碱性离子液体1-甲基-3-丁基咪唑氢氧化物催化地沟油制备生物柴油的研究

本研究合成了碱性离子液体1-甲基-3-丁基咪唑氢氧化物,通过红外光谱和核磁共振检测与文献报道一致,以此离子液体为制备生物柴油的催化剂,发现具有很高的催化活性.在生物柴油的合成过程中,考察了离子液体的用量、醇与油物质的量比、反应温度和反应时间对酯交换反应的影响.结果显示,以地沟油制备生物柴油的最佳工艺条件为:醇油摩尔比8:1、反应温度70 ℃、反应时间110 min、催化剂用量为原料油质量的3.0 %.在此条件下, 脂肪酸甲酯转化率为95.7 %.由地沟油制备的生物柴油,其低温流动性能好,闪点高,除碘值较高外,其他主要性能符合0# 柴油标准,并且可以和0# 柴油进行调和使用.     

超声辅助提取美洲大蠊药渣残油及其制备生物柴油的研究

为探索美洲大蠊药渣的综合利用的新途径,以美洲大蠊药渣为原料,石油醚为提取溶剂,通过正交设计优化超声辅助提取工艺条件,考察超声功率、提取时间、料液比和提取次数对残油提取率的影响。对制备的残油,进一步以硫酸作为催化剂,与甲醇进行酯交换反应制备生物柴油,通过正交设计优化制备工艺条件,考察反应温度、反应时间、油醇比和催化剂用量对转化率的影响。美洲大蠊药渣残油的最佳提取工艺条件为,超声波功率300 W、提取时间0.5 h、料液比1∶8、提取次数4次。在最佳提取工艺条件下,得油率可达24.25%。生物柴油的最佳制备工艺条件为:反应温度为65℃、反应时间2.5 h、油醇比为1∶5 mol/mol、催化剂用量为1.5%。转化率可达94.37%。     

脂肪酶催化合成生物柴油的研究

生物柴油是用动植物油脂或长链脂肪酸与甲醇等低碳醇合成的脂肪酸甲酯,是一种替代能源。这里探讨了生物法制备生物柴油的过程,采用脂肪酶酯化和酯交换两条工艺路线进行催化合成。深入研究制备过程中,不同脂肪酶、酶的用量和纯度、有机溶剂、低碳醇的抑制作用、吸水剂的作用、反应时间和进程、底物的特异性和底物摩尔比等参数对酯化过程的影响。试验结果表明,采用最佳酯化反应参数和分批加入甲醇并用硅胶作脱水剂的工艺过程,酯化率可以达到92％,经分离纯化后的产品GC分析的纯度可达98％以上,固定化酶的使用半衰期可达到360h。同时对酯交换制备生物柴油过程中,甲醇的用量和甲醇的加入方式对脂肪酶催化过程的影响作了初步研究,优化后的酯交换率可达到83％。     

固定化脂肪酶催化制备生物柴油条件优化

本文探讨了以固定化脂肪酶为催化剂催化制备生物柴油中醇油比、水含量、游离脂肪酸酸值和催化剂使用寿命对菜子油酯交换反应的影响,并与以NaOH、固体碱纳米水滑石为催化剂生物柴油的制备条件相比较.研究表明:固定化脂肪酶为催化剂所需最佳醇油比最低,仅为4:1,游离脂肪酸含量对酯交换反应影响甚微,且有较强的抗水性,固定化脂肪酶催化剂可可重复使用6次;NaOH为催化剂酯交换反应抗水性最强,随游离脂肪酸的增加,酯交换转化率显著降低;纳米水滑石为催化剂可重复使用5次,酯交换产物易分离,所得产品完全符合德国生物柴油标准.     

