首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
Biodiesel fuel is an alternative and renewable energy source, which may help to reduce air pollution, as well as our dependence on petroleum for energy. Several processes have already been developed for the production of biodiesel. Alkali-catalyzed transesterification with short-chain alcohols, for example, generates high yields of methyl esters in short reaction times. In this study, we have evaluated the efficacy of batch (one- and two-stage) transesterification of rapeseed oil in the production of rapeseed methyl ester. The conversion of rapeseed oil exhibited similar reaction patterns and yields in 30- and 1-L reaction systems. Approximately 98% of the rapeseed oil was converted at 400 rpm within 20 min, under the following conditions: 1% (w/w) KOH, 1∶10 methanol molar ratio, and at 60°C. In the 30-L, two-stage transesterification process, approx 98.5% of the rapeseed oil was converted at a 1∶4.5 molar ratio and 1% (w/w) KOH at 60°C for 30 min (first reaction condition), and at a 1∶1 molar ratio and 0.2% (w/w) KOH at 60°C for 30 min (second reaction condition).  相似文献   

2.
通过棉籽现场碱催化转酯化联产生物柴油和无毒棉粕,考察了棉仁中水的质量分数、粒径对产物中脂肪酸甲酯(FAME)的质量分数和棉粕中游离棉酚(FG)质量分数的影响;对反应过程中的醇油摩尔比、反应时间、催化剂用量、反应温度进行了单因素和正交实验考察。实验得到的反应适宜条件为,棉仁含水量在1.92%左右,棉仁粒径小于0.335mm,反应醇油摩尔比135∶1,反应3h,甲醇中氢氧化钠浓度0.10mol/L,反应温度30℃。在上述反应条件下,反应产物中甲酯的质量分数可达97%,棉粕中游离棉酚的质量分数为0.031%,低于FAO规定的国际标准。  相似文献   

3.
The crude rapeseed oil was transesterified using methanol and using sodium hydroxide as a catalyst, and the varieties affecting the monoester yield were investigated. The methyl ester fuel called Biodiesel, produced under the determined optimum reaction conditions, was tested according to the standard methods for its fuel properties. Biodiesel fuel properties were found to be very close to those of Grade No. 2-D diesel fuel.  相似文献   

4.
采用共沉淀法制备了Ca/Al复合氧化物固体碱催化剂,考察了沉淀剂种类、Ca/Al摩尔比、沉淀温度、溶液pH值、老化时间和焙烧温度等制备条件对其催化剂活性的影响。采用正交实验方法得到制备Ca/Al复合固体碱催化剂前躯体的最佳制备条件为,沉淀剂NaOH,Ca/Al摩尔比为3,沉淀温度为60 ℃,沉淀过程中pH值保持在10,在90 ℃老化18 h。在该最优条件下制备的催化剂前驱体主要以Ca4Al2O6(NO3)2·10H2O晶相存在,在N2气保护下300 ℃焙烧2 h后,催化剂形成高分散钙铝复合氧化物,且碱性强度达到26.5以上。在催化菜籽油和甲醇的酯交换反应中,菜籽油的转化率达到95%,脂肪酸甲酯的质量分数为95.9%。  相似文献   

5.
本文研究了不同石墨烯基材料用作转酯化反应制备生物柴油催化剂的性能.将磺酸基或磷酸盐基嫁接到热还原的氧化石墨烯表面,制备了固体酸石墨烯基样品.并采用扫描电镜、X射线衍射、热重分析、X射线光电子能谱、N_2吸附-脱附法、电位滴定法、元素分析以及红外光谱法对所制样品进行了全面表征.将所制样品用于130℃带压力的条件下菜籽油与甲醇转酯化反应中,并将其催化活性与商用的多相酸催化剂Amberlyst-15的进行了比较.结果表明,所有改进的样品在转酯化反应中均表现出催化活性,但各样品上生物柴油产率差别较大.其中以苯二氮磺酸基功能化的热还原氧化石墨烯样品上脂肪酸甲酯产率最高,反应6 h后达70%,也明显高于商用催化剂Amberlyst-15.该样品也表现出良好的重复使用性能.  相似文献   

6.
Fe-Ca磁性固体碱催化剂上菜籽油酯交换反应   总被引:2,自引:0,他引:2  
采用原位沉淀法合成了双功能磁性固体碱催化剂CaO·γ-Fe2O3,用于催化菜籽油酯交换反应制备生物柴油。利用XRD、BET、TG-DTA、SEM和VSM对催化剂进行了表征,用ICP-AES对产物脂肪酸甲酯(FAME)中Ca、Fe残留量进行了测定。结果表明,Fe和Ca两种组分间有较好复合,催化剂显示出较好的磁学性能,饱和磁化率达到45.7emu/g,明显高于文献报道的磁性碱催化剂。在温和的反应条件(常压、64℃、催化剂加入量为油重的2.5%、醇油摩尔比15、转速750r/min)下,反应2h,重复使用前三次酯交换反应转化率都维持在95%左右。  相似文献   

