Optimization of transesterification for methyl ester production from chicken fat

In this study, low cost feedstock chicken fat was used to produce methyl ester. After reducing the free fatty acid level of the chicken fat less than 1%, the transesterification reaction was completed with alkaline catalyst. Potassium hydroxide, sodium hydroxide, potassium methoxide and sodium methoxide were used as catalyst and methanol was used as alcohol for transesterification reactions. The effects of catalyst type, reaction temperature and reaction time on the fuel properties of methyl esters were investigated. The produced chicken fat methyl esters were characterized by determining their viscosity, density, pour point, flash point, acid value, methanol content, heat of combustion value, total-free glycerin, mono-di-tri glycerides, copper strip corrosion and ester yield values. The measured fuel properties of the chicken fat methyl ester met EN 14214 and ASTM D6751 biodiesel specifications when using potassium hydroxide and sodium hydroxide catalysts with high ester yield.     

膨润土催化脂肪酸甲酯合成二聚酸甲酯的工艺优化

利用响应面方法优化膨润土催化脂肪酸甲酯合成二聚酸甲酯的工艺参数,得到最优参数为:催化剂加入量10%,催化助剂LiCl 0.8%,反应温度220℃,反应时间6 h。在最优条件下,二聚体收率为64.8%,产物的理化特性分析显示各项性能指标优良。     

氯代甲氧基脂肪酸甲酯制备及应用研究

本文以主要成分为脂肪酸甲酯的生物柴油为主要原料,以甲醇为甲氧基化试剂,以过氧化苯甲酰为催化剂,进行氯化反应合成氯代甲氧基脂肪酸甲酯,通过添加一定添加剂的方法,就提高氯代脂肪酸甲酯的分解温度进行了研究和探讨。研究了氯代脂肪酸甲酯合成的基本条件和添加剂的不同比例的热稳定剂对氯代脂肪酸甲酯热稳定性的影响。     

Optimization of polyol ester production by transesterification of Jatropha-based methyl ester with trimethylolpropane using Taguchi design of experiment

Polyol ester production from transesterification of Jatropha oil methyl ester (JOME) and trimethylolpropane (TMP) was investigated. The effects of temperature, pressure, ratio of JOME:TMP and catalyst amount were studied in optimization experiment, using Taguchi L9 experimental layout. The parameters explored were found to have a significant impact on the reaction. The order of importance of the variables was found to be pressure, temperature, JOME:TMP molar ratio and catalyst. The optimum reaction conditions were identified to be 483 K, 25 kPa; 1.0% w/w catalyst and JOME:TMP molar ratio of 4:1. At this optimum condition the JOME conversion obtained was 91.5%. Confirmation experiments were performed to demonstrate the effectiveness of this approach after the optimum levels of process parameters were determined.     

Investigations on supercritical transesterification of chicken fat for biodiesel production from low-cost lipid feedstocks

Batch experiments on chicken fat reactions with methanol were performed at supercritical conditions to answer basic questions regarding the transesterification characteristics such as reactant ratios, lipid and reaction product thermal stability, reaction reversibility, nature of the intermediates, and glycerol consumption. The experiments were conducted at temperatures of 300-400 °C, pressures up to 41.1 MPa, methanol to triglyceride molar ratios of 3:1 and 6:1, and reaction times from 2 to 6 min. The results show that the transesterification process to produce biodiesel from low-cost lipid feedstocks with low excess of methanol and without glycerol generation is technically feasible. Since thermal decomposition of chicken fat at these temperatures is an important issue to be considered, batch experiments with emphasis on this aspect were also carried out. It was found that the thermal decomposition of chicken fat was not significant if heated up to 350 °C which will permit preheating the feedstock up to this temperature in a more practical flow process. Additional experiments showed that the overall transesterification at these conditions is not reversible and that the byproduct glycerol thermally decomposed and reacted with methanol to form ethers and other fuel components. The use of low-cost lipid feedstocks and moderate excess of methanol, associated with glycerol in situ consumption, has the potential to increase biodiesel profitability for continuous flow processes that are coupled with power generation.     

Process optimization for methyl ester production from waste cooking oil using activated carbon supported potassium fluoride

This paper presents the transesterification of waste cooking palm oil (WCO) using activated carbon supported potassium fluoride catalyst. A central composite rotatable design was used to optimize the effect of molar ratio of methanol to oil, reaction period, catalyst loading and reaction temperature on the transesterification process. The reactor was pressurized up to 10 bar using nitrogen gas. All the variables were found to affect significantly the methyl ester yield where the most effective factors being the amount of catalyst and reaction temperature, followed by methanol to oil ratio. A quadratic polynomial equation was obtained for methyl ester yield by multiple regression analysis using response surface methodology (RSM). The optimum condition for transesterification of WCO to methyl ester was obtained at 3 wt.% amount of catalyst, 175 °C temperature, 8.85 methanol to oil molar ratio and 1 h reaction time. At the optimum condition, the predicted methyl ester yield was 83.00 wt.%. The experimental value was well within the estimated value of the model. The catalyst showed good performance with a high yield of methyl ester and the separation of the catalyst from the liquid mixture is easy.     

