Editorial

3 pages, 161 KiB

Open AccessEditorial

Catalysts and Processes for H₂S Conversion to Sulfur

by Daniela Barba

Catalysts 2021, 11(10), 1242; https://doi.org/10.3390/catal11101242 - 15 Oct 2021

Cited by 2 | Viewed by 1541

Hydrogen sulfide is one of the main waste products of the petrochemical industry; it is produced by the catalytic hydrodesulfurization processes (HDS) of the hydrocarbon feedstocks, and it is a byproduct from the sweetening of sour natural gas and from the upgrading of [...] Read more.

Hydrogen sulfide is one of the main waste products of the petrochemical industry; it is produced by the catalytic hydrodesulfurization processes (HDS) of the hydrocarbon feedstocks, and it is a byproduct from the sweetening of sour natural gas and from the upgrading of heavy oils, bitumen, and coals [...] Full article

(This article belongs to the Special Issue Catalysts and Processes for H₂S Conversion to Sulfur)

3 pages, 152 KiB

Open AccessEditorial

Catalysts and Processes for H₂S Conversion to Sulfur

by Daniela Barba

Catalysts 2021, 11(8), 903; https://doi.org/10.3390/catal11080903 - 26 Jul 2021

Cited by 3 | Viewed by 1396

Abstract

The hydrogen sulfide (H₂S) is one of the main byproducts in natural gas plants, refineries, heavy oil upgraders, and metallurgical processes [...] Full article

(This article belongs to the Special Issue Catalysts and Processes for H₂S Conversion to Sulfur)

Research

Jump to: Editorial, Review

14 pages, 3633 KiB

Open AccessArticle

One-Pot Synthesis of Nano CuO-ZnO Modified Hydrochar Derived from Chitosan and Starch for the H₂S Conversion

by Lihua Zang, Chengxuan Zhou, Liming Dong, Leilei Wang, Jiaming Mao, Xiaomin Lu, Rong Xue and Yunqian Ma

Catalysts 2021, 11(7), 767; https://doi.org/10.3390/catal11070767 - 24 Jun 2021

Cited by 2 | Viewed by 1898

Abstract

A novel kind of hydrochar adsorbent, modified by CuO-ZnO and derived from chitosan or starch, was synthesized for H₂S adsorption. The prepared adsorbent was characterized by BET, XRD, EDX, SEM, and XPS. The results showed that the modified hydrochar contained many [...] Read more.

A novel kind of hydrochar adsorbent, modified by CuO-ZnO and derived from chitosan or starch, was synthesized for H₂S adsorption. The prepared adsorbent was characterized by BET, XRD, EDX, SEM, and XPS. The results showed that the modified hydrochar contained many amino groups as functional groups, and the nanometer metal oxide particles had good dispersion on the surface of the hydrochar. The maximum sulfur capacity reached 28.06 mg/g-adsorbent under the optimized conditions. The amine group significantly reduced the activation energy between H₂S and CuO-ZnO conducive to the rapid diffusion of H₂S among the lattices. Simultaneously, cationic polyacrylamide as a steric stabilizer could change the formation process of CuO and ZnO nanoparticles, which made the particle size smaller, enabling them to react with H₂S sufficiently easily. This modified hydrochar derived from both chitosan and starch could be a promising adsorbent for H₂S removal. Full article

(This article belongs to the Special Issue Catalysts and Processes for H₂S Conversion to Sulfur)

► Show Figures

Figure 1

13 pages, 3507 KiB

Open AccessFeature PaperArticle

Selective Catalytic Oxidation of Lean-H₂S Gas Stream to Elemental Sulfur at Lower Temperature

by Daniela Barba, Vincenzo Vaiano and Vincenzo Palma

Catalysts 2021, 11(6), 746; https://doi.org/10.3390/catal11060746 - 18 Jun 2021

Cited by 6 | Viewed by 2243

Abstract

Ceria-supported vanadium catalysts were studied for H₂S removal via partial and selective oxidation reactions at low temperature. The catalysts were characterized by N₂ adsorption at 77 K, Raman spectroscopy, X-ray diffraction techniques, and X-ray fluorescence analysis. X-ray diffraction and Raman [...] Read more.

