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采用熔融结晶法对甲醇合成油分离得到质量分数62.3%的均四甲苯富集液进行分离提纯以获得高纯度的均四甲苯副产品。实验中比较了静态结晶和鼓泡结晶的提纯效果,考察了鼓气速率、降温速率、结晶终温、结晶恒温时间、发汗终温和发汗恒温时间等操作参数对结晶过程的影响。最终确定了适宜的操作条件为速率比0.75 L/(h·g)、降温速率0.1℃/min,结晶恒温时间1.5 h和发汗恒温时间2 h。对不同质量分数的富集液进行结晶和发汗实验,得到以结晶终温和发汗终温为变量的操作平衡曲线。对质量分数为62.3%的原料通过三级结晶分离提纯,就可以获得99%以上的均四甲苯产品。通过实验与计算结果表明,本文计算模型与实验数据吻合较好,可以满足工程需要。 相似文献
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采用热法磷酸和尿素作为原料生产工业级磷酸脲。研究了磷酸浓度、反应时间、反应温度、磷酸与尿素物质的量比、结晶温度等条件对磷酸脲的氮、磷收率以及产品质量的影响。通过实验得到最佳工艺条件:磷酸中五氧化二磷质量分数为58%、反应时间为35 min、反应温度为80 ℃、尿素和磷酸物质的量比为1∶1、结晶温度为20 ℃。在最佳工艺条件下,产品磷酸脲中五氧化二磷质量分数为44.8%、氮质量分数为17.6%、纯度为99.7%,产品质量达到GB/T 27805—2011《工业磷酸脲》的要求;磷收率为85.7%,氮收率为86.0%。 相似文献
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乙醇-氨水介质中硫酸钾制备工艺研究 总被引:1,自引:0,他引:1
以氯化钾和磷石膏为原料,采用一步法制备硫酸钾。采用乙醇-氨水为介质,通过正交实验讨论了反应时间、反应温度、乙醇质量分数、氨水质量分数、配料比对产品质量、原料转化率以及产品晶形的影响,得出优化工艺条件为:反应时间60 min、反应温度45℃、乙醇质量分数30%、氨水质量分数20%、配料比(磷石膏与氯化钾质量比)1.29∶1。在该条件下,制得产品硫酸钾的氧化钾质量分数为37.34%,氧化钾的转化率为75.56%,氯离子质量分数为0.86%,水质量分数为1.06%。 相似文献
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以加氢柴油为原料,采用临氢降凝-补充精制-精密分馏工艺,通过调整催化剂级配考察制备满足GB/T 15894—2008低芳石油醚、NB/SH/T 0913—2015轻质白油(Ⅱ)、GB 2536 T-40℃变压器油的可行性。结果表明,在反应压力为15 MPa、氢油体积比为1 000∶1、降凝/精制体积空速为SV/SV-0.7 h-1的条件下,以加氢柴油为原料,当反应温度为T-20/T℃时经精密分馏切割工艺所得低芳石油醚产品芳烃质量分数均<0.005%,其他性质指标满足GB/T 15894—2008指标要求;所得轻质白油满足NB/SH/T 0913—2015轻质白油(Ⅱ)指标要求。 相似文献
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利用Origin软件中的解析功能,将中低温煤焦油样品的模拟蒸馏曲线转化为类实沸点蒸馏曲线。类实沸点蒸馏曲线是模拟蒸馏曲线的导函数曲线,是沸点与相应沸点下物质含量的关系图,与实沸点蒸馏曲线类似。通过类实沸点蒸馏曲线可知,随着终温的升高,轻质组分减少,重油增加,沥青含量由30%左右逐渐增加到50%;在350~420℃类实沸点曲线皆出现波峰,波峰沸点物质含量随着煤样热解终温的升高而依次减少。中低温热解以解聚反应为主,高温高能量有利于高键能键的断裂,低温低能量有利于低键能键的断裂。 相似文献
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采用共沉淀法合成出Fe_3O_4/氧化石墨烯(GO)纳米复合材料,然后通过静电作用将聚二烯丙基二甲基氯化铵(PDDA)修饰在Fe_3O_4/GO表面,制备出一种新型除油剂PDDA/Fe3O4/GO,并考察了Fe3O4与GO配比、p H、温度、反应时间和除油剂投加量等因素对除油效果的影响。实验结果表明:PDDA/Fe_3O_4/GO不仅除油性能良好,而且除油速度快;在室温20℃、反应时间10 min、投加质量浓度为300 mg/L的条件下,可将油田污水中的油降至50 mg/L以下。该除油剂具有制备方法简单、除油速度快、易于操作、可重复利用等特点,为油田污水处理提供了一种新的研究思路。 相似文献
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The purification and separation of durene from the mixture containing durene isomers were studied. Since the boiling points of tetramethyl benzene isomers are very close but their melting points are of great differences, stat-ic melt crystallization was applied to separate and purify durene from its isomers. Crystallization experiments were carried out under various operating conditions. The effects of cooling rate, crystallization temperature, sweating temperature and sweating time on the yield and purity of crystal were investigated. Orthogonal exper-imental design method was adopted to analyze the factors that may affect the yield of durene. Under the optimal crystal ization conditions, the purity of durene could reach as high as 99.06%with the yield of 75.3%through one crystal ization process. By fitting purification data based on sweating time in isothermal operations, the purifica-tion rate coefficient was obtained. 相似文献
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煤炭直接液化油中含有种类丰富且数量可观的酚类化合物,研究影响酚类含量和组成的因素,对于深入研究煤液化产物中酚类化合物的生成机理具有重要的理论意义和实践意义.考察了煤液化过程中反应温度、催化剂及添加高分油三种工艺条件对煤液化油(41℃~220℃)中酚类含量分布的影响.结果表明:随着反应温度升高和催化剂加入都能增加煤液化油中总粗酚产率,而添加高分油方式则不太明显;另外,升高反应温度和添加高分油两种方式可以促进高级酚类中间体发生裂解、脱烷基及脱羟基等二次反应向生成分子量更小、结构更简单的低级酚类进行转化,而通过催化剂的加入可以抑制部分高级酚类向低级酚类的转化. 相似文献
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超临界甲醇中制备生物柴油 总被引:24,自引:1,他引:23
