Desulfurization Sorbents Research Articles

Microwave heating intensified in-situ preparation of ZnO-based desulfurization sorbent with multi-stage structure and promoted performance

Fast mass transfer and gas diffusion is crucial to high performance coal gas desulfurization sorbent. In this paper, ZnO/M41-M sorbent is prepared via hydrothermal, in-situ pre-desulfurization and oxidation, combined with microwave treatment for hydrogen sulfide removal. As revealed by the desulfurization test at 500 °C, the highest sulfur capacity of 12.45 g S 100 g-1 sorbent has been achieved upon the ZnO/M41-M sorbent, which can be attributed to the rich pore structures, high activity and well dispersed reaction sites. Methods like N2 adsorption-desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were applied to characterize the property of sorbents. According to the results, the active components obtained through in-situ method are dispersed uniformly as revealed by the comparison of four preparation methods. Meanwhile, compared to the conventional in-situ heating, microwave radiation reduces the formation of Zn2SiO4 (Zn element: 7.64–7.31 wt.%) with low activity to H2S, maintains better channel structure, and promotes the in-situ oxidation rate (89.56%). After oxidation, the collaboration of S2- preoccupation and microwave effect provides enough space for the replacement of oxygen and sulfur ions. Besides, microwave effect optimizes the reaction activity of ZnO for adsorbing H2S more easily. Overall, effects derived from microwave and in-situ preparation imparted the sorbent with better performance, indicating the potentials in the improvement of sorbents for pollutants removal.

Carbon nanofibers supported sorbents with enhanced performance via microwave-assisted in-situ structural modifications for H2S removal

The construction of sorbent with excellent structure and highly dispersed active components is vital to improving its desulfurization activity. Herein, the Fe nanoparticles/carbon nanofibers (Fe/CNFs) desulfurization sorbents were fabricated via electrospinning, template method and microwave carbonization. The structure of sorbents was successfully regulated with the adjustments of Fe content and the types of sacrificial phases. It was found that the Fe content impacted strongly on both structural and desulfurization performance of the sorbents. The sorbents with various Fe contents showed a trend of first increasing and then decreasing with the increased Fe content in breakthrough sulfur capacity. Among the various samples, the sample with the highest sulfur content was 7.21 g S/100 g sorbent. Furthermore, the Fe/CNFs sorbents were optimized via soft and hard template methods, by taking polymethyl methacrylate (PMMA) and SiO2 nanospheres as sacrificial phases. Desulfurization tests implied that the PMMA and SiO2 modified sorbents involved sulfur capacity of 13.76 and 14.18 g S/100 g sorbent, respectively. According to the characterizations, the modified sorbents were imparted with micro- and open-type macro-porous structure, respectively, upon which, the active components were uniformly dispersed and exposed. The excellent performance of sorbent could be attributed to the synergistic effect of porous structure and widely distributed Fe nanoparticles on CNFs. This work highlights new strategy for the synthesis of desulfurization sorbent.

Investigation on the active site location, structure and ultra-deep desulfurization performance of CuY zeolite

Y zeolites modified with Cu are promising sorbents for adsorption desulfurization due to their cost-effectiveness. Only the supercage, which is larger than thiophene molecule, is the potential location of active sites for thiophene removal. However, numerous copper species cannot serve as effective active sites due to their inability to be located in the supercages. Based on this consideration, two strategies to regulate Cu location in Y zeolite to address the aforementioned challenges were explored. One is to adjust the molecular size of copper-ammonia ligands through pH value of cuprammonia solution, and the other is to prevent the migration of copper to small cages by heat treatment. The results showed that these two strategies could effectively regulate the location of copper active sites in Y zeolite. During heat treatment, Cu could transfer into supercages from sodalite cages at 350 °C. More effective copper would be targeted to be located in the supercages in the process of adjusting pH. For the best Cu10.74Y350 sorbent, which was prepared at 350 °C under pH of 10.74, the Cu content in the supercages was the highest (25 %), and thus it has an excellent desulfurization efficiency of 82.3 %.

