Yang Sun , Mingshen Yu , Sherif A. Younis , Kowsalya Vellingiri , Jan Szulejko , Ki-Hyun Kim
{"title":"解锁微孔碳在复杂空气混合物中对甲醛的全部吸附潜力","authors":"Yang Sun , Mingshen Yu , Sherif A. Younis , Kowsalya Vellingiri , Jan Szulejko , Ki-Hyun Kim","doi":"10.1016/j.seppur.2025.134476","DOIUrl":null,"url":null,"abstract":"<div><div>The widespread application of microporous activated carbon (AC) in air purification systems is challenged by its questionable efficacy against low-boiling, polar compounds, such as formaldehyde (FA), particularly when present in complex, multi-component streams (e.g., aromatic hydrocarbons [BTX], oxygenated [ethanol], and water vapors). Aiming to enhance its practical utility, this study undertakes a systematic investigation into the FA adsorption behavior of a commercial AC bed adsorbent with precise control over the packing particle sizes (i.e., small [AC-S: 0.075–0.212 mm], medium [AC-M: 0.212–0.6 mm], and large [AC-L: 0.6–1.7 mm]). Emphasis is also placed on the effects of relative humidity [0.015 % to 100 %], inlet FA concentrations [50–500 ppm]), and gas phase composition (non-competing single and competing multi-component streams) on the breakthrough (BT) adsorption dynamics of FA onto AC bed adsorbents. The 99 % BT adsorption capacity (mg g<sup>−1</sup>) for 100 ppm FA under trace humidity conditions (5 ppm H<sub>2</sub>O) is moderately influenced by AC particle size (AC-M (12.0) > AC-S (9.8) > AC-L (5.8)). BTX severely reduces FA uptake (by 77.5–96.0 %) and induces a roll-up effect. However, humidity and ethanol synergistically enhance FA adsorption by increasing the number of polar surface groups, which in turn suppresses the competition from BTX. The dominance of physisorption for FA is suggested by its adherence to the Freundlich isotherm. Kinetics transitions (e.g., from pseudo-first-order for smaller AC particles to pseudo-second-order for larger ones) is indicative of their differing diffusion mechanisms. Spectroscopic studies reveal that water and ethanol play a dual role: they aid adsorption via hydrogen bonding and paraformaldehyde formation at moderate levels, while blocking sites at saturation. This research offers crucial insights into tuning AC properties, paving the new way for the design of application-ready adsorbents for complex environments.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":"377 ","pages":"Article 134476"},"PeriodicalIF":9.0000,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Unlocking the full adsorption potential of microporous carbon for formaldehyde in complex air mixtures\",\"authors\":\"Yang Sun , Mingshen Yu , Sherif A. Younis , Kowsalya Vellingiri , Jan Szulejko , Ki-Hyun Kim\",\"doi\":\"10.1016/j.seppur.2025.134476\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>The widespread application of microporous activated carbon (AC) in air purification systems is challenged by its questionable efficacy against low-boiling, polar compounds, such as formaldehyde (FA), particularly when present in complex, multi-component streams (e.g., aromatic hydrocarbons [BTX], oxygenated [ethanol], and water vapors). Aiming to enhance its practical utility, this study undertakes a systematic investigation into the FA adsorption behavior of a commercial AC bed adsorbent with precise control over the packing particle sizes (i.e., small [AC-S: 0.075–0.212 mm], medium [AC-M: 0.212–0.6 mm], and large [AC-L: 0.6–1.7 mm]). Emphasis is also placed on the effects of relative humidity [0.015 % to 100 %], inlet FA concentrations [50–500 ppm]), and gas phase composition (non-competing single and competing multi-component streams) on the breakthrough (BT) adsorption dynamics of FA onto AC bed adsorbents. The 99 % BT adsorption capacity (mg g<sup>−1</sup>) for 100 ppm FA under trace humidity conditions (5 ppm H<sub>2</sub>O) is moderately influenced by AC particle size (AC-M (12.0) > AC-S (9.8) > AC-L (5.8)). BTX severely reduces FA uptake (by 77.5–96.0 %) and induces a roll-up effect. However, humidity and ethanol synergistically enhance FA adsorption by increasing the number of polar surface groups, which in turn suppresses the competition from BTX. The dominance of physisorption for FA is suggested by its adherence to the Freundlich isotherm. Kinetics transitions (e.g., from pseudo-first-order for smaller AC particles to pseudo-second-order for larger ones) is indicative of their differing diffusion mechanisms. Spectroscopic studies reveal that water and ethanol play a dual role: they aid adsorption via hydrogen bonding and paraformaldehyde formation at moderate levels, while blocking sites at saturation. This research offers crucial insights into tuning AC properties, paving the new way for the design of application-ready adsorbents for complex environments.