超稳分子筛制备工艺的改进
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摘要
随着原油的日益重质化和市场对重质燃料的需求日益减少,近二十年裂化原料中掺渣比例不断提高,重油的催化裂化发展很快。同时,国家对环保要求日趋严格,对清洁燃料需求量不断增加,也给炼油催化剂工业发展提出了新的挑战。为了适应这种需要,要求催化裂化催化剂要具有更高的性能。
超稳Y型分子筛是催化裂化催化剂的主要活性组分,其改性工艺对催化剂的重油裂解能力、水热稳定性、及产品的选择性等都有关键性的影响。
我厂的超稳分子筛装置近年来运用了一些新工艺:带式滤机取代板框滤机,进行分子筛的二次过滤交换洗涤,简化了流程,实现了连续生产,提高了产品收率和原料利用率;采用喷雾干燥工艺生产超稳分子筛,取得了以下效果:一是传热好,干燥速率快,提高了装置的利用效率,出口物料固含量稳定;二是利用焙烧炉烟道尾气作热源,提高了能源的利用率。但是这些新工艺在使用过程中也带来一些问题:带式滤机进行二次过滤交换洗涤,主要存在过滤速度慢,Na_2O不稳定的问题;喷雾干燥主要带来晶胞常数不收缩、分子筛粒度大的问题。本课题根据过滤和喷雾干燥的机理,结合分子筛合成和改性的研究,通过实验提出了对两种新工艺的改进措施,探讨了其对生产和质量的影响,使新工艺成功应用于超稳分子筛生产。
While crude oil is heavy-oriented and market demand of heavy fuel decreases, the ratio of resid blended feedstock increases continuously, and resid catalytic cracking technology also develops rapidly. Meanwhile, the deepening strict of national environmental requirements and the increasing demand of clean fuel also brings new challenges to the development of refinery industry. For the purpose of adapting to this requirement, better performances of catalytic cracking catalyst are needed.Ultrastable Y zeolite is the major active components of catalytic cracking catalyst, and its modification process can produce some key effects on the ability of resid cracking, hydrothermal stability, and product selectivity of catalyst.Some novel technologies have, been employed for the production of ultrastable Y zeolite in my plant in recent years. In the second filtration step, ion-exchange and scrubbing of zeolite are carried out with a belt filter instead of the traditional plate-and-frame filter press, so that the production process is simplified, the continuous production is implemented, and the yield and utilization ratio of raw materials are improved. The technology of spray drying is adopted in zeolite drying step, which has the following advantages: firstly, heat transfer is improved to obtain a faster drying rate, a higher efficiency of equipment and a stable solid content of the output materials; secondly, the energy efficiency is improved through the utilization of roasting furnace exhaust as heat resources. However, these novel technologies also resulted in two main problems: one was that the rate of the second filtration, exchange and scrubbing in the belt filter was slow, and the Na_2O content in zeolite was not stable: the other is that the cell constants did not contract and the particle size of zeolite was bigger in spray drying. In combination with the research of zeolite synthesis and modification, this subject elaborates the effects of ultrastable Y zelolite on performance of catalytic cracking catalyst. Based on the mechanism of filtration and spray drying process, this work proposed some improvements, by experiments in combination with the work of zeolite synthesis and modification, explored the influences of the improvements on production and quality, and made the new technologies implemented successfully in the production.