Ceria-supported vanadium catalysts were studied for H₂S removal via partial and selective oxidation reactions at low temperature. The catalysts were characterized by N₂ adsorption at 77 K, Raman spectroscopy, X-ray diffraction techniques, and X-ray fluorescence analysis. X-ray diffraction and Raman analysis showed a good dispersion of the V-species on the support. A preliminary screening of these samples was performed at fixed temperature (T = 327 °C) and H₂S inlet concentration (10 vol%) in order to study the catalytic performance in terms of H₂S conversion and SO₂ selectivity. For the catalyst that exhibited the higher removal efficiency of H₂S (92%) together with a lower SO₂ selectivity (4%), the influence of temperature (307–370 °C), contact time (0.6–1 s), and H₂S inlet concentration (6–15 vol%) was investigated. Full article

(This article belongs to the Special Issue Catalysts and Processes for H₂S Conversion to Sulfur)

► Show Figures

Figure 1

24 pages, 39828 KiB

Open AccessArticle

Application of Response Surface Methodology for Preparation of ZnAC₂/CAC Adsorbents for Hydrogen Sulfide (H₂S) Capture

by Nurul Noramelya Zulkefli, Mohd Shahbudin Masdar, Wan Nor Roslam Wan Isahak, Siti Nur Hatika Abu Bakar, Hassimi Abu Hasan and Nabilah Mohd Sofian

Catalysts 2021, 11(5), 545; https://doi.org/10.3390/catal11050545 - 24 Apr 2021

Cited by 12 | Viewed by 2479

Abstract

Hydrogen sulfide (H₂S) should be removed in the early stage of biogas purification as it may affect biogas production and cause environmental and catalyst toxicity. The adsorption of H₂S gas by using activated carbon as a catalyst has been [...] Read more.

Hydrogen sulfide (H₂S) should be removed in the early stage of biogas purification as it may affect biogas production and cause environmental and catalyst toxicity. The adsorption of H₂S gas by using activated carbon as a catalyst has been explored as a possible technology to remove H₂S in the biogas industry. In this study, we investigated the optimal catalytic preparation conditions of the H₂S adsorbent by using the RSM methodology and the Box–Behnken experimental design. The H₂S catalyst was synthesized by impregnating commercial activated carbon (CAC) with zinc acetate (ZnAc₂) with the factors and level for the Box–Behnken Design (BBD): molarity of 0.2–1.0 M ZnAc₂ solution, soaked temperature of 30–100 °C, and soaked time of 30–180 min. Two responses including the H₂S adsorption capacity and the BET surface area were assessed using two-factor interaction (2FI) models. The interactions were examined by using the analysis of variance (ANOVA). Hence, the optimum point of molarity was 0.22 M ZnAc₂ solution, the soaked period was 48.82 min, and the soaked temperature was 95.08 °C obtained from the optimum point with the highest H₂S adsorption capacity (2.37 mg H₂S/g) and the optimum BET surface area (620.55 m²/g). Additionally, the comparison of the optimized and the non-optimized catalytic adsorbents showed an enhancement in the H₂S adsorption capacity of up to 33%. Full article

(This article belongs to the Special Issue Catalysts and Processes for H₂S Conversion to Sulfur)

► Show Figures

Figure 1

17 pages, 4112 KiB

Open AccessArticle

Polyoxometalate Dicationic Ionic Liquids as Catalyst for Extractive Coupled Catalytic Oxidative Desulfurization

by Jingwen Li, Yanwen Guo, Junjun Tan and Bing Hu

Catalysts 2021, 11(3), 356; https://doi.org/10.3390/catal11030356 - 09 Mar 2021

Cited by 22 | Viewed by 2912

Abstract

Wettability is an important factor affecting the performance of catalytic oxidative desulfurization. In order to develop an efficient catalyst for the extractive coupled catalytic oxidative desulfurization (ECODS) of fuel oil by H₂O₂ and acetonitrile, a novel family of imidazole-based polyoxometalate [...] Read more.

