Reducing CO2 levels in CO2-rich natural gases converted into liquid fuels

A process for converting CO2 in a natural gas to hydrocarbons, the process comprising:

• a) reforming a Fischer-Tropsch naphtha to obtain a C6-C10 product and a hydrogen by-product;
• b) reacting the hydrogen by-product with CO2 in a natural gas feed stream being fed into a synthesis gas formation reactor to produce a synthesis gas used to obtain the Fischer-Tropsch naphtha, so that a reverse water gas shift reaction occurs converting the CO2 into additional CO;
• and
• c) converting the additional CO into hydrocarbons in a Fischer-Tropsch reactor, so that a volume amount of CO2 in the synthesis gas is less than a volume amount of CO2 present in the natural gas feed stream prior to reacting with the hydrogen by-product.

A process for converting a natural gas into liquid fuel, the process comprising:

• a) introducing a natural gas feed stream comprising CO2 and CH4 into a synthesis gas formation reactor;
• b) generating a synthesis gas comprising CO, H2 and CO2 in the synthesis gas formation reactor;
• c) introducing the synthesis gas into a Fischer-Tropsch reactor;
• d) performing a Fischer-Tropsch process on the synthesis gas to produce a Fischer-Tropsch product;
• e) separating the Fischer-Tropsch product into unreacted CO, H2 and CO2, a C1-C5 product having a hydrogen to carbon ratio of about 2.0, a naphtha, and a C10+ product, the C10+ product having a hydrogen to carbon ratio of about 2.0;
• f) reforming the naphtha to generate hydrogen by-product and C6-C10 product with a hydrogen to carbon ratio of less than about 2.0;
• and
• g) mixing the hydrogen by-product with the natural gas feed stream so that at least a portion of the CO2 present in the natural gas feed stream is converted into additional CO by a reverse water gas shift reaction so that the synthesis gas derived from the feed stream contains a volume amount of CO2 that is less than a volume amount of CO2 present in the natural gas feed stream prior to being mixed with the hydrogen by-product;
• and
• h) converting the additional CO into hydrocarbons in the Fischer-Tropsch reactor.

A process for converting CO2 in a natural gas to hydrocarbons, the process comprising:

• a) generating hydrogen by-product by reforming a Fischer-Tropsch naphtha using at least one of a conventional naphtha reforming reaction and a non-acidic zeolitic reforming reaction to obtain a C6-C10 product having a hydrogen to carbon ratio of less than about 2.0;
• b) reacting the hydrogen by-product with CO2 in a natural gas feed stream being used to obtain a synthesis gas used to obtain the Fischer-Tropsch naphtha, so that a reverse water gas shift reaction occurs converting the CO2 into additional CO;
• and
• c) converting the additional CO into hydrocarbons in a Fischer-Tropsch reactor, so that a volume amount of CO2 in the synthesis gas used to obtain the Fischer-Tropsch naphtha is less than a volume amount of CO2 in the natural gas feed stream prior to reacting with the hydrogen by-product.

A process for reducing an amount of CO2 present in a natural gas feed stream, the process comprising:

• a) introducing a natural gas feed stream comprising CH4 and CO2 into a synthesis gas formation reactor;
• b) forming a synthesis gas comprising CO, H2 and CO2 in the synthesis gas formation reactor;
• c) introducing at least a portion of the synthesis gas into a Fischer-Tropsch reactor;
• d) performing a Fischer-Tropsch process on the synthesis gas to obtain a Fischer-Tropsch product;
• e) introducing the Fischer-Tropsch product into a first separator and separating unreacted gases, comprising CO, H2 and CO2, and hydrocarbon products, from the Fischer-Tropsch product;
• f) feeding at least a portion of the unreacted gases into the synthesis gas being fed into the Fischer-Tropsch reactor;
• g) separating the hydrocarbon products from the Fischer-Tropsch reactor into a C1-C5 product having a hydrogen to carbon ratio of at least about 2.0, a naphtha and a C10+ product, the C10+ product having a hydrogen to carbon ratio of about 2.0;
• h) introducing the naphtha into a naphtha reformer;
• i) generating hydrogen by-product by reforming the naphtha in the reformer to produce a C6-C10 product with a hydrogen to carbon ratio of less than about 2.0;
• and
• j) recirculating the hydrogen by-product so that the hydrogen by-product mixes with the natural gas feed stream so that the hydrogen by-product reacts with at least a portion of the CO2 present in the feed stream so that the CO2 is converted into additional CO by a reverse water gas shift reaction so that the synthesis gas derived from the feed stream contains a volume amount of CO2 that is less than a volume amount of CO2 present in the feed stream prior to mixing with the hydrogen by-product;
• and
• k) converting the additional CO into hydrocarbons in the Fischer-Tropsch reactor.

A process for using CO2 in a natural gas to prepare hydrocarbons, the process comprising:

• a) reforming a Fischer-Tropsch naphtha using at least one of a conventional naphtha reforming reaction or a non-acidic zeolitic reforming reaction to obtain a C6-C10 product having a hydrogen to carbon ratio of less than about 2.0 and hydrogen by-product, and
• b) reacting the hydrogen by-product with CO2 in a natural gas so that a reverse water gas shift reaction occurs converting the CO2 into CO;
• and
• c) converting the CO into hydrocarbons in a Fischer-Tropsch reactor.