共查询到20条相似文献,搜索用时 31 毫秒
1.
以邻苯二甲酸二辛脂为原料,利用高压加氢反应评价装置,系统考察催化剂载体和活性物质的选择、活性组分负载量及焙烧温度对催化剂活性的影响。结果表明,载体选择大孔γ-Al2O3,活性组分选择铑和钌等贵金属,并通过镧改性以降低贵金属使用量,最佳制备条件:活性组分负载质量分数0.2%~0.5%,焙烧温度为550 ℃。催化剂在220 ℃还原2 h,在反应压力10 MPa、反应温度150 ℃、空速0.75 h-1和氢油体积比1 000∶1条件下,将不低于99.5%的邻苯二甲酸二辛脂转化为环己烷二甲酸二异辛酯。 相似文献
2.
Simultaneous Enzymatic Transesterification and Esterification of an Acid Oil Using Fermented Solid as Biocatalyst
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Erika C. G. Aguieiras Elisa D. Cavalcanti-Oliveira Aline M. de Castro Marta A. P. Langone Denise M. G. Freire 《Journal of the American Oil Chemists' Society》2017,94(4):551-558
This work studied the enzymatic synthesis of fatty acid ethyl esters (FAEE) for potential use as biodiesel via simultaneous esterification and transesterification of acid oil from macaúba in a solvent-free system. A fermented and dry babassu cake with lipase activity from Rhizomucor miehei was used as biocatalyst. FAEE content above 85% was achieved after 96 h of reaction with enzyme loading of 13 U per g of oil, 120 mmol of hydrous ethanol (95% ethanol and 5% water)/20 mmol of oil (molar ratio ethanol:oil of 6:1), at 40 °C. After two consecutive enzymatic reactions, 90.8 wt% FAEE content was obtained. These results demonstrate a promising transesterification/esterification method for FAEE production from an acid and low-cost oil and the process has potential to decrease the costs of enzymatic biodiesel production. 相似文献
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Biodiesel produced from crude Jatropha curcas L.oil with trace sulfuric acid catalyst(0.02%-0.08% oil) was investigated at 135-184 ℃.Both esterification and transesterification can be well carried out simultane-ously.Factors affecting the process were investigated,which included the reaction temperature,reaction time,the molar ratio of alcohol to oil,catalyst amount,water content,free fatty acid(FFA) and fatty acid methyl ester(FAME) content.Under the conditions at 165 ℃,0.06%(by mass) H2SO4 of the oil mass,1.6 MPa and 20:1 methanol/oil ratio,the yield of glycerol reached 84.8% in 2 hours.FFA and FAME showed positive effect on the transesterification in certain extent.The water mass content below 1.0% did not show a noticeable effect on trans-esterification.Reaction kinetics in the range of 155 ℃ to 175 ℃ was also measured. 相似文献
4.
Ethanolysis of castor and cottonseed oil: A systematic study using classical catalysts 总被引:1,自引:1,他引:1
Simoni M. Plentz Meneghetti Mario R. Meneghetti Carlos R. Wolf Eid C. Silva Gilvan E. S. Lima Masurquede de A. Coimbra João Inácio Soletti Sandra H. V. Carvalho 《Journal of the American Oil Chemists' Society》2006,83(9):819-822
Several classical catalytic systems for the transesterification reaction have been used to produce FA ethyl esters (FAEE)
from castor and cottonseed oils The effects of the amount and nature of the catalyst, and of the reaction temperature, on
the yields of FAEE were determined. The most efficient transesterification of castor oil was achieved in the presence of methoxide
and acid catalysts, whereas for cottonseed oil, which has a composition that is much more similar to most vegetable oils than
is castor oil, the highest yields of FAEE were obtained following base-catalysed ethanolysis. 相似文献
5.
采用浸渍法,将KOH负载在新型载体氧化锆上,通过高温煅烧得到了固体碱催化剂。探讨了制备条件对催化剂催化酯交换反应活性的影响,获得了催化剂的最佳制备条件,以大豆油和甲醇为原料研究并优化了催化酯交换反应制备生物柴油的工艺条件。结果表明,固体碱催化剂KOH/ZrO2的最佳制备条件为:KOH负载量20%,煅烧温度600℃,煅烧时间2 h。固体碱催化剂催化酯交换反应的最优反应条件为:醇油比9:1,反应温度75℃,反应时间3 h,催化剂用量4.0%。各因素对产率影响的大小为:醇油摩尔比 > 反应温度 > 反应时间 > 催化剂用量。 相似文献
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Krill oil dietary supplements are increasingly used for their high concentrations of phospholipids (PL), which offer reportedly greater bioavailability of n‐3 polyunsaturated fatty acids (PUFA) than those of triacylglycerols or fatty‐acid ethyl esters (FAEE) commonly found in fish oils and fish‐oil concentrates. This work evaluated the lipid composition of 22 commercial krill oil (CKO) supplements available in the US market, and found ten products (i.e. 45%) contained significant amounts of FAEE, varying from 41% to 75%, by weight. These concentrations of FAEE differed from the minor abundances of FAEE (<3%, by weight) found in manufacturer‐supplied krill oil. The potential clinical and regulatory implications for these findings warrant further investigation. 相似文献
8.