Wettability is an important factor affecting the performance of catalytic oxidative desulfurization. In order to develop an efficient catalyst for the extractive coupled catalytic oxidative desulfurization (ECODS) of fuel oil by H₂O₂ and acetonitrile, a novel family of imidazole-based polyoxometalate dicationic ionic liquids (POM-DILs) [C_n(MIM)₂]PW₁₂O₄₀ (n = 2, 4, 6) was synthesized by modifying phosphotungstic acid (H₃PW₁₂O₄₀) with double imidazole ionic liquid. These kinds of catalysts have good dispersity in oil phase and H₂O₂, which is conducive to the deep desulfurization of fuel oil. The catalytic performance of the catalysts was studied under different conditions by removing aromatic sulfur compound dibenzothiophene (DBT) from model oil. Results showed that [C₂(MIM)₂]PW₁₂O₄₀ had excellent desulfurization efficiency, and more than 98% of DBT was removed under optimum conditions. In addition, it also exhibited good recyclability, and activity with no significant decline after seven reaction cycles. Meanwhile, dibenzothiophene sulfone (DBTO₂), the only oxidation product of DBT, was confirmed by Gas Chromatography-Mass Spectrometry (GC-MS), and a possible mechanism of the ECODS process was proposed. Full article

(This article belongs to the Special Issue Catalysts and Processes for H₂S Conversion to Sulfur)

► Show Figures

Graphical abstract

19 pages, 7377 KiB

Open AccessArticle

Valorization of Raw and Calcined Chicken Eggshell for Sulfur Dioxide and Hydrogen Sulfide Removal at Low Temperature

by Waseem Ahmad, Sumathi Sethupathi, Yamuna Munusamy and Ramesh Kanthasamy

Catalysts 2021, 11(2), 295; https://doi.org/10.3390/catal11020295 - 23 Feb 2021

Cited by 13 | Viewed by 3769

Abstract

Chicken eggshell (ES) is a waste from the food industry with a high calcium content produced in substantial quantity with very limited recycling. In this study, eco-friendly sorbents from raw ES and calcined ES were tested for sulfur dioxide (SO₂) and [...] Read more.

Chicken eggshell (ES) is a waste from the food industry with a high calcium content produced in substantial quantity with very limited recycling. In this study, eco-friendly sorbents from raw ES and calcined ES were tested for sulfur dioxide (SO₂) and hydrogen sulfide (H₂S) removal. The raw ES was tested for SO₂ and H₂S adsorption at different particle size, with and without the ES membrane layer. Raw ES was then subjected to calcination at different temperatures (800 °C to 1100 °C) to produce calcium oxide. The effect of relative humidity and reaction temperature of the gases was also tested for raw and calcined ES. Characterization of the raw, calcinated and spent sorbents confirmed that calcined eggshell CES (900 °C) showed the best adsorption capacity for both SO₂ (3.53 mg/g) and H₂S (2.62 mg/g) gas. Moreover, in the presence of 40% of relative humidity in the inlet gas, the adsorption capacity of SO₂ and H₂S gases improved greatly to about 11.68 mg/g and 7.96 mg/g respectively. Characterization of the raw and spent sorbents confirmed that chemisorption plays an important role in the adsorption process for both pollutants. The results indicated that CES can be used as an alternative sorbent for SO₂ and H₂S removal. Full article

(This article belongs to the Special Issue Catalysts and Processes for H₂S Conversion to Sulfur)

► Show Figures

Graphical abstract

15 pages, 21354 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Tailoring Properties of Metal-Free Catalysts for the Highly Efficient Desulfurization of Sour Gases under Harsh Conditions

by Cuong Duong-Viet, Jean-Mario Nhut, Tri Truong-Huu, Giulia Tuci, Lam Nguyen-Dinh, Charlotte Pham, Giuliano Giambastiani and Cuong Pham-Huu

Catalysts 2021, 11(2), 226; https://doi.org/10.3390/catal11020226 - 09 Feb 2021

Cited by 6 | Viewed by 2359

Abstract

Carbon-based nanomaterials, particularly in the form of N-doped networks, are receiving the attention of the catalysis community as effective metal-free systems for a relatively wide range of industrially relevant transformations. Among them, they have drawn attention as highly valuable and durable catalysts for [...] Read more.

