New Technique Integrating Hydrate-Based Gas Separation and Chemical Absorption for the Sweetening of Natural Gas with High H2S and CO2 Contents

Abstract Downhole Natural Gas Separation Efficiency (NGSE) is flow regime dependent, and current analytical models in certain conditions lack accuracy. Downhole NGSE was investigated through 3D Computational Fluid Dynamics (CFD) transient simulations for pumping wells in the Churn flow regime. The Volume of Fluid (VOF) multiphase model was considered along with the k – ε turbulence model for most simulations. A mesh independence study was performed, and the final model results validated against experimental data, showing an average error of less than 6 %. Numerical simulation results showed that the steady state assumption used by current mathematical models for churn flow can be inaccurate. Several key parameters affecting the NGSE were identified, and suggestions for key improvements to the widely used mathematical formulations for viscous flow provided. Sensitivity studies were conducted on fluid/geometric parameters and operating conditions, to gain a better understanding of the influence of each parameter on NGSE. These are important results as they equip the ESP engineer with additional knowledge to maximise the NGSE from design stage to pumping operations.

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A hybrid method combining membrane separation and chemical absorption for flexible CH 4 refinement and CO 2 separation in natural gas

Greenhouse Gases Science and Technology ◽

10.1002/ghg.2138 ◽

2021 ◽

Author(s):

Jian Liu ◽

Chengdong Kong ◽

Zhongxiao Zhang ◽

Liu Yang

Keyword(s):

Natural Gas ◽

Hybrid Method ◽

Membrane Separation ◽

Chemical Absorption

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Gas Turbine Combined Cycle With CO2-Capture Using Auto-Thermal Reforming of Natural Gas

Volume 2: Coal, Biomass and Alternative Fuels; Combustion and Fuels; Oil and Gas Applications; Cycle Innovations ◽

10.1115/2000-gt-0162 ◽

2000 ◽

Cited By ~ 21

Author(s):

Thormod Andersen ◽

Hanne M. Kvamsdal ◽

Olav Bolland

Keyword(s):

Natural Gas ◽

Gas Turbine ◽

Process Integration ◽

Combined Cycle ◽

Co2 Removal ◽

Gas Turbine Combustor ◽

Chemical Absorption ◽

Fuel Gas ◽

The Impact ◽

Water Gas

A concept for capturing and sequestering CO2 from a natural gas fired combined cycle power plant is presented. The present approach is to decarbonise the fuel prior to combustion by reforming natural gas, producing a hydrogen-rich fuel. The reforming process consists of an air-blown pressurised auto-thermal reformer that produces a gas containing H2, CO and a small fraction of CH4 as combustible components. The gas is then led through a water gas shift reactor, where the equilibrium of CO and H2O is shifted towards CO2 and H2. The CO2 is then captured from the resulting gas by chemical absorption. The gas turbine of this system is then fed with a fuel gas containing approximately 50% H2. In order to achieve acceptable level of fuel-to-electricity conversion efficiency, this kind of process is attractive because of the possibility of process integration between the combined cycle and the reforming process. A comparison is made between a “standard” combined cycle and the current process with CO2-removal. This study also comprise an investigation of using a lower pressure level in the reforming section than in the gas turbine combustor and the impact of reduced steam/carbon ratio in the main reformer. The impact on gas turbine operation because of massive air bleed and the use of a hydrogen rich fuel is discussed.

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