共查询到17条相似文献,搜索用时 343 毫秒
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氢气分压对对苯二甲酸加氢反应的影响 总被引:1,自引:0,他引:1
在实验装置和工业装置上分别考察了氢气分压对对苯二甲酸(TA)加氢反应的影响,实验室研究表明,氢气分压对TA中的对羧基苯甲醛(4-CBA)的加氢速率有一定影响,氢气分压在0.5-1.5 MPa均能较快使4-CBA还原降到25μg/g以下,在工业装置上要根据催化剂的不同活性周期来调节氢气分压,合理的氢气分压操作范围为0.5-1.2 MPa。 相似文献
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对羧基苯甲醛在钯炭催化剂上串联加氢反应宏观动力学 总被引:1,自引:0,他引:1
在高压间歇反应釜中研究了对苯二甲酸中杂质对羧基苯甲醛(4-CBA)在钯炭催化剂上进行加氢反应的特性,考察了反应温度、氢气分压、内扩散对4-CBA加氢反应的影响。结果表明,4-CBA的加氢反应是一个中间产物为对羟甲基苯甲酸(4-HMBA)的串联反应,加氢反应内扩散影响严重;温度和氢气分压提高,反应速率增大;温度和氢气分压对4-HMBA加氢生成对甲基苯甲酸(PT)的影响大于对4-CBA加氢生成4-HMBA的影响。采用幂函数动力学模型拟合得到了4-CBA串联加氢反应体系的宏观动力学方程。4-CBA加氢生成4-HMBA反应的表观活化能为16.98kJ/mol,对4-CBA和H2的反应级数分别为0.96和0.24;4-HMBA加氢生成PT反应的表观活化能为23.44kJ/mol,对4-HMBA和H2的反应级数分别为0.61和0.75。 相似文献
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以喹啉为含氮模型化合物,在高压滴流床反应装置中考察了工业NiW/Al2O3催化剂RN-10上的加氢脱氮动力学规律,研究了反应温度330~420℃、氢分压1.2~5.2MPa、氢油比200~800(v/v)、重量空速(WHSV)20~70 h-1等反应条件对喹啉的加氢脱氮反应结果的影响.结果表明,反应温度对喹啉的脱氮率影响较大,提高反应温度可有效提高喹啉的脱氮率;同时,氢分压也是喹啉加氢脱氮的一个重要的影响因素,但是,当氢分压和氢油比较大时,氢分压和氢油比的变化对喹啉的脱氮率基本无影响.采用修正的n(n<1)级反应动力学模型对实验数据进行拟合,求得了喹啉加氢脱氮反应的表观活化能为180.4 kJ·mol-1.经检验,模型计算结果与实验结果能较好地吻合. 相似文献
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NiW/Al2O3催化剂上二苯并噻吩的加氢脱硫宏观动力学 总被引:2,自引:0,他引:2
以二苯并噻吩(DBT)为含硫模型化合物,在实验室中压滴流床反应装置中研究了工业NiW/Al2O3催化剂RN-10上的加氢脱硫反应的动力学规律,详细考察了工艺条件:氢分压2.4~4.5 MPa、氢油比150~700(v/v)、液时空速(WHSV)15~60 h-1、反应温度300~380C对DBT转化率的影响.实验结果表明:提高反应温度可大大提高DBT的转化率,但反应温度达到330℃后,再提高反应温度,对DBT转化率的提升有限;在较高氢分压的条件下,DBT的转化率受氢分压的影响很小;当氢油比较小时,随着氢油比的提高,DBT转化率逐渐增加,但当氢油体积比大到一定程度(500)时,继续增大氢油比对脱硫率几乎没有影响.采用修正了的2级反应动力学模型对实验数据进行拟合,求得了二苯并噻吩加氢脱硫反应的表观活化能为75.95 kJ·mol-1.经检验,模型计算结果与实验结果能较好地吻合. 相似文献
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对二甲苯氧化反应器连续全混流模型 总被引:10,自引:6,他引:10
在对二甲苯液相催化氧化动力学研究的基础上,比较了化学反应速率与气液传质速率的相对大小。结果表明,工业反应器中,该氧化过程受化学反应控制,动力学是影响反应速率的主要因素。从而不计传质,并将反应器考虑成CSTR模型,模拟计算结果与实际值比较吻合。用此模型对影响反应的各工艺条件的计算机试验表明,停留时间延长、催化剂浓度增加、温度升高、Br/Co(摩尔比)比增大有利于提高TA收率和降低4-CBA浓度,但燃烧消耗加剧;Co/Mn(摩尔比)配比对主反应影响不大,但燃烧副反应随Co/Mn配比增大而增大。 相似文献
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采用固定床加氢装置对原料油(蜡油)进行加氢精制研究,采用控制变量法,考察了反应温度,液时空速,氢油比等对加氢效果的影响。以Ni-Mo/γ-Al_2O_3作为催化剂对加氢工艺进行优化,由数据表明升高温度、适当降低液时空速、增大氢油体积比,均有助于提高催化剂的脱硫和脱氮效果。Ni-Mo/γ-Al_2O_3催化剂在中高压条件下,反应温度为400℃,液时空速为0.25 h~(-1),氢油体积比在2 000左右时,加氢精制的效果最好。 相似文献
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以邻苯二甲酸二异辛酯(DOP)为原料,考察了4种金属催化剂作用下加氢制取环己烷二甲酸二异辛酯(DEHCH)的催化效果,系统研究了反应温度、氢气压力、反应时间和催化剂用量的影响。结果表明,Rh/C的催化活性最高;反应温度对加氢反应速度的影响较小,而氢气压力和催化剂用量的影响比较显著。实验确定了DOP加氢的适宜工艺条件为:温度为170℃,氢气压力2.0 MPa,反应时间为4.0 h。在此条件下,DEHCH是反应的唯一产物,收率高达99.5%以上。DOP加氢的表观动力学分析表明,催化剂表面上的吸附氢气浓度是加氢过程的控制步骤。 相似文献
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分析了PTA产品中4-CBA异常高的影响因素,并针对氢气系统、氧化产品品质、加氢催化剂对产品品质的影响,提出了处理异常情况的方法。 相似文献
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S. Koritala K. J. Moulton Sr. J. P. Friedrich E. N. Frankel W. F. Kwolek 《Journal of the American Oil Chemists' Society》1984,61(5):909-913
Selective hydrogenation of soybean oil to reduce linolenic acid is accomplished better with copper than with nickel catalysts.
However, the low activity of copper catalysts at low pressure and the high cost of batch equipment for high-pressure hydrogenation
