Urea plant

Patent metadata

Field	Value
Publication number	US-10384184-B2
Application number	US-201715669818-A
Country	US
Kind code	B2
Filing date	Aug 4, 2017
Priority date	Jun 24, 2010
Publication date	Aug 20, 2019
Grant date	Aug 20, 2019

Abstract

The invention relates to a urea plant with a CO2 and a NH3 feed, which comprises a purge line, characterized in that the purge line is connected with a fuel gas input line of a utility plant or an NH3 plant.

First claim

The invention claimed is:

1. A method to reduce fuel consumption of a utility plant, which method comprises feeding a purge gas stream from a urea production plant, said urea production plant comprising a CO 2 feed and an NH 3 feed, into a fuel gas input line of said utility plant;
wherein said purge gas stream comprises at least one impurity from said CO 2 feed and at least one impurity from the NH 3 feed, and wherein the utility plant comprises a steam boiler and the purge stream is fed into a fuel gas supply of a steam boiler in said utility plant.

2. The method of claim 1 , wherein the purge gas stream contains oxygen at a concentration in the range of 0-10 mol %.

3. The method of claim 2 , wherein the purge gas contains oxygen at a concentration in the range of 0-1 mol %.

4. The method of claim 3 wherein oxygen is essentially absent in the purge gas stream.

5. The method of claim 1 , wherein the urea production plant comprises synthesis equipment and synthesis piping and the material used for the synthesis equipment and synthesis piping a duplex ferritic-austenitic that contains, in % by weight:
0-0.05 C;
0-0.8 Si;
0.3-4 Mn;
28-35 Cr;
3-10 Ni;
1.0-4.0 Mo;
0.2-0.6 N;
0-1.0 Cu;
0-2.0 W;
0-0.010 S;
0-0.2 Ce,
the remainder being Fe and normally occurring impurities and additives, having a ferrite content 30-70% by volume.

6. The method of claim 1 wherein said purge gas stream is derived solely from said urea production.

7. A urea production process, wherein urea is produced by reacting ammonia (NH 3 ) and carbon dioxide (CO 2 ), carried out in a urea plant comprising a CO 2 and a NH 3 feed, wherein the plant further comprises a purge line for a purge gas stream, wherein said purge gas stream comprises at least one impurity from said CO 2 feed and at least one impurity from said NH 3 feed, wherein the purge line is connected with a fuel gas input line of a utility plant, and wherein the method comprises using the purge gas as a fuel gas in said utility plant, wherein said utility plant comprises a steam boiler, and wherein the purge stream is directed to the fuel gas supply of said steam boiler.

8. A urea production process according to claim 7 , wherein the oxygen concentration in the purge gas is in the range of 0-10 mol %.

9. A urea production process according to claim 7 , wherein the oxygen concentration in the purge gas is in the range 0-1 mol %.

10. A urea production process according to claim 7 , wherein oxygen is essentially absent in the purge gas.

11. A urea production process according to claim 7 , wherein the plant comprises synthesis equipment and synthesis piping wherein as material for the synthesis equipment and synthesis piping a duplex ferritic-austenitic is used that contains, in % by weight: 0-0.05 C; 0-0.8 Si; 0.3-4 Mn; 28-35 Cr; 3-10 Ni; 1.0-4.0 Mo; 0.2-0.6 N; 0-1.0 Cu; 0-2.0 W; 0-0.010 S; 0-0.2 Ce, the remainder being Fe and normally occurring impurities and additives, the ferrite content being 30-70% by volume.

12. A process according to claim 7 , wherein said purge line is configured to conduct purge gas derived only from said urea production.

13. A method to reduce fuel consumption of an ammonia plant or a utility plant, which method comprises feeding a purge gas stream from a urea production plant, said urea production plant comprising a CO 2 feed and an NH 3 feed, into a fuel gas input line of said ammonia plant or utility plant;
wherein said purge gas stream comprises at least one impurity from said CO 2 feed and at least one impurity from the NH 3 feed wherein the CO 2 feed comprises H 2 and less than 0.05 vol % of oxygen.

14. The method of claim 13 , wherein the purge stream is fed into a reformer section in said ammonia plant.

15. The method of claim 13 , wherein the NH 3 feed comprises H 2 .

16. A urea production process, wherein urea is produced by reacting ammonia (NH 3 ) and carbon dioxide (CO 2 ), carried out in a urea plant comprising a CO 2 and a NH 3 feed, wherein the plant further comprises a purge line for a purge gas stream, wherein said purge gas stream comprises at least one impurity from said CO 2 feed and at least one impurity from said NH 3 feed, wherein the purge line is connected with a fuel gas input line of a utility plant or an NH 3 plant, and wherein the method comprises using the purge gas as a fuel gas in said utility plant or NH 3 plant, wherein the CO 2 feed comprises H 2 and less than 0.05 vol % of oxygen.

17. A urea production process according to claim 16 , wherein the NH 3 feed comprises H 2 .

18. A urea production process according to claim 16 wherein the purge stream is directed to the reformer section of said NH 3 plant.

Assignees

• Stamicarbon

Inventors

• Dieltjens Luc Louis Maria

Classifications

• C07C273/04 Primary

  from carbon dioxide and ammonia · CPC title

• B01J12/00

  Chemical processes in general for reacting gaseous media with gaseous media; Apparatus specially adapted therefor (B01J3/08, B01J8/00, B01J19/08 take precedence) · CPC title

• B01J12/005 Primary

  carried out at high temperatures, e.g. by pyrolysis · CPC title

• Y02P20/142

  Cross-Sectional Technologies · mapped topic

• Y02P20/141

  Feedstock · CPC title