生物柴油制备新工艺的研究进展

综述了生物柴油的特性及其生产方法,介绍了酯交换法制备生物柴油的反应机理及其近年来出现的各种新生产工艺,包括超临界法、生物催化法、超声波法、离子液体法等,指出了生物柴油技术发展面临的问题及研究方向。     

利用超临界技术制备生物柴油的研究现状

分析了超临界技术制备生物柴油的反应机理,重点阐述了温度、醇油比、压力、水、游离酸对超临界法制备生物柴油的影响.研究表明:超临界技术制备生物柴油在反应时间、对原料要求和产物回收等方面均具有传统碱催化法无法比拟的优势.展望了超临界技术制备生物柴油的工业应用前景,并对超临界技术制备生物柴油的研究提出了建议.     

生物柴油-生物质油乳化燃料最佳HLB值研究

生物质油是生物质快速热解液化的产物,与生物柴油乳化后可得到一种新的可再生清洁燃料.利用超声波乳化装置制备生物柴油-生物质油乳化燃料,首先采用亲油亲水平衡(HLB)值法确定了生物柴油-生物质油乳化燃料乳化剂的最佳HLB值,然后研究了乳化燃料制备过程中各种乳化条件对乳化燃料稳定性的影响.结果表明,生物柴油-生物质油乳化燃料乳化剂的最佳HLB值为4.3～4.7,乳化时间、乳化温度、生物质油浓度及乳化剂浓度等对乳化燃料的稳定性均有一定的影响.     

制备生物柴油中超声空化过程的研究

建立了超声波辅助制备生物柴油中空化气泡运动的动力学模型,采用MATLAB对模型方程进行数值模拟,探讨超声频率、声压幅值、空化泡的初始半径和环境压力对空化泡运动的影响.模拟结果表明,随着超声波频率的增加,空化效应减弱;超声声压较小时,超声波空化为稳态空化过程,随着声压的增加,空化气泡半径变化幅度增加,空化气泡所带来的空化效应必然增加;气泡的原始半径为超声波频率对应的共振尺寸时,空化情况最为激烈,声化效果最好;环境压力变化时,气泡运动的振幅差别不大.经分析得到提高生物柴油产率的较佳条件,即较低频率、较大声压幅值、气泡直径为共振尺寸、普通大气压.该研究可为超声在制备生物柴油中的应用提供基础理论依据.     

菜籽油超声波法制备生物柴油的研究

以菜籽油和甲醇为反应原料,以KNO3/Al2O3为催化剂,采用超声波法制备生物柴油,考察了超声波频率、醇油物质的量比、催化剂用量等条件对反应的影响。试验结果表明,该反应的最佳条件:超声波频率为30kHz,醇油物质的量比为7∶1,催化剂用量为菜籽油质量的2.0%。在此条件下,生物柴油产率为94%。所得生物柴油的主要性能指标均符合德国的生物柴油标准。     

野生小球藻生物柴油制备工艺的优化研究

文章开展了以野生小球藻为原料制备生物柴油的研究,首先分析比较了不同预处理方法的破壁效果,然后利用正交试验与神经网络预测相结合的方法,分析并优化了小球藻生物柴油的制备工艺,最后采用测量和计算的方法,分析了制备的生物柴油的理化特性。研究结果表明:超声波震荡和研磨相结合的方法的预处理效果最好;人工神经网络模型优化后的最佳制备工艺条件为甲醇用量为40 mL,浓硫酸用量为1.7 mL,反应温度为55℃,反应时间为6 h,搅拌速度为720 r/min,在此条件下,小球藻生物柴油的产率可达2.6%;制备的生物柴油的理化特性与0#车用柴油接近,但热值略低。     

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。     

非水介质脂肪酶在生物柴油制备中的应用研究

简述了非水介质中脂肪酶催化作用的优化过程,介绍了在制备生物柴油领域中的应用情况,认为在非水介质中用脂肪酶催化制备生物柴油可以有效提高生物柴油的转化率,降低脂肪酶的应用成本.     

地沟油超临界酯交换法制备生物柴油

地沟油制备生物柴油作为可再生能源具有巨大的潜力。作为制备生物柴油的原料,地沟油具有可再生、环境友好、使用和运输安全等优点。地沟油需经过酯交换转化为生物柴油。文中介绍了酯交换法在地沟油制备生物柴油生产中的应用,其中着重介绍地沟油经超临界甲醇酯交换法制备生物柴油。提出地沟油超临界酯交换制备生物柴油研究意见及优化工艺方法。     

菜籽油及其生物柴油低温流动特性研究

采用燃料低温性能测定仪考察了菜籽油及其生物柴油的冷滤点、凝点和运动粘度,采用旋转粘度计考察了菜籽油及其生物柴油粘温特性的差别,采用示差扫描量热分析仪研究了菜籽油及其生物柴油在低温下的相转变行为.研究结果表明:将菜籽油制备成生物柴油后,其冷滤点和粘度降低,粘温性能得到改善.在低温条件下,菜籽油粘度迅速增大,导致其失去流动性;菜籽油生物柴油在低温下析出固态物质,并逐渐连接成网状结构,将液态生物柴油吸附于其中,使生物柴油整体上失去流动性.     

