Cold flow properties and crystal morphologies of biodiesel blends

A soybean biodiesel was prepared and blended with a conventional China’s No. 0 petrodiesel. The pour points (PP) and cold filter plugging points (CFPP) of the biodiesel blends were evaluated on a low-temperature flow tester. Dynamic viscosities of the blends at different temperatures and different shear rates were measured on a rotatory rheometer. The crystal morphologies of the biodiesel blends at low temperatures were analyzed using a polarizing microscope. The results indicate that the blended fuels provided a slight decrease in PPs and CFPPs as compared with those of neat soybean biodiesel and pure petrodiesel. Below the temperatures of PPs or CFPPs, the dynamic viscosity of the biodiesel blends increased dramatically with decreasing temperature, but decreased with increasing shear rate, the biodiesel blends exhibiting non-Newtonian behavior. At temperatures higher than PPs or CFPPs, linear relationships appeared between dynamic viscosity and shear rate and the biodiesel blends became Newtonians. At low temperatures, wax crystals of the biodiesel blends grew and agglomerated rapidly. The loss of fluidity at low temperatures for the biodiesel blends can therefore be attributed, on the one hand, to the sharp increase of viscosity and, on the other hand, to the rapid growth and agglomeration of wax crystals.     

Low-temperature Properties of Biodiesel： Rheological Behavior and Crystallization Morphology

A soybean oil derived biodiesel was prepared and blended with a conventional No. 0 petrodiesel. The pour points (PP) and the cold filter plugging points (CFPP) of biodiesel blends were evaluated on a low-temperature flow tester. Dynamic viscosities of the blends at different temperatures and different shear rates were measured on a rotary rheometer. The crystal morphologies of biodiesel blends at low temperatures were analyzed using a polarizing microscope. The results indicated that blended fuels demonstrated slight decrease in PPs and CFPPs as compared with those of neat soybean oil derived biodiesel and pure petrodiesel. Below the temperatures of PPs or CFPPs, the dynamic viscosity of biodiesel blends dramatically increased with a decreasing temperature, but decreased with an increasing shear rate, so that biodiesel blends exhibited non-Newtonian behavior. At temperatures higher than PPs or CFPPs, a linear relationship appeared between the dynamic viscosity and shear rate and biodiesel blends became Newtonian fluids. At low temperatures, wax crystals of biodiesel blends grew and agglomerated rapidly. Loss of fluidity for biodiesel blends at low temperatures could therefore be attributed on one hand to the sharp increase of viscosity and on the other hand to the rapid growth and agglomeration of wax crystals.     

地沟油生物柴油排气颗粒氧化活性分析

为了研究地沟油生物柴油对柴油机排气颗粒氧化活性的影响,采用微孔沉积式碰撞采集器收集了柴油（B0）、地沟油生物柴油(B100)、地沟油生物柴油调和油(B20、B50)的排气颗粒,利用软X射线谱学显微光束线站、高分辨率透射电镜、X射线能谱仪和热重分析仪测量了颗粒的官能团、微观形貌、元素种类、化学组分和氧化活性。结果表明,随着生物柴〖JP2〗油掺混比从20%,50%增加到100%,颗粒中所含的“石墨性”C〖FY=,1〗C、酚类C-OH、酮类C〖FY=,1〗O、〖JP〗脂肪族C〖FY=,1〗C含量逐渐降低,脂肪烃C-H和羧基C=O含量逐渐增加;颗粒团聚体的微观形貌由环状向簇状转变,颗粒的平均粒径分别降低了79%、172%和242%;颗粒中的C元素含量降低,O、Na、Cu、Al、Ba和Zn元素含量增加;颗粒中挥发性有机成分含量增加,碳烟成分含量降低。当燃料中生物柴油的比例达到50%时,颗粒的起燃温度、失重速率峰值温度、燃尽温度和表观活化能降低明显,颗粒的着火难度降低,燃烧速率增加、燃烧所需能量降低,增强了颗粒的氧化活性。     

