초록 ▼

Pellets for removing hydrogen sulfide from a coal gasification stream at an elevated temperature are prepared in durable form usable over repeated cycles of absorption and regeneration. The pellets include a material reactive with hydrogen sulfide, in particular zinc oxide, a binder, and an inert ma

Pellets for removing hydrogen sulfide from a coal gasification stream at an elevated temperature are prepared in durable form usable over repeated cycles of absorption and regeneration. The pellets include a material reactive with hydrogen sulfide, in particular zinc oxide, a binder, and an inert material, in particular calcium sulfate (drierite), having a particle size substantially larger than other components of the pellets. A second inert material and a promoter may also be included. Preparation of the pellets may be carried out by dry, solid-state mixing of components, moistening the mixture, and agglomerating it into pellets, followed by drying and calcining. Pellet size is selected, depending on the type of reaction bed for which the pellets are intended. The use of inert material with a large particle size provides a stable pellet structure with increased porosity, enabling effective gas contact and prolonged mechanical durability.

대표청구항 ▼

Durable sorbent pellets chemically and physically stable for use in multi-cycle sulfidation and regeneration processes at temperatures over 260°C. (500°F.) consisting of a mixture of the following components: a material reactive with hydrogen sulfide and selected from the group consisting of metal o

Durable sorbent pellets chemically and physically stable for use in multi-cycle sulfidation and regeneration processes at temperatures over 260°C. (500°F.) consisting of a mixture of the following components: a material reactive with hydrogen sulfide and selected from the group consisting of metal oxides, acetates, formates, carbonates ad nitrates of zinc, copper, iron, manganese, chromium, and mixtures thereof and having a particle size below 50 microns－30 to 65 weight percent; a diluent selected from the group consisting of, calcium sulfate, calcium phosphate, magnesium sulfate, and zinc silicate, and having a particle size less than 50 microns－20 to 40 weight percent; an inert material comprising particles having a particle size at least twice that of said material reactive with hydrogen sulfide selected from the group consisting of silica, silica gel, alumina, alumina gel, calcium sulfate (drierite), zinc silicate, and sand, wherein the particle size of said inert material is chosen to create additional voids between the components, thus increasing the porosity of the sorbent pellets －2 to 40 weight percent; a binder unreactive with hydrogen sulfide, having a particle size less than said inert material, and selected from the group consisting of bentonite, kaolinite, and cement and mixtures thereof－2 to 45 weight percent; a promoter selected from the group consisting of oxides and salts of copper, cobalt, manganese, nickel and mixtures thereof－an amount greater than zero and up to 10 weight percent; said mixture having been moistened with water, formed into pellets, dried, and calcined at a temperature above 538°C. (1,000°F.), but low enough to avoid a chemical reaction of said material reactive with hydrogen sulfide with said diluent; and said material reactive with hydrogen sulfide being unreactive with all other components of said mixture at said calcination temperature.