Carbon-based nanomaterials, particularly in the form of N-doped networks, are receiving the attention of the catalysis community as effective metal-free systems for a relatively wide range of industrially relevant transformations. Among them, they have drawn attention as highly valuable and durable catalysts for the selective hydrogen sulfide oxidation to elemental sulfur in the treatment of natural gas. In this contribution, we report the outstanding performance of N-C/SiC based composites obtained by the surface coating of a non-oxide ceramic with a mesoporous N-doped carbon phase, starting from commercially available and cheap food-grade components. Our study points out on the importance of controlling the chemical and morphological properties of the N-C phase to get more effective and robust catalysts suitable to operate H₂S removal from sour (acid) gases under severe desulfurization conditions (high GHSVs and concentrations of aromatics as sour gas stream contaminants). We firstly discuss the optimization of the SiC impregnation/thermal treatment sequences for the N-C phase growth as well as on the role of aromatic contaminants in concentrations as high as 4 vol.% on the catalyst performance and its stability on run. A long-term desulfurization process (up to 720 h), in the presence of intermittent toluene rates (as aromatic contaminant) and variable operative temperatures, has been used to validate the excellent performance of our optimized N-C²/SiC catalyst as well as to rationalize its unique stability and coke-resistance on run. Full article

(This article belongs to the Special Issue Catalysts and Processes for H₂S Conversion to Sulfur)

► Show Figures

Graphical abstract

12 pages, 3257 KiB

Open AccessArticle

Reaction Mechanism of Simultaneous Removal of H₂S and PH₃ Using Modified Manganese Slag Slurry

by Jiacheng Bao, Xialing Wang, Kai Li, Fei Wang, Chi Wang, Xin Song, Xin Sun and Ping Ning

Catalysts 2020, 10(12), 1384; https://doi.org/10.3390/catal10121384 - 27 Nov 2020

Cited by 10 | Viewed by 1684

Abstract

The presence of phosphine (PH₃) and hydrogen sulfide (H₂S) in industrial tail gas results in the difficulty of secondary utilization. Using waste solid as a wet absorbent to purify the H₂S and PH₃ is an attractive [...] Read more.

The presence of phosphine (PH₃) and hydrogen sulfide (H₂S) in industrial tail gas results in the difficulty of secondary utilization. Using waste solid as a wet absorbent to purify the H₂S and PH₃ is an attractive strategy with the achievement of “waste controlled by waste”. In this study, the reaction mechanism of simultaneously removing H₂S and PH₃ by modified manganese slag slurry was investigated. Through the acid leaching method for raw manganese slag and the solid–liquid separation subsequently, the liquid-phase part has a critical influence on removing H₂S and PH₃. Furthermore, simulation experiments using metal ions for modified manganese slag slurry were carried out to investigate the effect of varied metal ions on the removal of H₂S and PH₃. The results showed that Cu²⁺ and Al³⁺ have a promoting effect on H₂S and PH₃ conversion. In addition, the Cu²⁺ has liquid-phase catalytic oxidation for H₂S and PH₃ through the conversion of Cu(II) to Cu(I). Full article

(This article belongs to the Special Issue Catalysts and Processes for H₂S Conversion to Sulfur)

► Show Figures

Figure 1

21 pages, 12568 KiB

Open AccessCommunication

The Impact of Surficial Biochar Treatment on Acute H₂S Emissions during Swine Manure Agitation before Pump-Out: Proof-of-the-Concept

by Baitong Chen, Jacek A. Koziel, Andrzej Białowiec, Myeongseong Lee, Hantian Ma, Peiyang Li, Zhanibek Meiirkhanuly and Robert C. Brown

Catalysts 2020, 10(8), 940; https://doi.org/10.3390/catal10080940 - 16 Aug 2020

Cited by 13 | Viewed by 3653

Abstract

Acute releases of hydrogen sulfide (H₂S) are of serious concern in agriculture, especially when farmers agitate manure to empty storage pits before land application. Agitation can cause the release of dangerously high H₂S concentrations, resulting in human and animal [...] Read more.