Variation of the physicochemical properties diesel-biodiesel blends – range 0–100%

Recently biodiesel has become more attractive because it is made from renewable resources. In this study we demonstrate how the proportion of diesel/biodiesel blends determines the qualitative parameters and energy efficiency of the final product. The use of biodiesel in blends with conventional diesel is becoming more and more valuable, based on European directive for use up to 20% biodiesel by 2020. We came to the conclusion that mixtures up 30% Biodiesel gives product within diesel specification limits which is suitable for commercial use. This methodology can be a manual for the production line of mixtures for commercial use.     

Diesel fuel based on mixtures of petroleum and vegetable raw materials

Сommercial petroleum diesel, distilled biodiesel and jet fuel JP8 were used to prepare the new fuel blend with physicochemical properties meeting the petroleum diesel standards. The proposed fuel blend consisted of 75% (v/v) petroleum diesel, 20% (v/v) distilled biodiesel and 5% (v/v) jet fuel JP8. The humidity of the prepared fuel blend was regulated using the distilled biodiesel. The key physicochemical properties of fuel such as density, kinematic viscosity, conductivity and water content were measured using standard ASTM methods. The storage stability test for the studied samples showed that they remained unchanged even after 30 and 120 days from the preparation moment. The suggested fuel blend composition may be recommended for the industrial applications due to the benefits of adding 20% of the distilled biodiesel. The composition of the fuel blend meets the European directive which proposes adding up to 20% (v/v) of biodiesel to the petroleum based fuels.     

Fuel properties and emission characteristics of biodiesel produced from unused algae grown in India

The high price of different biodiesels and the need for many of their raw ingredients as food materials are the main constraints to be overcome when seeking the best potential alternative fuels to petro-diesel. Apart from that, some properties like high density, viscosity and acid value along with low cloud and pour points preclude their use in compression ignition(CI) engines as these properties can cause serious damage to the parts of the engine and reduce engine life. In this experiment, biodiesel was produced from the oil of unused algae by a two-step ‘acid esterification followed by transesterification' procedure. Taguchi's method was applied to design the experiment, and a L25 orthogonal array was prepared to optimize the biodiesel production procedure. The optimized conditions for transesterification were: methanol to oil molar ratio of 6:1, catalyst(KOH) concentration of 2.5 wt%, reaction time of 90 min and reaction temperature of 50 ℃,achieving a biodiesel production of 89.7% with free fatty acid content of 0.25%. It was found that the CI engine emitted less CO, CO_2 and hydrocarbon and higher NO_x using algal biodiesel than that using petro-diesel. All properties of the algal biodiesel were within the limit of ASTM standards.     

Production of methyl and ethyl biodiesel fuel from pequi oil (Caryocar brasiliensis Camb.)

We studied the physical and chemical characteristics of methyl and ethyl esters (biodiesel) produced by transesterification of pequi oil (Caryocar brasiliensis Camb.) in the presence of potassium hydroxide. The oil extracted from pequi seed comprises 60% of the fruit content. Such characteristics as density, acidity, viscosity, and carbon residue of the biodiesel meet ANP (Brazilian National Petroleum Agency) standards. Our tests demonstrated the feasibility of utilizing pequi oil for biodiesel production.     

Effect of waste cooking-oil biodiesel on performance and exhaust emissions of a diesel engine

The ever increase in global energy demand, consumption of depletable fossil fuels, exhaust emissions and global warming, all these led to search about alternative fuels. Biodiesel was produced from waste cooking-oil by transesterification process. Blends of waste cooking-oil biodiesel and diesel oil were prepared in volume percentages of 10, 20 and 30% as B10, B20 and B30. Biodiesel blends have ASTM standards of physical and chemical characterization near to diesel fuel. Diesel engine performance and exhaust emissions were studied experimentally for burning waste cooking-oil blend with diesel fuel. This experimental was applied on a diesel engine at different engine loads from zero to full load. Thermal efficiencies for waste cooking-oil biodiesel blends were lower than diesel oil. Specific fuel consumptions of biodieselblends were higher than diesel fuel. Higher exhaust gas temperatures were recorded for biodiesel blends compared to diesel oil. CO₂ emissions for waste cooking-oil biodiesel blends were higher than diesel oil. CO, smoke opacity and HC emissions for biodiesel blends were lower than diesel fuel. NO_x emissions for biodiesel blends were higher than diesel fuel.     

