固体酸催化废油酯制备脂肪酸丁酯

研究以废油酯为原料在固体酸催化作用下与丁醇酯交换反应制备脂肪酸丁酯的过程,采用气相色谱对脂肪酸丁酯的含量进行分析。考察了醇油摩尔比、催化剂用量、反应温度和反应时间对酯化反应转化率的影响。结果表明,该反应的最适宜工艺条件为：醇油摩尔比16∶1,催化剂用量1.2%,反应温度115℃,反应时间4 h。废油酯在最优工艺条件下,经过酯交换反应得到的转化率超过83%。     

白云石非均相催化合成生物柴油的工艺研究

以大豆油、甲醇为原料,研究了通过白云石催化酯交换反应制取生物柴油的工艺的条件。用气相色谱-质谱分析法,并对反应温度、醇油摩尔比、反应时间、催化剂的用量及催化剂粒径进行考察,得出最佳合成条件为:反应温度65℃、反应时间2h、醇油摩尔比7:1,催化剂用量2%,催化剂粒径为80～150目,在此条件下得到生物柴油转化率为77.36%。     

负载型固体碱催化合成甲酯生物柴油的研究

采用浸渍法制备了Na2CO3/高岭土负载型固体碱催化剂,用于催化大豆油与甲醇酯交换反应制备甲酯生物柴油。考察了反应时间、催化剂用量、反应温度和醇油摩尔比对酯交换反应转化率的影响,并通过单因素试验确定了最优工艺条件。结果表明:反应时间4 h、反应温度60℃、催化剂用量3%和醇油摩尔比12∶1条件下,酯交换反应转化率达到90.5%。     

碱催化法制备生物柴油工艺研究

在250m l间歇式高压反应器中,以大豆油为原料,研究KOH催化甲醇酯交换反应制备生物柴油的工艺条件。主要考察了醇油摩尔比、反应温度、反应时间、催化剂用量等操作条件对脂肪酸甲酯转化率的影响。结果表明,当KOH用量为1%(wt),醇油摩尔比为5∶1,反应温度为65℃时,反应时间为15m in,脂肪酸甲酯的转化率可以达到92%。     

Na^＋／MgO固体碱催化制备生物柴油

利用等体积浸渍法制备了不同浓度NaOH浸渍的Na+/MgO固体碱,并考察了它们对制备生物柴油的催化性能.探讨了催化剂用量,醇油摩尔比,反应温度及反应时间对酯交换反应的影响,利用正交分析得到了反应的最佳条件:催化剂用量为原料油质量的2%,醇油摩尔比12:1,反应温度为60℃,反应时间90 min,转化率可达82.3%.     

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%。     

分子筛型固体碱催化剂用于酯交换反应制备生物柴油

采用等体积浸渍法制备了NaOH/NaX固体碱催化剂,用于催化大豆油与甲醇酯交换反应制备甲酯生物柴油。考察了NaOH负载量、焙烧温度、反应时间、反应温度、催化剂用量和醇油摩尔比对转化率的影响。结果表明,在NaOH负载量25%,焙烧温度500℃,反应时间4 h,反应温度65℃,催化剂用量3%和醇油摩尔比12条件下,转化率达95.3%。     

正交试验探讨固体碱催化制备生物柴油

采用等体积浸渍法制备了K2CO3/NaX固体碱催化剂,用于催化酯交换反应制备甲酯生物柴油。通过正交试验方法确定了最佳反应条件为:反应时间3 h、反应温度60℃、催化剂用量4%和醇油摩尔比14。在此反应条件下生物柴油的转化率可达87.5%。     

正交试验探讨固体碱催化制备生物柴油

采用等体积浸渍法制备了K2CO3/NaX固体碱催化剂,用于催化酯交换反应制备甲酯生物柴油。通过正交试验方法确定了最佳反应条件为:反应时间3 h、反应温度60℃、催化剂用量4%和醇油摩尔比14。在此反应条件下生物柴油的转化率可达87.5%。     

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。     

利用废食用油制备生物柴油的研究

对利用废食用油制备生物柴油的预酯化-酯交换工艺进行了研究。结果表明,预酯化的最佳工艺条件为：乙醇用量为80 mL、催化剂浓硫酸用量为1 g、反应时间为3 h、反应温度为70℃;酯交换的最佳工艺条件为：乙醇用量为60 mL、催化剂氢氧化钾用量1 g、反应时间为40 min、反应温度为70℃。在此条件下可使50 mL废食用油的酸值由40.27 mg KOH/g降到1.52 mg KOH/g,粗生物柴油的产率可达93.71%。     

Conversion of waste cooking oil to biodiesel using ferric sulfate and supercritical methanol processes

In this comparative study, conversion of waste cooking oil to methyl esters was carried out using the ferric sulfate and the supercritical methanol processes. A two-step transesterification process was used to remove the high free fatty acid contents in the waste cooking oil (WCO). This process resulted in a feedstock to biodiesel conversion yield of about 85-96% using a ferric sulfate catalyst. In the supercritical methanol transesterification method, the yield of biodiesel was about 50-65% in only 15 min of reaction time. The test results revealed that supercritical process method is probably a promising alternative method to the traditional two-step transesterification process using a ferric sulfate catalyst for waste cooking oil conversion. The important variables affecting the methyl ester yield during the transesterification reaction are the molar ratio of alcohol to oil, the catalyst amount and the reaction temperature. The analysis of oil properties, fuel properties and process parameter optimization for the waste cooking oil conversion are also presented.     

