Method for preparing liquid hydrocarbons from syngas

Patent metadata

Field	Value
Publication number	US-9255225-B2
Application number	US-201414569774-A
Country	US
Kind code	B2
Filing date	Dec 14, 2014
Priority date	Jun 26, 2012
Publication date	Feb 9, 2016
Grant date	Feb 9, 2016

Abstract

A method for preparing a liquid hydrocarbon from syngas. The method includes: 1) mixing crude syngas from a biomass gasifier and a hydrogen-rich gas to yield a mixed gas; 2) dehydrating and decarbonizing the mixed gas for removal of moisture, carbon dioxide, and impurities, to yield a fine syngas; 3) introducing the fine syngas to a Fischer-Tropsch synthesis device in the presence of a catalyst, controlling a reaction temperature of the Fischer-Tropsch synthesis at between 150 and 300° C. and a reaction pressure of between 2 and 4 MPa (A), to yield a liquid hydrocarbon and water which is discharged out of the Fischer-Tropsch synthesis device; and 4) returning 70-95 vol. % of exhaust gases from the Fischer-Tropsch synthesis device to step 3) to mix with the fine syngas, and introducing the resulting mixed gas to the Fischer-Tropsch synthesis device.

First claim

The invention claimed is:

1. A method for preparing a liquid hydrocarbon from syngas, the method comprising:
1) mixing crude syngas from a biomass gasifier and a hydrogen-rich gas to yield a mixed gas, wherein a volume ratio of the hydrogen-rich gas to the crude syngas is between 0.7 and 2.1;
2) removing moisture, carbon dioxide, sulfides, oxynitrides, and metal compounds from the mixed gas, and obtaining a fine syngas;
3) introducing the fine syngas to a Fischer-Tropsch synthesis device for Fischer-Tropsch synthesis in the presence of a catalyst, controlling a reaction temperature of the Fischer-Tropsch synthesis at between 150 and 300° C. and a reaction pressure of between 2 and 4 MPa (A), to yield a liquid hydrocarbon; and
4) returning 70-95 vol. % of exhaust gases from the Fischer-Tropsch synthesis device to step 3) to mix with the fine syngas, the exhaust gases comprising syngas, inert gas, and hydrocarbons, and introducing a resulting mixed gas to the Fischer-Tropsch synthesis device.

2. The method of claim 1 , wherein in 1), the hydrogen-rich gas comprises 60-99 vol. % of hydrogen.

3. The method of claim 2 , wherein in 3), the fine syngas has a H 2 /CO volume ratio of between 1.8 and 3.0, and comprises 50-99 vol. % of effective components H 2 +CO.

4. The method of claim 3 , wherein 3), the fine syngas has a H 2 /CO volume ratio of between 2 and 2.5, and comprises 80-99 vol. % of effective components H 2 +CO.

5. The method of claim 2 , wherein in 1 ), the volume ratio of the hydrogen-rich gas to the crude syngas is between 0.7:1 and 1.34:1, and the hydrogen-rich gas comprises 70-99 vol. % of hydrogen.

6. The method of claim 5 , wherein in 1), the volume ratio of the hydrogen-rich gas to the crude syngas is between 0.96:1 and 1.1:1, and the hydrogen-rich gas comprises 80-90 vol. % of hydrogen.

7. The method of claim 2 , wherein in 3), the reaction temperature of the Fischer-Tropsch synthesis is between 180 and 230° C. and a reaction pressure is between 2 and 2.5 MPa (A).

8. The method of claim 2 , wherein in 3), part of the exhaust gases is used for combustion to generate power or supply heat.

9. The method of claim 2 , wherein in 1), the volume ratio of the hydrogen-rich gas to the crude syngas is between 0.96:1, and the hydrogen-rich gas comprises 90 vol. % of hydrogen; in step 3), the reaction temperature of the Fischer-Tropsch synthesis is 200° C. and a reaction pressure is 2.5 MPa (A); the fine syngas has a H 2 /CO volume ratio of 2.15, and comprises 90 vol. % of effective components H 2 +CO.

10. The method of claim 2 , wherein in 1 ), the volume ratio of the hydrogen-rich gas to the crude syngas is between 1.1:1, and the hydrogen-rich gas comprises 80 vol. % of hydrogen; in step 3), the reaction temperature of the Fischer-Tropsch synthesis is 190° C. and a reaction pressure is 2.2 MPa (A); the fine syngas has a H 2 /CO volume ratio of 2.2, and comprises 84 vol. % of effective components H 2 +CO.

Assignees

• Wuhan Kaidi Eng Tech Res Inst

Inventors

• Chen Yilong
• Song Kan
• Kuai Pingyu
• Gong Yan
• Zhang Yanfeng
• Jin Jiaqi

Classifications

• C10J2300/1659

  to liquid hydrocarbons · CPC title

• C01B2203/0475

  the impurity being carbon dioxide · CPC title

• C01B2203/0495

  the impurity being water · CPC title

• C10K3/00

  Modifying the chemical composition of combustible gases containing carbon monoxide to produce an improved fuel, e.g. one of different calorific value, which may be free from carbon monoxide · CPC title

• C10J2300/0916

  Biomass · CPC title