生物柴油低温流动性能研究

采用气相色谱法测定了菜籽油生物柴油、大豆油生物柴油和花生油生物柴油中脂肪酸甲酯的分布和含量,采用燃料低温性能测定仪和旋转黏度计考察了生物柴油的低温流动性能及流变特性。结果表明:生物柴油的低温流动性能与其饱和脂肪酸甲酯的分布和含量密切相关。花生油生物柴油的饱和脂肪酸甲酯含量比菜籽油生物柴油的高10.5%,其冷滤点和凝点比菜籽油生物柴油的高8℃,0℃时花生油生物柴油黏度比菜籽油生物柴油高57.42 mPa·s。生物柴油在低温下失去流动性的主要原因是析出晶体,并连接成网状结构,将低熔点的柴油吸附于其中。     

均相碱催化高动物油含量餐饮废油制备生物柴油

针对重庆餐饮废油动物油含量高的特点,用氢氧化钠作催化剂制备生物柴油,得到的最佳工艺条件为:醇油质量比25%、催化剂用量1.0%、反应温度60℃、反应时间60 min、搅拌速率3000 r/min。在最佳工艺条件下进行放大实验,生物柴油的产率可达93.6%。生物柴油产品理化性质中部分指标达到国家标准,与0号柴油调合使用可改善其低温流动性能。     

我国发展生物柴油产业的挑战与对策

从长远来看，矿物燃料（煤、石油、天然气）终将枯竭，而利用取之不尽、用之不竭的可再生资源生产能源必将兴起。生物柴油就是一种由可再生资源生产的优质清洁燃料，发展生物柴油不仅可以保护环境，减少温室气体排放量，而且可以缓解我国石油进口的压力，推动新农村建设。但由于植物油脂价格飙升，生物柴油产业发展也面临仅生产生物柴油燃料在经济上难以立足的挑战。对发展我国生物柴油的原料资源、生产技术以及生物柴油化工技术开发的现状与未来发展动态进行了分析，提出了促进我国生物柴油产业健康发展的对策：①如果以进口棕榈油等量大植物油为原料，则应采用连续化、大型化生产技术，并配套开发相应的生物柴油化工技术，形成生物柴油化工炼油厂；②如果采用廉价、量小的垃圾油等为原料，则应采用小型、多样化（固定或可移动）并与周边设施（如水、电、蒸气、污水排放等）相适应的技术。     

泡沫镍负载乙酸钾催化废油脂制备生物柴油研究

通过浸渍的方法制备泡沫镍负载乙酸钾固体碱催化剂,并用于煎炸废油脂和甲醇酯交换反应制备生物柴油。考察了催化剂制备及酯交换反应条件对反应过程的影响。试验表明:当浸渍液KAc的质量分数为35%、浸渍8h、650℃焙烧4h,n(醇)/n(油)=7/1、反应温度为70℃、时间3.5h、催化剂用量为油脂质量的3.0%时,酯交换反应的转化率可达94.3%。且生物柴油容易分离,其外观为透明、淡黄色,运动粘度为(40℃)5.25mm/s2、密度为0.8815g/mL,符合我国生物柴油质量标准。     

发展我国生物柴油的初探

生物柴油是绿色可再生能源。文中介绍了西方国家和我国生物柴油的产业发展现状，着重论述了发展我国生物柴油应采取的策略，提出了建立稳定可靠的原料基地，建设合适的生产规模，以及开发先进的生产工艺技术等措施。     

