Factors affecting the cold flow properties of biodiesel: Fatty acid esters

Biodiesel is renewable, sustainable, and cost-effective; it possesses good lubricity and high cetane number. Nevertheless, its poor cold flow properties impede the popularization and application of biodiesel. In this study, the cold flow properties of peanut and rapeseed biodiesel and their blends with different fatty acid esters were investigated, including different chain lengths (saturated and unsaturated), different double bond numbers, and different alcohol chains. Results showed that shorter chain length, more double bonds, and branched alcohol chain could effectively improve the biodiesel cold filter plugging point (CFPP). This study also tried to explore the mechanism action of this phenomenon.     

Solubility limitations of residual steryl glucosides,saturated monoglycerides and glycerol in commercial biodiesel fuels as determinants of filter blockages

Newer, improved high pressure common rail diesel engines require increased protection from damaging particles in fuel, resulting in tighter, low-micron filtration requirements. The unobstructed flow of fuel through filters underlies the well-known efficiencies and reduced exhaust emissions of diesel engines, and when flows are hindered, these efficiencies become severely compromised. Biodiesel fuels frequently contain saturated monoglycerides, glycerol (GLY) and/or steryl glucosides, systemic impurities that become problematic when low concentrations exceed ill-defined solubility limits, usually unexpectedly at low temperatures. Here, filters and blended fuels from seven flow obstruction incidents were subjected to detailed compositional analyses. With one exception the fuels contain estimated levels within international specifications, yet exhibit heterophase (HP) formation in the laboratory at 2°C, well above measured cloud points. Feedstock composition, pretreatment and/or purification processes are found to modulate insolubility risks. Interferences in standard gas chromatography methods used without modification can hide or complicate estimates of residual levels of GLY. The data show that classical variables controlling solubility, such as concentrations and temperatures, play important roles in setting the risks associated with in situ formation of HPs from these common impurities. Further, such risks are likely attenuated considerably by reductions in critical impurities beyond currently specified limits.     

Fuel properties of blend and biodiesel generated from acid oil using whole cell biocatalyst

Biodiesel was generated through whole cell catalyzed transesterification of acid oil, to the extent of up to 92%. The fuel properties of biodiesel (B100) and its blend (B20) were determined and compared with standard biodiesel as per American Society for Testing and Materials (ASTM) standard (ASTM D6751). B100 and B20 showed good pour point of ?26°C and ?29°C, respectively, indicating their operation viability in colder environment. Other properties of biodiesel are quite similar to petroleum diesel and ASTM standard. The results of this study reveal the potential use of acid oil as feedstock for generation of fuel grade biodiesel through biocatalyzed transesterification.     

Refining technologies for the purification of crude biodiesel

In biodiesel production, downstream purification is an important step in the overall process. This article is a critical review of the most recent research findings pertaining to biodiesel refining technologies. Both conventional refining technologies and the most recent biodiesel membrane refining technology are reviewed. The results obtained through membrane purification showed some promise in term of biodiesel yield and quality. Also, membranes presented low water consumption and less wastewater discharges. Therefore, exploration and exploitation of membrane technology to purify crude biodiesel is necessary. Furthermore, the success of membrane technology in the purification of crude biodiesel could serve as a boost to both researchers and industries in an effort to achieve high purity and quality biodiesel fuel capable of replacing non-renewable fossil fuel, for wide range of applications.     

A review on prospect of Jatropha curcas for biodiesel in Indonesia

Energy is fundamental to the quality of life in the earth. Meeting the growing demand for energy sustainably is one of the major challenges of the 21st century. Indonesia is a developing country and the world's fourth most populous nation. Total annual energy consumption increased from 300,147 GWh in 1980, 625,500 GWh in 1990, 1,123,928 in 2000 and to 1,490,892 in 2009 at an average annual increase of 2.9%. Presently, fossil-fuel-based energies are the major sources of energy in Indonesia. During the last 12 years, Indonesia has recorded the most severe reduction in fossil fuel supplies in the entire Asia-Pacific region. This reduction has stimulated promoting the usage of renewable energy resources capable of simultaneously balancing economic and social development with environmental protection. Biodiesel is an alternative and environmentally friendly fuel that will participate in increasing renewable energy supply. Jatropha curcas is one of biodiesel resources that offer immediate and sustained greenhouse gas advantages over other biodiesel resources. Globally, J. curcas has created an interest for researchers because it is non-edible oil, does not create a food versus fuel conflict and can be used to produce biodiesel with same or better performance results when testing in diesel engines.The present study is concerned with the prospect of biodiesel produced from J. curcas in Indonesia. The first part gives a summary and overview of energy resources and consumption in the country, second part discusses the potential of biodiesel as a powerful renewable energy resource and third part investigates the potential of J. curcas as a feedstock for biodiesel in Indonesia. The final part discusses the development of biodiesel market in Indonesia. The paper found out that the production of biodiesel from J. curcas offers many social, economical and environmental benefits for the country and can play a great role to solve the problem of energy crisis in Indonesia.     