Acute releases of hydrogen sulfide (H₂S) are of serious concern in agriculture, especially when farmers agitate manure to empty storage pits before land application. Agitation can cause the release of dangerously high H₂S concentrations, resulting in human and animal fatalities. To date, there is no proven technology to mitigate these short-term releases of toxic gas from manure. In our previous research, we have shown that biochar, a highly porous carbonaceous material, can float on manure and mitigate gaseous emissions over extended periods (days–weeks). In this research, we aim to test the hypothesis that biochar can mitigate H₂S emissions over short periods (minutes–hours) during and shortly after manure agitation. The objective was to conduct proof-of-the-concept experiments simulating the treatment of agitated manure. Two biochars, highly alkaline and porous (HAP, pH 9.2) made from corn stover and red oak (RO, pH 7.5), were tested. Three scenarios (setups): Control (no biochar), 6 mm, and 12 mm thick layers of biochar were surficially-applied to the manure. Each setup experienced 3 min of manure agitation. Real-time concentrations of H₂S were measured immediately before, during, and after agitation until the concentration returned to the initial state. The results were compared with those of the Control using the following three metrics: (1) the maximum (peak) flux, (2) total emission from the start of agitation until the concentration stabilized, and (3) the total emission during the 3 min of agitation. The Gompertz’s model for determination of the cumulative H₂S emission kinetics was developed. Here, 12 mm HAP biochar treatment reduced the peak (1) by 42.5% (p = 0.125), reduced overall total emission (2) by 17.9% (p = 0.290), and significantly reduced the total emission during 3 min agitation (3) by 70.4%. Further, 6 mm HAP treatment reduced the peak (1) by 60.6%, and significantly reduced overall (2) and 3 min agitation’s (3) total emission by 64.4% and 66.6%, respectively. Moreover, 12 mm RO biochar treatment reduced the peak (1) by 23.6%, and significantly reduced overall (2) and 3 min total (3) emission by 39.3% and 62.4%, respectively. Finally, 6 mm RO treatment significantly reduced the peak (1) by 63%, overall total emission (2) by 84.7%, and total emission during 3 min agitation (3) by 67.4%. Biochar treatments have the potential to reduce the risk of inhalation exposure to H₂S. Both 6 and 12 mm biochar treatments reduced the peak H₂S concentrations below the General Industrial Peak Limit (OSHA PEL, 50 ppm). The 6 mm biochar treatments reduced the H₂S concentrations below the General Industry Ceiling Limit (OSHA PEL, 20 ppm). Research scaling up to larger manure volumes and longer agitation is warranted. Full article

(This article belongs to the Special Issue Catalysts and Processes for H₂S Conversion to Sulfur)

► Show Figures

Graphical abstract

Review

Jump to: Editorial, Research

45 pages, 13529 KiB

Open AccessFeature PaperReview

Direct Selective Oxidation of Hydrogen Sulfide: Laboratory, Pilot and Industrial Tests

by Sergei Khairulin, Mikhail Kerzhentsev, Anton Salnikov and Zinfer R. Ismagilov

Catalysts 2021, 11(9), 1109; https://doi.org/10.3390/catal11091109 - 15 Sep 2021

Cited by 11 | Viewed by 6223

Abstract

This article is devoted to scientific and technical aspects of the direct catalytic oxidation of hydrogen sulfide for the production of elemental sulfur. It includes a detailed description of the Claus process as the main reference technology for hydrogen sulfide processing methods. An [...] Read more.

This article is devoted to scientific and technical aspects of the direct catalytic oxidation of hydrogen sulfide for the production of elemental sulfur. It includes a detailed description of the Claus process as the main reference technology for hydrogen sulfide processing methods. An overview of modern catalytic systems for direct catalytic oxidation technology and known processes is presented. Descriptions of the scientific results of the Institute of Catalysis of the SB RAS in a study of the physical and chemical foundations of the process and the creation of a catalyst for it are included. The Boreskov Institute of Catalysis SB RAS technologies based on fundamental studies and their pilot and industrial testing results are described. Full article

(This article belongs to the Special Issue Catalysts and Processes for H₂S Conversion to Sulfur)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Catalysts and Processes for H₂S Conversion to Sulfur

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Published Papers (11 papers)

Editorial

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI

Journal Menu

Journal Browser

Catalysts and Processes for H2S Conversion to Sulfur

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Published Papers (11 papers)

Editorial

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI

Catalysts and Processes for H₂S Conversion to Sulfur