白木通种子油的理化特性及制备生物柴油的研究

以白木通种子为实验材料,索氏提取法提取种子油,GC-MS测定脂肪酸组成,国标法测定理化性质,运用响应面法对碱催化白木通种子油酯交换制备生物柴油工艺进行优化。结果表明:白木通种子油含有5种脂肪酸,其中油酸含量最高,硬脂酸次之。白木通种子油的得率、含水量、碘值、酸值、皂化值、过氧化值、凝固点、闪点和冷滤点分别为32.76%、0.36%、67.89 g/100 g、8.85 mg KOH/g、235.03 mg KOH/g、47.08 mmol/kg、-12℃、215℃和-7℃。优化的生物柴油制备工艺为:反应时间80 min,醇油摩尔比6.7∶1,催化剂用量1.3%(按反应体系总质量计算)。白木通种子含油率高,可作为藤本油料作物开发利用。     

荧光假单胞菌脂肪酶固定化及催化制备生物柴油的工艺研究

研究了不同因素对制备固定化荧光假单胞菌脂肪酶的影响及固定化酶的酶学性质,并初步探讨了利用该固定化酶制备生物柴油的工艺。以海藻酸钠明胶为复合载体,采用包埋法制备固定化荧光假单胞菌脂肪酶,考察了载酶量、颗粒直径等因子对固定化效果的影响,并用制备的固定化酶进行了酶促酯交换合成生物柴油的工艺研究,考察了反应条件如酶量、反应温度、甲醇流加方式、醇油比等因素对甲酯得率的影响。试验结果表明,制备固定化荧光假单胞菌脂肪酶的最优条件为:每克载体给酶量为300 IU,选用6号注射器针头(内径为0.5 mm);通过酯交换,催化大豆油合成生物柴油的最佳反应工艺参数为:固定化酶25%,醇油比4:1,含水量6%,反应温度40℃;此条件下反应35 h后,甲酯的最高得率可达82%。     

叔丁醇体系中复合酶催化餐饮废油制备生物柴油工艺优化

以叔丁醇为反应体系,研究固定化Novozym 435 和Lipozyme TLIM 脂肪酶协同催化餐饮废油合成生物柴油.采用5 因素5 水平响应面法优化工艺参数,最佳工艺条件为:复合酶用量4%( wt.)、复合酶配比1:1(w/w),油/醇摩尔比1:5,反应温度50℃,叔丁醇用量50%(油体积比v/v).在此条件下反应10 h,生物柴油转化率为83.65 %.复合酶操作稳定性较高,重复使用10 个批次,生物柴油转化率仍保持在80% 以上.     

K_2CO_3/γ-Al_2O_3催化棕榈油和甲醇酯交换反应制备生物柴油

采用浸渍法制备K2CO3/γ-Al2O3负载型固体碱催化剂,用X线衍射(XRD)和热质量分析法(DSC-TGA)表征催化剂的物化性质,考察催化剂在棕榈油和甲醇酯交换制备生物柴油中的反应性能。结果表明:活性组分已成功负载到载体γ-Al2O3上,且在高温焙烧过程中K2CO3和γ-Al2O3之间产生了相互作用;在K2CO3负载量22.6%、醇油摩尔比12∶1、反应时间3h、催化剂质量分数3%、反应温度65℃的条件下,甲酯产率最高可达91.6%。     

超临界流体技术制备生物柴油进展及前景

超临界流体技术制备生物柴油不使用催化剂,生产过程清洁环保,是极具发展潜力的绿色可再生能源生产技术。本文首先简述超临界流体的特点及其用于生物柴油制备的物理、化学基础;其次详细分析超临界流体技术制备生物柴油的过程中反应温度、反应压力、醇油摩尔比、低碳醇种类、水、脂肪酸、反应器及反应形式等工艺控制条件对反应的影响和原因,并介绍超临界流体制备生物柴油中的过程强化方法和技术经济性。尽管超临界流体制备生物柴油具有原料适应性好、投资和运行成本低、生产过程清洁等优点,但存在反应条件苛刻、甲醇用量高等问题,从工业化角度指出使用廉价废弃油脂原料降成本、调节原料酸值降低反应苛刻度、连续化和大型化是超临界流体制备生物柴油技术的重点提升方向。     

