Back to results
US 5,158,668 AGranted
Preparation of recarburizer coke
AssigneeConoco Inc.
InventorsBharat S. Chahar, John K. Shipley
Life of this patent
Estimating the term…
Abstract
Recarburizer coke containing not more than 0.1 weight percent sulfur and not more than 0.1 weight percent nitrogen is prepared by the catalytic hydrogenation, thermal cracking, and delayed coking of a mixture of pyrolysis tar and petroleum distillate.
Claims23
A process for the production of low sulfur and low nitrogen coke which comprises:
- (1) combining a pyrolysis tar and a petroleum distillate to obtain a combined feed material,
- (2) contacting the combined feed material with a gamma alumina or a y zeolite, hydrogenating catalyst comprising an inorganic refractory oxide support or matrix composited with a metal selected from the group consisting of a Group VIB metal, a Group VIII metal and mixtures thereof in the presence of hydrogen and under hydrogenation reaction conditions, said hydrogenating catalyst having been activated by contact with an agent selected from the group consisting of tertiarnonyl polysulfide, carbon disulfide, or dimethyl sulfide and mixtures thereof in the presence of a diesel fuel stream under catalyst activation conditions,
- (3) subjecting the hydrotreated feed material to thermal cracking,
- (4) subjecting thermal tar obtained form the thermal cracking step to delayed coking;
- and
- (5) recovering a coke product containing not more than 0.10 weight percent sulfur and not more than 0.10 weight percent nitrogen.
3 more elements
A process for the production of low sulfur and low nitrogen recarburizer coke which comprises:
- (1) combining a pyrolysis tar and a petroleum distillate to obtain a combined feed material,
- (2) contacting the combined feed material with a gamma alumina or y zeolite, hydrogenating catalyst comprising an inorganic refractory oxide support or matrix composited with a metal selected from a mixture of a molybdenum and nickel or molybdenum and chromium in the presence of hydrogen and under hydrogenation reaction conditions, said hydrogenating catalyst having been activated by contact with an agent selected from the group consisting of tertiarnonyl polysulfide, carbon disulfide, or dimethyl sulfide and mixtures thereof in the presence of a diesel fuel stream under catalyst activation conditions,
- (3) introducing effluent form hydrogenation step (2) to a fractionation zone,
- (4) removing a heavy stream from the fractionation zone in step (3) and subjecting it to thermal cracking,
- (5) returning effluent from the thermal cracking to the fractionation zone,
- (6) removing thermal tar from the fractionation zone and subjecting it to delayed coking;
- and
- (7) Calcining the resulting coke product to obtain a recarburizer coke containing not more than 0.10 weight percent sulfur and not more than 0.10 weight percent nitrogen.
5 more elements
Dependencies are inferred from the claim text.