In situ production of fatty acid methyl ester from low quality rice bran: An economical route for biodiesel production

Low quality rice bran was used to produce fatty acid methyl ester (FAME) via in situ extraction, esterification and transesterification process. The effects of the acid and alkaline catalysts on the ester yield, esterification and transesterification process were studied. When 75 ml of absolute methanol, 150 ml of petroleum ether, 0.75 g of concentrated sulfuric acid and 0.71 g of sodium hydroxyl were used, 16.69% (w_FAME/w_{rice bran}) of FAME was obtained. The esterification rate and the transesterification rate reached 98.83% and 80.47%. Based on the proposed route, the production process of FAME (biodiesel) could be simplified and the production cost could be reduced.     

Kinetics of methyl ester production from mixed crude palm oil by using acid-alkali catalyst

The production of biodiesel from high free fatty acid mixed crude palm oil using a two-stage process was investigated. The kinetics of the reactions was determined in a batch reactor at various reaction temperatures. It was found that the optimum conditions for reducing high free fatty acid (FFA) in MCPO (8-12 wt.%/wt oil) using esterification was a 10:1 molar ratio of methanol to FFA and using 10 wt.%/wt of sulfuric acid (based on FFA) as catalyst. The subsequent transesterification reaction to convert triglycerides to the methyl ester was found to be optimal using 6:1 molar ratio of methanol to the triglyceride (TG) in MCPO and using 0.6 wt.%/vol_TG sodium hydroxide as catalyst. Both reactions were carried out in a stirred batch reactor over a period of 20 min at 55, 60 and 65 °C. The concentration of compounds in each sample was analyzed by Thin Layer Chromatography/Flame Ionization Detector (TLC/FID), Karl Fischer, and titration techniques. The results were used for calculating the rate coefficients by using the curve-fitting tool of MATLAB. Optimal reaction rate coefficients for the forward and reverse esterification reactions of FFA were 1.340 and 0.682 l mol⁻¹ min⁻¹, respectively. The corresponding optimal transesterification, rate coefficients for the forward reactions of TG, diglyceride (DG), and monoglyceride (MG) of transesterification were 2.600, 1.186, and 2.303 l mol⁻¹ min⁻¹, and for the reverse reactions were 0.248, 0.227, and 0.022 l mol⁻¹ min⁻¹, respectively.     

脂肪酸甲酯乙氧基化物中未反应脂肪酸甲酯的测定

采用气相色谱法(GC)测定了不同脂肪酸甲酯乙氧基化物(MEE)中未反应的脂肪酸甲酯的质量分数。以十三酸甲酯为内标，对不同MEE进行了定性和定量分析，同时以十二酸甲酯为标准考察了回收率。实验结果表明：该法相对标准偏差在1．2％以内，回收率大于96％。由测定结果可知：GC法简便、快速、准确率高、重现性好、能准确测定不同MEE中未反应脂肪酸甲酯的质量分数，可作为MEE产品质量监控的方法，也可为MEE新产品、新配方研究与开发提供有效的参考依据。     

乙炔羰基化制丙烯酸甲酯工艺的优化

研究高压法乙炔羰基化合成丙烯酸甲酯的催化剂、反应条件及工艺。采用镍基复合催化剂,以丙酮为溶剂,加入固体酸分子筛,在催化剂用量为原料总质量的4.5%、阻聚剂用量为原料总质量的0.25%、HBEA分子筛加入量为原料总质量的0.50%、搅拌转速1 000 r·min-1、反应温度185℃、反应压力5.5 MPa和反应时间1.5 h条件下,丙烯酸甲酯选择性为85.4%,乙炔转化率为94.0%,丙烯酸甲酯收率为80.3%。     

杂化膜催化酯化与固体碱酯交换集成工艺制备生物柴油

以废鸡油为原料,建立杂化膜催化酯化-固体碱催化酯交换集成工艺制备生物柴油。考察醇油质量比、反应温度等对酯化反应的影响。采用气相色谱分析产物中脂肪酸组成;核磁共振氢谱计算鸡油中甘油三酯酯交换反应的转化率。结果表明,最佳工艺条件为:反应温度338 K,甲醇与废鸡油质量比为3∶1,鸡油酯化反应转化率为93.5%。气相色谱显示,废鸡油原料中含有的五种脂肪酸都转化成为脂肪酸甲酯,鸡油酯交换反应转化率为98.1%。制备出的生物柴油样品酸值、密度、运动黏度、闪点和硫含量多项指标均满足我国GBT 20828—2015、美国ASTM 6751—06e1和欧洲EN 14214生物柴油标准。     

