HIGH PRESSURE AND LOW TEMPERATURE RECYCLED NH3 REFORMING PROCESS

Abstract

The present invention relates to a process for NHI; reforming, the process comprising (i) feeding a feed stream comprising NH.sub.3 into a reactor unit, wherein the reactor unit has a reactor unit inlet and a reactor unit outlet, wherein the reactor unit comprises a catalytic material: (ii) contacting the feed stream with the catalytic material in the reactor unit, for obtaining a product stream comprising H.sub.2, N.sub.2, NH.sub.3, and optionally H.sub.2O, wherein contacting is performed at a pressure in the range of from 1 to 100 bar(abs) and at a temperature in the range of from 50 to 750 C.; (iii) optionally separating H.sub.2O in the product stream obtained in (ii) for obtaining a dehydrated product stream comprising H.sub.2, N.sub.2, and NH.sub.3; (iv) separating NH.sub.3 from the product stream obtained in (ii) or from the dehydrated product stream obtained in (iii) for obtaining a purified product stream comprising N.sub.2 and H.sub.2: (v) recycling the separated NH.sub.3 obtained in (iv) to (i).

Claims

1-15. (canceled)

16. A process for NH.sub.3 reforming, the process comprising (i) feeding a feed stream comprising NH.sub.3 into a reactor unit, wherein the reactor unit has a reactor unit inlet and a reactor unit outlet, wherein the reactor unit comprises a catalytic material; (ii) contacting the feed stream with the catalytic material in the reactor unit, for obtaining a product stream comprising H.sub.2, N.sub.2, NH.sub.3, and optionally H.sub.2O, wherein contacting is performed at a pressure in the range of from 1 to 100 bar(abs) and at a temperature in the range of from 50 to 750 C.; (iii) optionally separating H.sub.2O in the product stream obtained in (ii) for obtaining a dehydrated product stream comprising H.sub.2, N.sub.2, and NH.sub.3; (iv) separating NH.sub.3 from the product stream obtained in (ii) or from the dehydrated product stream obtained in (iii) for obtaining a purified product stream comprising N.sub.2 and H.sub.2; and (v) recycling the separated NH.sub.3 obtained in (iv) to (i).

17. The process of claim 16, wherein from 90 to 100 volume-% of the feed stream according to (i) consist of NH.sub.3.

18. The process of claim 16, wherein feeding the feed stream into the reactor unit according to (i) is performed at a gas hourly space velocity in the range of from 400 to 40,000 h.sup.1.

19. The process of claim 16, wherein contacting according to (ii) comprises transferring heat from a reaction of a chemical conversion process, wherein transferring heat is conducted using a heat exchanger or a heat pump.

20. The process of claim 19, wherein the heat which is transferred is obtained from an exothermic reaction or wherein the heat which is transferred is excess heat of the heat employed for performing an autothermal reaction or an endothermic reaction.

21. The process of claim 16, wherein the reactor unit comprises one or more reactors, wherein the catalytic material is comprised in the one or more reactors.

22. The process of claim 21, wherein each of the one or more reactors independently from one another is selected from the group consisting of a polytropic reactor, a two-stage reactor, an adiabatic reactor and a combination of a polytropic and an adiabatic reactor.

23. The process of claim 21, wherein each of the one or more reactors independently from one another is tubular.

24. The process of claim 21, wherein the reactor unit comprises, wherein the reactor unit inlet is the reactor inlet and wherein the reactor unit outlet is the reactor outlet.

25. The process of claim 21, wherein the reactor unit comprises, two or more reactors, the two reactors being a first reactor and a second reactor, wherein the first reactor is arranged upstream of the second reactor, wherein the first reactor has a first reactor inlet and a first reactor outlet, wherein the reactor unit inlet is the first reactor inlet and wherein the reactor unit outlet is the second reactor outlet, wherein feeding according to (i) and contacting according to (ii) comprises (i.1) feeding the feed stream comprising NH.sub.3 into the first reactor, for obtaining an intermediate stream; (ii.1) contacting the feed stream with the catalytic material in the first reactor, wherein contacting is performed at a pressure in the range of from 1 to 100 bar(abs) and at a temperature in the range of from 50 to 750 C.; (i.2) feeding the intermediate stream obtained in (i.1) into the second reactor; and (ii.2) contacting the intermediate stream with the catalytic material in the second reactor, wherein contacting is performed at a pressure in the range of from 1 to 100 bar(abs) and at a temperature in the range of from 50 to 700 C.; for obtaining the product stream comprising H.sub.2, N.sub.2, NH.sub.3, and optionally H.sub.2O.

