1
|
Yu H, Shan C, Li J, Hou X, Yang L. Alkaline absorbents for SO 2 and SO 3 removal: A comprehensive review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 366:121532. [PMID: 38986382 DOI: 10.1016/j.jenvman.2024.121532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Revised: 06/13/2024] [Accepted: 06/16/2024] [Indexed: 07/12/2024]
Abstract
Injection of an alkaline absorbent into the flue gas can significantly reduce SO2 and SO3 emissions. The article presents alkaline absorbents employed in industrial processes to remove SO2 and SO3 from flue gases, detailing their characteristics and applications across various process conditions. It summarizes the mechanisms and influencing factors behind SO2 and SO3 removal, outlines the impact of multi-component gases, particularly SO2, on SO3 removal in actual flue gases, and elucidates this competitive phenomenon from a theoretical standpoint. The article compares the application scenarios and efficiencies of alkaline absorbents across different processes, identifies the optimal combinations of various absorbents and processes, and proposes a synergistic approach for the removal of SO2 and SO3. The findings demonstrate that by injecting calcium- or sodium-based absorbents into dry processes, SO2 and SO3 can be removed efficiently and cost-effectively, with process optimization and absorbent modifications further enhancing the SOx removal efficiency. In the future, by blending two or more absorbents and applying them to dry processes, a synergistic removal of SO2 and SO3 can be achieved.
Collapse
Affiliation(s)
- Hang Yu
- Key Laboratory of Energy Thermal Conversion and Control of Ministry Education, School of Energy and Environment, Southeast University, Nanjing, China.
| | - Chuanjia Shan
- Key Laboratory of Energy Thermal Conversion and Control of Ministry Education, School of Energy and Environment, Southeast University, Nanjing, China.
| | - Jinjin Li
- College of Materials Science and Engineering, Nanjing Forestry University, Nanjing, China.
| | - Xueyan Hou
- Key Laboratory of Energy Thermal Conversion and Control of Ministry Education, School of Energy and Environment, Southeast University, Nanjing, China.
| | - Linjun Yang
- Key Laboratory of Energy Thermal Conversion and Control of Ministry Education, School of Energy and Environment, Southeast University, Nanjing, China.
| |
Collapse
|
2
|
Qian W, Yang Y, Liu Z, Zhang J, Song X, Shi N, Xie M, Li B, Ning P. Enhanced absorption of SO 2 from phosphogypsum decomposition by phosphate slurry for phosphoric acid production. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133431. [PMID: 38185091 DOI: 10.1016/j.jhazmat.2024.133431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 12/21/2023] [Accepted: 01/02/2024] [Indexed: 01/09/2024]
Abstract
Phosphogypsum (PG) is a major industrial by-product of wet process phosphoric acid production, and untreated PG stockpiled on land will cause severe environmental pollution. Thermal treatment of PG is currently the mainstream treatment method PG can be thermally decomposed to produce CaO, and the decomposition process produces large amounts of SO2. In this paper, phosphate slurry was used to absorb SO2 generated during the PG decomposition to produce phosphoric acid. The effects of operating conditions such as pressure, inlet SO2 concentration, and additive content on the desulfurization efficiency, as well as phosphoric acid yield, were investigated. Under the optimal experimental parameters, the desulfurization efficiency was 100% in the first 3 h, and decreased to 67.42% after 5 h, the maximum phosphate concentration in the solution was 1445.92 mg/L. The Density functional theory (DFT) calculations showed that SO2 and O2 adsorbed on the surface of P2O5 underwent to generate SO3, which can react with H2O to produce H2SO4. Moreover, it was found that Fe3+ could enhance the catalytic oxidation process of SO2 and O2 by decreasing the reaction energy barrier. This study should be helpful for the recycling of phosphorus resources.
Collapse
Affiliation(s)
- Wenmin Qian
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China; Yunnan Appraisal Center for Ecological and Environmental Engineering, Kunming 650228, China
| | - Yanyu Yang
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Zewei Liu
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Jin Zhang
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Xin Song
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Nan Shi
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Ming Xie
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Bin Li
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China.
| | - Ping Ning
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China.