杂化膜催化酯化与固体碱酯交换集成工艺制备生物柴油

以废鸡油为原料,建立杂化膜催化酯化-固体碱催化酯交换集成工艺制备生物柴油。考察醇油质量比、反应温度等对酯化反应的影响。采用气相色谱分析产物中脂肪酸组成;核磁共振氢谱计算鸡油中甘油三酯酯交换反应的转化率。结果表明,最佳工艺条件为:反应温度338 K,甲醇与废鸡油质量比为3∶1,鸡油酯化反应转化率为93.5%。气相色谱显示,废鸡油原料中含有的五种脂肪酸都转化成为脂肪酸甲酯,鸡油酯交换反应转化率为98.1%。制备出的生物柴油样品酸值、密度、运动黏度、闪点和硫含量多项指标均满足我国GBT 20828—2015、美国ASTM 6751—06e1和欧洲EN 14214生物柴油标准。     

乙酰丙酮酸甲酯的合成

叙述了在催化剂甲醇钠的存在下,以草酸二甲酯和丙酮为原料合成乙酰丙酮酸甲酯的工艺。通过对原料配比、温度、催化剂、溶剂等因素进行对比实验,确定了最佳工艺条件。结果表明:最佳配比为n(草酸二甲酯):n(丙酮):n(甲醇钠)=1:1.2:1.2,在此工艺条件下,可得白色针状的乙酰丙酮酸甲酯,收率为82.3%。     

脂肪酸甲酯磺酸盐的产业化

鉴于脂肪酸甲酯磺酸盐（MES）可以从廉价的动植物油中制取，对其生产的研究已有30多年。但是，早期研究脂肪酸甲酯磺酸盐生产的成果不理想，产品色泽深，从原料甲酯（ME）到MES的收率也低。消费者认为色泽浅的产品纯度高，所以色泽深不受欢迎。MES要想成为消费品中传统表面活性剂的一种替代品就必须先解决色泽深的问题。ME到MES的收率低是一个经济问题，因为它会显著增高MES的成本。收率低的原因是MES中的酯键断裂而生成甲醇和羧酸磺酸盐（二盐）。二盐无优良表面活性，所以生成二盐被视为收率的损失。因此，MES成功产业化的基本前提就是解决好色泽和收率这两个关键问题。     

Optimization of pretreatment of Jatropha oil with high free fatty acids for biodiesel production

A central composite rotatable design and response surface methodology were used in order to investigate the individual and combined effects of the ethanol-to-oil ratio, H₂SO₄ concentration, temperature and time of reaction on the reduction of free fatty acid (FFA) in jatropha oil. A quadratic polynomial model relating the reaction variables with FFA reduction was developed, presenting a good coefficient of determination (R²= 0.893). For reducing FFA to less than 1%, the optimal combination was found to be 0.62 v·v^-1 ethanol-to-oil ratio (14.9 v·v^-1 ethanol-to-FFA ratio), 1.7% v·v^-1 H₂SO₄ concentration, and 79 min reaction time at a reaction temperature of 54°C. These results are of great relevance to maximize methyl esters formation by transesterification using an alkaline catalyst.     

环保增塑剂环氧脂肪酸甲酯催化合成工艺优化

以甲酸、过氧化氢和脂肪酸甲酯为原料,通过改变工艺条件合成环氧脂肪酸甲酯。考察过氧化氢浓度、甲酸用量、反应温度、反应时间、过氧化氢滴加时间以及过氧化氢用量对环氧化产品环氧值和碘值的影响。经单因素实验得到最佳工艺条件：甲酸用量为脂肪酸甲酯质量的6%,反应温度80 ℃,反应时间4 h,过氧化氢滴加时间30 min,50%过氧化氢用量为脂肪酸甲酯质量的32%。与传统工艺相比,新工艺条件降低了甲酸用量,提高了过氧化氢浓度与反应温度,缩短了反应时间。     

湿法磷酸预处理工艺优化

提出一种湿法磷酸预处理的工艺优化方案,分别对脱砷、脱铅与脱氟引入二级过滤流程,使磷的回收更加充分,磷收率较其他湿法磷酸预处理类的工艺提高2～3百分点;同时将二级过滤回收的磷酸送磷矿石浮选工序作酸碱调节剂,实现了磷资源的综合利用.     

Optimization of the transesterification reaction in biodiesel production

In this paper response surface methodology (RSM) was used to study the transesterification reaction of rapeseed oil for biodiesel production. The three main factors that drive the conversion of triglycerides into fatty acid methyl esters (FAME) were studied according to a full factorial design at two levels. These factors were catalyst concentration (KOH), temperature and reaction time. The range investigated for each factor was selected taking into account the process of Fox Petroli S.p.A. Analysis of variance (ANOVA) was used to determine the significance of the factors and their interactions which primarily affect the first of the two transesterification stages. This analysis evidenced the best operating conditions of the first transesterification reaction performed at Fox’s plant: KOH concentration 0.6% w/w, temperature 50 °C and reaction time 90 min with a CH₃OH to KOH ratio equal to 60. Three empirical models were derived to correlate the experimental results, suitable to predict the behavior of triglyceride, diglyceride and monoglyceride concentration. These models showed a good agreement with the experimental results, demonstrating that this methodology may be useful for industrial process optimization.     

Modeling phase equilibrium in reaction mixture of methyl tert-butyl ether production

The complete mathematical model of phase equilibrium in four-component system forming in the methyl tert-butyl ether production was developed, and the assessment of its separation possibilities have been carried out using special techniques variety.