Integrated drying and gasification process for simultaneously producing synthetic gas and high rank coal

Patent metadata

Field	Value
Publication number	US-9909076-B2
Application number	US-201314653339-A
Country	US
Kind code	B2
Filing date	Dec 18, 2013
Priority date	Dec 20, 2012
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

The present invention relates to a gasification process for efficiently co-producing synthesis gas and high-grade coal from water-containing coal, and to an integrated drying and gasification system for realizing the same.

First claim

What is claimed is:

1. A gasification method of co-producing synthesis gas and high-quality coal, comprising the steps of:
a) supplying low-quality water-containing coal to a dryer;
b) drying the low-quality water-containing coal in the dryer, in which thermal energy necessary for drying the low-quality water-containing coal is supplied in contact with synthesis gas recycled to the dryer from a gasification step;
c) separating dried coal and synthesis gas discharged from the dryer using solid-gas separation and then recovering the separated synthesis gas;
d) transferring target amounts of the separated dried coal to a gasifier in a fluidic state using a loop seal type transfer means to which aeration gas is supplied by a plurality of ports and simultaneously recovering a high-quality dried coal which is not transferred to the gasifier;
e) gasifying the transferred dried coal in the gasifier to prepare synthesis gas; and
f) directly recycling the synthesis gas of 400 to 1500° C. discharged from the gasifier without passing the synthesis gas through a heat exchanger(s),
wherein the dryer provides a drying capacity necessary for producing the dried coal separated and recovered from the low-quality water-containing coal and the dried coal transferred to the gasification step.

2. The gasification method of claim 1 , wherein the content of water in the low-quality water-containing coal is 10 to 70 wt %.

3. The gasification method of claim 1 , wherein the dried coal has a water content of 10 wt % or less.

4. The gasification method of claim 1 , wherein the low-quality water-containing coal is pulverized to a particle size of 50 to 6000 μm and then introduced into the dryer, before the step a).

5. The gasification method of claim 1 , wherein the content of carbon in the low-quality water-containing coal is at least 20 wt %.

6. The gasification method of claim 1 , wherein the dryer is a pneumatic or flash dryer, a fluidized-bed dryer, a rotary dryer or a rotary tube dryer.

7. The gasification method of claim 6 , wherein the dryer is a pneumatic or flash dryer.

8. The gasification method of claim 1 , wherein the low-quality water-containing coal and synthesis gas are in contact with each other in a parallel stream in the dryer.

9. The gasification method of claim 1 , wherein the operating pressure in the dryer is 60 kg/cm 2 or less, the operating temperature at an inlet of the dryer is adjusted in a range of 400 to 1500° C., and the operating temperature at an outlet of the dryer is adjusted in a range of 200 to 700° ° C.

10. The gasification method of claim 1 , further comprising the step of forming the dried coal separated and recovered in the step d) into pellets, briquettes or granules.

11. The gasification method of claim 1 , the aeration gas is nitrogen, carbon dioxide, steam, synthesis gas generated from the gasifier, or a mixture thereof.

12. The gasification method of claim 1 , wherein the operating temperature in the gasifier is 400 to 1500° C., and the operating pressure in the gasifier is 1 to 60 kg/cm 2 .

13. The gasification method of claim 1 , wherein, in the step e), the molar ratio of O 2 /C is 0.1 to 1.0, and the molar ratio of CO 2 /C is 0 to 1.

14. The gasification method of claim 1 , wherein, in the step e), the molar ratio of steam/C is 0 to 2.

15. The gasification method of claim 1 , wherein the weight ratio of synthesis gas recycled to the dryer in the step b): low-quality water-containing coal is 1:1 to 10:1.

16. The gasification method of claim 1 , wherein the weight ratio of dried coal separated and recovered in the step d): dried coal transferred to the gasifier is 1:1 to 4:1.

17. The gasification method of claim 1 , further comprising the step of separating and recovering tar generated in the step of drying the low-quality water-containing coal and included in the synthesis gas in the step c) of recovering the synthesis gas.

18. The gasification method of claim 17 , wherein the dryer provides a heat capacity larger than a drying capacity necessary for producing the dried coal separated and recovered from the low-quality water-containing coal and the dried coal transferred to the gasification step.

Assignees

• Sk Innovation Co Ltd
• Sk Energy Co Ltd

Inventors

• Kim Yong Jeon
• Park Jong Sung
• Kim Gyoo Tae
• Ko Nan Hee
• Lee Chun Won
• Shin Jae Wook

Classifications

• C10J2300/093

  Coal · CPC title

• C10J3/485

  Entrained flow gasifiers · CPC title

• C10L5/04

  Raw material {of mineral origin} to be used; Pretreatment thereof {(pretreatment of fuels of non-mineral origin C10L5/40)} · CPC title

• C10L2290/06

  Heat exchange, direct or indirect · CPC title

• C10L9/08

  by heat treatments, e.g. calcining · CPC title