| |
Collapse
|
3
|
Larki I, Zahedi A, Asadi M, Forootan MM, Farajollahi M, Ahmadi R, Ahmadi A. Mitigation approaches and techniques for combustion power plants flue gas emissions: A comprehensive review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 903:166108. [PMID: 37567281 DOI: 10.1016/j.scitotenv.2023.166108] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 07/29/2023] [Accepted: 08/05/2023] [Indexed: 08/13/2023]
Abstract
Population growth and urbanization are driving energy demand. Despite the development of renewable energy technologies, most of this demand is still met by fossil fuels. Flue gases are the main air pollutants from combustion power plants. These pollutants include particulate matter (PM), sulfur oxides (SOx), nitrogen oxides (NOx), and carbon oxides (COx). The release of these pollutants has adverse effects on human health and the environment, including serious damage to the human respiratory system, acid rain, climate change, and global warming. In this review, a wide range of conventional and new technologies that have the potential to be used in the combustion power plant sector to manage and reduce flue gas pollutants have been examined. Nowadays, conventional approaches to emissions control and management, which focus primarily on post-combustion techniques, face several challenges despite their widespread use and commendable effectiveness. Therefore, studies that have proposed alternative approaches to achieve improved and more efficient methods are reviewed. The results show that new advances such as novel PM collectors, attaining an efficiency of nearly 100 % for submicron particles, microwave systems, boasting an efficiency of nearly 90 % for NO and over 95 % for SO2, electrochemical systems achieving above 90 % efficiency for NOx reduction, non-thermal plasma processes demonstrating an efficiency close to 90 % for NOx, microalgae-based methods with efficiency ranging from 80 % to 99 % for CO2, and wet scrubbing, exhibit considerable potential in addressing the shortcomings of conventional systems. Furthermore, the integration of hybrid methods, particularly in regions prioritizing environmental concerns over economic considerations, holds promise for enhanced control and removal of flue gas pollutants with superior efficiency.
Collapse
Affiliation(s)
- Iman Larki
- Department of Energy Systems Engineering, School of Advanced Technologies, Iran University of Science and Technology, Tehran, Iran
| | - Alireza Zahedi
- Department of Energy Systems Engineering, School of Advanced Technologies, Iran University of Science and Technology, Tehran, Iran.
| | - Mahdi Asadi
- Department of Energy Systems Engineering, School of Advanced Technologies, Iran University of Science and Technology, Tehran, Iran
| | - Mohammad Mahdi Forootan
- Department of Energy Systems Engineering, School of Advanced Technologies, Iran University of Science and Technology, Tehran, Iran
| | - Meisam Farajollahi
- Department of Energy Systems Engineering, School of Advanced Technologies, Iran University of Science and Technology, Tehran, Iran
| | - Rouhollah Ahmadi
- Department of Energy Systems Engineering, School of Advanced Technologies, Iran University of Science and Technology, Tehran, Iran
| | - Abolfazl Ahmadi
- Department of Energy Systems Engineering, School of Advanced Technologies, Iran University of Science and Technology, Tehran, Iran
| |
Collapse
|
4
|
Che X, Wu F, Ren H, Li M, Zhang H. Numerical study on the effect of longitudinal vortex generator on semi-dry desulfurization process in 3D spouted beds. ADV POWDER TECHNOL 2023. [DOI: 10.1016/j.apt.2023.103961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
|
5
|
Wang S, Wu F, Di BB, Yan Y, Tang YC. Intensification Effect of a Multi-Jet Structure on a Multiphase Flow and Desulfurization Process in a Fluidized Bed. ACS OMEGA 2023; 8:5861-5876. [PMID: 36816639 PMCID: PMC9933478 DOI: 10.1021/acsomega.2c07658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 01/23/2023] [Indexed: 06/18/2023]
Abstract
The introduction of a multi-jet structure at the bottom and middle of a fluidized bed can intensify the interphase mixing and improve desulfurization efficiency. The computational fluid dynamics were used to study the gas-liquid-solid flow in a bottom multi-jet fluidized bed and middle multi-jet fluidized bed (BMJFB and MMJFB). It was found that for the gas-liquid-solid interphase mixing, the intensification effect of introducing the multi-jet structure in the middle of the bed is more obvious than that in the bottom. The effect of the water spray volume flow rate on the MMJFB was examined under the same conditions. The results showed that with the increase of the water flow rate, the gas-liquid-solid interphase mixing and desulfurization process are promoted in the MMJFB, and its desulfurization efficiency reaches 68.2%. The effects of the width and number of multi-jet structures on the MMJFB were also investigated. The results show that when the jet width is 20 mm and the number of jets is four, the gas-liquid-solid three-phase is uniformly mixed and the desulfurization efficiency of the MMJFB equals 69.3%, which is 18.5% higher than that of the conventional fluidized bed.
Collapse
Affiliation(s)
- Shuai Wang
- School
of Chemical Engineering, Northwest University, Xi’an710069, China
| | - Feng Wu
- School
of Chemical Engineering, Northwest University, Xi’an710069, China
| | - Bei bei Di
- School
of Chemical Engineering, Northwest University, Xi’an710069, China
| | - Yuan Yan
- School
of Chemical Engineering, Northwest University, Xi’an710069, China
| | - Yang chao Tang
- Luoyang
Jianguang Special Equipment Co., Ltd., Luoyang471003, China
| |
Collapse
|