Hollow Fiber Sorbents for Desulfurization of Natural Gas

Abstract

Pipeline natural gas is the primary fuel of choice for distributed fuel cell-based applications due to its well-developed infrastructure. The concentration of sulfur in odorized pipeline natural gas is about 30 ppm, with the acceptable level being <1 ppm for catalyst stability in such applications. Packed bed technology for desulfurization suffers from several disadvantages including high pressure drop and slow regeneration rates that require large unit sizes. This paper describes a new sorption platform utilizing hollow fibers with polymer “binder”, impregnated with high loadings of sulfur selective zeolite sorbent “fillers”. Temperature Swing Adsorption (TSA) can be utilized to thermally cycle the sorbents between sorption and regeneration cycles. A simplified flow pattern minimizes pressure drop, while a porous core morphology maximizes sorption efficiencies and high surface area to volume ratio structures can enable smaller bed sizes. This new technology represents a fusion of membrane science and adsorption technology.

Thermally moderated hollow fiber sorbent modules in rapidly cycled pressure swing adsorption mode for hydrogen purification

“…Dual-layer hollow fiber spinning Fiber sorbents can be created using a process similar to dryjet, wet-quench hollow fiber membrane spinning [2,3,7,13]. A polymer solution (known as a "dope") with homogenously dispersed and suspended zeolite particles is co-extruded with a pure polymer sheath solution and a bore fluid through a triple orifice annular die (spinneret), whereupon the polymer solutions undergo phase separation via a non-solvent coagulant.…”

“…Small-scale steam methane reforming (SMR) for the production of hydrogen has been proposed as a path forward for enabling distributed hydrogen production by utilizing the existing natural gas infrastructure [1]. Due to the small scales required for these "local" hydrogen production systems, we have recently proposed the use of hollow fiber sorbents for both the separation of sulfur odorants from feed natural gas [2,3] and here, removal of CO 2 from the steam methane reformate gas. Impurities in the post-reformer gas are typically CO 2 , CO, CH 4 , and H 2 O.…”

In situ Formation of a Monodispersed Spherical Mesoporous Nanosilica–Torlon Hollow‐Fiber Composite for Carbon Dioxide Capture

“…This highly heat‐integrated technique that uses hollow‐fiber sorbents results in an overall parasitic load that decreases dramatically compared to liquid amine sorption systems . Temperature‐ or pressure‐swing adsorption (TSA/PSA) processes that use pellets have been considered for CO 2 capture as well; however, a long regeneration time in the case of TSA and high costs associated with pressurizing the flue gas in PSA, may limit their use for large‐scale postcombustion CO 2 capture . Therefore, alternative low‐cost carbon capture technologies have been suggested to circumvent problems associated with amine‐based systems .…”

“…Hollow‐fiber sorbents are pseudomonolithic materials with a porous polymer that contains high loadings of selective solid adsorbent particles such as silica, zeolite, metal–organic frameworks, or ionic liquids as “fillers” . The fiber sorbent morphology and structure offer advantages over traditional spherical pellets, which include a high surface area to volume ratio, avoidance of particle attrition, low pressure drop, increase in flow pattern reliability for scale‐up, and the ability to tune mass transfer resistances . However, fiber sorbents require high sorbent loadings (>50 wt %) to achieve sorption capacities comparable to conventional packed‐bed technology .…”

Size effect of mesoscopic‐scale silver particles on the adsorption capacity of silver/cotton for fuel oil desulphurization

“…[33] Natural fibres, such as cotton, can be easily produced in a farm field, instead of factories with high energy consumption and pollution. The pressure drops of liquid flowing through fibre sorbents are super-low.…”