利用上段热解下段催化的两段固定床反应器,针对府谷煤研究了半焦和半焦负载Co催化剂对煤热解产物的催化裂解效果。结果表明,半焦和半焦负载钴对热解产物催化裂解后,热解气收率增加,焦油收率降低,但焦油中沸点低于360℃的轻质组分含量提高,轻质焦油收率基本保持不变或略有增加。与煤在600℃直接热解相比,在热解和催化温度均为600℃,采用煤样质量20%的半焦为催化剂时焦油中轻质组分质量含量提高了约25%,轻质组分收率基本不变,热解气体积收率增加了31.2%;在热解温度600℃,催化温度500℃时,采用煤样质量5%的半焦负载钴催化剂,焦油中轻质组分质量收率和含量分别提高了约8.8%和28.8%,热解气体积收率增加了21.5%。煤热解产物的二次催化裂解的总体效果是将焦油中重质组分转化为轻质焦油和热解气。 相似文献
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铜绿假单胞菌脂肪酶无溶剂催化棕榈油甘油解Ⅰ.单甘酯酶促合成工艺的研究 总被引:4,自引:0,他引:4
以自产铜绿假单胞菌脂肪酶为催化剂 ,通过无溶剂法棕榈油甘油解反应催化合成了单脂肪酸甘油酯。实验结果表明 :适宜加酶量为 50 0u g棕榈油 ,甘油相适宜水质量分数为w (H2 O)=3%~ 4 5% ,反应物量比宜设定为 n(甘油 )∶n(棕榈油 ) =( 2 0~ 2 5)∶1。反应器材质对单甘酯产率有影响 ,31 6L型不锈钢为适宜材质。最佳反应温度为 38~ 42℃ ,在此温度区间内适宜反应时间为 2 4h。临界反应温度为 44℃。 相似文献
11.
合成了聚氨酯丙烯酸酯预聚体,配制了紫外光固化胶粘剂,研究了预聚体含量和种类对紫外光固化胶粘剂固化膜性能的影响。确定了预聚体合成的最佳条件为:反应温度75-80℃、催化剂用量0.45%左右。预聚体在胶粘剂配方中的最佳含量为50%-60%;芳香族预聚体剪切强度明显高于脂肪族预聚体,但胶层较硬,韧性较差;脂肪族预聚体柔顺性较好,180°剥离强度和附着力高于芳香族预聚体;不挥发物含量越高则固化得越完全,综合强度越好;芳香族预聚体的玻璃化温度高于脂肪族预聚体,二者分别贡献胶粘剂固化膜的剪切强度和剥离强度。 相似文献
12.
以固体酸TSOH/HY-SBA-15(对甲苯磺酸改性的介孔分子筛)为催化剂,催化大豆油和甲醇制备生物柴油,考察了反应的最适宜条件。结果表明,催化剂为(0.5 mol/L)TSOH/(10 %)HY-SBA-15,反应温度为180 ℃,反应时间为7 h,n(醇)/n(油)为25,催化剂用量为油质量的5 %,溶剂用量为油质量的30 %,生物柴油的收率可达到94.6 %。 相似文献
13.
采用后合成法合成了HY-SBA-15复合分子筛,并以其为载体,负载不同比例的磷钨酸(HPW)制备催化剂.用XRD对HY-SBA-15复合分子筛及HPW/HY-SBA-15催化剂进行了表征,结果表明:适量磷钨酸的引入并没有改变复合分子筛的介孔结构,但会使其衍射峰的强度有所降低.以硫含量为500 μg/g模拟油进行氧化脱硫反应,考察了反应温度、反应时间、磷钨酸负载比例、剂油比、氧化剂用量等工艺条件对脱硫率的影响.研究结果表明:磷钨酸的负载量为20%(质量分数),活化温度为300℃时的HPW/HY-SBA- 15催化剂效果最好,在模拟油用量为30 mL,反应温度50 ℃,反应时间90 min,剂油比(催化剂与模拟油的质量比)为0.02,n(H2O2)∶n(S)=8,无水乙醇用量3 mL的条件下,脱硫率可达95.7%. 相似文献
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探讨了以重质松节油为原料进行直接异构化制备异长叶烯的新工艺,选出了较为理想的GO4n-/TiO2(A)固体超强酸催化剂,确定了较好的反应条件为:催化剂用量为原料质量的 1%~2%、异构化反应温度190~200℃,反应时间 4 h,异长叶烯得率达到 90% 以上,为工业化生产异长叶烯探索了一条"绿色"新工艺途径。 相似文献
17.
