{"title":"Synergistic integration of zeolite engineering and fixed-bed column design for enhanced biogas upgrading: Adsorbent synthesis, CO2/CH4 separation kinetics, and regeneration assessment","authors":"","doi":"10.1016/j.seppur.2024.129772","DOIUrl":null,"url":null,"abstract":"<div><div>Biogas, a renewable energy vector derived from anaerobic digestion of organic waste, requires CO<sub>2</sub> separation to enhance its calorific value for engine fuel. This study integrates CO<sub>2</sub>/CH<sub>4</sub> separation in biogas using a novel approach integrating dual chemically-activated zeolites and fixed-bed column purification. Biogas produced via CSTR/ultrafiltration (69 % CH<sub>4</sub>, 30 % CO<sub>2</sub>, 14 ppm H<sub>2</sub>S) was further upgraded using HCl + NaOH and H<sub>2</sub>SO<sub>4</sub> + NaOH activated zeolites. Optimal absorption capacity of 97.77 ± 0.01 % was achieved at 140 mesh, 60-minute H<sub>2</sub>SO<sub>4</sub> + NaOH activation, 2-hour calcination (400 °C), and 200 mL/min flow rate. Breakthrough was observed at 18.12 min. Langmuir isotherm (R<sup>2</sup> = 0.9992) and Elovich kinetics (R<sup>2</sup> = 0.9846) best described the adsorption process. XRD analysis showed significant crystal size reduction post-activation (53.31 nm to 16.90 nm). Notably, BET analysis revealed enhanced surface properties surface area of 286.71 m<sup>2</sup>/g, pore volume of 0.213 cc/g, and pore diameter of 3.532 Å. An innovative dual-column system with non-isothermal TSA protocol optimized CO<sub>2</sub> adsorption (30 mins) and desorption (17 mins, 40 °C, 100 mL/min), yielding superior near-pure methane biogas (99.29 % CH<sub>4</sub>, 0.66 % CO<sub>2</sub>, trace H<sub>2</sub>S). A methane loss of 2.75 % during upgrading demonstrated high CO<sub>2</sub> selectivity. This synergistic approach presents a promising solution for sustainable biogas purification and engine fuel applications.</div></div>","PeriodicalId":427,"journal":{"name":"Separation and Purification Technology","volume":null,"pages":null},"PeriodicalIF":8.1000,"publicationDate":"2024-09-19","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/S1383586624035111","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}
引用次数: 0
Abstract
Biogas, a renewable energy vector derived from anaerobic digestion of organic waste, requires CO2 separation to enhance its calorific value for engine fuel. This study integrates CO2/CH4 separation in biogas using a novel approach integrating dual chemically-activated zeolites and fixed-bed column purification. Biogas produced via CSTR/ultrafiltration (69 % CH4, 30 % CO2, 14 ppm H2S) was further upgraded using HCl + NaOH and H2SO4 + NaOH activated zeolites. Optimal absorption capacity of 97.77 ± 0.01 % was achieved at 140 mesh, 60-minute H2SO4 + NaOH activation, 2-hour calcination (400 °C), and 200 mL/min flow rate. Breakthrough was observed at 18.12 min. Langmuir isotherm (R2 = 0.9992) and Elovich kinetics (R2 = 0.9846) best described the adsorption process. XRD analysis showed significant crystal size reduction post-activation (53.31 nm to 16.90 nm). Notably, BET analysis revealed enhanced surface properties surface area of 286.71 m2/g, pore volume of 0.213 cc/g, and pore diameter of 3.532 Å. An innovative dual-column system with non-isothermal TSA protocol optimized CO2 adsorption (30 mins) and desorption (17 mins, 40 °C, 100 mL/min), yielding superior near-pure methane biogas (99.29 % CH4, 0.66 % CO2, trace H2S). A methane loss of 2.75 % during upgrading demonstrated high CO2 selectivity. This synergistic approach presents a promising solution for sustainable biogas purification and engine fuel applications.
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.