生物炭基材料在生物柴油制备中的研究进展

不同种类的生物质原料可通过热转化的方式制备生物炭,由于其独特的特性被广泛应用于不同的研究领域。近期,随着生物炭合成方法的大规模涌现,生物炭及生物炭基材料相关的研究广受关注。总结了生物炭基催化剂在生物柴油制备（酯交换/酯化反应）过程中的研究现状,简要描述了生物炭催化剂的设计和合成方法,并总结了生物炭催化剂在制备生物柴油中的应用,最后归纳了生物炭基催化剂在生物柴油制备中存在的问题,对今后的研究重点及前景做出展望,以期为将来低成本生物炭基催化剂的制备以及生物柴油合成的研究和发展提供指导建议。     

酯交换法制备生物柴油反应机理和影响因素分析

阐述了生物柴油的生产制备技术,从生物柴油酯交换合成反应出发,探讨了各种酯交换反应的反应机理;从原料油中的水分、游离脂肪酸、温度、压力、催化剂、反应时间、醇油比和原料混合程度等各个方面分析了对生物柴油制备的影响,得出了最佳的反应工艺条件。     

固体碱催化剂在麻疯树油合成生物柴油中的应用

简述了生物柴油作为燃料的优越性,讨论了以固体碱作催化剂、以麻疯树油为原料合成生物柴油的工艺条件.试验研究了该反应的最佳反应条件:固体碱催化剂的用量为麻疯树油质量的1%,油醇物质的量比为1:6,反应温度为70℃.     

棉籽油乙二醇甲醚酯新型生物柴油的合成

以棉籽油和乙二醇甲醚为原料,KOH为催化剂合成出一种含氧量更高的新型生物柴油。采用正交试验,研究了醇油比、催化剂用量、温度和反应时间四种因素对产物产率的影响,得出了最佳合成条件。运用红外光谱法、核磁共振法、凝胶渗透色谱法对产物结构进行了表征。柴油机台架试验表明,燃烧该新型生物柴油可大幅度减少柴油机的废气排放。     

一种新型菜籽油酯生物柴油的制备

以精制菜籽油、乙二醇单甲醚为原料,以KOH为催化剂,制备出一种含氧量更高的新型生物柴油.采用正交试验研究了反应物配比、催化剂用量、温度、反应时间等因素对产物产率的影响,得出了最佳合成条件,并运用红外光谱与核磁共振法分析了产物的结构.柴油机台架试验表明,燃烧该新型生物柴油后,废气排放大幅度降低.     

季铵碱催化剂在合成生物柴油中的应用

本文讨论了季铵碱作催化剂,以大豆油为原料合成生物柴油的工艺条件,并研究了原料油的酸值和含水量对酯转化率的影响.     

季铵碱催化剂在合成生物柴油中的应用

对合成生物柴油的几种方法进行了比较,讨论了以季铵碱作催化剂,以大豆油为原料合成生物柴油的工艺条件,并研究了原料油的酸值和含水量对脂肪酸甲酯转化率的影响.试验结果表明,该酯化及转酯化反应的最佳反应条件:催化剂的投入量为油重的0.5%,油醇的物质的量比为1∶6,反应温度为60℃,搅拌时间为30min;原料油的酸值小于2,原料水分质量分数在1%以下.     

国外可再生能源文献信息

超临界甲醇中生物柴油的热稳定性;纳米空心Pt—Ir材料对甲醇氧化和氧还原的电催化活性;用于甲醇电氧化的多壁碳纳米管（MWCNT）Pt—Ru催化剂的制备和特征;用声学和流体动力学空化法强化生物柴油合成时酸类的酯化     

生物柴油精细化学品-蔗糖酯合成技术研究

以生物柴油和蔗糖为原料,在N2保护下采用无溶剂法合成蔗糖酯,以活性炭负载的碳酸钾为催化剂,确定了蔗糖酯合成技术的各项工艺条件:生物柴油与蔗糖的物质的量比为2∶1,在N2保护下,催化剂活性炭负载碳酸钾加入量为总物料量的6%,助溶剂硬脂酸钾加入量为15%,在135℃下反应3h,采用溶剂萃取法纯化粗产物,精制后的蔗糖酯产率以蔗糖记为86.4%。     

