Improving Natural Gas Amine Treating (Acid Gas Sweetening) Plant Operations

Carbon dioxide and hydrogen sulfide are often found in natural gas streams. When combined with water CO2 creates carbonic acid which is corrosive. CO2 also reduces the BTU value of gas and makes gas unmarketable. H2S is an extremely toxic gas that is also very corrosive to equipment.

Amine treating (also known as gas sweetening) processes remove these contaminants so that the gas is marketable and suitable for transportation.

These technologies utilize amines to remove contaminants from natural gas through absorption and chemical reaction.

  • MEA (Monoethanolamine)
    Used in low pressure natural gas treatment applications requiring stringent outlet gas specifications
  • MDEA (Methyldiethanolamine)
    Has a higher affinity for H2S than CO2 which allows some CO2 "slip" while retaining H2S removal capabilities.
  • DEA (Diethanolamine)
    Used in medium to high pressure treating.

K-Patents provides instant feedback in the control of the amine concentrations. For example, MEA process for carbon dioxide removal from Methane gas CH4 employs a K-Patents Intrinsically Safe Process Refractometer PR-23-IA/IE to control MEA in aqueous solution before it enters the distillation column, and after it is recycled and fed back to the carbon dioxide absorption tower. The optimum MEA concentration is 10-15 wt%.

Silicon oil is often added to the MEA solution to prevent foaming and therefore periodical prism cleaning (every 3-4 weeks) may be needed. Installation in a by-pass is recommended. Proper concentration of MEA needs to be fed to the process, as:

  • too low MEA will affect the absorption efficiency
  • too high MEA will increase corrosion in process equipment (corrosion protection).