超声波制取生物柴油工艺技术探讨

介绍了新兴的超声波制取生物柴油工艺技术,并与液体碱催化技术进行了比较。众多试验结果表明,超声波能加速酯交换反应,反应时间仅需5-30min,其催化剂消耗量仅为液体碱催化技术的30％-50％,甲酯转化率可达99％。但在工业化应用方面仍需要原料预处理、甲醇回收、甲酯洗涤以及甲酯干燥等工艺过程。据估算,商业规模生物柴油加工中超生波处理的成本在0．002～0．015欧元／L之间。     

Reaction conditions of ultrasound‐assisted production of biodiesel: A review

Ultrasound‐assisted biodiesel production is an emerging technology that features high energy density, high conversion efficiency, and environment friendliness. This review evaluates the influence of process parameters, including ultrasonic power, ultrasonic frequency, catalyst dosage, alcohol/oil ratio, reaction temperature, reaction time, and alcohol type, on the yield of ultrasonic‐assisted production of biodiesel. Limitations associated with ultrasonic‐assisted production of biodiesel are also analyzed. Further development of this technology is explored. Copyright © 2016 John Wiley & Sons, Ltd.     

Biodiesel production from Nerium oleander (Thevetia peruviana) oil through conventional and ultrasonic irradiation methods

In the present research work, Nerium oleander oil has been used as raw material for producing biodiesel using both ultrasonic transesterification and a magnetic stirrer method. A two-step transesterification process was carried out for optimum condition of 0.40% V/V methanol to oil ratio, 1% V/V H₂SO₄ catalyst, 55°C temperature, and 60 min reaction time followed by treatment with 0.2% V/V methanol to oil ratio, 1% V/W KOH alkaline catalyst, 55°C temperature, and 60 min reaction time. The process is repeated with an ultrasonic method at the frequency of 28 kHz using ultrasonic horn type reactor (50 W) for about 10–15 min. Biodiesel obtained from ultrasonic method and magnetic stirrer was then compared for their percentage yield and physiochemical properties. Ultrasonic transesterification process gave a maximum yield of 97% by weight of oleander biodiesel along with improved physiochemical characteristics. Therefore, it is concluded that ultrasonic method is the most effective method for converting crude oleander oil into biodiesel.     

A model for evaluating the economic feasibility of small-scale biodiesel production systems for on-farm fuel usage

Farming operations in Africa have, in general, not adopted small-scale biodiesel production technology well for on-farm fuel usage. This is mainly due to the lack of an acceptable method to assess the economic feasibility of constructing small-scale biodiesel production facilities, and the impact of such operations on existing farming production processes. The research study summarised in this paper subsequently set out to develop a model, termed the Biodiesel Production System Optimisation Model (BPSOM), which predicts the cost of producing biodiesel on a small-scale, and optimises on-farm production processes to maximise profits. The model was validated using a South African case study to evaluate the predicted cost of biodiesel per litre produced, and the economic impact of a small-scale facility on the production profits of a farm. A proxy indicator, profit per hectare cultivated land, is introduced to measure the impact. BPSOM predicts a positive profit increase of 33% for the specific farm case study, which proves the economic potential of small-scale biodiesel production facilities for fuel usage at farm level in Africa.     

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.     

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。     

Biodiesel production from Cedrus deodara oil in different types of ultrasonic reactors and energy analysis

This paper deals with the production of biodiesel using vegetable oil, extracted from Deodar (Cedrus deodara) in various types of ultrasonic reactors. The biodiesel so produced is tested for its property and stability. Biodiesel yield is optimized as a function of reaction time for various ultrasonic reactors. The biodiesel production through the triple-frequency flow cell ultrasonic reactor is found the most energy efficient when compared to other types of ultrasonic reactors. Biodiesel so produced from deodar oil is stable under atmospheric conditions with its various physicochemical properties within the range of acceptable limits of the diesel engine.     

酯交换法制备生物柴油及其在我国的实践

生物柴油是一种对环境友好的可再生燃料，以其是好的环境效应受到越来越多的关注。综述并比较了生物柴油的各种化学制备方法，介绍了该产业的国内外生产应用情况，指出了生物柴油的优势，分析了生物柴油在生产厦使用过程中存在的一些问题并对生物柴油的未来研究与发展作了展望。     

产油微生物的研究及其应用

介绍了微生物产油脂机理,讨论了产油微生物的种类及油脂合成的影响因素,并对微生物油脂制备生物柴油的应用前景进行了分析。