has precluded their commercial use so far. To evaluate continuous systems as an alternative, soybean oil was hydrogenated
in a 120 ft × 1/8 in. tubular reactor with copper catalyst. A series of hydrogenations were performed according to a statistical
design by varying processing conditions: oil flow (0.5 L/hr, 1.0 L/hr and 2.0 L/hr), reaction temperature (180 C and 200 C),
hydrogen pressure (1,100 psig and 4,500 psig) and catalyst concentration (0.5% and 1.0%). An iodine value (IV) drop of 8–43
units was observed in the products whereas selectivity varied between 7 and 9. Isomerization was comparable to that observed
with a batch reactor. Analysis of variance for isomerization indicated interaction between catalyst concentration and hydrogen
pressure and between catalyst concentration and temperature. The influence of pressure on linolenate selectivity was different
for different temperatures and pressure. Hydrogenation rate was significantly affected by pressure, temperature and catalyst
concentration. 相似文献
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丁二酸二甲酯催化加氢制备γ-丁内酯的工艺研究 总被引:1,自引:0,他引:1
在微型固定床反应器中,丁二酸二甲酯在复合铜基催化剂Cu-ZnO-ZrO2/A12O3作用下,催化加氢制备了γ-丁内酯。实验中考察了催化剂组成、反应温度、压力、氢酯摩尔比、溶剂比和液时空速等因素对加氢反应的影响。结果显示,在反应温度为220℃、压力为3.0 MPa、n(H2)∶n(丁二酸二甲酯)=150∶1、V(CH3OH)∶V(丁二酸二甲酯)=4∶1、床层液时空速为0.25 h-1的条件下,丁二酸二甲酯的转化率达到100%,γ-丁内酯的选择性达到90%。 相似文献
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Michael A. Wilson Horst Rottendorf Philip J. Collin Anthony M. Vassallo Peter F. Barron 《Fuel》1982,61(4):321-328
Liddell coal (New South Wales, Australia) has been hydrogenated at 400, 425 and 450 °C with excess tetralin as vehicle and nitrogen or hydrogen as charge gas for 4 h at reaction temperature. In some experiments a nickel-molybdenum catalyst was used. The structures of the liquid and solid products were investigated by nuclear magnetic resonance spectroscopy, gel permeation chromatography and combustion analysis. Increasing the hydrogenation temperature from 400 to 450 °C decreases the yield of liquid products but increases conversion. At higher temperatures the liquid products are smaller in molecular size and molecular weight and contain a greater proportion of aromatic carbon and hydrogen; the solid residues also contain a greater proportion of aromatic carbon. The changes in variation of yield and structure with temperature are independent of the presence of catalyst under nitrogen and the nature of the charge gas. However, as the reaction system is capable of absorbing more hydrogen than can be supplied by the tetralin, the products from reactions with hydrogen as charge gas contain more hydrogen, some in hydroaromatic groups. Catalyst has little, if any, role in dissolution of the coal when a nitrogen atmosphere is used. When nitrogen is used as charge gas, reactions of coal-derived liquids with the catalyst do not alter the hydrogen, carbon or molecular size distributions in the products. The results show that the changes in composition of the liquid and solid products with increase in hydrogenation temperature are due to pyrolytic reactions and not to increased hydrogenation of aromatic rings. 相似文献