超稳Y型分子筛是催化裂化催化剂的主要活性组分,其改性工艺对催化剂的重油裂解能力、水热稳定性、及产品的选择性等都有关键性的影响。
我厂的超稳分子筛装置近年来运用了一些新工艺:带式滤机取代板框滤机,进行分子筛的二次过滤交换洗涤,简化了流程,实现了连续生产,提高了产品收率和原料利用率;采用喷雾干燥工艺生产超稳分子筛,取得了以下效果:一是传热好,干燥速率快,提高了装置的利用效率,出口物料固含量稳定;二是利用焙烧炉烟道尾气作热源,提高了能源的利用率。但是这些新工艺在使用过程中也带来一些问题:带式滤机进行二次过滤交换洗涤,主要存在过滤速度慢,Na_2O不稳定的问题;喷雾干燥主要带来晶胞常数不收缩、分子筛粒度大的问题。本课题根据过滤和喷雾干燥的机理,结合分子筛合成和改性的研究,通过实验提出了对两种新工艺的改进措施,探讨了其对生产和质量的影响,使新工艺成功应用于超稳分子筛生产。
While crude oil is heavy-oriented and market demand of heavy fuel decreases, the ratio of resid blended feedstock increases continuously, and resid catalytic cracking technology also develops rapidly. Meanwhile, the deepening strict of national environmental requirements and the increasing demand of clean fuel also brings new challenges to the development of refinery industry. For the purpose of adapting to this requirement, better performances of catalytic cracking catalyst are needed.Ultrastable Y zeolite is the major active components of catalytic cracking catalyst, and its modification process can produce some key effects on the ability of resid cracking, hydrothermal stability, and product selectivity of catalyst.Some novel technologies have, been employed for the production of ultrastable Y zeolite in my plant in recent years. In the second filtration step, ion-exchange and scrubbing of zeolite are carried out with a belt filter instead of the traditional plate-and-frame filter press, so that the production process is simplified, the continuous production is implemented, and the yield and utilization ratio of raw materials are improved. The technology of spray drying is adopted in zeolite drying step, which has the following advantages: firstly, heat transfer is improved to obtain a faster drying rate, a higher efficiency of equipment and a stable solid content of the output materials; secondly, the energy efficiency is improved through the utilization of roasting furnace exhaust as heat resources. However, these novel technologies also resulted in two main problems: one was that the rate of the second filtration, exchange and scrubbing in the belt filter was slow, and the Na_2O content in zeolite was not stable: the other is that the cell constants did not contract and the particle size of zeolite was bigger in spray drying. In combination with the research of zeolite synthesis and modification, this subject elaborates the effects of ultrastable Y zelolite on performance of catalytic cracking catalyst. Based on the mechanism of filtration and spray drying process, this work proposed some improvements, by experiments in combination with the work of zeolite synthesis and modification, explored the influences of the improvements on production and quality, and made the new technologies implemented successfully in the production.
引文
1. Blazek JJ. Oil & Gas J., 1971, 69(45): 66
2. Eastwood SC, Plank CJ and Weisz PB. Proced. 8th Word PetroCongr., England, 1971. London: Applied Science Publishers LTD, 1972, 425
