The plant for processing APG into liquid hydrocarbons (synthetic oil) has a process flow that involves catalytic partial oxidation of hydrocarbonaceous gas (APG, NG) by using atmospheric oxygen to obtain synthesis-gas consisting of carbon oxide and hydrogen to enable its conversion into liquid hydrocarbons by Fischer-Tropsch (FT) technology in micro-channel reactors.

 Mini-GTL plant comprises following process stages:

  1. Catalytic desulfurization of feed gas to achieve H2S concentration of ≤ 0.02 ppm;
  2. Catalytic conversion of the feed gas in to synthesis gas in a reactor at a pressure of 0.8 MPa and temperature between 800 - 830°С in the presence of a blocked catalyst based of nickel coated platinum-group metal additives;
  3. Decrease of the synthesis gas temperature from 800 - 830°С to 40 - 50°С with the help of quenching by water and cooling in air-cooled heat exchangers;
  4. Compressing the synthesis gas to a pressure of 2.1 - 2.8 MPa;
  5. Obtaining hydrocarbons from  the synthesis gas in a microchannel FT reactor at the temperature of 210 - 230°С;
  6. Cooling the gas downstream the FT reactor and separation of the reaction products into liquid, water and gaseous phase;
  7. Isolation of a hydrogen-containing gas from the  gaseous phase (effluent gases) and return of that gas into the process in order to maintain the optimum ratio of the components reacting in the FT reactor; 
  8. Flaring the effluent gases containing unreacted carbon oxide;
  9. Obtaining, storing and compressing pure hydrogen for periodic FT catalyst regeneration;
  10. Compressing the air feed to the APG partial oxidation reactor to the pressure of 0.8 - 1.0 MPa;
  11. Purification of the circulating process water from dissolved carbon dioxide, oxygen, and other impurities produce water with the required standard.

 All the equipment, required to be operated the at above-zero temperatures, is placed in containers, and the rest of equipment with non-freezing process media – on open areas.

Mini-GTLTM process flow diagram

APG (associated petroleum gas), or natural gas, which is to be processed to obtain synthetic liquid hydrocarbons (SLH) is desulphurized before entering partial oxidation reactor untill the residual content of sulfur is not more than 0,02 ppm. The conversion of the APG to synthesis gas containing hydrogen (Н2) and carbon monoxide (СО) takes place in a partial oxidation reactor at the pressure of 6-8 atm on a nickel catalyst. Necessary for oxidation of the APG oxygen enters from the atmosphere being fed to the partial oxidation reactor by an air compressor. Steam is also fed into the partial oxidation reactor to increase the yield of hydrogen and carbon oxide, and preventing formation of carbon black. Synthesis gas from the partial oxidation reaction is then cooled and being separated from the water feed by a synthesis gas compressor where it is compressed to the pressure of 25-28 atm. The synthesis gas is then heated to 200-230°C and fed to the microchannel Fischer-Tropsch reactor. In the Fischer-Tropsch reactor the synthesis gas components (Н2 and СО) are converted by a catalyst in paraffin straight chain hydrocarbons. Removal of the Fischer-Tropsch reaction heat is achieved by circulating water with the temperature of approximately 200°C, which is partly vaporized, and the produced steam enters a steam pipeline. Downstream the Fischer-Tropsch reactor the reaction mixture consisting of synthetic hydrocarbons, unreacted synthesis gas and water is cooled and fed to a three-phase separator. From the three-phase separator the gaseous products (nitrogen, unreacted СО and Н2, lower hydrocarbons) are flared, the water is directed to a treatment plant and then used for steam generation, and the synthetic liquid hydrocarbons (after stabilization) are mixed with mineral oil or further processed to obtain (isolate) marketable products.

Process packages, utilities and power-generating facilities (for installation in fully autonomous version):

  • Feed gas receiving and primary processing package;
  • Feed gas desulfurization package;
  • Feed gas compression package;
  • Feed gas heating package;
  • Air compressors package;
  • Air heating package;
  • Mobile power-generating package;
  • Combustion gases heat recuperation package of mobile power-generating package;
  • Partial oxidation reactor package;
  • Synthesis gas heat recuperation package;
  • Synthesis gas compression package;
  • Fischer-Tropsch reactor package;
  • Products cooling and isolation package;
  • Hydrogen isolation from effluent gases and catalyst regeneration package;
  • Effluent gases afterburner package;
  • Water treatment and condensate collection package;
  • Steam generating system package;
  • Power-generating package (including  distributing gear 6 kV, complete transformer substation, electrical distribution point);
  • Modular boiler;
  • Emergency diesel electric power station (EDEPS) to supply a group of special consumers.

Supporting facilities:

  • Nitrogen and instrumentation air generation package;
  • Flare facility package;
  • Firefighting water supply storage tanks and pumping station;
  • Local waste treatment facilities;
  • Administration building (including operators’ room, control room, means of analytical monitoring).