Enhancement effect of Ce addition on Mn3O4/diatomite sorbent for moderate-temperature flue gas desulfurization

To improve the performance of single manganese oxide (MnOx) for moderate-temperature flue gas desulfurization, a series of cerium (Ce) modified Mn3O4/diatomite sorbents with different Ce/Mn molar ratios are prepared by the sol–gel method. Results show that the desulfurization performance of single Mn-based sorbents is significantly enhanced by the addition of CeO2. The strong redox couples are formed between CeO2 and Mn3O4 to further improve the desulfurization activity of sorbents. Moreover, the agglomeration of active component on the surface of carrier is restrained by the designed CeO2-Mn3O4 binary oxides with a micro-reticulated framework to provide more active sites, which is conducive to improving the utilization of active component. The M2C2D6 sorbent is verified as the most outstanding sorbent with the desulfurization efficiency of 96 %, sulfur capacity of 221 mg-SO2/g-sorbent and breakthrough time of 251 min. To master the reaction path and control the types of products, the mechanism of desulfurization-regeneration of M2C2D6 is systematically elaborated by the combination of thermodynamic calculation and product calibration. The above results further prove the effectiveness of Ce doping in the enhancement of desulfurization performance of single Mn-based sorbents for moderate-temperature flue gas desulfurization.

An efficient calcium-based sorbent for flue gas dry-desulfurization: promotion roles of nitrogen oxide and oxygen.

The development of sorbents for flue gas desulfurization in a dry mode is essential to control emission of sulfur dioxide. Based on the novel concept of "treating waste with waste", a low-cost and highly activated calcium-based sorbent (ACS) was prepared using coal fly ash, CaO and waste gypsum as the raw materials via the one-step incipient wetness impregnation method. Based on characterization using scanning electron microscopy and nitrogen adsorption-desorption, the ACS possessed a fibrous and netted structure with high porosity, which improved SO2 adsorption greatly. The SO2 adsorption capacity of ACS with coal fly ash/CaO/CaSO4 = 1/2/1 was high, up to 44.26 mg g-1, with 100% removal efficiency at 150 °C. In the absence of O2, SO2 was rapidly adsorbed on the sorbent to form CaSO3 according to in situ DRIFTS analysis, while when O2 was present in the flue gas, SO2/SO3 2- tended to be oxidized into SO4 2- species. Moreover, the presence of NO can further enhance the SO2 adsorption capacity of the ACS due to the formation of adsorbed NO2 or nitrate species with strong oxidizing properties. Therefore, the ACS can be considered as a sustainable sorbent with the advantage of employing fly ash for the removal of sulfur dioxide.

Insights to the microwave effect in formation and performance promotion of iron-based carbon nanofibrous composites for H2S removal

Iron-based carbon nanofibrous composites were synthesized as high-temperature coal gas desulfurization sorbents by electrospinning, pre-oxidation and conventional/microwave carbonizations. Compared with conventional method, microwave carbonization effectively promoted the nucleation and growth of zero-valent iron (ZVI) among nanofibers, which in turn expedited the carbonization process of carbon matrix via the catalytic graphitization. Desulfurization performance evaluations showed that the sorbent carbonized by microwave at 700 °C possessed the highest breakthrough sulfur capacity (3.81 g S 100 g−1 sorbent), which might be attributed to the porous structure and rich content of iron species on the surface of nanofibers. The local high temperature induced by the interaction of microwaves and ZVI imparted the sorbent with porous microstructure. In addition, the rapid and high-temperature carbonization of microwave greatly enhanced the diffusion of Fe to the fiber surface due to the difference in thermal expansion coefficients of Fe and carbon. As a consequence, microwave carbonization involves the advantages of high energy efficiency and structural strengthening effect, suggesting its potential for the preparation of desulfurization sorbent.

Bimetallic-MOF-Derived ZnxCo3-xO4/Carbon Nanofiber Composited Sorbents for High-Temperature Coal Gas Desulfurization.

Desulfurization sorbent with a high active component utilization is of importance for the removal of H2S from coal gas at high temperatures. Thus, the hypothesis for producing ZnxCo3-xO4/carbon nanofiber sorbents via the combinations of electrospinning, in situ hydrothermal growth, and carbonization technique has been rationally constructed in this study. ZnxCo3-xO4 nanoparticles derived from metal-organic frameworks are uniformly loaded on the electrospun carbon nanofibers (CNFs) with high dispersion. ZnxCo3-xO4/CNFs sorbents possess the highest breakthrough sulfur adsorption capacity (12.4 g S/100 g sorbent) and an excellent utilization rate of the active component (83.2%). The excellent performance of ZnxCo3-xO4/CNFs can be attributed to the synergetic effect of the hierarchical structure and widely distributed ZnxCo3-xO4 on the CNFs supporter. The decomposition of Zn/Co-ZIFs not only generates the nucleus of oxides but also realizes their physical isolation through the formation of carbon grids on the surface of CNFs, avoiding the aggregation of oxides. Furthermore, ZnxCo3-xO4/CNFs sorbents show an overwhelming superiority over the ZnO/CNFs sorbent, which is attributed to the introduction of Co and then the promotion of the stability of Zn at high temperatures. The presence of Co also accelerates the adsorption of H2S on the active site of the oxide surface. The presented method is beneficial for promoting desulfurization performances and producing sorbents with high utilization of active components.

