【作者】 徐泽辉；

【导师】 房鼎业；

【作者基本信息】 华东理工大学 ， 化学工艺， 2010， 博士

【摘要】 随着乙烯工业的持续发展,作为副产物的异丁烯、异戊烯资源量显现快速增长的态势。异丁烯和异戊烯分别是C4及C5馏份中非常具有价值的成份。目前高纯度的异丁烯和异戊烯的生产工艺基本相同,都采用选择加氢、醚化、醚裂解工艺来生产。高纯度的异丁烯作为单体可用于生产丁基橡胶、聚异丁烯等聚合物,甲基丙烯酸甲酯、叔丁胺、对叔丁基苯酚系列抗氧剂和异戊烯醇等精细化工产品；而异戊烯则侧重于精细化工领域,用作农药和香料生产的中间体。在异丁烯和异戊烯生产过程中,除了对生产工艺要进行不断的优化,降低生产成本和提高反应收率外,还要在提升产品质量、抽余后C4及C5馏份的综合利用以及下游产品的开发方面开展有关的研究工作,以达到原料的有效且充分的利用,增强装置的综合竞争能力。为此本文对异丁烯、异戊烯及其下游产品制备工艺的进行了研究,研究内容主要包括MTBE醚裂解制备异丁烯、异丁烯二聚工艺及动力学、C4烯烃加氢催化剂及工艺、TAME醚裂解催化剂和工艺、2M1B异构化工艺他粗异戊烯加氢工艺。主要结论如下：1.使用SPC-01催化剂,MTBE裂解制异丁烯反应的适宜操作条件为：反应压力0.4MPa,温度210～230℃,LHSV为0.5～1.0h-1,在该条件下MTBE单程转化率大于92.2%,异丁烯选择性大于99.9%。2.以强酸性阳离子交换树脂为催化剂,在高压釜内考察了异丁烯二聚反应工艺条件对DIB选择性的影响。当反应温度为75～95℃、原料中IB质量分数为17%-20%、TBA质量分数为0.6%、搅拌速率750r/min、反应时间为3h时,IB的转化率达到60%左右,DIB的选择性在80%左右。3.通过IB齐聚动力学实验及模型分析表明,IB齐聚过程为一级串联不可逆反应。根据实验结果,IB齐聚反应速率方程可写成：4.通过加入TBA时,IB齐聚动力学实验及过程分析表明,IB齐聚具有一级串联不可逆反应特征。加入的TBA使IB齐聚机理发生了变化,所测得的IB反应活化能其实是IB水合反应活化能。根据实验结果,IB齐聚反应速率方程可写成：5.Ni/Al2O3-SiO2催化剂是一种C4馏分加氢适应性非常广泛的催化剂,具有良好的加氢活性和活性稳定性。对于单烯烃含量约为20%的C4馏分进行加氢时,当LHSV为5.5h-1、进口温度为室温、反应压力为2.0MPa、v(H2)/v(C4)=219时,丁烯转化率均接近98%。6.SPC-01型催化剂在上海石化异戊烯装置首次工业应用获得成功,3年运行结果表明：该催化剂对TAME裂解生产异戊烯具有良好的活性和稳定性,TAME转化率和异戊烯选择性均超过99%。通过对新鲜和卸出催化剂的表征,发现导致活性降低的主要原因是催化剂的结焦、比表面积和酸强度的降低。7.在异构化原料中加入TAA后,降低了磺酸基阳离子交换树脂催化剂表面的酸性,提高了催化剂对2M1B的吸附选择性,可以有效降低2M1B二聚反应速率,达到提高目标产物选择性的目的,并使异构化反应平稳进行,易于控制。与现有异戊烯装置的异构化反应相比较,在反应温度为28～33℃,系统压力为0.5MPa,粗异戊烯质量空速为8.0h-1和TAA加入量为进料质量0.7%～0.9%的条件下,2M1B平均转化率由0.5474增加到0.72～0.73,2M2B选择性则由0.6864上升至0.95以上,在产物中二聚物的含量从4.38%降至1.0%以下,产品中2M2B与2M1B质量比由7.32提高至12以上。8.所开发的粗异戊烯加氢工艺的工业化获得了成功,加氢产物中烷烃的含量可以保持在99%以上,其中异戊烷和正戊烷含量平均值分别为32.53%及67.11%,是一种提高裂解装置“双烯”收率的优良裂解原料。装置目前运行平稳,加氢效果与小试数据基本吻合。与常规的高压高温加氢工艺相比较,使用Ni/Al2O3-SiO2催化剂后,加氢工艺更加缓和,催化剂的活性稳定性较为理想。更多还原