响应面法优化棉籽油超声强化合成生物柴油工艺的研究

以棉籽油为原料,KOH为催化剂,通过超声波强化制备生物柴油(FAME)。采用四因素二次正交旋转组合设计实验。结果表明:采用超声波强化与机械搅拌反应体系相比,反应时间从40min缩短至20min,节能效果明显;得出了超声强化合成FAME的最佳工艺条件为:醇油比6.5:1,超声时间20min,占空比28%,催化剂用量0.9%,FAME的得率为97.35%,所得生物柴油各项指标基本达到欧洲EN14214和0#生物柴油标准。     

Catalytic performance of a novel amphiphilic alkaline ionic liquid for biodiesel production: Influence of basicity and conductivity

Three novel alkaline guanidine ionic liquids as amphiphilic catalysts have been successfully synthesized for two-phase transesterification, which can efficiently improve the catalytic activity for the synthesis of biodiesel. They were characterized by a series of techniques including ¹H NMR, thermal stability, electronegativity (DFT calculation), basicity and conductivity. It was demonstrated that 1,1,3,3-trimethyl-2-octyl-guanidine hydroxide(IL3) exhibited better catalytic activity compared with other base guanidine ionic liquid catalysts, which was related to the better basicity and electronegativity of the ILs. The experimental results indicated that catalytic performance was relative to both enough alkaline center and conductivity of ionic liquid catalysts, but the former was a main factor in the catalytic system. The catalytic performance also revealed that optimum catalyst dosage was about 6 wt.%, the appropriate reaction temperature was about 55 °C, the optimum n(Methanol)/n(Soybean Oil) for the biodiesel synthesis was about 15:1 and the suitable reaction time was 4 h on the basis of biodiesel yield of 97%. In addition, the reaction mechanism of the amphiphilic catalyst was illuminated by the interaction between the methoxyl group and the carbonyl group of the triglyceride after activating for two-phase transesterification.     

Inorganic heterogeneous catalysts for biodiesel production from vegetable oils

Biofuels are renewable solutions to replace the ever dwindling energy reserves and environmentally pollutant fossil liquid fuels when they are produced from low cost sustainable feedstocks. Biodiesel is mainly produced from vegetable oils or animal fats by the method of transesterification reaction using catalysts. Homogeneous catalysts are conventionally used for biodiesel production. Unfortunately, homogeneous catalysts are associated with problems which might increase the cost of production due to separation steps and emission of waste water. Inorganic heterogeneous catalysts are potentially low cost and can solve many of the problems encountered in homogeneous catalysts. Many solid acid and base inorganic catalysts have been studied for the transesterification of various vegetables oils. The work of many researchers on the development of active, tolerant to water and free fatty acids (FFA), as well as stable inorganic catalysts for biodiesel production from vegetable oils are reviewed and discussed.     

Recent developments on heterogeneous catalysts for biodiesel production by oil esterification and transesterification reactions: A review

Heterogeneous catalysis is widely applied in industry due to important advantages it offers to chemical processes such as improved selectivity and easy catalyst separation from reaction mixture, reducing process stages and wastes. This is the reason why nowadays heterogeneous catalysts are being developed to produce biodiesel. Several catalytic materials have been showed in bibliography: acid solids capable to carry out free fatty acids esterification reaction, base solids which are able to carry out triglycerides transesterification reaction and bifunctional solids (acid–base character) which show ability to simultaneously catalyze esterification and transesterification reaction. This review discusses the latest advances in research and development related with heterogeneous catalysts used to produce biodiesel.     

Synthesis and characterization of monk fruit seed (Siraitia grosvenorii)-based heterogeneous acid catalyst for biodiesel production through esterification process

This research investigated for the first time the synthesis of monk fruit seed (Siraitia grosvenorii)-based solid acid catalyst for biodiesel production. The catalyst was synthesized using a two-step surface functionalization method with trimethoxy phenyl silane and chlorosulfonic acid. The as-synthesized catalyst was characterized to ascertain its catalytic characteristics through surface morphology, chemical bonding, and thermal stability. The effects of activating agent impregnation ratio, carbonization temperature, and sulfonation temperature towards fatty acid methyl ester (FAME) yield were elucidated. The esterification reaction with palmitic acid was found to produce FAME yield up to 98.5% with 4 wt.% catalyst loading, 6-h reaction duration and 120°C reaction temperature. The catalyst also demonstrated high reusability with 84.4% FAME yield being successfully maintained after four successive cycles without reactivation. These proved that the as-synthesized catalyst had high prospect to become a suitable low-cost alternative for biodiesel production through catalytic esterification process in the future.     

