Advanced Gas Conversion

Another current development in the use of F-T chemistry in a three-phase slurry reactor is Exxon s Advanced Gas Conversion or AGC-21 technology (Eidt et al., 1994 Everett et al., 1995). The slurry reactor is the second stage of a three-step process to convert natural gas into a highly paraffinic water-clear hydrocarbon liquid. The AGC-21 technology, as in the Sasol process, is being developed to utilize the large reserves of natural gas that are too remote for economical transportation via pipelines. The converted liquid from the three-step process, which is free of sulfur, nitrogen, nickel, vanadium, asphaltenes, polycyclic aromatics, and salt, can be shipped in conventional oil tankers and utilized by most refineries or petrochemical facilities. 

Everett, B. M., Eisenberg, B., and Baumann, R. F., Advanced Gas Conversion Technology A New Option for Natural Gas Development, presented at the First Doha Conference on Natural Gas, Doha, Qatar (1995)... 

Qatar ExxonMobil and Qatar Petroleum Advanced gas conversion for the 21th centure (AGC-21) technology 154000 2011... 

Advanced Gas Conversion Process British Gas and Lurgi process cost of electricity... 

Exxon Mobil developed the AGC-21 process (Advanced Gas Conversion for 21st century) for converting natural gas to liquid fuels. The process involves methane reforming, slurry-phase FT synthesis with a cobalt-based catalyst, and hydroisomerization and hydrocracking of the waxes (12). A 6.3 Mt per year FT plant was designed to operate in Qatar, but the plans were cancelled in 2007 (10). 

Exxon developed an advanced gas conversion process (AGC-21) that produces synthesis gas by combined partial oxidation and steam reforming in a fluidized bed. A multiphase, slurry Fischer-Tropsch reactor has also been developed. Syntroleum uses an autothermal air/natural gas reformer to produce synthesis gas. A fluidized bed Fischer-Tropsch reactor has been developed (20-35 atm 190-230°C). 

The new marketplace of energy conversion will have many new and novel concepts in combined cycle power plants. Figure 1-1 shows the heat rates of these plants, present and future, and Figure 1-2 shows the efficiencies of the same plants. The plants referenced are the Simple Cycle Gas Turbine (SCGT) with firing temperatures of 2400 °F (1315 °C), Recuperative Gas Turbine (RGT), the Steam Turbine Plant (ST), the Combined Cycle Power Plant (CCPP), and the Advanced Combined Cycle Power Plants (ACCP) such as combined cycle power plants using Advanced Gas Turbine Cycles, and finally the ITybrid Power Plants (HPP). 

Advances in Natural Gas Conversion, 4th European Congr. Catalysis, F. Basile, G. Fomasari, J. R. Rostrup-Nielsen, and A. Vaccari, eds. Catal. Today 64, 1-138 (2001). 

The dioxide difluorides of U, Np, Pu, and Am have all been isolated. Uranyl fluoride, being an important intermediate in the conversion of enriched UF6 to UO2 for the production of fuel rods for Advanced Gas-Cooled Nuclear Reactors, is undoubtedly the most studied. The majority of papers on UO2F2, therefore, are concerned with its formation from the reaction of UF6 with steam or its conversion to UO2 by reduction with hydrogen. 

G-3 Estimated costs for conversion of natural gas to hydrogen in plants of three sizes, current and possible future cases, with and without sequestration of C02, 202 G-4 Estimated effects of the price of natural gas on the cost of hydrogen at plants of three sizes using steam methane reforming, 204 G-5 Power cycle net efficiency (qel) and thermal-to-hydrogen efficiency (qH) for the gas turbine modular helium reactor (He) high-temperature electrolysis of steam (HIES) and the supercritical C02 (S-C02) advanced gas-cooled reactor HTES technologies, 212... 

Modelling the Characteristics of the Endothermic Reaction Potential of Tar for Flue Gas Clean-up in Advanced Thermochemical Conversion Processes... 

Relative to other advanced combustion conversion systems, such as magnetohydrodynamics (MHD), ceramic blade turbine gas turbine, and potassium Rankine cycle, thermionic development costs should be substantially lower. The cost effectiveness is a result of the modularity of thermionics, which makes it possible to perform mean-ingftil ejqreiiments with small equipment. Thus, large investments should not be required until there is a high prob-abihty of success. 

The Advanced Gas-Cooled Reactor (AGR) was previously discussed in some detail. The AGR is reported to have a development potential beyond the Dungeness B design. If the unclad fuel element development for the reactor is successful, the conversion ratio of the AGR may be improved significantly with some probable decrease in fuel cycle cost. 

The experimental problems with the high temperature, high pressure test rig showed that the first high temperature cyclone which is used to separate reacting particles from the gas stream is a critical component of the system. The coupling of gas flow, particle flow and particle combustion presents a complicated problem which has to be solved in order to achieve the aim of the project. More experimental and theoretical research is needed to enable a reliable design of this essential part of many advanced coal conversion systems. 

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