花椒籽油生物柴油制备工艺研究

以花椒籽油为原料,对KOH催化其与甲醇发生酯交换反应制备生物柴油进行研究.采用物理萃取法降低花椒籽油中游离脂肪酸的含量,三次萃取后酸值达到2 mgKOH/g以下.研究了花椒籽油和甲醇在氢氧化钾催化下的酯交换反应.进行了不同醇油摩尔比、催化剂用量、反应时间、反应温度等反应条件下对产率的影响,得到最佳反应条件为醇油物质的量之比为12∶1,催化剂添加量为油脂质量的1.2％,反应温度为60 ～65℃,反应时间为45 min.     

亚临界甲醇中固体催化剂催化酯交换反应的活性比较

对几种固体催化剂用于亚临界甲醇与大豆油的酯交换反应制备生物柴油的催化活性进行了研究。考察在不同催化剂作用下酯交换反应产物中脂肪酸甲酯（FAMEs）含量随反应时间的变化规律。结果表明。在醇油摩尔比为40，反应温度为180℃，反应压力为2～3MPa，催化剂用量为3g及反应时间为10min的条件下，K2O／γ-Al2O3催化酯交换反应的产物中FAMEs含量达90％。     

氨基磺酸非均相催化菜籽油及废油脂制备生物柴油

采用正交试验和单因素试验的方法研究了氨基磺酸催化菜籽油及废油脂与甲醇的酯交换过程,考察了醇油物质的量比、催化剂用量、反应温度和反应时间对反应收率的影响。结果表明:菜籽油酯交换的最佳反应条件为醇油物质的量比6∶1,氨基磺酸用量为原料油质量的1.0%,反应温度60℃,反应时间20 min,此工艺条件下,脂肪酸甲酯的收率达到95.6%;废油脂酯交换的最佳反应条件为醇油物质的量比8∶1,氨基磺酸用量为原料油质量的1.0%、反应温度65℃,反应时间30 min,此工艺条件下,脂肪酸甲酯的收率达到87.5%。利用红外光谱表征了菜籽油和生物柴油的结构,气相色谱分析了生物柴油的组成。     

橡胶籽油制备生物柴油的工艺研究

实验研究了乙醇钠催化下橡胶籽油与乙醇进行酯交换反应制备生物柴油的工艺条件。通过正交实验和单因素实验,发现酯交换反应的最佳工艺条件:催化剂用量为油重的1.0%,醇油物质的量比为15∶1,反应温度为78℃,搅拌时间为120 min,在此反应条件下,橡胶籽油转化率为92.14%。     

桐油制备生物柴油的研究

以桐油为原料,研究了高酸值原料油的预酯化工艺条件,以及酯交换反应过程中甲醇加入的方式.对桐油预酯化工艺条件的研究结果表明,在搅拌速度一定的情况下,预酯化工艺的最佳条件为醇油摩尔比7∶1、硫酸用量为1.5%(质量比)、反应温度70℃、反应时间2 h;在研究的四个因素(醇油摩尔比,催化剂浓度,反应温度,反应时间)中,反应温度对酯化反应转化率的影响最大.在酯交换反应过程中,对分批加入甲醇的初步研究结果表明,在醇油摩尔比6 ∶1、KOH浓度 1%(质量比)、反应温度60℃、反应时间1 h的条件下,分两批加入甲醇的收率比一次加入甲醇的收率提高了4%.     

植物油制备生物柴油的研究

以植物油为原料，在催化剂（KOH）的作用下，通过甲醇酯交换反应生成脂肪酸甲酯即生物柴油的试验研究，考察了醇油比、催化剂用量、反应温度、反应时间等反应条件的变化对植物油转化率和产品纯度的影响。     

固体碱催化猪油制备生物柴油

运用实验研究和理论分析相结合的方法,阐述猪油和甲醇在CaO催化剂作用下进行酯交换反应制取生物柴油的基本原理和操作方法,分光光度法测定甘油含量,计算生物柴油转化率,得出以CaO催化猪油制取生物柴油的适宜反应条件。结果表明:CaO做催化剂时,催化剂用量为2.0%,醇油物质的量比为6∶1,反应时间为150min,温度为60℃进行磁力搅拌,反应产率最高可达93.68%。     

硫酸氢钠催化生物柴油合成反应的研究

以固体酸硫酸氢钠(NaHSO4·H20)为催化剂,以菜籽油和甲醇为反应物进行酯交换反应制备脂肪酸甲酯(生物柴油).采用正交实验考察了各因素对生物柴油产率的影响,得出最佳反应条件:反应温度为90℃,反应时间为12h,醇油物质的量比为40:1,催化剂用量为菜籽油质量的6%.极差顺序为温度、反应时间、醇油物质的量比、催化剂用量.     