以小桐梓油生物柴油为原料,在固定床连续反应器中,以Hβ型分子筛为催化剂,采用异构化反应改善生物柴油的低温流动性。考察了反应温度、质量空速、助剂(水)加入量等不同条件对生物柴油低温流动性的影响。实验结果表明,催化剂选用硅铝比为25的Hβ分子筛的情况下,反应温度为250℃、质量空速为1.0 h-1、助剂加入量为1.2%为最佳反应条件,小桐梓油生物柴油在最佳反应条件下进行异构化反应,凝点从1℃降低到-5℃,降幅为6℃。对生物柴油和异构化产物进行了色谱、质谱、核磁共振等表征,结果发现,低温流动性改善的原因是生物柴油的主要成分油酸甲酯、亚油酸甲酯发生了异构化反应,产生了带支链的异构体。 相似文献
18.
以活性成分负载量、负载顺序和焙烧温度等关键制备参数因素进行正交实验设计制备了V_2O_5-WO_3/TiO_2催化剂,对其进行XRD和TPR表征,并在自行设计搭建的SCR烟气脱硝实验平台上评价其(300~390)℃的SCR脱硝性能。结果表明,活性成分钒和钨绝大多数以非晶态形式存在于载体表面,且具有良好的分散性;主要活性成分V_2O_5负载量越高,脱硝率越高;400℃焙烧温度可以形成催化反应所需的晶相,且维持催化剂较高的比表面积;催化剂低温活性和高温活性是由表面富集和各种成分之间相互作用共同产生的结果,活性组分与载体之间的相互作用对315℃低温脱硝活性影响明显,以先钒后钨负载顺序为宜,表面富集对390℃高温脱硝活性起主要作用,以钒钨同时负载或先钒后钨负载顺序较好;随着m(WO_3)∶m(V_2O_5)的增加,在7.5∶1处催化剂的脱硝率升至最高,随后迅速下降,WO_3负载质量分数以6%为宜。在优化条件V_2O_5负载质量分数0.8%、WO_3负载质量分数6%、先钒后钨负载和400℃焙烧温度下制备了催化剂并进行脱硝性能验证,315℃低温脱硝活性达到69.56%。 相似文献
19.
在Al Cl3催化剂作用下,将癸烯与1-n C18按不同比例合成高性能聚α-烯烃基础油,考察反应温度、反应时间和C10与C18质量分数对混合齐聚反应的影响,采用响应面法设计实验,并对实验条件进行最优选择。结果表明,在实验条件下,用癸烯与1-n C18烯烃混聚可制备高性能的润滑油基础油。响应曲面法分析中,对黏度交互影响最显著的因素是时间A和温度B,最佳取值为3 h和50℃;对黏度指数交互影响最显著的因素是时间A和温度B,最佳取值为3 h和75℃;对倾点交互影响最显著的因素是时间A和温度B,最佳取值为3 h和25℃;对收率交互影响最显著的因素是时间A和C10与C18质量分数C,最佳取值为3 h,C10与C18质量分数分别为100%和15%。 相似文献
20.
Optimization of Cottonseed Oil Ethanolysis to Produce Biodiesel High in Gossypol Content 总被引:1,自引:0,他引:1
Hem Chandra Joshi Joe Toler Terry Walker 《Journal of the American Oil Chemists' Society》2008,85(4):357-363
Transesterification of cottonseed oil was carried out using ethanol and potassium hydroxide (KOH). A central composite design
with six center and six axial points was used to study the effect of catalyst concentration, molar ratio of ethanol to cottonseed
oil and reaction temperature for percentage yield (% yield) and percentage initial absorbance (%A
385nm) of the biodiesel. Catalyst concentration and molar ratio of ethanol to cottonseed oil were the most significant variables
affecting percentage conversion and %A
385nm. Maximum predicted % yield of 98% was obtained at a catalyst concentration of 1.07% (wt/wt) and ethanol to cottonseed oil
molar ratio of 20:1 at reaction temperature of 25 °C. Maximum predicted %A
385nm of more than 80% was obtained at 0.5% (wt/wt) catalyst concentration and molar ratio of 3:1 at 25 °C. The response surfaces
that described % yield and %A
385nm were inversely related. Gossypol concentration (% wt), oxidative stability and %A
385nm of biodiesel were found to be highly correlated with each other. Hence, color %A
385nm is a measure of the amount of pigments present in biodiesel fuels that have not yet been subjected to autoxidation. High
gossypol concentration also corresponds to a fuel with high oxidative stability. The fatty acid ethyl esters (FAEE) produced
from cottonseed oil had superior oxidative stability to fatty acid methyl esters (FAME) produced from cottonseed oil. 相似文献