碘催化餐饮废油合成生物柴油

以餐饮废油脂为原料,先用硅藻土对其进行脱色,再在I2的催化作用下,用已脱色的餐饮废油为原料合成生物柴油。并考察了反应温度,反应时间,醇油比和催化剂用量4个因素对产量的影响,得到了利用餐饮废油合成生物柴油的工艺条件：反应温度为60℃,反应时间为2h,醇油比为2∶1,催化剂用量为1.3%。在最佳工艺条件下,生物柴油的收率为58.8%。     

固定化脂肪酶催化废油合成生物柴油

研究了固定化假丝酵母99-125脂肪酶在有溶剂的体系下催化废油合成生物柴油过程中,油醇摩尔比、有机溶剂性质、底物浓度、体系含水量、甲醇流加等因素对反应过程的影响.研究结果表明,在最佳实验条件下,反应转化率最高可达92％,酶的使用寿命可达7批以上.     

利用废食用油制备生物柴油的研究

研究了利用废食用油制备生物柴油的方法和工艺流程.以浓硫酸为催化剂,将废食用油中的游离脂肪酸先进行甲酯化,再以氢氧化钠为催化剂,对其中的甘油三酯进行酯交换制备生物柴油,通过正交实验分析游离脂肪酸甲酯化及甘油三酯酯交换的最佳条件.     

Rice husk ash as an adsorbent for purifying biodiesel from waste frying oil

The goal of this work is to study the purification of biodiesel from waste frying oil (WFO) using rice husk ash (RHA) at concentrations of 1%, 2%, 3%, 4% and 5% (w/w) and compare it with two other different purification methods, the traditional acid solution (1% aqueous H₃PO₄) and with the commercial adsorbent Magnesol® 1% (w/w). The structure and composition of the RHA were studied to better understand its properties as an adsorbent. In a concentration of 4%, the RHA showed excellent results for removal impurities from biodiesel. The high concentration of silica in its composition and the presence of meso and macropores can explain its high capacity of adsorption. Thus, the RHA, that is a byproduct of the rice processing, can appear as an alternative material for biodiesel purification.     

Physical-chemical properties of waste cooking oil biodiesel and castor oil biodiesel blends

This work presents the physical-chemical properties of fuel blends of waste cooking oil biodiesel or castor oil biodiesel with diesel oil. The properties evaluated were fuel density, kinematic viscosity, cetane index, distillation temperatures, and sulfur content, measured according to standard test methods. The results were analyzed based on present specifications for biodiesel fuel in Brazil, Europe, and USA. Fuel density and viscosity were increased with increasing biodiesel concentration, while fuel sulfur content was reduced. Cetane index is decreased with high biodiesel content in diesel oil. The biodiesel blends distillation temperatures T₁₀ and T₅₀ are higher than those of diesel oil, while the distillation temperature T₉₀ is lower. A brief discussion on the possible effects of fuel property variation with biodiesel concentration on engine performance and exhaust emissions is presented. The maximum biodiesel concentration in diesel oil that meets the required characteristics for internal combustion engine application is evaluated, based on the results obtained.     

废动植物油生产生物柴油的工程设计

介绍了以废动植物油为原料,在自制新型微酸性DYD催化剂的作用下,通过酯交换反应生成生物柴油的设计过程。根据各个步骤的反应条件及其生产物的特性,结合工业化生产流程的一般规律,通过物性计算,设计出工业化生产工艺流程。结果表明:醇解与酯化转化率达到95.9%,无污染物排放,生物柴油的各项性能指标均达到美国同类产品的标准(D6751-03a),为发展生物柴油探索了一条切实可行的途径。     

响应面法优化脂肪酶催化废油脂合成生物柴油工艺的研究

利用响应面法对酶催化废油合成生物柴油复杂的反应条件进行优化研究.采用6因素5水平和中心组分旋转设计法研究了反应温度、酶用量、流加次数、有机溶剂用量、底物摩尔比和水含量诸因素共同作用对反应转化率的影响.优化后的反应条件为反应温度34℃、酶用量30%(相对于油的质量分数)、流加次数4次、有机溶剂用量和水含量皆为0、底物醇油摩尔比为2,在该反应条件下转化率可达94.6%.     