SO42-/TiO2-ZrO2固体酸催化乌桕籽油制备生物柴油的研究

乌桕籽油是一种可再生的木本植物油料,可与甲醇发生酯交换反应制得生物柴油.试验表明,固体酸催化剂SO42-/TiO2-ZrO2对乌桕籽油酯交换反应表现出了较高的催化活性,当反应温度为150 ℃、醇油物质的量比为12:1、催化剂用量为乌桕籽油质量的5%、反应时间为6 h时,乌桕籽油的酯化率达到95%以上,催化剂重复和再生使用效果良好.同时,对该催化剂的SEM,TEM,XRD,BET结构表征表明,该催化剂表面呈多孔状,颗粒大小分布在10～100 nm,比表面积为114 m2/g,是一种纳米固体催化剂.     

高酸值生物柴油原料的预酯化反应装置的实验研究

以固体酸为催化剂,对高酸值废弃油脂进行预酯化反应研究。讨论了不同降低水分含量的方法对反应的影响,并考察了反应条件(醇油摩尔比、反应时间)对预酯化效果的影响。实验结果表明:在反应体系中添加吸水剂分子筛可提高预酯化反应效率;反应体系中添加过量的甲醇能大大缩短反应时间,在反应温度75℃,催化剂加入量为10%(W/W),最佳醇油摩尔比8∶1,最佳反应时间4h的条件下,可将酸化油的酸值降至3.8mgKOH.g-1,满足酯交换反应酸值小于4.0mgKOH.g-1要求。     

A comparative study of vegetable oil methyl esters (biodiesels)

In the present study, rubber seed oil, coconut oil and palm kernel oil, which are locally available especially in Kerala (India), are chosen and their transesterification processes have been investigated. The various process variables like temperature, catalyst concentration, amount of methanol and reaction time were optimized. Biodiesel from rubber seed oil (with high free fatty acid) was produced by employing two-step pretreatment process (acid esterification) to reduce acid value from 48 to 1.72 mg KOH/g with 0.40 and 0.35 v/v methanol-oil ratio and 1.0% v/v H₂SO₄ as catalyst at a temperature of 63(±2) °C with 1 h reaction time followed by transesterification using methanol-oil ratio of 0.30 v/v, 0.5 w/v KOH as alkaline catalyst at 55(±2) °C with 40 min reaction time to yield 98-99% biodiesel. Coconut oil and palm oil, being edible oils, transesterification with 0.25 v/v methanol-oil ratio, 0.50% w/v KOH as at 58(±2) °C, 20 min reaction time for coconut oil and 0.25% v/v methanol-oil ratio, 0.50% w/v KOH as alkaline catalyst at 60(±2) °C for palm kernel oil will convert them to 98-99% biodiesel. The brake thermal efficiency of palm oil biodiesel was higher with lower brake specific fuel consumption, but rubber seed oil biodiesel(ROB) showed less emission (CO and NO_x) compared to other biodiesels.     

Preparation, characterization and application of heterogeneous solid base catalyst for biodiesel production from soybean oil

A solid base catalyst was prepared by neodymium oxide loaded with potassium hydroxide and investigated for transesterification of soybean oil with methanol to biodiesel. After loading KOH of 30 wt.% on neodymium oxide followed by calcination at 600 °C, the catalyst gave the highest basicity and the best catalytic activity for this reaction. The obtained catalyst was characterized by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Thermogravimetric analysis (TGA), N₂ adsorption-desorption measurements and the Hammett indicator method. The catalyst has longer lifetime and maintained sustained activity after being used for five times, and were noncorrosive and environmentally benign. The separate effects of the molar ratio of methanol to oil, reaction temperature, mass ratio of catalyst to oil and reaction time were investigated. The experimental results showed that a 14:1 M ratio of methanol to oil, addition of 6.0% catalyst, 60 °C reaction temperature and 1.5 h reaction time gave the best results and the biodiesel yield of 92.41% was achieved. The properties of obtained biodiesel are close to commercial diesel fuel and is rated as a realistic fuel as an alternative to diesel.     