Fuel bioadditive production by chitosan/sulfosuccinic acid catalytic membrane

Global warming is one of the biggest environmental problems of late. The use of renewable raw material resources as biomass and its conversion into alternative energy resources have attracted considerable attention during the recent years. Ethyl levulinate (EL) is a kind of fuel bioadditive for use in diesel and biodiesel engines, which is produced by the esterification of ethanol and levulinic acid. In the present study, sulfosuccinic acid (SSA) catalysts supported on chitosan catalytic membrane is used for the synthesis of EL. The effects of temperature, catalyst amount, and molar feed ratio were studied.     

Synthesis and characterisation of rubber seed oil trans-esterified biodiesel using cement clinker catalysts

The synthesis of biodiesel using rubber seed oil by a transesterification reaction using cement clinker catalysts was studied. The mineral composition and morphology of both the catalysts were analysed using X-ray diffraction and scanning electron microscopy. The gas chromatography–mass spectrometry, Fourier transform infrared spectroscopy and nuclear magnetic resonance studies were used to find the Fatty acid methyl ester content and various compounds of esters in the synthesised biodiesel, which showed an efficient conversion of rubber seed oil to biodiesel. The highest yield of 80% was obtained from calcium oxide catalyst (1.5?g) activated at 50°C with a methanol-to-oil ratio of 6:1. The highest yield of 70% biodiesel was obtained using a cement clinker catalyst (0.5?g) activated at 50°C with a methanol-to-oil ratio of 6:1. The significant physical properties of biodiesel flash point, acid value and saponification value were found, and the results are within the American standard test method (ASTM D6751) limits.     

Biodiesel production by ultrasound-assisted transesterification: State of the art and the perspectives

In the present paper state-of-the art and perspectives of ultrasound-assisted (UA) biodiesel production from different oil-bearing materials using acid, base and enzyme catalysts are critically discussed. The ultrasound action in biodiesel production is primarily based on the emulsification of the immiscible liquid reactants by microturbulence generated by radial motion of cavitation bubbles and the physical changes on the surface texture of the solid catalysts generating new active surface area. The importance of ultrasound characteristics and other process variables for the biodiesel yield and the reaction rate is focused on. UA transesterification is compared with other techniques for biodiesel production. Several different developing methods reducing the biodiesel production costs such as the optimization of process factors, the development of the process kinetic models, the use of phase transfer catalysts, the application of the continuous process, the design of novel types of ultrasonic reactors and the in situ ultrasound application in transesterification of oily feedstocks are also discussed.     

多相催化剂用于制备生物柴油的研究进展

生物柴油是绿色可再生能源,属环境友好型燃料,是常规的化学柴油的优良替代品。综述了酯交换方法生产生物柴油过程中的多相催化剂的研究进展,主要包括固体酸催化剂、固体碱催化剂、固定化酶的研究状况,并对催化油脂酯交换反应的多相催化剂的今后研究方向提出几点建议。     

Magnesium oxide prepared via metal-chitosan complexation method: Application as catalyst for transesterification of soybean oil and catalyst deactivation studies

A simple method to prepare magnesium oxide catalysts for biodiesel production by transesterification reaction of soybean oil with ethanol is proposed. The method was developed using a metal-chitosan complex. Compared to the commercial oxide, the proposed catalysts displayed higher surface area and basicity values, leading to higher yield in terms of fatty acid ethyl esters (biodiesel). The deactivation of the catalyst due to contact with CO₂ and H₂O present in the ambient air was verified. It was confirmed that the active catalytic site is a hydrogenocarbonate adsorption site.     

The utilization of waste egg and cockle shell as catalysts for biodiesel production from food processing waste oil using stirring and ultrasonic agitation

The use of calcined egg and cockle shell as heterogeneous solid catalysts for a transesterification reaction to produce biodiesel from food processing waste has been investigated in this work. The CaO catalysts were obtained from the calcination of egg and cockle shell and were characterized by surface analysis, X-ray diffractometry (XRD), and scanning electron microscopy (SEM). The experiments employed stirring and ultrasonic agitation, which proved to be a time-efficient approach for biodiesel production from food processing waste oil. A response surface methodology (RSM) was used to evaluate the effects of the process variables methanol to oil molar ratio, catalyst concentration, and reaction time on biodiesel production. The optimal % fatty acid methyl ester values obtained when using egg and cockle shells as catalysts were found to be 94.7% and 94.4% when the methanol to oil molar ratios were 9.3:1 and 8.5:1, egg and cockle shell catalyst mass fraction percentages were 3.8% and 3.5%, and reaction times were 47 and 44 min, respectively. The study has shown that ultrasonic agitation might be employed in a practical pilot reactor for biodiesel production.