微水相超声波协同固定化脂肪酶催化酯交换过程优化

超声波协同固定化脂肪酶催化制备生物柴油的最佳工艺条件为：超声波功率70W、叔丁醇为反应介质、叔丁醇用量3％（v／v）、醇油比3：1且甲醇分三批加入、反应温度40℃、水含量为2％（v／v）。副产物甘油对固定化脂肪酶使用寿命影响最大,使用后的固定化脂肪酶用丙酮洗去表面的甘油,进行酯交换反应,酶的稳定性大为提高,可连续使用16批次。     

Direct preparation of biodiesel from rapeseed oil leached by two-phase solvent extraction

A new method which coupled the two-phase solvent extraction (TSE) with the synthesis of biodiesel was studied. Investigations were carried out on transesterification of methanol with oil-hexane solution coming from TSE process in the presence of sodium hydroxide as the catalyst. Biodiesel (fatty acid methyl esters) were the products of transesterification. The influential factors of transesterification, such as reaction time, catalyst concentration, mole ratio of methanol to oil and reaction temperature were optimized. The results showed that the optimal reaction parameters were sodium hydroxide concentration 1.1% by weight of rapeseed oil, mole ratio of methanol to oil 9:1, reaction time 120 min, and reaction temperature 55-60 degrees C. Under these conditions, the TG conversion would rise up to 98.2%. Based on the new method, biodiesel production process could be simplified and the biodiesel cost could be reduced.     

Optimization Studies and Chemical Kinetics of Silica Sulfuric Acid-Catalyzed Biodiesel Synthesis from Waste Cooking Oil

In the present study conversion of waste cooking oil to biodiesel has been carried out via simultaneous esterification and transesterification reaction over silica sulfuric acid as a solid acid catalyst. The process variables that influence the fatty acid methyl ester (FAME) conversion, such as reaction temperature, reaction time, catalyst concentration and methanol to oil molar ratio were investigated and optimized using Taguchi method. Highest FAME production obtained under the optimized condition was 98.66 %. Analysis of variance revealed that temperature was the most significant factor effecting the FAME production among four factors studied. From the kinetic study, the reaction was found to follow pseudo first-order kinetics and rate constant of the reaction under optimum condition was 0.00852 min^?1.     

Transesterification of palm oil to methyl ester on activated carbon supported calcium oxide catalyst

In this study, methyl ester (ME) was produced by transesterification of palm oil (CPO) (cooking grade) using activated carbon supported calcium oxide as a solid base catalyst (CaO/AC). Response surface methodology (RSM) based on central composite design (CCD) was used to optimize the effect of reaction time, molar ratio of methanol to oil, reaction temperature and catalyst amount on the transesterification process. The optimum condition for CPO transesterification to methyl ester was obtained at 5.5 wt.% catalyst amount, 190 °C temperature, 15:1 methanol to oil molar ratio and 1 h 21 min reaction time. At the optimum condition, the ME content was 80.98%, which is well within the predicted value of the model. Catalyst regeneration studies indicate that the catalyst performance is sustained after two cycles.     

Ultrasonic monitoring of glycerol settling during transesterification of soybean oil

A low-intensity ultrasonic measurement system was used to monitor the products of transesterification of soybean oil in methanol to FAME (biodiesel). The byproducts of the transesterification reaction are methyl esters, glycerol and other products. During the transesterification reaction, the glycerol, having a higher density than the methyl ester, settles at the bottom of the reaction vessel. The aim of this study was to measure the glycerol deposition rate during transesterification and to assess the reaction rate and end time. Soybean oil was converted into biodiesel at four temperature levels. The amount of catalyst (KOH) used in the transesterification reactions was determined by titration. The ultrasonic waveforms captured during the reaction were recorded and analyzed automatically. The ultrasonic system monitored the effects of reaction temperatures on the glycerol settling rate and the reaction end times. The ultrasonic measurement of glycerol settling would be a useful non-destructive method for evaluating the effects of parameters such as catalyst amount, mixing time and temperature on transesterification reactions.     