无甘油副产生物柴油的组分分析及其燃烧性能

以氢氧化钾为催化剂催化棕榈油和新型甲酯化试剂MC进行酯交换反应制备生物柴油,采用气相色谱和气质联用的方法对反应产物进行了定性、定量分析。分析结果表明,由该工艺制得的生物柴油由主产物脂肪酸甲酯和副产物甘油碳酸酯组成。测定了生物柴油的主要物理性能指标,同时在柴油机未作任何调整的情况下进行了台架试验,考察了生物柴油与0#柴油混合燃料对柴油机燃烧过程、经济性和排放性的影响。实验结果表明,制得的生物柴油的密度、酸值和运动黏度均符合国家标准,将其与0#柴油混合(生物柴油体积分数20%)后可直接应用于柴油机,MC和甘油碳酸酯对缸内燃烧过程和经济性影响很小;燃用添加MC和甘油碳酸酯的混合燃料能有效降低柴油机碳烟、碳氢化合物和CO的排放量,NOx排放量稍有增加。     

Castor oil biodiesel production and optimization

Biodiesel is evolving to be one of the most employed biofuels for partial replacement of petroleum based diesel fuel, especially in recent years. The most widely used feedstocks for biodiesel production are vegetable oils. In this work, biodiesel production from castor oil has been synthesized by homogenous alkaline transesterification. The influence of catalyst concentration, methanol:oil molar ratio, reaction temperature and reaction time in the methyl ester content reached by castor oil transesterification have been evaluated. A yield of 95?wt% biodiesel was achieved at 1?wt% KOH, 60?°C, 9:1 methanol:oil ratio and 30?min reaction time. Transesterification at temperature 30?°C gave a yield compatibles with that obtained at 60?°C. The composition of the fatty acid methyl ester was determined by Gas Chromatography. The castor oil biodiesel produced was blended with different concentrations of petrodiesel to obtain B5, B10 and B20. The biodiesel properties and its blends were determined according to the standard test methods of analysis. The results showed that Castor oil biodiesel in the blends could lower the cloud point value, but simultaneously, increases the viscosity of the diesel–biodiesel blends. Thus, castor oil biodiesel with its very low cloud and pour points is suitable for using in extreme winter temperatures.     

生物柴油的现状和发展

石油是一种不可再生资源,产量将逐渐减少,而石化柴油燃烧排放的废气是造成空气污染的一个重要原因,生物柴油能够在一定程度上缓解这些问题。介绍了生物柴油的生产方法、性能及应用现状,讨论了生物柴油存在的问题,指出生物柴油值得大力发展。     

Kinetic study and techno-economic indicators for base catalyzed transesterification of Jatropha oil

Fatty acid methyl ester (biodiesel) has been identified as biodiesel alternative fuel obtained from renewable sources. Efforts in Egypt are directed toward the development of new non-edible sources. At the forefront of these non-edible sources comes Jatropha curcas oil (JCO) because it has been grown successfully in Egypt using primary treated municipal wastewater for irrigation. Based on previous research findings for the production of biodiesel from (JCO) using heterogeneous catalyst, some kinetic data on the transesterification reaction were provided. This was achieved by conducting the reaction at various temperatures, reaction time, and dose of catalyst and reactant molar ratios. The transesterification reaction was observed with regard to the percent biodiesel yield versus time and the reaction order was found to be a first order reaction rate equation. Techno-economic indicators revealed that the price of biodiesel produced by heterogeneous base catalyzed method was $0.665/L with a gross profit per year of $37,403,643.     