Optimization of biodiesel produced from watermelon (Citrullus vulgaris) using batch-type production unit

In the present work the production of a biodiesel from watermelon seed oil (Citrullus vulgaris) by methanol-induced transesterification using an alkaline catalyst (potassium hydroxide, KOH) has been examined. The influence of the operating variables such as agitation speed, temperature, reaction time, alcohol amount, and catalyst concentration was determined experimentally and found to be 550 rpm agitation rate, 60°C reaction temperature, 55 min reaction time, 20% of methanol, and 13 g of catalysts concentration for 2.5 liters of oil. The yield of biodiesel from the watermelon methyl ester (WME) under optimized conditions is found to be 91%. The properties of biodiesel are measured as per ASTM standards and compared with the base diesel.     

Biodiesel production from refined sunflower vegetable oil over KOH/ZSM5 catalysts

ZSM5 zeolite was impregnated with different KOH loadings (15 wt.%, 25 wt.% and 35 wt.%) to prepare a series of KOH/ZSM5 catalysts. The catalysts were calcined at 500 °C for 3 h and then characterized by N₂ adsorption–desorption and X-ray diffraction (XRD) techniques. The catalysts were tested in the transesterification reaction in a batch reactor at 60 °C and under atmospheric pressure. It was found that KOH/ZSM5 with 35 wt.% loading showed the best catalytic performance. The best reaction conditions in the presence of KOH/ZSM5 (35 wt.%) were determined while modifying the catalyst to oil ratio and the reaction time. The highest methyl ester yield (>95%) was obtained for a reaction time of 24 h, a catalyst to oil ratio of 18 wt.%, and a methanol to oil molar ratio of 12:1. The properties of produced biodiesel complied with the ASTM specifications. The catalytic stability test showed that 35KOH/ZSM5 was stable for 3 consecutive runs. Characterization of the spent catalyst indicated that a slight deactivation might be due to the leaching of potassium oxides active sites.     

A comparative study of KOH/Al2O3 and KOH/NaY catalysts for biodiesel production via transesterification from palm oil

The transesterification of palm oil to methyl esters (biodiesel) was studied using KOH loaded on Al₂O₃ and NaY zeolite supports as heterogeneous catalysts. Reaction parameters such as reaction time, wt% KOH loading, molar ratio of oil to methanol, and amount of catalyst were optimized for the production of biodiesel. The 25 wt% KOH/Al₂O₃ and 10 wt% KOH/NaY catalysts are suggested here to be the best formula due to their biodiesel yield of 91.07% at temperatures below 70 °C within 2–3 h at a 1:15 molar ratio of palm oil to methanol and a catalyst amount of 3–6 wt%. The leaching of potassium species in both spent catalysts was observed. The amount of leached potassium species of the KOH/Al₂O₃ was somewhat higher compared to that of the KOH/NaY catalyst. The prepared catalysts were characterized by using several techniques such as XRD, BET, TPD, and XRF.     

Production of biodiesel from food processing waste using response surface methodology

The optimum conditions for biodiesel production by the transesterification of waste oil form the pork grilling process in the food factory in Udon Thani, Thailand, using NaOH and KOH as catalysts, has been investigated. A Box–Behnken Design (BBD) followed by a Response Surface Methodology (RSM) with 30 runs was used to assess the significance of three factors: the methanol to oil molar ratio, the amount of NaOH and KOH used, and the reaction time required to achieve the optimum percent fatty acid methyl ester (%FAME). The measured %FAME following transesterification using NaOH as a catalyst was an optimum 95.6% with a methanol to oil molar ratio of 12.2:1, a NaOH percentage mass fraction of 0.49% and a reaction time of 63 min. Using KOH as a catalyst, the %FAME was an optimum 93.0% with a methanol to oil molar ratio of 12:1, a KOH percentage mass fraction of 0.61% and a reaction time of 72 min. The coefficient of determination (R²) for regression equations were 98.55% and 93.99%, respectively. The probability value (P<0.05) demonstrated a very good significance for the regression model. The physicochemical properties of the biodiesel obtained from the waste oil met the ASTM 6751 biodiesel standard, illustrating that waste oil from the pork grilling process can be used as a raw material for biodiesel production by transesterification.     

