Autonomous Modular Flare Gas Conversion Systems and Methods
There are provided systems and methods for using fuel-rich partial oxidation to produce an end product from waste gases, such as flare gas. In an embodiment, the system and method use air-breathing piston engines and turbine engines for the fuel-rich partial oxidation of the flare gas to form synthesis gas, and reactors to convert the synthesis gas into the end product. In an embodiment the end product is methanol.
1 . A method of converting a flare gas to an end product, the method comprises:
a. receiving a flare gas from a source;
b. forming a mixture of the flare gas and an oxygen source, wherein the oxygen source primarily comprises air, thereby defining a fuel/air mixture, wherein the fuel/air mixture defines a starting specific entropy;
c. partially oxidizing the fuel/air mixture at a predetermined reformer temperature; thereby providing a reprocessed gas flow comprises a syngas having a syngas composition;
d. converting the reprocessed gas flow in a synthesis unit to thereby provide a first product stream comprising an end product and an exhaust product stream; thereby defining a final specific entropy;
e. wherein the starting specific entropy and the final specific entropy are less than about 1 kJ/kg ° C. of each other; and,
f. wherein steps a) to d) produce less than 2.0 kg of CO 2 per kg of flare gas received.
2 . A method of converting a flare gas to an end product, the method comprises:
a. receiving a flare gas from a source;
b. forming a mixture of the flare gas and an oxygen source, wherein the oxygen source primarily comprises air, thereby defining a fuel/air mixture, wherein the fuel/air mixture defines a starting specific entropy;
c. partially oxidizing the fuel/air mixture at a predetermined reformer temperature; thereby providing a reprocessed gas flow comprises a syngas having a syngas composition;
d. converting the reprocessed gas flow in a synthesis unit to thereby provide a first product stream comprising an end product and an exhaust product stream; thereby defining a final specific entropy;
e. wherein the starting specific entropy and the final specific entropy are less than about 1 kJ/kg ° C. of each other; and,
f. wherein steps a) to d) are net carbon-negative, whereby these steps produce less than about −20 kg CO2e per kg of end product provided.
3 . A method of converting a flare gas to an end product, the method comprises:
a. receiving a flare gas from a source;
b. forming a mixture of the flare gas and an oxygen source, wherein the oxygen source primarily comprises air, thereby defining a fuel/air mixture, wherein the fuel/air mixture defines a starting specific entropy;
c. partially oxidizing the fuel/air mixture at a predetermined reformer temperature; thereby providing a reprocessed gas flow comprises a syngas having a syngas composition;
d. converting the reprocessed gas flow in a synthesis unit to thereby provide a first product stream comprising an end product and an exhaust product stream; thereby defining a final specific entropy;
e. wherein the starting specific entropy and the final specific entropy are less than about 1 kJ/kg ° C. of each other;
f. wherein steps a) to d) produce less than 2.0 kg of CO 2 per kg of flare gas received; and,
g. wherein steps a) to d) are net carbon-negative, whereby these steps produce less than about −20 kg CO2e per kg of end product provided.
4 . The method of claim 1 , comprising compressing the fuel/air mixture to a predetermined reformer pressure.
5 . The method of claim 2 , comprising providing the fuel/air mixture at a predetermined reformer pressure, to a reformer, wherein the partial oxidation is conducted in the reformer at a predetermined reformer temperature.
6 . The method of claim 3 , comprising controlling the pressure and the temperature of the reprocessed gas flow to provide a predetermined synthesis temperature and a predetermined synthesis pressure of the reprocessed gas flow.
7 . The method of claim 1 , wherein the end product comprises a compound selected from the group consisting of methanol, ethanol, ammonia, dimethyl-ether, and F-T liquids.
8 . The method of claim 1 , wherein the end product comprises methanol.
9 . The method of claim 8 , comprising the further steps of removing a material from the first product stream, the material comprising hydrogen; to thereby provide a second product stream; wherein the second product stream comprises at least about 90% methanol, and is thereby at least about 90% pure.
10 . The method of claim 8 , wherein second product stream comprises at least 93% methanol and is thereby at least 93% pure.