Ethanesulfonic acid-based esterification of industrial acidic crude palm oil for biodiesel production

An industrial grade acidic crude palm oil (ACPO) pre-treatment process was carried out using ethanesulfonic acid (ESA) as a catalyst in the esterification reaction. ESA was used in different dosages to reduce free fatty acid (FFA) to a minimum level for the second stage of biodiesel production via alkaline transesterification reaction. Different process operating conditions were optimized such as ESA dosage (0.25-3.5% wt/wt), methanol to ACPO molar ratio (1:1-20:1), reaction temperature (40-70 °C), and reaction time (3-150 min). This study revealed the potential use of abundant quantities of ACPO from oil palm mills for biodiesel production. The lab scale results showed the effectiveness of the pre-treatment process using ESA catalyst. Three consecutive catalyst recycling runs were achieved without significant degradation in its performance. Second and third reuse runs needed more reaction time to achieve the target level of FFA content. Esterification and transesterification using ESA and KOH respectively is proposed for biodiesel industrial scale production. The produced biodiesel meets the international standards specifications for biodiesel fuel (EN 14214 and ASTM D6751).     

高含游离脂肪酸的香果树籽油制备生物柴油的方法

目前生物柴油因其环保和可再生利用资源的特性备受关注。多数生物柴油是通过甲醇和碱催化食用油得到的,而大量非食用油也可以制备生物柴油。本文报道用高含游离酸脂肪油快速高效低成本制备成其单酯的二步法工艺。先用1% H2SO4以少于1.5%量对甲醇和云南特产香果树（Lindera communis）籽的粗原料油以10∶1摩尔比组成的混合液酸催化酯化游离脂肪酸;之后再对醇和得到的油脂产品按摩尔比15∶1的混合液碱催化转化为单甲酯和甘油。本方法是一个直接甲脂化制备生物柴油的工艺简洁、降低成本的新技术。文中还讨论了该工艺影响转化效率的主要因素,如摩尔比,催化量,温度,反应时间和酸度。香果树生物柴油不重蒸,而其生物柴油的主要特性,如粘度、热值、比重、闪点、冷滤点等与生物柴油标准的匹配度,也做了报道,研究结果将为香果树生物柴油以非重蒸油料制备生物柴油产品,作为潜在的柴油燃料替代产品提供技术支撑。     

Production of biodiesel and lactic acid from rapeseed oil using sodium silicate as catalyst

Biodiesel and lactic acid from rapeseed oil was produced using sodium silicate as catalyst. The transesterification in the presence of the catalyst proceeded with a maximum yield of 99.6% under optimized conditions [3% (w/w) sodium silicate, methanol/oil molar ratio 9/1, reaction time 60 min, reaction temperature 60 °C, and stirring rate 250 rpm]. After six consecutive transesterification reactions, the catalyst was collected and used for catalysis of the conversion of glycerol to lactic acid. A maximum yield of 80.5% was achieved when the reaction was carried out at a temperature of 300 °C for 90 min. Thus, sodium silicate is an effective catalyst for transesterification and lactic acid production from the biodiesel by-product, glycerol.     

Optimization of alkali-catalyzed transesterification of Pongamia pinnata oil for production of biodiesel

Studies were carried out on transesterification of Karanja oil with methanol for the production of biodiesel. The reaction parameters such as catalyst concentration, alcohol/oil molar ratio, temperature, and rate of mixing were optimized for production of Karanja oil methyl ester (KOME). The fatty acid methyl esters content in the reaction mixture were quantified by HPLC and 1H NMR method. The yield of methyl esters from Karanja oil under the optimal condition was 97-98%.     

Soybean oil methyl esters preparation using NaX zeolites loaded with KOH as a heterogeneous catalyst

The transesterification of soybean oil with methanol to methyl esters was carried out using NaX zeolites loaded with KOH as a solid base catalyst. Best result was obtained with NaX zeolite loaded with 10% KOH, followed by heating at 393 K for 3 h. When the transesterification reaction was carried out at reflux of methanol (338 K), with a 10:1 molar ratio of methanol to soybean oil, a reaction time of 8 h and a catalyst amount of 3 wt.%, the conversion of soybean oil was 85.6%.