# US 4,400,181 A · Method for using fast fluidized bed dry bottom coal gasification

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- Number: US 4,400,181 A
- Document ID: US4400181A
- Status: Granted
- Kind: A
- Application number: 06/343,626
- Filed: 1982-01-28
- Granted: 1983-08-23
- Earliest claimed: 1982-01-28
- Assignees: Hydrocarbon Research, Inc.
- Inventors: George J. Snell; Paul H. Kydd
- Web page: https://patentgrep.com/patent/US4400181A

## CPC

- C10J 3/54: Gasification of granular or pulverulent fuels by the Winkler technique, i.e. by fluidisation
- C10J 3/56: Apparatus; Plants
- C10J 3/74: Construction of shells or jackets
- C10J 3/78: High-pressure apparatus
- C10J 2200/152: Nozzles or lances for introducing gas, liquids or suspensions
- C10J 2300/093: Coal
- C10J 2300/0943: Coke
- C10J 2300/0946: Waste, e.g. MSW, tires, glass, tar sand, peat, paper, lignite, oil shale
- C10J 2300/0956: Air or oxygen enriched air
- C10J 2300/0959: Oxygen
- C10J 2300/0976: as steam
- C10J 2300/1884: with one stream being synthesis gas
- C10J 2300/1892: with one stream being water/steam
- C10J: PRODUCTION OF PRODUCER GAS, WATER-GAS, SYNTHESIS GAS FROM SOLID CARBONACEOUS MATERIAL, OR MIXTURES CONTAINING THESE GASES (synthesis gas from liquid or gaseous hydrocarbons C01B; underground gasification of minerals E21B43/295); CARBURETTING AIR OR OTHER GASES

## Abstract

Carbonaceous solid material such as coal is gasified in a fast fluidized bed gasification system utilizing dual fluidized beds of hot char. The coal in particulate form is introduced along with oxygen-containing gas and steam into the fast fluidized bed gasification zone of a gasifier assembly wherein the upward superficial gas velocity exceeds about 5.0 ft/sec and temperature is 1500.degree.-1850.degree. F. The resulting effluent gas and substantial char are passed through a primary cyclone separator, from which char solids are returned to the fluidized bed. Gas from the primary cyclone separator is passed to a secondary cyclone separator, from which remaining fine char solids are returned through an injection nozzle together with additional steam and oxygen-containing gas to an oxidation zone located at the bottom of the gasifier, wherein the upward gas velocity ranges from about 3-15 ft/sec and is maintained at 1600.degree.-200.degree. F. temperature. This gasification arrangement provides for increased utilization of the secondary char material to produce higher overall carbon conversion and product yields in the process.

## Claims

### Claim 1

A process for gasifying particulate hydrocarbon feed materials to produce a fuel gas product, having low-to-medium heating value, comprising:
(a) introducing the hydrocarbon feed material with steam and oxygen into a gasification zone containing a fast fluidized bed of char particles for gasification therein, said zone being maintained at temperature of 1500.degree.-1850.degree. F., at pressure exceeding about 30 psig, and at upward superficial gas velocity exceeding about 5 ft/sec to heat and gasify the feed and produce a gaseous material;
(b) withdrawing said gaseous material along with char particles from the upper portion of the gasification zone and passing the materials to a primary gas-solids separation step for char solids removal;
(c) withdrawing a first gas stream from said primary gas-solids separation step and returning particulate char solids to the gasification zone;
(d) passing said first gas stream to a secondary gas-solids separation step and removing fine char solids therefrom;
(e) returning the fine particulate char solids from the secondary gas-solids separation step to the lower end of a fluidized bed oxidation zone located immediately below the fast fluidized bed gasification zone; said oxidation zone having temperature maintained within the range of 1600.degree.-2000.degree. F.; and
(f) withdrawing a fuel gas product stream from the secondary gas-solids separation step.

### Claim 2 (depends on 1)

The process of claim 1, wherein the feed stream is introduced into the gasification zone through a shrouded injection nozzle, and the velocity in the solids injection nozzle is between about 6 and about 100 ft/sec.

### Claim 3 (depends on 1)

The process of claim 1, wherein the feed is coal and the weight ratio of gasification zone char to coal is between about 20 and 30.

### Claim 4 (depends on 1)

The process of claim 1, wherein the fine char solids from the secondary cyclone separator are returned to the oxidation zone through a gas shrouded nozzle together with an oxygen-containing gas.

### Claim 5 (depends on 1)

The process of claim 1, wherein the gasification zone temperature is within the range of 1600.degree.-1800.degree. F., the pressure is 50-750 psig, and the upward superficial gas velocity is 6-20 ft/sec.

### Claim 6 (depends on 1)

The process of claim 1, wherein the temperature of the oxidation zone is maintained within the range of 1650.degree.-1950.degree. F.

### Claim 7 (depends on 1)

The process of claim 1, wherein the feed material is anthracite coal having particle size within the range of 0.040-0.004 inch (18-140 mesh U.S. Sieve Series).

### Claim 8 (depends on 4)

The process of claim 4, wherein the secondary char solids are injected into the oxidation zone at a velocity within the range of 3-10 ft/sec and the shroud gas has exit velocity within the range of 20-80 ft/sec to provide a grinding effect on the char solids.

### Claim 9 (depends on 1)

The process of claim 1, wherein the coarse ash particles are withdrawn from the lower portion of the oxidation zone.

### Claim 10

A process for gasifying coal to produce a fuel gas product, having low-to-medium heating value, comprising:
(a) introducing coal feed into a gasification zone containing a fast fluidized bed of char particles for gasification therein, said zone being maintained at 1500.degree.-1850.degree. F. temperature range, at pressure exceeding about 30 psig and at upward superficial gas velocity exceeding about 5 ft/sec, and a weight ratio of char to coal feed maintained between about 20 to 30 to heat and gasify the coal and produce a gaseous material;
(b) withdrawing said gas and substantial char from the upper portion of the fast fluidized bed gasification zone and passing the materials to a primary gas-solids separation step for char solids removal;
(c) withdrawing a first gas stream from said primary solids separation step and returning particulate char solids to the gasification zone;
(d) passing said first gas stream to a secondary gas-solids separation step and removing a fine char solids therefrom;
(e) returning the fine particulate char solids from the secondary gas-solids separation step through a gas shrouded nozzle into the lower end of a fluidized bed oxidation zone maintained at temperature within the range of 1600.degree.-2000.degree. F. and located immediately below the fast fluidized bed gasification zone; and
(f) withdrawing a fuel gas product stream from the secondary gas-solids separation step.

### Claim 11 (depends on 10)

The process of claim 10, wherein the percentage conversion of carbon in the coal exceeds about 50 W %.