(380h) Sulfatrap Sorbents for Effective Sulfur Removal for Fuel Cells: Dimethyl Sulfide, Mercaptan and COS Adsorption

The effective utilization of natural gas, liquefied petroleum gas (LPG) and biogas in fuel cell applications requires removal of odorants (sulfur compounds such as hydrogen sulfide (H₂S), dimethyl sulfide (DMS), organic disulfides, mercaptans and carbonyl sulfide (COS)) to below 0.1 ppm. Adsorption is a promising technology for accomplishing such low levels of sulfur in the feed gas to the fuel cells. TDA Research Inc. (TDA) has developed the SulfaTrap^TM series of sorbents that are tailored for natural gas, LPG and biogas desulfurization, and has successfully carried out multiple field demonstrations with fuel cell developers.

It is important to realize that pipeline natural gas usually has few ppm to few hundred ppm of moisture, and this has an impact on adsorptive desulfurization. Water either competes for adsorption sites or may induce side reactions depending on the odorant. Similarly, the sulfur compounds and their concentrations in LPG vary widely from supplier to supplier. Biogas contains a wide variety of sulfur species depending on the source of the biogas i.e., if the biogas is generated from a waste water treatment facility or a food processing facility or a dairy farm.

TDA’s sorbent can remove both the H₂S and organic sulfur species in these gases to the ppb levels.  The results from the sorbent development and field demonstrations will be presented in the meeting.