Metakaolinite as a catalyst for biodiesel production from waste cooking oil

The use of metakaolinite as a catalyst in the transesterification reaction of waste cooking oil with methanol to obtain fatty acid methyl esters (biodiesel) was studied. Kaolinite was thermally activated by dehydroxylation to obtain the metakaolinite phase. Metakaolinite samples were characterized using X-ray diffraction, N₂ adsorption-desorption, simultaneous thermo-gravimetric analyse/differential scanning calorimetry (TGA/DSC) experiments on the thermal decomposition of kaolinite and Fourier-transform infrared spectrometer (FTIR) analysis. Parameters related to the transesterification reaction, including temperature, time, the amount of catalyst and the molar ratio of waste cooking oil to methanol, were also investigated. The transesterification reaction produced biodiesel in a maximum yield of 95% under the following conditions: metakaolinite, 5 wt-% (relative to oil); molar ratio of oil to methanol, 1∶23; reaction temperature, 160°C; reaction time, 4 h. After eight consecutive reaction cycles, the metakaolinite can be recovered and reused after being washed and dried. The biodiesel thus obtained exhibited a viscosity of 5.4?mm²?s^–1 and a density of 900.1 kg?m^–3. The results showed that metakaolinite is a prominent, inexpensive, reusable and thermally stable catalyst for the transesterification of waste cooking oil.     

甲醇钠催化地沟油制备生物柴油研究

以浓硫酸为催化剂,高酸值地沟油与甲醇酯化反应降酸的最优工艺条件为:n(甲醇):n(地沟油)=9:1,m(浓硫酸):m(地沟油)=1.1％,反应温度60℃,反应时间5h.制备生物柴油的最优工艺条件为:以甲醇钠为催化剂,反应时间2h,反应温度65℃,n(甲醇):n(地沟油)=7:1,m(甲醇钠):m(地沟油)=0.8％.制...     

高酸值废油制备生物柴油的研究

以高酸值废弃油脂为原料,以同体酸为催化剂催化酸化油的预酯化反应,KOH催化转酯化反应,较系统地研究了醇-油摩尔比、反应温度、催化剂加入量、反应时间等因素对预酯化效果的影响.其优化的操作条件为:醇-油摩尔比8∶1,反应釜温度75℃,催化剂加入量为10%,反应4 h,高酸值废油的酸值由140 mg/g可降至3.8 ms/g,达到下一步酯交换阶段不出现皂化现象的要求.经KOH催化酯交换和精馏后制得的生物柴油产品部分主要指标达到德国现行生物柴油标准DIN V51606.     

预酯化-酯交换法利用餐饮废油脂制备生物柴油

以高酸值餐饮废油脂和乙醇为原料,采用预酯化-酯交换法制备生物柴油。第一步为预酯化反应,控制反应温度为70℃,最佳条件为:催化剂加入量为4%,反应时间为90min,带水剂加入量为10%,乙醇加入量控制在醇酸摩尔比为6∶1,可使油脂酸值降至4mg KOH·g-1以下,满足酯交换反应要求。第二步为酯交换反应,最佳条件是:醇油摩尔比为8∶1,碱性催化剂加入量为0.8%,反应温度为70℃,反应时间为30min。本方法具有反应时间短、转化率高,反应条件温和,清洁环保等优点。     

废油脂预处理及制备生物柴油研究进展

介绍了废油脂的预处理工艺及我国废油脂的现状,重点阐述了国内外以废油脂为原料经碱法、酸法和酶法酯交换制备生物柴油的研究情况,并对目前存在的问题和相应的解决对策进行了简单的讨论。     