酸性离子液体［(CH2)4SO3HMIM］［HSO4］催化潲水油制备生物柴油的研究

制备了酸性离子液体[(CH₂)₄SO₃HMIM］［HSO₄］并用于催化潲水油制备生物柴油,研究了反应时间、反应温度、醇油物质的量比和剂油物质的量比等对酯交换反应转化率的影响,确定了较适宜的反应条件。结果表明,在反应时间4 h、反应温度140 ℃、醇油物质的量比12和剂油物质的量比0.08条件下,酯交换反应转化率为92.13%。制备的生物柴油达到了中国柴油机燃料调合用生物柴油(BD100)标准GB/T20828-2007。     

Production of mixed methyl/ethyl esters from waste fish oil through transesterification with mixed methanol/ethanol system

Biodiesel (mixed fatty acid methyl/ethyl esters) was prepared from waste fish oil through base-catalyzed transesterification with mixed methanol/ethanol system. Effect of methanol/ethanol (% v/v), type and concentration of the catalyst, mixed alcohols to oil molar ratio, the reaction temperature, and the reaction time on the biodiesel yield was optimized. Maximum biodiesel yield (97.30?wt%) was produced by implementing 1:1 methanol/ethanol (v/v), 1.0?wt% KOH, 6:1 mixed alcohols to oil molar ratio, 40°C reaction temperature, and 30?min of reaction time. Conversion of the waste fish oil to mixed methyl/ethyl esters was confirmed by ¹H NMR spectroscopy. Fuel properties of the resulting biodiesel in addition to its blends with petrodiesel were in good agreement with specifications of ASTM D6751 and ASTM D7467, respectively. Therefore, it was concluded that using mixed alcohol system for biodiesel production could reduce the production cost through reducing conditions required for maximum conversion.     

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.     

微波强化棉籽油制备生物柴油的研究

利用微波强化以棉籽油和甲醇为原料,KOH为催化剂制备生物柴油。考察醇油摩尔比、催化剂用量、反应时间和微波功率对酯交换反应的影响。结果表明,醇油摩尔比为9∶1,催化剂用量为1.0%,反应时间为3 min,微波功率360 W为最优反应条件。在此反应条件下生物柴油产率可达94%。与传统合成方法相比,该方法可缩短反应时间30~35 min。所得生物柴油主要质量指标达到我国和欧洲(EN14214)生物柴油质量标准,通过红外光谱分析表明,棉籽油生物柴油具有生物柴油所含的官能团。     

Biodiesel production from waste cooking palm oil using calcium oxide supported on activated carbon as catalyst in a fixed bed reactor

A reactor has been developed to produce high quality fatty acid methyl esters (FAME) from waste cooking palm oil (WCO). Continuous transesterification of free fatty acids (FFA) from acidified oil with methanol was carried out using a calcium oxide supported on activated carbon (CaO/AC) as a heterogeneous solid-base catalyst. CaO/AC was prepared according to the conventional incipient-wetness impregnation of aqueous solutions of calcium nitrate (Ca(NO₃)₂·4H₂O) precursors on an activated carbon support from palm shell in a fixed bed reactor with an external diameter of 60 mm and a height of 345 mm. Methanol/oil molar ratio, feed flow rate, catalyst bed height and reaction temperature were evaluated to obtain optimum reaction conditions. The results showed that the FFA conversion increased with increases in alcohol/oil molar ratio, catalyst bed height and temperature, whereas decreased with flow rate and initial water content in feedstock increase. The yield of FAME achieved 94% at the reaction temperature 60 °C, methanol/oil molar ratio of 25: 1 and residence time of 8 h. The physical and chemical properties of the produced methyl ester were determined and compared with the standard specifications. The characteristics of the product under the optimum condition were within the ASTM standard. High quality waste cooking palm oil methyl ester was produced by combination of heterogeneous alkali transesterification and separation processes in a fixed bed reactor. In sum, activated carbon shows potential for transesterification of FFA.     

活性炭负载型固体碱催化酯交换反应的研究

采用浸渍法制备了活性炭负载KOH固体碱催化剂,考察了它们在三醋酸甘油酯与甲醇酯交换反应中的催化性能,及时间、温度、催化剂用量、醇酯摩尔比等因素对酯交换反应的影响。结果表明,当醇酯比为9：1,催化剂用量为0．3g（三醋酸甘油酯为0．02mol）,KOH浸渍液浓度为20．0wt％,反应温度为65℃,反应1．0h,三醋酸甘油酯转化率可达到94．7％。该工艺操作简单,催化剂可以回收,过程无三废污染。