3.高滋,何鸣元,戴逸云.沸石催化与分离技术,化学工业出版社.1999:1～3,6～7
4. Scherzer. J. Catalysis Materials. Washington D. C.: American Chemical Society, 1984, 157
5.栾兆华 等.石油化工,1993,22(3):194
6.栾兆华 等.石油学报(石油加工),1993,9(4):35
7. Scherzer J, et al. J: Catal. 1973, 28(1): 101
8. Treacy M M J, Higgins J B, von Ballmoos R. Collection of Simulated XRD Powder Patterns for Zeolites. 3rd Revised Ed.. New York: Elsevier, 1996
9. Breck DW, Flanigen FM. Molecular Sieves. London: Soc. Chem. Ind., 1968. 47
10.刘维桥,孙桂大.固体催化及使用研究方法.北京:中国石化出版社.1999,87
11. Gao Z, Tang Y. Zeolites, 1988, 8: 232
12. Breck DW. Zeolite Molecular Sieves. New York: John Wiley and Sons, 1974
13. Fraissard J, Ito T. Zeolites, 1988, 8: 351
14. Frilette VJ, Haag WO, Lago RM. J. Catal., 1981, 67: 218
15. Martens JA, Jacobs PA. Zeolites, 1986, 6: 334
16.黄凤林.催化裂化催化剂酸性控制的研究.石油与天然气化工 2001,30(6):289
17.任杰.催化裂化催化剂水热失活动力学模型.石油学报(石油加工)2002,18(5):44
18.何农跃等.超稳Y沸石热稳定性的研究石油化工.1994,23:92
19.著,赵鸿章,张茂隆,戴人利等译.石油馏分的分子筛催化裂化.北京:烃加工出版社,1986,56
20. Skeels GW, Breck W, Olsen D. BisioAcds. Proc. 6th Int. Zeolite Conf.. 1984. UK: Butterworths, 1984: 87
21.潘永康,王喜忠.现代干燥技术,北京:化学工业出版社.1998:288
22.谭天恩,麦本熙,丁惠华等.化工原理,北京:化学工业出版社.1990:151
23.王喜忠等.喷雾干燥,北京:化学工业出版社.2003:93
24.沈志虹,付玉梅,蒋明,李淑云.化学改性对催化裂化催化剂氢转移性能的影响,催化学报.2004,25(3):229～230
25.张健.冷却速度对分子筛结构和性能的影响.复旦学报(自然科学版),1997,36(1):27
26.黄永泉,陈帆.喷雾干燥器新型喷嘴的开发研究与工业试验,佛山陶瓷.1996,2:36
27.黄永泉,陈帆.压力式喷雾干燥塔新型喷嘴,陶瓷.1996,120(2):5
2. Eastwood SC, Plank CJ and Weisz PB. Proced. 8th Word PetroCongr., England, 1971. London: Applied Science Publishers LTD, 1972, 425
3.高滋,何鸣元,戴逸云.沸石催化与分离技术,化学工业出版社.1999:1～3,6～7
4. Scherzer. J. Catalysis Materials. Washington D. C.: American Chemical Society, 1984, 157
5.栾兆华 等.石油化工,1993,22(3):194
6.栾兆华 等.石油学报(石油加工),1993,9(4):35
7. Scherzer J, et al. J: Catal. 1973, 28(1): 101
8. Treacy M M J, Higgins J B, von Ballmoos R. Collection of Simulated XRD Powder Patterns for Zeolites. 3rd Revised Ed.. New York: Elsevier, 1996
9. Breck DW, Flanigen FM. Molecular Sieves. London: Soc. Chem. Ind., 1968. 47
10.刘维桥,孙桂大.固体催化及使用研究方法.北京:中国石化出版社.1999,87
11. Gao Z, Tang Y. Zeolites, 1988, 8: 232
12. Breck DW. Zeolite Molecular Sieves. New York: John Wiley and Sons, 1974
13. Fraissard J, Ito T. Zeolites, 1988, 8: 351
14. Frilette VJ, Haag WO, Lago RM. J. Catal., 1981, 67: 218
15. Martens JA, Jacobs PA. Zeolites, 1986, 6: 334
16.黄凤林.催化裂化催化剂酸性控制的研究.石油与天然气化工 2001,30(6):289
17.任杰.催化裂化催化剂水热失活动力学模型.石油学报(石油加工)2002,18(5):44
18.何农跃等.超稳Y沸石热稳定性的研究石油化工.1994,23:92
19.著,赵鸿章,张茂隆,戴人利等译.石油馏分的分子筛催化裂化.北京:烃加工出版社,1986,56
20. Skeels GW, Breck W, Olsen D. BisioAcds. Proc. 6th Int. Zeolite Conf.. 1984. UK: Butterworths, 1984: 87
21.潘永康,王喜忠.现代干燥技术,北京:化学工业出版社.1998:288
22.谭天恩,麦本熙,丁惠华等.化工原理,北京:化学工业出版社.1990:151
23.王喜忠等.喷雾干燥,北京:化学工业出版社.2003:93
24.沈志虹,付玉梅,蒋明,李淑云.化学改性对催化裂化催化剂氢转移性能的影响,催化学报.2004,25(3):229～230
25.张健.冷却速度对分子筛结构和性能的影响.复旦学报(自然科学版),1997,36(1):27
26.黄永泉,陈帆.喷雾干燥器新型喷嘴的开发研究与工业试验,佛山陶瓷.1996,2:36
27.黄永泉,陈帆.压力式喷雾干燥塔新型喷嘴,陶瓷.1996,120(2):5