离子液体催化大豆油制备生物柴油

制备了对水稳定性好、带—SO₃H官能团的咪唑丙烷磺酸硫酸氢盐离子液体，并以其作为催化剂进行了大豆油酯交换反应制备生物柴油的研究。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及离子液体的稳定性。实验结果表明，在n(甲醇)∶n(大豆油) =12∶1、反应温度120 ℃、反应时间8 h和催化剂用量为原料油质量的4.0%条件下,产物中脂肪酸甲酯收率可达96.5%,且离子液体的稳定性好,可循环使用。     

Effect of methanol content on enzymatic production of biodiesel from waste frying oil

The enzymatic production of biodiesel from waste frying oil with methanol has been studied using immobilized lipase Novozym 435 as catalyst. The effects of methanol to oil molar ratio, dosage of enzyme and reaction time were investigated. The optimum reaction conditions were methanol to oil molar ratio of 25:1, 10% of Novozym 435 based on oil weight and reaction period of 4 h at 50 °C obtaining a biodiesel yield of 89.1%. Moreover, the reusability of the lipase over repeated cycles was also investigated under standard conditions.     

An experimental investigation of biodiesel synthesis from waste canola oil using supercritical methanol

Synthesis of biodiesel from waste canola oil using supercritical methanol is investigated under relatively moderate reaction conditions (240–270 °C/10 MPa) with residence time of 15–45 min and methanol to oil weight ratio of 1:1, 1.5:1 or 2:1. The effects of reaction conditions on the biodiesel yield were studied using design of experiments (DOE). The results showed that reaction time, temperature, and their interaction were the most significant factors on the yield. The highest biodiesel yield of 102% was achieved at 270 °C, 10 MPa, and methanol/oil weight ratio of 2 for 45 min reaction time. The GC–MS analysis of the reaction products showed that the by-product, glycerol, further reacted with methanol, generating methyl ethers of glycerol. Further confirmation of this side reaction was obtained by reacting glycerol and methanol at 270 °C/10 MPa for 15, 30, and 45 min. The experimental results showed these reactions could positively affect the overall biodiesel yield by providing oxygenated compounds such as 3-methoxy-1,2-propanediol, dimethoxymethane, and 2,2-dimethoxypropane as well as methyl palmitate and methyl oleate.     

Statistical optimization for lithium silicate catalyzed production of biodiesel from waste cooking oil

Lithium silicate is one of the suitable heterogeneous catalysts for biodiesel production. The possibilities of large number of combinations of different reaction parameters make the optimization of biodiesel production process over various heterogeneous catalysts highly tedious, necessitating the development of alternate strategies for parameter optimization. Here, Box-Behnken design (BBD) coupled with response surface methodology (RSM) is employed to optimize the process parameters required for the production of biodiesel from waste cooking oil using lithium silicate as catalyst. Simple method of impregnation was performed for the material preparation and the catalyst was analyzed using different techniques. It was found that the activity is directly proportional to the basicity data obtained from temperature programmed desorption (TPD) of CO₂ over various catalyst systems. The material exhibits macroporous morphology and the major crystalline phase of the most active catalyst was found to be Li₂SiO₃. The effects of different reaction parameters were studied and a biodiesel yield of 100% was obtained under the predicted optimum reaction conditions of methanol : oil molar ratio 15 : 1, catalyst amount 7 wt%, reaction temperature 55 °C and reaction time 2.5 h. The validation experiments showed a correlation coefficient of 0.95 between the predicted and experimental yield of biodiesel, which indicates the high significance of the model. The fuel properties of biodiesel obtained under the optimum conditions met the specifications as mentioned in ASTM D6751 and EN 14214 standards. Catalyst heterogeneity and low reaction temperature are the major attractions of the present biodiesel preparation strategy.     

