Role of Amine Structure on Hydrogen Sulfide Capture from Dilute Gas Streams Using Solid Adsorbents

Abstract

The hydrogen sulfide composition in biogas ranges from 0 to 5% depending on the feed source to the biogas digester. To meet renewable natural gas specifications of 0–4 ppm of H2S content, technologies that remove H2S from raw biogas feeds are needed. This contribution assesses three adsorbents with similar textural and physical properties but with different amines grafted to the surface. Specifically, materials containing primary, secondary, and tertiary amines at the end of a propyl surface linker grafted on a silica support are explored. H2S adsorption isotherms and cyclic studies are presented for these materials, and it is shown that secondary amines have the best amine efficiency while tertiary amines are the most stable for H2S capture, of the materials studied. The results suggest the consideration of secondary and tertiary amines for the design of amine adsorbents suitable for H2S removal in dilute gas streams over multiple cycles.

Effect of Humidity on the Sorption of H2S from Multicomponent Acid Gas Streams on Silica-Supported Sterically Hindered and Unhindered Amines

“…The higher H 2 S sorption capacities for SBA-15_TBAPS compared to those for SBA-15_DMAPS are likely due to the higher proton basicity of the secondary amines in SBA-15_TBAPS compared to the weaker base of the tertiary amine sorbent. 2,47 Both SBA-15_TBAPS and SBA-15_DMAPS exhibited higher H 2 S sorption capacities under humid conditions than in dry conditions (Figure 3). Under humid conditions, SBA-15_DMAPS had twice the H 2 S sorption capacity of SBA-15_TBAPS.…”

“…In addition, a tertiary amine, based on a dimethylaminopropylsilyl-grafted species, showed good stability when exposed to high H 2 S concentrations (10% H 2 S in N 2 ). 2,35 To the best of our knowledge, the effect of humidity on H 2 S sorption under single-and multicomponent gas conditions is yet to be investigated for sterically hindered amine sorbents.…”

“…Biogas streams are composed of methane (CH 4 ), carbon dioxide (CO 2 ), hydrogen sulfide (H 2 S), and water vapor (H 2 O), and to increase the calorific value of biogas, CO 2 and H 2 S removal by biogas upgrading is required. CO 2 removal from biogas has been extensively explored but there is limited information on H 2 S capture from this source. − H 2 S is a poisonous and corrosive gas that releases sulfur oxides when combusted, leading to acid rain, causing environmental hazards. − Upgrading of biogas to biomethane makes it a potential source of renewable energy that can be injected into natural gas pipelines and used as fuels for heating or transportation . This additional source of energy could help meet the growing global energy demand and reduce waste and greenhouse gas (GHG) emissions …”

“…Specifically, a sterically hindered secondary amine, based on a tert -butylaminopropylsilyl-grafted species, showed high H 2 S selectivity and good stability in the presence of H 2 S, CO 2 , and CH 4 . In addition, a tertiary amine, based on a dimethylaminopropylsilyl-grafted species, showed good stability when exposed to high H 2 S concentrations (10% H 2 S in N 2 ). , To the best of our knowledge, the effect of humidity on H 2 S sorption under single- and multicomponent gas conditions is yet to be investigated for sterically hindered amine sorbents.…”

A highly selective electron affinity facilitated H2S sensor: the marriage of tris(keto-hydrazone) and an organic field-effect transistor

“…[32][33][34] They uniquely possess both basic and acidic characteristics owing to the presence of functional groups. 32,35 These versatile characteristics enable their wide use in sensing anions/cations, medical biotechnology, molecular switching, sensing applications and so on. 36,37 As the tailored attributes of both CPs and hydrazones can effectively enable them to realize a fully functional solid-state sensor device, we thus propose a novel DPP copolymer with a thiophene donor block (PDVT-10)/tris(keto-hydrazone) heterostructure-based OFET device that is both CMOS compatible and highly sensitive to H 2 S. The realization of the conceived organic (polymermonomer) heterostructure gives rise to excellent charge transport properties of the ultra-thin PDVT-10 film to be combined with copious gas-binding active sites in the form of secondary amine functional groups of the porous tris(keto-hydrazone) film.…”