Light hydrocracking of vacuum distillate

Autor: V. A. Khavkin, Ruslan Aliev, Roman R. Aliev, V. M. Kurganov
Rok vydání: 1999
Předmět:
Zdroj: Chemistry and Technology of Fuels and Oils. 35:73-76
ISSN: 1573-8310
0009-3092
Popis: Technology developed previously at VNII NP [3, 4] for two-stage hydrocracking at a pressure of 15 MPa, with the feed hydrotreatod in the first stage (a process aimed at obtaining motor fuels), has not yet been commercialized. The selection of a particular hydrocracking technology will be determined by the end result desired, the quality of the feedstock, and the properties of the catalyst that is used. The process design is influenced considerably by the catalyst type and composition and the charging conditions. As shown by an analysis of the literature and patent data, catalyst compositions for hydrocracking generally contain ultrastable Y zeolites in the REE or H form [5 - 7]. Zeolites in the REE form are more resistant to the action of catalyst poisons present in the feed (nitrogen bases, heavy metals, etc.). Such zeolites are used extensively in manufacturing catalysts for cracking untreated or partially hydrotreated feeds. Zeolites in the H form are less resistant to catalyst poisons, but they are more active in cracking reactions. Hence they are used in manufacturing catalysts for hydrocracking feedstocks that have been thoroughly treated. The content of sodium oxide in the zeolite must not exceed 1%, and should be less than 0.5%. Therefore, in obtaining hydrocracking catalysts, Y zeolite in the REE form is recommended as the most resistant to poisoning. The functional properties of hydrocracking catalysts are determined to a great degree by the zeolite type and content. In the first application of the domestic multifunctional zeolitic catalyst GK-8, in single-stage cracking at 15 MPa and 405-410~ it was found that the process could yield up to 50% jet fuel fractions or up to 70% winter-grade diesel fuel. However, this catalyst did not come into any extensive use, owing to problems in catalyst manufacture. Another commercial catalyst, GKO-1, for which the commercial manufacturing technology has been worked out at the Omsknefteorgsintez Production Association, has a high hydrodesulfurizing activity but is insufficiently stable, owing TABLE 1
Databáze: OpenAIRE
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