Methane Purification

Methane Purification

The Challenge

The customer is an important manufacturer of industrial and rare gases and needs to purify methane from a natural source for an electronic application. They want to obtain a highly pure methane product and find the best and most cost-effective separation technology for this application.

The typical feed composition is:

  • N2: 0.6 %
  • CO2: 1000 ppm vol.
  • Ethane: 6.0 %
  • Propane: 2 %
  • Iso-Butane: 0.9 %
  • Methane: 90 %
  • Oxygen: 800 ppm

Our Solution

The proposed system consists of two main sections:

  1. A pre-treatment section that removes water and carbon dioxide by adsorbing them on molecular sieves in a parallel double bed system. One bed remains in service, while the other undergoes regeneration using waste hot gas after separating pure CH4.
  2.  A cryogenic distillation section for the separation of other impurities, which is composed of two distillation columns:
Plant Design Data:
  • Methane Feed: 15 Nm3/h
  • Outlet methane composition:
    • CH4: 99.9995 %
    • O2: < 0.5 ppm
    • H2O: < 1 ppm
    • N2: < 4 ppm
    • CO2: < 0.5 ppm
    • Other impurities: < 0.5 ppm

Main Utilities Consumption:
  • Liquid Nitrogen: 45 kg/h
  • Electric power: 5 kW
Methane Purification

The Results

Innovative Solution – The Polaris plant offered an integrated system combining multiple technologies to solve the problem of removing several different types of contaminating compounds for premium methane purification.

Safe and Reliable – A guaranteed safe and reliable solution was provided for regeneration of the molecular sieves – even in the presence of highly flammable streams such as methane.

Improved Product Quality & Value – Overall, when a client is interested in reaching very pure products, the Polaris plant can upgrade product quality, thus improving resale value.