Enhancement of Desulfurization Capacity with Cu-Based Macro-Porous Sorbents for Hydrogen Production by Gasification of Petroleum Cokes

Macro-porous alumina was used as a support for a pellet-type Cu-based desulfurization sorbent in the gas purification process for producing blue hydrogen by the gasification of petroleum coke. The effects of the macro-porous alumina on the pellet-type sorbents in reducing the gas diffusion resistance into the pores were investigated. The results showed that the macro-porous alumina enhances the diffusion resistance, resulting in an improved sulfur capacity of CuO absorbents. Such effects were more significant on the pellet type CuO absorbents than the powder type. In addition, CO production was observed experimentally during the desulfurization reaction of carbonyl sulfide (COS) at low temperatures (~473 K). Density functional theory calculations were also performed to understand the kinetics of desulfurization and CO production. The simulation results predicted that the kinetics of desulfurization is strongly affected by the local surface environment. The CO generated from C–O bond breaking from COS had a lower adsorption energy than the CO2 formation. These results suggest that the Cu-based desulfurization sorbent has potential catalytic activity for producing CO from COS dissociation.

Desulfurization sorbents for green and clean coal utilization and downstream toxics reduction: A review and perspectives

The efficient utilization and clean conversion of coal have become one of the urgent tasks in the current situation of energy utilization in China. Aiming to promote the energy efficiency and sustainability, coal to gas is playing a more and more important role in the national environmental and climate change. However, the presence of harmful H2S in the syngas not only corrodes the equipment and poisons the catalyst, but also pollutes the environment seriously after it is discharged to the atmosphere, so it must be removed. The preparation of desulfurization materials with high sulfur capacity, high efficiency, good regenerability and stable performance has always been the research hotspot in this field. Based on previous works, first, newly developing desulfurization sorbents prepared with excellent performance and novel methods and materials emerging in recent years have been reviewed and highlighted in the present paper. Second, the preparation method, performance indicators and merits of various single metal oxides (Fe2O3, ZnO, Mn2O3, CuO, CaO) and composite metal oxides (Fe–Zn–O, Mo–Fe–Mn–O, Mn–Ca, etc.) have been discussed and compared. More important, the further perspectives, such as techno-economic analysis and life cycle assessment of the relating field were also proposed based on the existing understandings, which will make sense for the promotion of energy efficiency and sustainability, pollution reduction and resource recovery. The in depth development status and the state of the art of clean coal utilization sorbents for hydrogen sulfide clean-up reviewed in the present paper aiming to offer theoretical basis and experience to the accurate design and performance improvement of cost-effective desulfurization sorbent.

Modular manganese/diatomite-Santa Barbara Amorphous-15 sorbent for moderate-temperature flue gas desulfurization

As two typical silicon source carrier, the features of diatomite and Santa Barbara Amorphous-15 (SBA-15) supported Mn-based sorbents for moderate-temperature flue gas desulfurization are investigated in this paper. The framework structure, high mechanical strength and large density of diatomite make great contributions to the high desulfurization efficiency (96%) of diatomite supported Mn-based sorbents (MxDy). Nevertheless, the excessive Mn doping (50 wt%) exhibits the decline in desulfurization efficiency, resulting from the self-seeding nucleation and the bareness of micro-pores. Compared to M4D6, the dispersion of active component on the surface of SBA-15 is much more uniform and the sulfur capacity of SBA-15 supported Mn-based sorbent (M4S6) is sharply increased from 186 mg/g to 494 mg/g. On the other hand, the small density of SBA-15 and formation of some bare micro-regions of Mn2O3 in M4S6 lead to the weak contact between SO2 molecule and the active component on the surface of sorbent, as well as the decrease of desulfurization efficiency of M4S6 (88%). Further, the desulfurization mechanism of M4D6 and M4S6 is explored through analyzing the chemical reaction, external mass transfer and internal diffusion. The modular Mn/diatomite-SBA sorbents are developed by combining the advantages of M4D6 and M4S6. When the weight ratio of M4D6 and M4S6 reaches 3:2, the SO2 removal efficiency of modular sorbent and sulfur capacity can reach 96% and 366 mg/g, respectively.

