Objective
The aim of the project is to develop an efficient and compact scrubbing process for the removal of acidic components (like CO2 and H2S) from natural gas. The innovative aspect of the project is, that the absorption fluid is directly injected into the gasstream in co-current flow. In contrast to counter-current absorbers this allows very high gasflows, in a compact installation.
1. HYDRODYNAMIC BEHAVIOUR OF THE EQUIPMENT
- several techniques have been used to determine the gas/liquid interfacial area under variation of gas and liquid velocities.
The influence of the use of liquid injectors on interfacial area and the mass transfer was studied. Experiments have shown that the liquid can be separated from the gasstream with an efficiency of > 99. 95 % in the operating region (gas velocities < 50 m/s).
2. ABSORPTION/DESORPTION EXPERIMENTS WITH VARIOUS LIQUIDS
- Absorption/desorption equilibria and kinetics were determined for several (commercially available) absorption liquids. The results of these experiments determined which liquids were tested in the model experiments in phase 3. MEA (Mono Ethanol Amine) and a-MDEA ( activated Methyl Di Ethanol Amine) were the most promising liquids in this test.
3. MODEL EXPERIMENTS IN THE TEST UNIT
- In the co-current test unit with "groningen gas" artificially enriched to 1 % CO2 as a test gas, experiments were performed at various temperatures (20-40 deg) and pressures (20-40 bar).
The technical feasibility of the process was shown with MEA and a -MDEA as absorption fluids. Also was shown that sufficient CO2 absorption could be reached within an acceptable lenght (50 m) of the absorber. Because of the high regeneration duty needed for MEA, a-MDEA was choosen for an extensive economic evaluation.
4. ECONOMIC EVALUATION
- The economic evaluation demonstrated that for the on-shore situation the advantage in investment costs of the compact installation is not enough to compensate the increase in energy costs in case of the co-current process.
Off-shore economics completely depend on specific circumstances
. Because of this the pilot plant phase was cancelled.
5. PILOT PLANT
- because of the results of the economic evaluation the pilot plant phase was cancelled.
The research in this project was especially focussed on the removal of acidic components from natural gas, in a co-current absorber . The following phases were distinguished within this project : PHASE 1.
Investigation of the hydrodynamic behaviour in the equipment.
The co-current absorption unit was installed and experiments were performed to examine the dispersion of the liquid in the gasstream under various conditions.
Experiments were done to determine the efficiency of the liquid separation from the gasstream using the Gasunie separator. PHASE 2.
Determination of the absortion/desorption behaviour of various absorption fluids. In a stirred cell reactor the kinetic and equilibrium data of the various absorption fluids were studied. PHASE 3.
Investigation of mass transfer with selected absorption liquids in the co-currently operated contacting equipment.
Regeneration of the solvent after gas/liquid separation.
PHASE 4.
Economic evaluation.
An economic evaluation was based uponthe data obtained in phase 3 . This evaluation had to result in a "go or no go" decision with regard to phase 5.
PHASE 5.
Pilot plant tests under real operating conditions.
Programme(s)
Topic(s)
Call for proposal
Data not availableFunding Scheme
DEM - Demonstration contractsCoordinator
9700 Groningen
Netherlands