7.
邢晓平  戴勇 《燃料化学学报》2011,39(12):907-911
以黄连木籽为原料,采用乙醇/异己烷两相不互溶溶剂对其进行萃取处理.考察了乙醇/异己烷体积比、萃取温度和萃取时间对萃取过程的影响.通过实验确定最佳的萃取条件为,黄连木仁粉50 g,乙醇异己烷总体积300 mL,乙醇/异己烷体积比为50∶50,萃取温度40℃,萃取时间30 min.在此条件下,黄连木籽油出油率达到99.5%...  相似文献   

8.
华根霉全细胞脂肪酶催化合成生物柴油   总被引:1,自引:0,他引:1  
贺芹  徐岩  滕云  王栋 《催化学报》2008,29(1):41-46
比较了5种不同商品化脂肪酶和自制的华根霉CCTCCM201021全细胞脂肪酶(RCL)催化油脂合成生物柴油的转化效果,结果表明,RCL能有效应用于无溶剂体系催化合成生物柴油.在无溶剂体系中对该酶催化生物柴油的转酯化反应工艺进行优化,考察了甲醇用量、体系含水量、酶的添加量和反应温度对生物柴油收率的影响,使生物柴油最终收率大于86.0%.在有机溶剂体系中选择不同有机溶剂作为助溶剂进行转酯化反应,发现logP值在4.0~4.5的有机溶剂具有较好的转化效果.其中以正庚烷为助溶剂的转酯化反应具有最高的生物柴油收率86.7%.在无溶剂体系中RCL催化转化油酸和模拟高酸价油脂合成脂肪酸甲酯的研究表明,该酶具有很好的催化合成生物柴油的潜力.  相似文献   

9.
麻疯油转酯化产物的高效液相色谱分析   总被引:2,自引:0,他引:2  
建立了高效液相色谱法同时测定麻疯油转酯化产物中4种主要脂肪酸甲酯的分析方法。样品经膜处理后用丙酮溶解,采用Hypersil ODS(C18)色谱柱进行分离。以乙腈为流动相进行等度洗脱,内标法定量,同时对色谱条件进行优化。结果表明,在优化的色谱条件下4种脂肪酸甲酯在10 min内得到良好的分离,标准曲线的线性相关系数均达到0.999以上,平均回收率为96%~98%,重现性相对标准偏差为7.2%~10.2%,重复性相对标准偏差为0.31%~2.02%。与气相色谱法相比,该方法具有较高的灵敏度,可用于麻疯油转酯化产物中脂肪酸甲酯含量的测定,为麻疯油转酯化反应制备生物柴油的定性定量分析提供了参考依据。  相似文献   

10.
袁冰  张新  侯万国 《化学研究》2011,22(6):25-28
采用共沉淀法制备了不同锂-铝比[n(Li)/n(Al)]的Li-Al类水滑石,经不同温度下焙烧得到复合氧化物;将复合氧化物作为大豆油与甲醇反应制备生物柴油的催化剂,考察了其对大豆油酯交换反应的催化性能.结果表明,n(Li)/n(Al)=13的类水滑石在400℃下焙烧得到的复合氧化物对大豆油酯交换反应具有极高的催化活性....  相似文献   

11.
Comparative characterization of Jatropha,soybean and commercial biodiesel   总被引:1,自引:0,他引:1  
Oil was extracted from seeds of Jatropha Curcas,in high yields(up to 40% by weight).The extracted Jatropha oil was converted in a laboratory reactor to biodiesel by transesterification.Analysis of Jatropha oil and Jatropha biodiesel by GC/MS and GC/SIMDIS showed that Jatropha oil could be readily converted to a biodiesel product through NaOH catalyzed transesterification.The resulting biodiesel has desirable properties such as high cetane number and low flash point,which are major improvements over the prop...  相似文献   

12.
13.
气相色谱法测定生物柴油中脂肪酸甲酯含量   总被引:10,自引:0,他引:10  
生物柴油是利用动植物油脂等可再生资源通过酯交换技术制造的可以替代石化柴油的新型清洁安全燃料[1-3]它的主要成分是脂肪酸甲酯。由于不同油脂原料所生产的生物柴油的脂肪酸甲脂组成不同因而测定时所需的气相色谱条件与方法也不尽相同[4-6]。本文采用HP-innowax毛细管色谱柱,  相似文献   

14.
钙镁负载型固体碱催化剂制备生物柴油   总被引:2,自引:0,他引:2  
固体碱催化剂;酯交换反应;脂肪酸甲酯;生物柴油  相似文献   

15.
以水滑石为载体,负载钾盐作为酯交换合成生物柴油的催化剂,采用XRD、Hammett指示剂-苯甲酸滴定、N2吸附-脱附、TG-DSC研究了活性组分和载体类型、焙烧温度和时间以及负载量对催化剂碱性和酯交换活性的影响.H-介于9.3 ~15的中强碱量是决定催化剂活性的主要因素.钾与水滑石高温焙烧形成的相互作用物种是催化剂中强...  相似文献   