Microwave heating motivated performance promotion and kinetic study of iron oxide sorbent for coal gas desulfurization

High temperature coal gas desulfurization is an efficient and environment-friendly process for clean coal technologies. In this study, microwave heating is adopted as the energy source to prepare iron oxide desulfurization sorbents and the effect on the properties of the sorbents is investigated. Sorbent synthesized through the conventional heating method is obtained as well for comparison. Characterization techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), scanning electron microscope (SEM) and N2 adsorption are used to evaluate the as-prepared sorbents. Results from XAS and XRD show that Fe2O3 crystal possesses smaller volume and shorter length in bonds Fe-O and Fe-Fe, suggesting that there is a better dispersion of crystallites under microwave irradiation. According to XPS results, microwave irradiation induces sorbents with higher contents of surface lattice O2−, which is contributive to increasing the absorption efficiency and desulfurization reactivity towards the removal of H2S. With the help of thermogravimetry devices, kinetic studies produce the result that both the desulfurization and regeneration processes adapt the model of unreacted shrinking core. The reaction rates are limited via surface chemical reaction at first and then controlled by internal diffusion control in the later stage. Sorbents produced by microwave heating, on the whole, show a better H2S removal performance due to their facilitated chemical reaction and mass transfer, suggesting the potential of the preparation of improved industrial sorbents.

Improvement on Sulfur Capacity of Cu-Al-Based Desulfurization Sorbents with Various Transition Metal Additives for Coal Derived Synthetic Gas Cleaning.

This study examined the effects of additives to improve the COS absorption capacity of Cu-Al-based sorbents for the integrated gasification fuel cell (IGFC) process. To absorb a small amount of COS, an Al-based precursor was added to the precursor solution for Cu-Al-based sorbents because a high surface area absorber was required. Various transition metals (Zn, Fe, Mn) were used as additives to improve the stability of the Cu-Al-based absorbent. The changes in surface properties and sulfur absorption capacity of the Cu-Al-based absorbent were investigated according to the composition of transition metals. As a result of the sulfur absorption test, the difference in the sulfur absorption capacity of the Cu-based sorbents was confirmed depending on the type of additive, and changes in their surface area. Moreover, the pore characteristics were observed by the nitrogen adsorption method. Sorbents with high surface areas generally have high sulfur capacity, but the additive component has a strong effect. These results can be explained by the transition metal additive binding to Cu to form a composite metal oxide. Furthermore, manganese was found to be suitable for improving the stability and surface area of the copper-based absorbent.

Lattice substitution and desulfurization kinetic analysis of Zn-based spinel sorbents loading onto porous silicoaluminophosphate zeolites

Green Zn-based spinel sorbents for hot coal gas desulfurization have been developed with the assistance of optimization procedures. The pilot study highlights an outstanding ordered mesoporous support (SBET = 323 m2 g−1, Da = 4.3 nm) of SAPO-34@as-prepared SBA-15 (SS) for loading active metal oxides. ZnCo2O4 spinel loaded onto SS (ZnCo2/SS) exhibits a prominent desulfurization performance compared to other sorbents whose partial Co is substituted by Mn or Fe in spinel B-site, owing to the slight effect of PO43− in SS. After systematic evaluation on role of sulfidation condition, 50 wt% ZnCo2/SS sorbent possesses the sulfur storage capacity of 138.08 mg g−1at550 °C and little loss of active species in 5 desulfurization-regeneration cycles. Results of high resolution transmission electron microscopy (HRTEM), Brunauer–Emmett–Teller (BET), X-ray photoelectron spectroscopy (XPS) etc. demonstrate that 70.42% of initial sulfur capacity of ZnCo2/SS presented in the 2nd utilization is associated with zinc evaporation, existence of high stable sulfides and partial sintering. The improved deactivation kinetic model suitably describes that the H2S concentration distribution relates with the spatial position of fixed-bed reactor and desulfurization time.