26. The process of claim 16, wherein the reactor unit comprises one or more reactors, and wherein the catalytic material is comprised by one or more of the one or more reactors.

27. The process of claim 16, wherein the catalytic material comprises a metal M1, wherein M1 is Ni, Co, or Ni and Co.

28. The process of claim 16, wherein the catalytic material comprises Ru and one or more support materials, wherein Ru is supported on the one or more support materials, wherein the one or more support materials display a BET surface area of 20 m.sup.2/g or more, and wherein the catalytic material contains 1 wt.-% or less of Ni and Co calculated as the respective element and based on 100 wt.-% of the catalytic material.

29. The process of claim 16, wherein the catalytic material comprises Ni, Ru, and a promoter metal M1, wherein the catalytic material displays an Ru: Ni weight ratio in the range of from 0.0001:1 to 0.5:1, wherein the promoter metal M1 is selected from the group consisting of Li, K, Na, Cs, Mg, Ca, Sr, and Ba, including mixtures of two or more thereof, and wherein the catalytic material further comprises one or more support materials onto which Ni, Ru, and the promoter metal M1 are respectively supported.

30. The process of claim 16, further comprising after (iv) and prior to (v) expanding the NH.sub.3 obtained in (iv).

Description

TABLE-US-00009 TABLE 5a Characteristics of the individual process streams, determined for the simulation according to Example 5 (Part 1). Mixture of feed stream Heated Reactor Feed and recycle Intermediate intermediate outlet stream stream stream stream stream Phase Gaseous Gaseous Gaseous Gaseous Gaseous Temperature 500 500 265.9 500 330 [ C.] Pressure 1 1 1 1 1 [bar(abs)] Mole Flows 234.8247 603.6876 733.6036 733.6036 833.1232 [kmol/h] Mole Fractions X X_NH.sub.3 0.9949 0.9664 0.6182 0.6182 0.4249 X_H.sub.2O 0.0050 0.0023 0.0019 0.0019 0.0017 X_H.sub.2 0.0001 0.0016 0.2670 0.2670 0.4143 X_N.sub.2 0.0000 0.0297 0.1130 0.1130 0.1592 Mass Flows 4000.0000 10464.5132 10464.5132 10464.5132 10464.5132 [kg/h] Volume Flow 15095.0593 38806.4198 32880.0275 47157.6818 41772.0673 [cum/h]

TABLE-US-00010 TABLE 5b Characteristics of the individual process streams, determined for the simulation according to Example 5 (Part 2). Heated NH.sub.3- H.sub.2- and NH.sub.3- H.sub.2-containg NH.sub.3-containing containing H.sub.2O-containing containing product stream for stream for stream stream stream recycling recycling Phase Liquid Gaseous Gaseous Liquid Gaseous Temperature 50 50 80 80 500 [ C.] Pressure 30 30 50 50 1 [bar(abs)] Mole Flows 4.9380 828.1852 459.3220 368.8632 368.8629 [kmol/h] Mole Fractions X X_NH.sub.3 0.7590 0.4229 0.0010 0.9483 0.9483 X_H.sub.2O 0.2378 2.58 .Math. 10.sup.4 4.06 .Math. 10.sup.14 5.79 .Math. 10.sup.4 5.79 .Math. 10.sup.4 X_H.sub.2 0.0006 0.4167 0.7493 0.0026 0.0026 X_N.sub.2 0.0027 0.1601 0.2497 0.0486 0.0486 Mass Flows 85.3561 10379.1571 3914.6375 6464.5195 6464.5132 [kg/h] Volume Flow 0.1315 741.7160 147.5262 8.7978 23711.3307 [cum/h]

[0266] From the results shown in Tables 5a and 5b, a conversion of 54% can be obtained at the reactor unit outlet under steady state recycle conditions. In particular, the conversion after the first reactor was 35%, comparable with the conversion obtained according to Example 4. The residue of NH.sub.3 in the H.sub.2-containing product stream was reduced to 1000 ppm in a separation step.

BRIEF DESCRIPTION OF FIGURES

[0267] FIG. 1: shows the parity plot of simulated and experimental values for the Ru-containing low temperature NH.sub.3 reforming catalytic material according to Reference Example.

CITED LITERATURE

[0268] U.S. Pat. No. 8,961,923 B2 [0269] U.S. Pat. No. 8,691,182 B2 [0270] U.S. Pat. No. 8,464,515 B2 [0271] WO 2019/038251 A1 [0272] Banares-Alcantara et al. in Applied Energy 2021, 282, 116009