废弃油脂超临界法制备生物柴油研究

以废弃油脂为原料,利用超临界法制备生物柴油.通过单因素实验及正交实验研究了醇油摩尔比、反应压力、催化剂用量、反应时间、反应温度等因素对生物柴油产率的影响.结果表明,在实验范围内各影响因素对生物柴油产率作用的大小依次为:反应温度>反应压力>催化剂用量>反应时间>醇油摩尔比.废弃油脂超临界法制备生物柴油的最佳工艺条件为:反应温度240℃,反应压力10MPa,反应时间6min,催化剂用量0.06%,醇油摩尔比40/1.在此条件下,生物柴油产率达到99.37%.     

Production of biodiesel from waste vegetable oil using impregnated diatomite as heterogeneous catalyst

In this study, biodiesel was produced from waste vegetable oil using a heterogeneous base catalyst synthesized by impregnating potassium hydroxide (KOH) onto diatomite. Response surface methodology based on a central composite design was used to optimize four transesterification variables:temperature (30–120 °C), reaction time (2–6 h), methanol to oil mass ratio (10%–50%) and catalyst to oil mass ratio (2.1%–7.9%). A quadratic poly-nomial equation was obtained to correlate biodiesel yield to the transesterification variables. The diatomite–KOH catalyst was characterized using X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR) and a scanning electron microscope (SEM) equipped with an energy dispersive X-ray detector (EDS). A maximum biodiesel yield of 90%(by mass) was obtained. The reaction conditions were as follows:methanol to oil mass ratio 30%, catalyst to oil mass ratio 5%, reaction time 4 h, and reaction temperature 75 °C. The XRD, FTIR and SEM (EDS) results confirm that the addition of KOH modifies the structure of diatomite. During impregnation and calcination of the diatomite catalyst the K2O phase forms in the diatomite structural matrix and the active basicity of this compound facilitates the transesterification process. It is possible to recycle the diatomite–KOH catalyst up to three times. The crucial biodiesel properties from waste vegetable oil are within the American Stan-dard Test Method specifications.     

高酸值废弃油脂制备生物柴油的预酯化

为了有效解决现有酯化体系中存在反应慢、时间长、产能低等问题,提出了一种高温下甲醇连续酯化反应的新技术,并采用该技术以对甲苯磺酸为催化剂催化高酸值废弃油脂预酯化试验研究。系统讨论了不同酯化方法对反应的影响,并着重研究了工艺条件对预酯化效果的影响。实验结果表明:高温下甲醇连续酯化的新技术可显著提高酯化反应效率,在反应温度120℃、甲醇流量4.0mL/min、催化剂加入量0.8%的条件下,酯化率达98.8%以上,可将油脂的酸值降至1.0mgKOH/g以下,满足下一步酯交换制备生物柴油的要求;并基于实验研究的基础上将该技术工艺对不同酸值的废弃油脂进行了放大试验研究,皆取得了较好的酯化效果,为产业化、规模化的应用提供理论依据和参数指导。     

A novel ultrasonic reactor for continuous production of biodiesel from waste acid oil

FAME was produced by a two-step in-situ transesterification of acid oil (AO) with methanol in a novel continuous flow ultrasonic reactor system composed of four ultrasonic reactors with different frequency. The hydrodynamic behavior of the reactor was investigated by a step response technique, and the effect of ultrasonic frequency on mono-alkyl esters of long chain fatty acids (FAMEs) formation was also investigated. The production process includes an in-situ sulfuric acid-catalyzed esterification of AO with methanol in the first two ultrasonic reactors successively followed by an in-situ base-catalyzed transesterification in the other two ultrasonic reactors. The AO initial free fatty acids (FFA) content about 17.5 w% was cut down to less than 1 w% by sulfuric acid-catalyzed esterification. FAME yields in excess of 97.0% identified by gas chromatography/mass spectrometry (GC/MS) were obtained by the two-step in-situ reaction. The maximum and minimum volumetric productivity could reach 13.76 L·h^?1 and 10.24 L·h^?1 respectively.