Emission and performance analysis of a diesel engine burning cashew nut shell oil bio diesel mixed with hexanol

In this study, the effect of doping hexanol into biodiesel which is from neat cashew nut shell biodiesel oil on the emissions and the performance characteristics was studied in a constant speed diesel engine. The main purpose of this work is to reduce various emissions and also to improve the performance of the diesel engine when fueled with blends of hexanol and neat cashew nut shell biodiesel. Cashew nut shell oil is not edible, and hence it can be used as a viable alternative to diesel. Cashew nut shell biodiesel is prepared by conventional transesterification. Hexanol with 99.2% purity was employed as an oxygenated additive. Experimental studies were conducted by fueling diesel as a baseline and by fueling hexanol and neat cashew nut shell biodiesel mixture. A fuel comprising 10% (by volume) of hexanol and 90% (by volume) neat cashew nut shell biodiesel was referred to as CNSBD900H100 and fuel comprising 20% (by volume) of hexanol and 80% (by volume) of neat cashew nut shell biodiesel was referred to as CNSBD800H200. This study also investigated the possibility of using pure biofuel in an unmodified naturally aspirated diesel engine. The outcome of this study showed that adding hexanol at 10% and 20% (by volume) to cashew nut shell biodiesel results in a reduction in emissions. In addition, a significant improvement in brake thermal efficiency and reduction in brake-specific fuel consumptions were achieved. Hence, it could be concluded that hexanol could be a viable and promising additive for improving the drawbacks of biodiesel when it was used to fuel an unmodified diesel engine.     

High operative heterogeneous catalyst in biodiesel production from waste cooking oil

Our work aims to produce a new catalyst that was a highly operative in the production of biodiesel from waste cooking oil WCO. A heterogeneous solid acid catalyst (RS-SO₃H) was prepared by fast pyrolysis of rice straw, then it was followed by a sulfonation process. It was formed by using concentrated sulfuric acid. The Fourier transform infrared spectroscopy (FTIR) analysis confirmed that the chemical structure consists of sheets of amorphous carbon with hydroxyl and carbonyl (OH and COOH) groups as well as high density of SO₃H. The surface area of RS–SO₃H and the average pore size were characterized by scanning electron microscopy (SEM) and surface area analyzer. The results of Thermogravimetric analysis (TGA) showed that RS–SO₃H has favorable thermal stability. Conventional energy sources were exhausted. So, we examined the catalyst activity on developing alternative energy resources, It became more imperative and environment friendly. WCO is attracting increased attention in the biodiesel production by transesterification process. The factors affecting the transesterification process include reaction time and temperature, catalyst concentration and methanol: oil molar ratio, were studied. The maximum mass yield of biodiesel extended to 90.37%. The content of fatty acid methyl ester (FAME) is around 97.71 wt%, conversion efficiency% of raw material reached 90.38 wt% and %free fatty acid (%FFA) conversion was 91.1% at optimum conditions: 10 wt% catalyst using methanol: oil molar ratio (20:1) at 70 °C for 6 h. The FAME content% was determined by gas chromatography (GC). The physicochemical properties of the biodiesel produced are close to the commercial diesel and the ASTM standards biodiesel D6751. The reusability of the used catalyst indicated that the catalyst was highly operative in production biodiesel. Where % conversion efficiency of raw oil under optimized conditions decreased from 90.37 to 88.56% after 8 cycles. The %FFA conversion was constant around 91.1% until 7 runs then it decreased.     

采用废弃油脂生产生物柴油的SRCA技术工业应用及其生命周期分析

废弃油脂是食用油生产和使用过程中产生的非食用性油脂,全世界要产生30Mt/a以上,对其处置不当将危害环境。废弃油脂品质差、酸值高,难于采用传统的碱催化酯交换技术加工生产生物柴油。中国石化石油化工科学研究院针对废弃油脂的质量特性,开发了近临界甲醇醇解(SRCA)生物柴油技术。2009年首次建成了60kt/a工业化示范装置,以酸化油为原料,打通了全流程,实现了连续运行生产,产品质量满足国家标准(GB/T 20828)要求。在实验室和工业运行数据的基础上,对选择废弃油脂生产生物柴油的SRCA工艺进行了生命周期分析。与传统工艺相比,SRCA工艺没有增加环境负担。