【Abstract】 With the continuous development of the ethylene industry, the resource amount of by-product, isobutene and isopentene was increasing rapidly. The isobutene and isopentene was the highly valuable composition of C4 and C5 fraction respectively. The production technology of isobutene and isopentene with high purity was basically similar at present, the hydrogenation, etherification and decomposition technology were used in the two productions. The isobutene with high purity which was used as monomer to product the polymer such as butyl-rubber and polyisobutene, and also could to product the fine chemical productions such as methyl methacrylate, tert-butylamine, p-tert-butylphenol series antionxidant and allylic alcohols, however, the isopentene was profile to fine chemical field, which was used as the intermediate in the production of pesticide and perfume.Besides the optimization of production technology constantly, reducing the production costs and improving the reaction yield, the research works on lifting production quality, the comprehensive utilization on raffinate C4/C5 fraction and development of downstream production were carried out in the production process of isobutene and isopentene to utilize the raw material effectively and adequately, to enhance the comprehensive competence ability of plant. The preparation technology of isobutene, isopentene and its downstream products was studied in the paper, main research contents including:(1) the preparation of isobutene by ether-solution from MTBE, (2) dimerization process of isobutene and its kinetics, (3) hydrogenation catalyst and process of C4-olefins, (4) decomposition catalyst of TAME and decomposition process, (5)isomerization process of 2M1B, (6)hydrogenation process of crude isopentene. The main conclusions were as follows:1. The optimum operation conditions of product isobutene by cracking from MTBE with the SPC-01 catalyst:reaction pressure of 0.4MPa, temperature was ranging from 210～230℃, liquid hourly space velocity was ranging from 0.5～1.0h-1, the single conversion of MTBE was more than 92.2%, the selectivity of isobutene was more than 99.9%.2. The influence of dimerization process of isobutene conditions on the selectivity of DIB was investigated in the high pressure autoclave with catalyst of strong acid cation exchange resin. The conversion of IB was around 60%, the selectivity of DIB was around 80% at the conditions of the reaction temperature was ranging from 75～95℃, the mass fraction of IB in the raw material was ranging from 17%～20%, the mass fraction of TBA was 0.6%, the stirring rate was 750r/min, and the reaction time was 3h.3. The kinetics experiments of IB oligomerization and model analysis showed that the IB oligomerization was irreversible first-order series reaction. According to the experiments results, the rate equation of IB oligomerization was:4. The kinetics experiments of IB oligomerization with the adding of TBA and process analysis showed that the IB oligomerization was in accord with the characteristics of irreversible first-order series reaction. The IB oligomerization mechanism was changed as the adding of TBA, the measured IB oligomerization reaction activation energy was the IB hydration reaction activation energy in fact. According to the experiments results, the rate equation of IB oligomerization was:5. The Ni/Al2O3-SiO2 catalyst has relatively high hydrogenation activity and excellent stability was used very extensively on hydrogenation of C4 fractions. The conversion of C4-olifiens were all close to 98% at the reaction pressure of 2.0MPa when the mass fraction of mono-olefins in C4 fraction was about 20%, the LHSV was 5.5h-1, the inlet temperature was room-temperature, the ratio of H2 to C4 was 219.6. First industrial application of SPC-01 catalyst in the IA plant in SINOPEC Shanghai Petrochemical Company Limited was rewarded by success,3 years operation results showed that:the catalyst has favorable activity and stability on cracking of TAME to product isobutene, both the conversion of TAME and the selectivity of isobutene were more than 99%. The characterization of fresh and used catalyst found that the coking of catalyst, reducing of specific surface area and acid strength was the main reason of the activity decreased, however the catalyst had a certain activity remained.7. Addition of TAA in the isomerization raw material was regarded to decrease the surface acidity of the strongly acidic ion exchange resin catalyst, thus improved its adsorption ability for 2M1B and effectively suppressed the dimerization. Therefore, the yield of objective product was enhanced and the reaction process was apt to stabilization. The process was applied in a 3.5kt/a industrial isobutene plant, the operation results was basically same to the laboratory. The conclusions were as follows:1) The based theory of isomerization reaction was established. For the isomerization of 2M1B, The mass exchange capacity (acid concentration) and the surface-SO3H (acid strength) acidity of the resin were important factors to determine the isomerization reaction. Only by the favorable matching ability between the acid concentration of resin and the TAA concentration in the raw material, the tenability of conversion and selectivity in the isomerization reaction could realize.2) The selectivity of 2M2B at a high conversion level for the isomerization of crude isobutene was significantly increased by the adding of a small amount of tertiary amyl alcohol in the reaction raw material. Compared with the results from the current isobutene units, the average conversion of 2M1B, the selectivity of 2M2B and the mass ratio of 2M2B to 2M1B were increased from 0.5474,0.6864 and 7.32 to 0.72～0.73,0.95 and 12, respectively, while the dimmers content in the products decreased from 4.38%to below 1.0%. Optimized conditions for isobutene isomerization consisted of temperature between 28 and 33℃, and system pressure of 0.5 MPa, crude isobutene mass hourly space velocity of 8.0h-1 with mass fraction of 0.7～0.9% in raw material.3) Industrial application:the average concentrations of 2M1B,2M2B and dimmer consisted of 7.19%,89.41% and 0.62% in the liquid products after the addition of TAA in the 3.5kt/a industrial isobutene plant, while the concentration of dimmer in raw material was 0.23%, the average conversion of 2M1B was 0.6651, the average selectivity of 2M2B was 0.9727, the average mass ratio of 2M2B and 2M1B was 12.45. The addition of TAA increased the activity of catalyst and the selectivity of objective product, the mass ratio of 2M2B and 2M1B was also significantly increased.8. The industrialization of hydrogenation process on crude isopentene achieved success, the concentrations of alkanes in the hydrogenation products remained at more than 99%, the average concentrations of isopentane and n-pentane was 32.53% and 67.11% respectively, which was superior cracking raw material to improve yield of“two-olefins”in cracking plant. The plant operating stationary at present, the results of hydrogenation were basically agreed with the small experiment. Compared with the results from the conventional hydrogenation process with high temperature and high pressure, the hydrogenation process was more inirritative, and the activity and stability of catalyst was comparatively ideal after the using of Ni/Al2O3-SiO2 catalyst.更多还原