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Gas Processing Systems > Molecular Gate Adsorbent Technology
What is Molecular Gate™?
Pressure Swing Adsorption processes have been commercialized
for over 60 years. So what makes
Molecular Gate unique for PSA processes?
The key is the patented Molecular Gate adsorbent. Originally developed by Engelhard (now a part of BASF), Guild Associates is the sole licensee of the
technology.
Pressure Swing Adsorption is a chemical separation process
in which a mixture of gases is passed through a bed of adsorbent media at high
pressure. Under high pressure, the specific
gasses will be selectively adsorbed on to the surface and pores of the adsorbent
media. The gasses are removed from the
media by “swinging” the media to low pressure, hence the moniker “Pressure
Swing Adsorption”. Commercialized systems
generally use multiple adsorbent vessels so that one is always in the adsorption
mode, while other vessels are regenerated, thus enabling continuous streams of separated gasses.
Molecular Gate adsorbent is unique in that the pore size is
tightly controlled during the manufacturing of the adsorbent, and thus is
customized to most preferentially adsorb a specifically sized target
molecule. In the diagram below, note
that the size of the pore in the adsorbent is controlled to 3.7 Angstroms. Smaller molecules, such as carbon dioxide (CO2)
and nitrogen (N2) are able to fit into the pores and be strongly adsorbed,
while the methane (CH4) molecule is too large to fit in the pore. The result is a reliable separation of
methane from CO2 and N2.
PSA systems with Molecular Gate adsorbent offer advantages
over conventional adsorbents for upgrading methane gas streams.
1. The methane passes through the adsorbent bed
rather than being adsorbed, thus the product gas stream is delivered at high
pressure. For applications that are
injecting the product gas into gas distribution networks, frequently the
additional expense of product compression can be avoided.
2. The Molecular Gate adsorbent will preferentially adsorb CO2 over N2. Thus,
if a N2 rich feed stream contains a small amount of CO2, the CO2 will be removed to a very low level (typically to <0.005%). Thus, more N2 can be passed through to
the product stream without exceeding the product gas specification for inerts, allowing more product flow in a smaller system.
3. Molecular Gate adsorbent does not normally degrade
in operation and therefore can last the life of the equipment. This reduces maintenance costs and
contributes to higher equipment uptime.
Molecular Gate adsorbent has exceeded 12 years of life at multiple
locations.
Do you have a project in mind? Download our
CUSTOMER QUESTIONNAIRE and send the completed form to Guild Associates. If you have questions or want to discuss your specific application, contact Paul Baker at 614-760-8013 or email to at
Information Requests.