe vera into biodiesels. Aloe vera, having higher calorific value vnthan other plant sources used as biodiesels, enhanced us in making another alternative biodiesel, which has lesser emissions and better performance. In this research work, four biodiesel blends from aloe vera oil with cerium oxide additive are explored for their performance and emission characteristics. The results proved B30 (30% biodiesel, 68% diesel and 1% cerium oxide) gives good performance when compared to other blends.     

Activated Carbon Supported CaO from Waste Shells as a Catalyst for Biodiesel Production

In the wake of increasing environmental constraints, this work is aimed at developing a catalyst purely prepared from waste biomass source as the raw material. The catalyst is investigated for its applicability in transesterification of vegetable oil with the objectives: (i) to use waste shells of mollusk as raw material for the preparation of activated carbon and CaO; (ii) to use it as heterogeneous catalyst in the transesterification of waste cooking oil; (iii) to optimize the different parameters affecting the transesterification reaction; and (iv) to study its reusability. Under optimized conditions it was observed that a conversion >90% was possible and the catalyst could be reused five times with a slight loss in activity. This study indicates that the biomass source could also be used as a potential raw material in the synthesis of environmentally benign catalysts.     

An experimental investigation on the application potential of heterogeneous catalyzed Nahar biodiesel and its diesel blends as diesel engine fuels

From the inception of commercialization of biodiesel, feedstock scarcity is a major issue to be pondered upon in developing countries. In this study, an attempt has been made to use an abundantly available underutilized high oil content (67% of Nahar seed kernel) feedstock derived biodiesel in a compression ignition engine. The experimental investigation on diesel engine reveals slightly reduced brake thermal efficiency and excellent exhaust emissions up to 40% blending of Nahar biodiesel with conventional diesel fuel. At full load, compared to diesel fuel, the BTE dropped by 1.64% and 1.83%, whereas the BSFC increased by 5.07% and 6.76% for B30 and B40 blends, respectively. The tested emission parameters such as CO, HC, NOx, and smoke were decreased by 12.66%, 17.99%, 8.31%, and 10.61% for B30 and 4.87%, 12.76%, 7.98%, and 11.78% for B40, respectively, compared to diesel fuel.

Abbreviation: BD: Biodiesel; DF: Diesel fuel     

Impact of oxygenated cottonseed biodiesel on combustion,performance and emission parameters in a direct injection CI engine

In the present study, biodiesel production from the crude cotton-seed oil (CSO) and its feasibility to be used as fuel in compression ignition engine was analysed. Single-stage transesterification at molar ratio of 8:1 on crude CSO yielded 94% of cottonseed biodiesel (CBD). Gas chromatogram/mass spectrometry analysis revealed the presence of 19.5% unsaturated and 80.5% saturated esters in cotton seed biodiesel. Taguchi approach identified the stable fuel blend with oxygenate concentration. Increased oxygen concentration up to 20% were also analysed to understand the variation. Higher peak in-cylinder pressure was observed in D80CBD20 fuel blend. Diesel–biodiesel blend with oxygenate significantly affected the ignition delay and also resulted in varied exhaust gas temperature. D80CBD20nB10 showed an increase in brake thermal efficiency, whereas D80CBD20 exhibited higher brake specific energy consumption at full load. Carbon monoxide, hydrocarbon and smoke emission was found to be high in diesel with higher oxides of nitrogen in D80CBD20nB10. This experimental investigation finally revealed that, D80CBD20nB10 improved the combustion and performance characteristics with minimal emissions.

Abbreviations ASTM: American Society for Testing and Materials; BP: brake power; BSEC: brake specific energy consumption; BTE: brake thermal efficiency; CBD: cottonseed biodiesel; CI: compression ignition; CO: carbon monoxide; CO₂: carbon dioxide; CSO: cottonseed oil; DEE: diethyl ether; DOE: design of experiments; EGT: exhaust gas temperature; FTIR: Fourier transform infrared spectrometry; GC/MS: gas chromatogram/mass spectrometry; HC: hydrocarbon; HRR: heat release rate; HSDI: high speed direct injection; IDI: indirect injection; KOH: potassium hydroxide; MFB: mass fraction burned; NaOH: sodium hydroxide; NMR: nuclear magnetic resonance; N₂O: nitrous oxide; NO: nitric oxide; NO₂: nitrogen dioxide; NO _x : oxides of nitrogen; ROHR: rate of heat release; ROPR: rate of pressure rise; SOC: start of combustion; aTDC: after top dead centre; bTDC: before top dead centre     

Prediction of the water content of biodiesel using ANN-MLP: An environmental application

Fuel quality, especially biodiesel, is highly dependent on its water content, and the major sources of water in the fuel relate to the transportation, production, and storage processes. In this present contribution, the multilayer perceptron artificial neural network (MLP-ANN) was applied to predict the water content of biodiesel and diesel blend in terms of temperature and composition. The proposed algorithm was trained and tested by utilizing 400 experimental data points which were extracted from the literature. Based on the results, the MLP-ANN model has great ability to estimate the water content of biodiesel and diesel blend. The R-squared (R²), root mean square error, average absolute relative deviation, and a?bsolute deviation parameters for the total data set are obtained, respectively, as 0.99784, 123919.1172, 3.3632, and 1.17%, which indicate the effective performance suggested by ANN. As the computational study is cheaper and easier than the experimental study, the developed software could be considered as an alternative for laboratory study, and the environmental effect of biodiesel and produced undesired product after biodiesel combustion which is directly related to the water content of biodiesel is estimable with the information released in this study.     

小桐子油及其生物柴油在旋流喷嘴中雾化特性数值模拟

为了掌握入射压力对生物质燃油在旋流喷嘴中雾化特性的影响规律,在不同入射压力条件下,采用Fluent数值模拟的方法对小桐子油和小桐子生物柴油进行雾化过程模拟仿真研究。结果表明:使用的旋流雾化喷嘴比普通喷嘴对索特平均直径(D32)有更好的优化效果,内螺旋结构增强了雾化的湍流强度,使得气液两相混合及对雾化液滴的破碎效果更好;在等温条件下,不同入射压力对D32、雾化总表面积、雾化速度、雾化贯穿距影响较大。入射压力越大,D32越小;入射压力越大,雾化总表面积、雾化速度、雾化贯穿距越大。入射压力对D32的影响存在临界值,即小桐子油雾化入射压力达到0.8 MPa、小桐子生物柴油雾化入射压力达到0.7 MPa后,D32趋于稳定,不会随入射压力的增大继续减小;通过曲线拟合及雾滴粒径数量密度分析,得到了不同入射压力距离喷嘴不同位置处轴向D32变化的拟合方程及雾化液滴不同粒径数量密度分布情况。     

CaO-CeO2 @LiFe5 O8磁性固体碱催化剂的表征及性能评价

首先采用溶胶凝胶法制备了LiFe_5O_8磁核,并用共沉淀法制备了CaO-CeO_2@LiFe_5O_8磁性固体碱催化剂。通过XRD、SEM、TEM和CO_2-TPD对催化剂进行表征,并对其性能进行评价。结果表明:成功地制备了CaO-CeO_2@LiFe_5O_8磁性固体碱催化剂,并且CaO-CeO_2也成功地被吸附在LiFe_5O_8磁核表面,催化剂具备十分优良的铁磁性; CO_2-TPD表征结果说明,制备的催化剂具备较强的碱性,用于棕榈油酯交换反应体系中,生物柴油收率可达到95. 37%;制备的催化剂具有很好的耐酸、耐水性,重复使用5次后仍然保持较好的催化活性,且在外加磁场中易分离。