The Cleaner Production Technology Research Of Hydrothermal Ultrastable Y Zeolite

Catalytic cracking of petroleum processing technology is one of the important, ultrastable Y zeolite is the major active component of catalytic cracking catalyst. Ultrastable Y zeolite by hydrothermal calcination, ion exchange, chemical extraction of aluminum silicon reinsertion modified prepared. Hydrothermal ultrastable Y zeolite is mainly divided into the synthesis of NaY and NaY modified NaY, modified, which consists of the exchange of washing and filtering, the roasting process.Modified NaY process, using ammonium exchanged zeolite sodium exchange process, washing and filtering process uses a lot of water impurities washing in the molecular sieve, the water consumption is greater at the same time, resulting in a large number of high ammonia nitrogen wastewater; roasting process produces a large amount of exhaust gas, dust content and ammonia pollution exhaust.In view of the above problems, this paper firstly studied the hydrothermal ultrastable molecular sieve ammonium free exchange, a lower sieve effect of ammonium on hydrothermal ultrastable molecular sieve performance. Through the experiment, optimization of process parameters of MY-5 molecules after the use of non A ammonium medium instead of ammonium exchange of product quality is almost the same Y-4 molecule sieve; using an ammonium salt medium B and C instead of ammonium exchange sieve product quality.Secondly study the hydrothermal ultrastable molecular sieve with ammonium exchange and filtration process optimization of ammonium concentration and filtration process influence on the quality of the products. The test results show that by optimizing the process parameters and process, reduce the amount of salt in the exchange did not affect the quality of the product.Third, the exchange rate and improve the effect of temperature on the quality of the molecular sieve water circulation.Experimental results show that:the extension of exchange by reducing the temperature and time of exchange, can achieve low temperature hydrothermal ultrastable molecular sieve exchange, does not affect the product quality, reduces the molecular sieve in the production process of steam consumption;increase the reasonable water recycling rate, reuse of catalyst filter instead of fresh water, back water tower to production system the sedimentation tank and water absorption, molecular sieve product quality, reduce water consumption.Finally, the research of molecular sieve calcination tail gas recycling of molecular sieve on the quality, energy consumption and the effect of different treatment process, water absorption and retention time on the flash gas absorption effect. Test results show that:the reuse of roasting gas molecular sieve drying, not on the molecular sieve product impact, reducing the molecular sieve gas, steam consumption. At the same time can be obtained, by optimizing the flash gas treatment process, to increase the circulation of water and increase the residence time in the tail gas absorption device will reduce exhaust emissions flash.