研究了超临界甲醇法制备生物柴油中反应条件对甲酯生成率的影响。结果表明,醇油摩尔比越大,大豆油转化率越高;升温有助于提高反应速率,在临界温度239℃附近,温度的影响尤其明显;当压力高于13.5 MPa时,压力对反应的影响不明显;原料油中,不同脂肪酸酯甲酯化的速率不同,按亚油酸酯、油酸酯、棕榈酸酯、硬脂酸酯的顺序依次降低;大豆油中w(游离油酸)<50%时,不影响反应转化率;原料油中w(H2O)<20%时对反应影响不大。当醇油摩尔比为42∶1,反应温度280℃,反应1 h,油脂转化率可达78%。 相似文献
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Umer Rashid Muhammad Ibrahim Imededdine Arbi Nehdi Saud Ibrahim Al-Resayes Sammi Ullah Muhammad Aamer Mehmood Saira Shahzadi 《中国化学工程学报》2016,24(8):1087-1096
Response surface methodology(RSM) was used to determine the optimum conditions of the methanolysis of crude poppy seed oil using Na OCH3 as catalyst. The experiments were run according to five levels, four variable central composite rotatable design(CCRD) using RSM. The reaction variables, i.e., molar ratio of methanol/oil(3:1–9:1), catalyst concentration(0.5 wt%–1.25 wt% Na OCH3), reaction temperature(25–65 °C), and reaction time(20–90 min) were studied. We demonstrated that the molar ratio of methanol/oil, catalyst concentration,and reaction temperature were the significant parameters affecting the yield of poppy seed oil methyl esters(PSOMEs). The optimum transesterification reaction conditions, established using the RSM, which offered a89.35% PSOME yield, were found to be 7.5:1 molar ratio of methanol/oil, 0.75% catalyst concentration, 45 °C reaction temperature, and 90 min reaction time. The proposed process provided an average biodiesel yield of more than 85%. A linear correlation was constructed between the observed and predicted values of the yield.The gas chromatography(GC) analyses have shown that PSOMEs contain linoleic-, oleic-, palmitic-, and stearic-acids as main fatty acids. The FTIR spectrum of the PSOMEs was also analyzed to confirm the completion of the transesterification reaction. The fuel properties of the PSOMEs were discussed in light of biodiesel standards(ASTM D 6751 and EN 14214). 相似文献
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采用甲醇溶剂法分离蚕蛹油多不饱和脂肪酸。通过单因素实验探讨了温度、甲醇浓度、甲醇脂肪比、时间对多不饱和脂肪酸分离效果的影响,然后通过正交实验确定了多不饱和脂肪酸分离的较佳条件。结果表明,适宜的分离条件为:温度-10℃,甲醇浓度90%(w),甲醇脂肪比2.5,结晶时间30min,在上述条件下多不饱和脂肪酸得率为62.3%,含量由71.0%提高到95.8%。 相似文献
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为了提高超临界汽油中煤焦油加氢裂化轻质油的收率,研究了Co-Mo-Pd-Y沸石催化剂制备条件对轻质油收率的影响。分别考察了催化剂负载金属中Co/(Co+Mo)原子比、催化剂焙烧温度、分子筛酸处理浓度、酸处理温度及时间对煤焦油加氢裂化催化反应收率的影响。结果表明:当Co/(Co+Mo)原子比(摩尔比)为0.5,催化剂焙烧温度为550℃,分子筛酸处理浓度为2 mol/L,酸处理温度为70℃及处理时间4 h时,轻质油收率(质量分数)可达81.5%,并且对此条件下制备的催化剂通过N2吸附及XRD进行了表征。制得的催化剂在超临界溶剂中煤焦油加氢裂化反应中表现出较高的活性,煤焦油获得了高的轻质油收率。 相似文献
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Seung Bum Lee Kyong Ho Han Jae Dong Lee In Kwon Hong 《Journal of Industrial and Engineering Chemistry》2010,16(6):1274-1010
Biodiesel has been recommended as an environmentally benign alternative fuel because it emits a comparatively small amount of air pollutants. Biodiesel can be processed from canola oil, which has a low liquefaction temperature owing to its high unsaturated fatty acid content, which also limits its engine-clogging effects. In this study, optimum conditions such as the amount of methanol, the alkali catalyst, and the reaction temperature were determined for production of biodiesel from canola oil. A maximum biodiesel yield was shown at an oil/methanol mole ratio of 1:6. The optimum amount of catalyst was 1 wt% of potassium hydroxide. The biodiesel yield and the methyl ester content were high when the reaction temperature was 55 °C. The consolute temperature for determining the maximum biodiesel yield was proposed in consideration of the boiling point of methanol. The energy density was analyzed for the final products of biodiesel in comparison to the raw canola oil and other plant oil based biodiesels. 相似文献