Adsorptive Desulfurization of Natural Gas Using Lithium-Modified Mesoporous Silica

Abstract

The dynamic adsorption and desorption behaviors of lithium-modified mesoporous silica adsorbents (YSP-Li and MCF-Li) were investigated to remove sulfur compounds from natural gas. A mixture of methane and methyl mercaptan (291 μmol/mol) was used as feed gas. The adsorption capacities were determined from breakthrough experiments conducted at different temperatures and flow rates. The dynamic thermal desorption of both adsorbents was studied by applying stepwise temperature increases using nitrogen or methane. Both adsorbents could easily be regenerated at 100 °C with a purge gas. MCF-Li exhibited stronger adsorption affinity and higher adsorption capacity to methyl mercaptan than YSP-Li even though its surface area and the doping amount of Li were smaller. The desorption from MCF-Li was more affected by the applied purge gas (CH 4 or N 2 ) than YSP-Li.

Mesoporous magnesium oxide and its composites: Preparation, characterization, and removal of 2-chloroethyl ethyl sulfide

“…However, the migration of products through the small pore of particle in the bed reactor was slow. And it was known that SiO 2 had low reactivity for sulfur-containing compounds [13][14]22]. In the study, AP-MgO had a larger mesopore volume but a smaller micropore volume than MgOÁSiO 2 composite in Table 1.…”

“…When sorbent particles were tested in the breakthrough experiment, the difference in the pressure drop and the bed porosity among the breakthrough experiments resulted in experimental deviations in the performance evaluation. Therefore, it is important to evaluate materials at the same packing conditions in the breakthrough experiments [10,12,13].…”

“…The breakthrough slope implies the shape of the concentration propagation in the bed, which can be affected by the sorption affinity and rate [10,13]. As shown in Fig.…”

“…MgO added by Fe 2 O 3 has been synthesized successfully by several different routes such as the precipitation method (a specific surface area between 23 and 34.5 m 2 /g) [8] and the wet impregnated method (a specific surface area of around 170 m 2 /g) [9]. As an alternative route, it was reported that silica impregnated with magnetite nanoparticles [10] and surface modified silica [11][12][13][14] are a good candidate to improve the adsorption capacity and reactivity of sulfur and nitrogen compounds. Then, to improve the physical properties and sorption capacity, porous silica was added to MgO particle by using various methods such as spray pyrolysis (a specific surface area of about 148 m 2 /g) [5], supercritical drying under different prehydrolysis conditions for TEOS (a specific surface between 207 and 340 m 2 /g) [15], a wet mixing method (a specific surface area under 520 m 2 /g) [16], and a sol-gel method (a specific surface area between 86 and 317 m 2 /g) [17].…”

Sulfur removal from municipal gas using magnesium oxides and a magnesium oxide/silicon dioxide composite

“…It was also determined from the breakthrough results that the sorption rate is equally important as the sorption capacity. Then, mesoporous silica-based adsorbents, such as magnetite-mesoporous silica composites [21] and lithium-modified mesoporous silica adsorbents [22], could contribute to minimizing the mass transfer resistance in the adsorption and regeneration processes in sulfur removal from natural gas due to their relatively large pore size.…”