PROCESS FOR PRODUCING POWER IN A GAS TURBINE
A process for providing heat energy to an ammonia cracking reactor. The invention comprising recovering an oxygen containing off-gas from a hydrogen fueled gas turbine and supplying at least a portion of the off-gas to a fuel combustion zone to produce heat energy for the ammonia cracking reactor. The invention finds use in chemical production facilities, such as ammonia production facilities.
1 . A process for generating power using a gas turbine fueled by a carbon free fuel derived from the catalytic cracking of ammonia, the process comprising:
supplying an ammonia stream to an ammonia cracking reactor;
cracking the ammonia in the ammonia stream in the ammonia cracking reactor to produce a hydrogen containing stream;
combining the hydrogen containing stream with an oxygen containing feed and combusting the hydrogen containing stream with the oxygen containing feed to produce a combusted gas stream;
using the combusted gas stream to drive a gas turbine and produce an oxygen containing off-gas stream;
supplying at least a portion of the oxygen containing off-gas stream to a fuel combustion zone; and
combusting a fuel stream and the oxygen containing off-gas stream in the fuel combustion zone to produce heat energy for the ammonia cracking reactor.
2 . The process according to claim 1 , further comprising the step of pre-heating the ammonia stream to a temperature of from 350° C. to 1000° C.
3 . The process according to claim 1 , wherein the temperature of the ammonia stream at the inlet of the ammonia cracking reactor is in the range of 350° C. to 1000° C., from 400 to 950° C., from 450° C. to 850° C., or from 500° C. to 750° C.
4 . The process according to claim 1 , wherein the hydrogen containing stream comprises from 40 mol % to 75 mol % hydrogen.
5 . The process according to claim 1 , further comprising the step of feeding the hydrogen containing stream to a purification unit and increasing the hydrogen content of the hydrogen containing stream to produce a hydrogen-enriched stream and a tail gas.
6 . The process according to claim 5 , wherein the hydrogen-enriched stream comprises from 50 mol % to 100 mol % hydrogen.
7 . The process according to claim 1 , wherein the oxygen containing feed is a compressed oxygen containing feed.
8 . The process according to a claim 1 , wherein the oxygen containing feed is air, oxygen, or oxygen-enriched air.
9 . The process according to claim 1 , wherein the oxygen containing off-gas stream may comprise oxygen in an amount greater of from 5 mol % to 25 mol %.
10 . The process according to claim 1 , wherein the oxygen containing off-gas stream is supplied to the fuel combustion zone at a temperature of from 500° C. to 800° C., from 500° C. to 750° C., or from 600° C. to 700° C.
11 . The process according to claim 1 , wherein the portion of the oxygen containing off-gas stream supplied to the fuel combustion zone is from 5% to 75%, from 7% to 50%, from 8% to 30%, or from 9% to 20% of the total off-gas stream exiting the gas turbine.
12 . The process according to claim 1 , wherein the fuel stream comprises ammonia.
13 . The process according to claim 1 , wherein the fuel stream comprises ammonia in an amount of from 1 mol % to 100 mol % of the total fuel stream, preferably from 5 mol % to 75 mol %, from 10 mol % to 50 mol %, or from 15 mol % to 30 mol % of the total fuel stream.
14 . The process according to claim 5 , wherein the process comprises the step of feeding the tail gas to the fuel combustion zone; and combusting the fuel stream and the tail gas with the oxygen containing off-gas.
15 . The process according to claim 1 , wherein the fuel stream comprises one or more additional fuel sources selected from hydrogen, natural gas, methane, refinery off gas, biogas, the tail gas from the hydrogen purification unit, and a portion of the hydrogen containing stream from the ammonia cracking reactor.
16 . The process according to claim 12 , wherein the fuel stream comprises ammonia and the ammonia containing fuel stream is supplied from the same source as the ammonia stream being supplied to the ammonia cracking reactor.
17 . The process according to claim 1 , wherein the heat energy produced by combustion using the oxygen containing off-gas stream in the combustion zone provides more than 50% and up to 100% of the heat energy required by the ammonia cracking reactor.
18 . A method for revamping an ammonia production facility, the method comprising the step of implementing the claim 1 in an ammonia production facility.