16.
Emission profile of rapeseed methyl ester and its blend in a diesel engine   总被引:1,自引:0,他引:1  
Fatty acid methyl esters, also known as biodiesel, have been shown to have a great deal of potential as petro-diesel substitutes. Biodiesel comprise a renewable alternative energy source, the development of which would clearly reduce global dependence on petroleum and would also help to reduce air pollution. This paper analyzes the fuel properties of rapeseed biodiesel and its blend with petro-diesel, as well as the emission profiles of a diesel engine on these fuels. Fuels performance studies were conducted in order to acquire comparative data regarding specific fuel consumption and exhaust emissions, including levels of carbon monoxide (CO), carbon dioxide (CO2), smoke density, and NOx, in an effort to assess the performance of these biodiesel and blend. The fuel consumption amount of oil operations at high loads was similar or greater than that observed during petro-diesel operation. The use of biodiesel is associated with lower smoke density than would be seen with petro-diesel. However, biodiesel and its blend increased the emission of CO, CO2, and nitrogen oxides, to a greater degree than was seen with petro-diesel. The above results indicate that rapeseed biodiesel can be partially substituted for petro-diesel under most operating conditions, regarding both performance parameters and exhaust, without any modifications having to be made to the engine.  相似文献   

17.
This article reports experimental data on the production of fatty acid ethyl esters from refined and degummed soybean oil and castor oil using NaOH as catalyst. The variables investigated were temperature (30–70°C), reaction time (1–3 h), catalyst concentration (0.5–1.5 w/wt%), and oil-to-ethanol molar ratio (1:3–1:9). The effects of process variables on the reaction conversion as well as the optimum experimental conditions are presented. The results show that conversions >95% were achieved for all systems investigated. In general, an increase in reaction temperature, reaction time, and in oil-to-ethanol molar ratio led to an enhancement in reaction conversion, whereas an opposite trend was verified with respect to catalyst concentration.  相似文献   

18.
A magnetically recyclable eggshell-based catalyst (MKEC) was synthesized to circumvent saponification during the conversion of neem, Jatropha, and waste cooking oils (free fatty acid, 2.3–6.6%) to biodiesel. The characterization results indicated that MKEC had a mesoporous structure with the pore width of 3.24 nm, a specific surface area of 128 m2/g, and a pore volume of 0.045 cm3/g. The results confirmed that the MKEC is more tolerant to fatty acid poisoning than calcined eggshell. The effects of process parameters for maximum fatty acid methyl ester (FAME) content were evaluated by central composite design (CCD) and artificial neural network (ANN). The experimental FAME content of 94.5% was achieved for neem oil with a standard deviation (SD) of 0.68, which was in reasonable agreement with predicted values (CCD, 96.9%; ANN, 95.9%; SD, 0.73). The reusability studies showed that the mesoporous catalyst can be reused efficiently for five cycles without much deterioration in its activity.  相似文献   

19.
《Comptes Rendus Chimie》2015,18(5):525-529
The increasing demand for energy has encouraged the development of renewable resources and environmentally benign fuel such as biodiesel. In this study, ethyl fatty esters (EFEs), a major component of biodiesel fuel, were synthesized from soybean oil using sodium ethoxide as a catalyst. By-products were glycerol and difatty acyl urea (DFAU), which has biological characteristics, as antibiotics and antifungal medications. Both EFEs and DFAU have been characterized using Fourier transform infrared (FTIR) spectroscopy, and 1H nuclear magnetic resonance (NMR) technique. The optimum conditions were studied as a function of reaction time, reactant molar ratios, catalyst percentage and the effect of organic solvents. The conversion ratio of soybean oil into pure EFEs was 76% after 10 h of reaction. The highest conversion yield of EFEs is obtained when the urea/soybean oil ratio was from 6.2 mmol to 1 mmol, while the highest production of DFAU is obtained when the ethoxide (as a catalyst)/soybean oil ratio is from 6.4 mmol to 1 mmol in hexane as the reaction medium.  相似文献   

20.
双核碱性离子液体催化棉籽油酯交换制备生物柴油   总被引:12,自引:2,他引:12  
采用两步法制备了五种新型咪唑类碱性双核功能化离子液体化合物,并考察了对棉籽油酯交换制备生物柴油的催化性能。结果表明,咪唑类碱性双核功能化离子液体具有很好的催化活性,其催化活性与阳离子中碳链长度有关。其中,双-(3-甲基-1-咪唑)亚乙基双氢氧化物离子液体的催化活性最好。催化剂量、反应时间、反应温度及醇油比对生物柴油中脂肪酸甲酯含量及选择性影响的研究发现,在催化剂用量为0.4%(质量分数),醇油摩尔比为12,反应温度为55℃,反应时间为4 h时,脂肪酸甲酯的含量和选择性分别达98.5%和99.9%。催化剂7次循环后,产物中脂肪酸甲酯含量仍达到96.2%,单甘酯和双甘酯的含量很少,表明该催化剂重复使用良好。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号