餐饮废油生物柴油中甘油和硫含量的同步优化

为提高餐饮废油生物柴油的品质,降低其甘油和硫含量,分析了离心、静置、水洗-旋蒸3种方法的脱甘油效果,以及氧化、吸附(活性炭作吸附剂)2种方法的脱硫效果,并对甘油和硫含量进行同步优化研究。结果表明：在3种脱甘油方法中,水洗-旋蒸的脱甘油效果最好;氧化脱硫在将硫化物脱除的同时会导致生物柴油的损失,并降低生物柴油的氧化稳定性,与静置和超声氧化脱硫相比,搅拌氧化脱硫的效果较好,脱硫率和生物柴油损失率分别为28.5%和2.0%;在活性炭用量为2%时,脱硫率较高,为23.8%;水洗-旋蒸可以有效地对生物柴油中甘油和硫同时脱除,脱除后的硫、甘油单酯、游离甘油、总甘油含量分别为9.31 mg/kg、0.182%、0.008%、0.054%,脱除率分别达到11.9%、64.3%、78.9%和68.4%,符合GB 25199—2017附录C中BD100生物柴油标准要求。因此,实际生产中可以采用水洗-旋蒸的方法对生物柴油中的甘油和硫进行同步脱除。     

偏甘油酯脂肪酶的研究进展及应用现状

相较于甘油三酯脂肪酶,偏甘油酯脂肪酶因其独特的底物选择性和催化高效性,逐渐成为相关领域的研究热点。旨在为偏甘油酯脂肪酶在油脂加工、脂质分子的定向合成等领域的研究提供理论和技术参考,并为挖掘新型的偏甘油酯脂肪酶打下基础,首先对偏甘油酯脂肪酶的来源和分类进行介绍,随后阐述了偏甘油酯脂肪酶的结构特征和催化特性,最后对其应用现状进行了总结归纳和展望。偏甘油酯脂肪酶有动物来源、植物来源和微生物来源,分为甘油单酯脂肪酶和甘油单酯-甘油二酯脂肪酶;偏甘油酯脂肪酶有帽区、催化三联体和氧负离子洞穴等结构,具有底物特异性和位置特异性;偏甘油酯脂肪酶在食品、有机合成、医疗等领域有着广泛的应用和独特的发展潜力。     

Above-ground morphological predictors of rooting success in rooted cuttings of Jatropha curcas L.

Cuttings of 1–3 cm diameter and 45 cm length were collected during the first week of February from branches of previous year’s growth in a mature plantation of Jatropha curcas. The cuttings, without application of any growth regulator, were planted in nursery beds having loam: gravel (1:1 v/v) mixture rooting media. The nursery beds existed inside a polyethylene tunnel where intermittent misting was done. When sprouting percentage had stabilised, sprouted cuttings were removed from the media, and root and shoot characteristics of the cuttings were recorded. The number of roots and root length were found to be significantly correlated (P < 0.01) with one another as well as with sprout length, number of sprouts and number of leaves. The following equations were fitted for prediction of root characteristics of a cutting from of its above-ground characteristics: (i) No. of roots = −0.409 + 0.452 (no. of leaves) + 0.395 (sprout length), and (ii) Root length = 2.656 + 0.206 (no. of leaves) + 0.270 (sprout length); the sprout length and root length are in centimetres in both equations. Thicker cuttings possessed better root and above-ground characteristics.     

基于不同原料生物柴油混合燃料的发动机性能研究

对一台TDI柴油机燃用花椒籽、棉籽、棕榈和餐饮废油脂4种不同原料制成的生物柴油(以10%体积比分别与柴油混合制成)的动力性、经济性和排放特性进行了试验研究,探讨了4种生物柴油对发动机性能的影响。研究结果表明:在燃用4种生物柴油时,棕榈油制生物柴油的功率和纯柴油基本一致,其余混合燃料的功率都比纯柴油略有下降;4种混合燃料的油耗与纯柴油基本一致;与纯柴油相比,生物柴油混合燃料的碳烟、CO、HC排放均较低,而NOx排放略高。