</div></div>\",\"PeriodicalId\":427,\"journal\":{\"name\":\"Separation and Purification Technology\",\"volume\":\"377 \",\"pages\":\"Article 134476\"},\"PeriodicalIF\":9.0000,\"publicationDate\":\"2025-07-25\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Separation and Purification Technology\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1383586625030734\",\"RegionNum\":1,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ENGINEERING, CHEMICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Separation and Purification Technology","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1383586625030734","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
Unlocking the full adsorption potential of microporous carbon for formaldehyde in complex air mixtures
The widespread application of microporous activated carbon (AC) in air purification systems is challenged by its questionable efficacy against low-boiling, polar compounds, such as formaldehyde (FA), particularly when present in complex, multi-component streams (e.g., aromatic hydrocarbons [BTX], oxygenated [ethanol], and water vapors). Aiming to enhance its practical utility, this study undertakes a systematic investigation into the FA adsorption behavior of a commercial AC bed adsorbent with precise control over the packing particle sizes (i.e., small [AC-S: 0.075–0.212 mm], medium [AC-M: 0.212–0.6 mm], and large [AC-L: 0.6–1.7 mm]). Emphasis is also placed on the effects of relative humidity [0.015 % to 100 %], inlet FA concentrations [50–500 ppm]), and gas phase composition (non-competing single and competing multi-component streams) on the breakthrough (BT) adsorption dynamics of FA onto AC bed adsorbents. The 99 % BT adsorption capacity (mg g−1) for 100 ppm FA under trace humidity conditions (5 ppm H2O) is moderately influenced by AC particle size (AC-M (12.0) > AC-S (9.8) > AC-L (5.8)). BTX severely reduces FA uptake (by 77.5–96.0 %) and induces a roll-up effect. However, humidity and ethanol synergistically enhance FA adsorption by increasing the number of polar surface groups, which in turn suppresses the competition from BTX. The dominance of physisorption for FA is suggested by its adherence to the Freundlich isotherm. Kinetics transitions (e.g., from pseudo-first-order for smaller AC particles to pseudo-second-order for larger ones) is indicative of their differing diffusion mechanisms. Spectroscopic studies reveal that water and ethanol play a dual role: they aid adsorption via hydrogen bonding and paraformaldehyde formation at moderate levels, while blocking sites at saturation. This research offers crucial insights into tuning AC properties, paving the new way for the design of application-ready adsorbents for complex environments.
期刊介绍:
Separation and Purification Technology is a premier journal committed to sharing innovative methods for separation and purification in chemical and environmental engineering, encompassing both homogeneous solutions and heterogeneous mixtures. Our scope includes the separation and/or purification of liquids, vapors, and gases, as well as carbon capture and separation techniques. However, it's important to note that methods solely intended for analytical purposes are not within the scope of the journal. Additionally, disciplines such as soil science, polymer science, and metallurgy fall outside the purview of Separation and Purification Technology. Join us in advancing the field of separation and purification methods for sustainable solutions in chemical and environmental engineering.