Process for the reactivation of sulfur deactivated cobalt titania catalysts; the catalyst compositions, use of the reactivated catalysts for conducting carbon monoxide hydrogenation, reactions and the products of such reactions

Abstract

A process for the desulfurization, and reactivation of a sulfur deactivated catalyst constituted of cobalt composited with a titania support. The sulfur deactivated cobalt titania catalyst is first contacted with a gaseous stream of molecular oxygen at temperature sufficiently high to oxidize the sulfur component of the catalyst. The sulfur oxidized catalyst is next contacted with a liquid, preferably water, to remove the oxide, or oxides of the sulfur. The catalyst is then contacted with a reducing agent, suitably hydrogen, to restore the activity of the catalyst. During the treatment there is no substantial loss, if any, of cobalt from the catalyst.

Description

1. FIELD OF THE INVENTION[0001] This invention relates to a process for the reactivation, or regeneration of cobalt catalysts deactivated by sulfur; particularly cobalt catalysts as used in hydrogenation of carbon monoxide or Fischer-Tropsch reactions. It also relates to cobalt-titania catalysts, to the process utilizing the catalyst, and the products of such process.2. BACKGROUND[0002] Fischer-Tropsch (F-T) reactions, i.e., catalytic reactions for the production of C.sub.5+ liquid hydrocarbons from mixtures of hydrogen and carbon monoxide, are well known. The F-T process has become the subject of intense study for commercial development. The catalysts used in conducting F-T reactions are typically constituted of an Iron Group metal (Periodic Table of the Elements, Sargent-Welch Scientific Company, Copyright 1979) of Group VIII, e.g., iron, nickel or cobalt, distributed on a particulate refractory inorganic oxide support, e.g., titania. In formation of the catalyst, the catalytic pr...

AI Technical Summary

Benefits of technology

[0006] This need and others is achieved in accordance with the present invention which embodies, in the preparation of a cobalt catalyst, compositing cobalt with titania sufficient that when the catalyst is sulfided and deactivated by sulfur, or sulfur-bearing compounds, it can be reactivated, or regenerated, without significant loss of cobalt, if any, from the catalyst. The reactivation, or regeneration is accomplished by treating the sulfided cobalt titania catalyst in a series of steps requiring (1) contact, and treatment, with a gaseous stream of molecular oxygen, preferably air, or oxygen-enriched air or nitrogen, at temperature ranging from about 150.degree. C. to about 600.degree. C., preferably from about 300.degree. C. to about 500.degree. C., sufficient to oxidize the sulfur component (and metal component) of the catalyst, and then (2) contacting, treating or washing the sulfur oxidized catalyst, in situ or ex situ of the reaction zone in which Step (1) was conducted, with a liquid, preferably water, at temperature ranging from about 0.degree. C. to about 100.degree. C., preferably from about 20.degree. C. to about 80.degree. C., sufficient to remove the oxide, or oxides of sulfur. The catalyst is then contacted with hydrogen, or other reducing agent, to reduce the metal, or metals, or oxide of the metal, or metals, component to restore the activity of the catalyst, as measured by CO hydrogenation after reduction of the catalyst. It has been found that the activity, and selectivity of a cobalt-titania catalyst, e.g., a cobalt-rhenium-titania catalyst, sulfur deactivated and used in an F-T synthesis reaction, on reactivation, or regeneration in this manner can be restored to that of the fresh catalyst originally used for conducting the similar operation.

Problems solved by technology

When the catalyst comes in contact with sulfur, the activity of the catalyst gradually declines; eventually to such point that it is not economically sound to continue the operation without a new, or reactivated catalyst.