Process for selectively producing C3 olefins in a fluid catalytic cracking process with recycle of a C4 fraction to a secondary reaction zone separate from a dense bed stripping zone
US7374660B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 19, 2004 |
| Grant date | May 20, 2008 |
| Priority date | — |
| Expiry date | May 30, 2026 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/584
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for selectively producing C3 olefins from a catalytically cracked or thermally cracked naphtha stream is disclosed herein. The naphtha stream is introduced into a process unit comprised of a reaction zone, a stripping zone containing a dense phase, a catalyst regeneration zone, and a fractionation zone. The naphtha feedstream is contacted in the reaction zone with a catalyst containing from about 10 to about 50 wt. % of a crystalline zeolite having an average pore diameter less than about 0.7 nanometers at reaction conditions. Vapor products are collected overhead and the catalyst particles are passed through the stripping zone on the way to the catalyst regeneration zone. Volatiles are stripped with steam in the stripping zone and the catalyst particles are sent to the catalyst regeneration zone where coke is burned from the catalyst, and are then recycled to the reaction zone. Overhead products from the reaction zone are passed to a fractionation zone where a stream of C3 products is recovered and a stream rich in C4 olefins is recycled to a dilute phase reaction zone in the stripping zone separate from the dense phase of the stripping zone. The olefins can be further p…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.