Biodiesel synthesis from Hevea brasiliensis oil employing carbon supported heterogeneous catalyst: Optimization by Taguchi method

The present work illustrates the parametric effects on biodiesel production from Hevea brasiliensis oil (HBO) using flamboyant pods derived carbonaceous heterogeneous catalyst. Activated carbon (AC) was prepared maintaining 500 °C for 1 h and steam activated at optimised values of activation time 1.5 h and temperature 350 °C. Carbonaceous support was impregnated with KOH at different AC/KOH ratios. The transesterification process was optimized and significant parameters affecting the biodiesel yield was identified by Taguchi method considering four parameters viz. reaction time, reaction temperature, methanol to oil ratio and catalyst loading. The physicochemical properties of Hevea brasiliensis methyl ester (HBME) were examined experimentally at optimised condition and found to meet the global American standards for testing and materials (ASTM). The optimum condition observed to yield 89.81% of biodiesel were: reaction time 60 min, reaction temperature 55 °C, catalyst loading 3.5wt% and methanol to oil ratio 15:1. Contribution factor revealed that among four parameters considered, catalyst loading and methanol to oil ratio have more prominent effect on biodiesel yield. The cost for preparing carbonaceous catalyst support was estimated and observed to be fairly impressive. Thus, Hevea brasiliensis oil (HBO) could be considered as suitable feedstock and flamboyant pods derived carbon as effective catalyst for production of biodiesel.     

Alkaline-catalyzed transesterification of Silurus triostegus Heckel fish oil: Optimization of transesterification parameters

The present work reports the production of biodiesel from Silurus triostegus Heckel fish oil (STFO) through alkaline-catalyzed transesterification by using potassium hydroxide (KOH) as an alkaline catalyst with methanol. Chemical and physical properties of the extracted oil were determined. It was found that STFO has a low acid value (1.90 mg KOH/g oil); hence no pre-treatment such as acid esterification is required to produce the biodiesel. The influence of the experimental parameters such as KOH concentration (0.25–1.0% w/w of oil), methanol to oil molar ratio (3:1, 6:1, 9:1 and 12:1), reaction temperature (32, 45 and 60 °C), reaction duration (30, 60, 90 and 120 min), type of the catalyst (potassium or sodium hydroxide) and step multiplicity (single- and two-step transesterification) on the yield of the biodiesel were investigated. The maximum biodiesel yield (96%) was obtained under the optimized parameters of the transesterification (KOH 0.50% w/w, 6:1 methanol to oil, at 32 °C for 60 min). The properties of the produced biodiesel were found to conform with the ASTM standard, indicating its suitability for internal combustion engines. Blending of the produced biodiesel with petro diesel with various volume percentages was investigated as well.     

Analysis and evaluation of operating variables for the yield of Karanja and neem oil-based biodiesel production

The aim of this research is to present the possibilities of the use of non-edible oils in biodiesel production, to consider the various methods for treatment of non-edible oils and to emphasise the influence of the operating and reaction conditions on the process rate and the ester yield. Because of biodegradability and non-toxicity biodiesel has become more attractive as alternative fuel. Biodiesel is produced mainly from vegetable oils by transesterification. For economic and social reasons, edible oils should be replaced by lower-cost and reliable feedstock for biodiesel production, such as non-edible plant oils. In this work biodiesel is produced from neem and Karanja by using butanol, propanol, ethanol and methanol as alcohols and KOH and NaOH as alkali catalysts by the transesterification process. The aim of this research is to analyse the different reaction parameters such as catalyst concentration, type of catalyst, types of alcohol, alcohol to oil molar ratio, reaction time and reaction temperature on the yield of biodiesel from non-edible oils. The maximum yield obtained was 95% with Karanja as oil with methanol and KOH as alkali catalyst at oil to alcohol molar ratio of 6:1 in 1 h at 60°C. Special attention is paid to the possibilities of producing biodiesel from non-edible oils.