Sorbents for hydrogen sulfide capture from biogas at low temperature: a review

Biogas, e.g., biomethane, is produced by fermentation of organic matter and can be used as an alternative fuel or as a raw material for the production of hydrogen and syngas. However, biogas includes hydrogen sulfide (H2S) as a byproduct of fermentation. Hydrogen sulfide is toxic, has a foul odor, corrodes equipments, and deactivates catalysts. Thus, hydrogen sulfide has to be removed before biogas combustion or conversion. Compared with classical wet desulfurization, low-temperature dry desulfurization is of interest due to higher desulfurization, simpler operation, less pollution, and less energy consumption. Here, we review solid sorbents for low-temperature biogas desulfurization, such as activated carbon, metal-exchanged zeolites, single metal oxides, composite metal oxides, ordered mesoporous silica, and metal–organic frameworks.

Verification of proper operation of dry acid gas removal process on syngas derived by O2/CO2-blown gasifier

Dry syngas purification process was demonstrated on the bench scale test facility comprised of halide removal unit and sulfur removal unit with three fixed bed reactors in which regenerable honeycomb sorbents were installed. The first-ever test of the facility aims to verify the resistance of the zinc ferrite desulfurization sorbent to the carbon deposition in actual syngas condition and proper operation of the cyclic run of the three-reactors system. The test was so challenging that the sulfur removal sorbent was exposed to the severe condition for carbon deposition in the actual syngas derived from oxygen/carbon dioxide blown coal gasifier. The process was operated at 450 °C and 0.98 MPa abs. under the duration of reactor switching of sulfur removal unit of 1 hr for the initial cyclic operation. The dry syngas purification process exhibited sufficient performance of halide and sulfur removal that was evaluated with gas analytical instruments and chemical analysis of the spent sorbent. The sulfur removal unit was operated for the initial cycle of sulfidation, regeneration, and reduction steps without any detrimental effect of carbon deposition. This result encouraged that the process is ready to perform the proper operation in the actual syngas condition during the longer duration of multiple cyclic operation of the bench scale test facility.

Evaluation of dry acid gas removal process on bench scale test facility coupled with syngas produced by O2/CO2-blown gasifier

Dry acid gas removal test facility that comprises of halide and sulfur control units was coupled with O2/CO2-blown gasifier to demonstrate performance and operability of the dry gas purification process for the oxy-fuel IGCC power generation with efficient carbon dioxide separation. The facility was operated for initial five desulfurization cycles of sequential operation of sulfidation, regeneration, and reduction. The duration of each step was fixed to three hours which includes the purge operation to change the gas condition from syngas to oxidative gas, and vice versa. The test facility has the sulfur removal unit equipped with three fixed-bed reactors. Honeycomb shaped desulfurization sorbent that was improved to prevent harmful carbon deposition was installed in those reactors. The cyclic operation results revealed that the unit could reasonably remove sulfur compounds in the sulfidation steps and released the absorbed sulfur during succeeding regeneration steps for the initial five cycles of operation. The spent sorbent did not suffered with carbon deposition and retained their performance on sulfur removal. The absorbed sulfur in the spent sorbent was adequately released in regeneration steps for further operation of desulfurization cycles. The performance and operability of the dry acid gas removal process was successfully demonstrated in the actual syngas operation test.

A hot syngas purification system integrated with downdraft gasification of municipal solid waste

Gasification of municipal solid waste (MSW) with subsequent utilization of syngas in gas engines/turbines and solid oxide fuel cells can substantially increase the power generation of waste-to-energy facilities and optimize the utilization of wastes as a sustainable energy resources. However, purification of syngas to remove multiple impurities such as particulates, tar, HCl, alkali chlorides and sulfur species is required. This study investigates the feasibility of high temperature purification of syngas from MSW gasification with the focus on catalytic tar reforming and desulfurization. Syngas produced from a downdraft fixed-bed gasifier is purified by a multi-stage system. The system comprises of a fluidized-bed catalytic tar reformer, a filter for particulates and a fixed-bed reactor for dechlorination and then desulfurization with overall downward cascading of the operating temperatures throughout the system. Novel nano-structured nickel catalyst supported on alumina and regenerable Ni-Zn desulfurization sorbent loaded on honeycomb are synthesized. Complementary sampling and analysis methods are applied to quantify the impurities and determine their distribution at different stages. Experimental and thermodynamic modeling results are compared to determine the kinetic constraints in the integrated system. The hot purification system demonstrates up to 90% of tar and sulfur removal efficiency, increased total syngas yield (14%) and improved cold gas efficiency (12%). The treated syngas is potentially applicable in gas engines/turbines and solid oxide fuel cells based on the dew points and concentration limits of the remaining tar compounds. Reforming of raw syngas by nickel catalyst for over 20 h on stream shows strong resistance to deactivation. Desulfurization of syngas from MSW gasification containing significantly higher proportion of carbonyl sulfide than hydrogen sulfide, traces of tar and hydrogen chloride demonstrates high performance of Ni-Zn sorbents.

