Filtering medium and method for contacting solids containing feeds for chemical reactors

Abstract

A filtering medium and method for removing contaminants from an organic-based feed stream that includes the use of a layer of ceramic filter units having a plurality of elliptical or trisoidal openings extending therethrough to filter organic-based feed streams and to provide liquid distribution upstream of the catalyst beds.

Description

RELATED APPLICATION [0001] This application is a continuation patent application that claims the benefit of U.S. application Ser. No. 09 / 320,950, filed May 27, 1999, which claimed the benefit of U.S. Provisional Application Ser. No. 60 / 087,235, filed May 29, 1998.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The invention relates to a filtering medium and method for filtering solids from organic-based feed streams to chemical reactors. In another aspect, this invention relates to a filtering medium and method for providing flow distribution of organic-based feed streams to chemical reactors. More particularly, the invention relates to a filtering medium and method for filtering solids and providing liquid distribution for organic-based feed streams that are subsequently processed in chemical reactors having discrete solid element catalyst bed(s). A further aspect of the invention relates to a filtering medium and method for partially reacting polymer precursors...

AI Technical Summary

Benefits of technology

"The present invention relates to a media and methods for filtering and distributing an organic-based feed for chemical reactors. The filtering medium includes ceramic filter units with elliptical and trisoidal shaped openings that create areas of reduced liquid velocity, similar to bends in a river. These ceramic filter units can be made from a variety of ceramic precursors and have a thickness ranging from ⅛ to 1½ inches. The ceramic filter units can also have top and bottom surfaces that are smooth or irregularly shaped to increase contact with entrained solids and remove them from the fluid. The number and size of the openings can be adjusted to change the void fraction of the filter unit and affect filtration of varying particle sizes. The ceramic filter units can also be coated with a selected catalyst to extend the run life of the reactor. Overall, the ceramic filter units provide improved filtration and distribution of the organic-based feed for chemical reactors."

Problems solved by technology

However, attempts to trap particulate matter have not been as successful.

Catalyst bed plugging with contaminants such as dirt, iron oxide, iron sulfide, asphaltenes, coke fines, catalyst fines, sediments, or other entrained foreign particulate material remains to be a problem for the industry.

In addition to catalyst fouling by particulate matter in the organic-based stream, polymerization of polymer precursors, e.g., diolefins, found in the organic-based feed stream may also foul the catalyst.

In particular, two mechanisms of polymerization, free radical polymerization and condensation-type polymerization, may cause catalyst bed fouling, gumming or plugging.

Therefore, filtering prior to the organic-based feed stream entering the reactor may not be helpful to remove these foulants as the polymerization reactions generally take place in the reactors.

Disadvantages associated with current filtration and liquid distribution designs and methods in fixed bed chemical reactors may result in poor liquid distribution to the catalyst bed.

Partial plugging of the catalyst bed with contaminants, or gumming by reactive diolefins or other polymer precursors, may also cause maldistribution.

The maldistribution may result in channeling and corresponding bypassing of portions of the catalyst bed, reducing the catalyst efficiency.

Usually, a maldistribution problem is evidenced by radial temperature differences across the reactor.

Relatively large pressure drops across the filtering and / or distribution media of the previous apparatus and methods require excessive capital and operating costs and cause process safety and environmental concerns arising from maintenance required shutdowns and start-ups.

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