11 . The method of claim 8 , wherein second product stream comprises from 90% to 95% methanol and is thereby from 90% to 95% pure.
12 . The method of claim 8 , wherein the end product consists essentially of methanol.
13 . The method of claim 1 , wherein the partial oxidation takes place in a reformer.
14 . The method of claim 2 , further comprising using, water, steam, or both in the step of partially oxidizing the flare gas.
15 . The method of claim 3 , wherein the reformer comprises an air-breathing reformer.
16 . The method of claim 1 , wherein the reformer comprises one or more of a gas turbine engine, a combustion box, an internal combustion engine, an otto cycle reciprocating engine, a diesel cycle reciprocating engine.
17 . The method of claim 2 , wherein the rich fuel/air mixture has a fuel/air equivalence ratio of from 1.1 to about 4.
18 . The method of claim 3 , wherein the rich fuel/air mixture has a fuel/air equivalence ratio of from about 1.5 to about 3.0.
19 . The method of claim 1 , wherein the rich fuel/air mixture has a fuel/air equivalence ratio of from about 1.5 to about 2.5.
20 . The method of claim 2 , wherein the ratio of H 2 to CO in the syngas is from about 1.0 to about 2.0.
21 . The method of claim 3 , wherein the ratio of H 2 to CO in the syngas is from 0.8 to 2.5.
22 . The method of claim 1 , wherein the ratio of H 2 to CO in the syngas is from about 2 to about 3.
23 . The method of claim 2 , wherein the ratio of H 2 to CO in the syngas is from 1.1-2.5.
24 . The method of claim 1 , wherein the ratio of H 2 to CO is less than 3.
25 . The method of claim 2 , wherein the ratio of H 2 to CO is less than 2.5.
26 . The method of claim 1 , wherein the partial oxidation of the flare gas is conducted at a specific entropy of greater than about 7.1 kJ/kg ° C., wherein a reference state for the specific entropy is based upon −273.15° C. and 1 atmosphere.
27 . The method of claim 2 , wherein the partial oxidation of the flare gas is conducted at a specific entropy of greater than about 7.5 kJ/kg ° C., wherein a reference state for the specific entropy is based upon −273.15° C. and 1 atmosphere.
28 . The method of claim 3 , wherein the partial oxidation of the flare gas is conducted at a specific entropy of greater than about 8.0 kJ/kg ° C., wherein a reference state for the specific entropy is based upon −273.15° C. and 1 atmosphere.
29 . The method of claim 1 , wherein the partial oxidation of the flare gas is conducted at a specific entropy of about 7.1 kJ/kg ° C. to about 8.6 kJ/kg, wherein a reference state for the specific entropy is based upon −273.15° C. and 1 atmosphere.
30 . The method of claim 13 , wherein the reformer is a reciprocating engine; and the reciprocating engine has one, more than one, or all of:
a. a compression ratio in the range of about 8:1 to about 17:1;
b. an inlet manifold air temperature of ambient temperature to about 300° C.;
c. an inlet manifold air pressure of ambient to about 5 bar; to about 300° C.; and,
d. a spark timing that is between TDC and 50 degrees before TDC;
e. an engine speed for from about 8,000 rpm to about 1,800 rpm;
31 . The methods of claim 13 , wherein the reformer is selected from the group consisting of a two-stroke reciprocating engine and a four-stroke reciprocating engine.
32 . The method of claim 13 , wherein the reformer is a gas turbine assembly; and the gas turbine assembly has one, more than one, or all of:
a. a first partial oxidation combustor;
b. a two-stage combustion;
c. a gas turbine combustor; and,
d. a combustion cycle time of from 5 to 50 milliseconds.
33 . The method of claim 1 , wherein the starting specific entropy and the final specific entropy are less than about 0.5 kJ/kg ° C. of each other.
34 . The method of claim 2 , wherein the starting specific entropy and the final specific entropy are less than 0.3 kJ/kg ° C. of each other.
35 . The method of claim 3 , wherein the starting specific entropy and the final specific entropy are less than 0.2 kJ/kg ° C. of each other.
36 . (canceled)
37 . (canceled)