Utilization of CFBC Fly Ash as a Binder to Produce In-Furnace Desulfurization Sorbent

Circulating fluidized bed combustion (CFBC) power generation technology is known to efficiently reduce the emission of air pollutants, such as SO2 and NO2, from coal combustion. however, CFBC coal ash contains high contents of free CaO, making it difficult to recycle. This research has been conducted to find ways to use the self-hardening property of CFBC coal ash, one of its inherent characteristics. As part of these efforts, the present study intended to investigate the properties and desulfurization efficiency of Ca-based desulfurization sorbents using CFBC fly-ash as a binder. Limestone powder was mixed with CFBC fly-ash and Ca(OH)2 to fabricate desulfurization sorbents, and it generated hydrate of cement, including portlandite, ettringite, and calcium silicate, etc. The compressive strength of the desulfurization absorbent prepared by CFBC fly ash and Ca(OH)2 was 72–92% that of the desulfurized absorbent prepared by using general cement as a binder. These absorbents were then compared in terms of desulfurization efficiency using a high-temperature fluidized bed reactor. It was confirmed that the desulfurization absorbents fabricated using CFBC fly-ash as a binder achieved the best performance in terms of absorption time, which reflects the time taken for them to remove over 90% of high-concentration SO2 gas, and the conversion ratio, which refers to the ratio of CaO turning into CaSO4.

A review of sorbents for high-temperature hydrogen sulfide removal from hot coal gas

Integrated gasification combined cycle (IGCC) and solid oxide fuel cell (SOFC) systems are considered as the most promising clean coal technologies. Syngas derived from coal gasification is the major fuel sources for IGCC and SOFC power systems; however, large amounts of sulfur compounds, mainly in the form of hydrogen sulfide, are produced during gasification. Hydrogen sulfide has to be removed prior to syngas utilization to protect downstream equipment from high-temperature corrosion. Therefore, hydrogen sulfide removal from raw syngas plays a key role in successful application of IGCC and SOFC systems. Hot coal gas desulfurization using solid sorbents is a more efficient technique for hydrogen sulfide removal, compared with conventional cold coal gas desulfurization with amine solution. This article reviews solid sorbents for high-temperature desulfurization, e.g., transition metal oxides, rare-earth oxides, spinel oxides, perovskite oxides, nanoelemental metals and mesoporous desulfurizers. Composite oxides that combine the properties of diverse metal oxides are promising candidates for hot coal gas desulfurization. The extensive background knowledge and the state of the art on high-temperature sorbents for hydrogen sulfide removal in this review provides inspiration and guidance to develop new cost-effective sorbents.

Tea Garden Lateritic Soil as a High-Temperature Desulfurization Sorbent: Effect of Oxygen on Regeneration Process

The lateritic soils collected from a tea garden were used to explore the regeneration process using different O2 contents for high-temperature desulfurization. The desulfurization and regeneration experiments were carried out using a fixed-bed reactor at 500°C and the gaseous mixture composed of 1% H2S, 25% CO, 15% H2, and balance N2 for the desulfurization process. Experimental results showed that the regenerability is better when the air was used as a regeneration gas and the regeneration time is shortened. Multiple regeneration experiments indicated that lateritic soils can be regenerated by passing air and can thus be reused many times and its regeneration efficiency is slightly better than that regenerated by 1% O2. The sulfur capacity after air desulfurization/regeneration cycles was examined by elemental analysis with a value ranging from 1.40% to 1.49%, and residual sulfur was detected with a value of 0.12% after the diluted 1% O2 regeneration. No sulfur was detected for the regenerated lateritic soil after air regeneration. From NMR structural identification, the 6-coordinated octahedral structure of Al and trioctahedral coordinated Si are the major Al-containing and Si-containing compounds. Broad shoulder peaks were detected after regeneration process that may be associated with the formation of aluminosilicate and further reduces the dispersion of iron on the surface of lateritic soils.