{"title":"Effect of Mixing Technique on Physico-Chemical Characteristics of Blended Membranes for Gas Separation","authors":"Danial Qadir, Humbul Suleman, Faizan Ahmad","doi":"10.3390/gases3040009","DOIUrl":"https://doi.org/10.3390/gases3040009","url":null,"abstract":"Polymer blending has attracted considerable attention because of its ability to overcome the permeability–selectivity trade-off in gas separation applications. In this study, polysulfone (PSU)-modified cellulose acetate (CA) membranes were prepared using N-methyl-2-pyrrolidone (NMP) and tetrahydrofuran (THF) using a dry–wet phase inversion technique. The membranes were characterized using scanning electron microscopy (SEM) for morphological analysis, thermogravimetric analysis (TGA) for thermal stability, and Fourier transform infrared spectroscopy (FTIR) to identify the chemical changes on the surface of the membranes. Our analyses confirmed that the mixing method (the route chosen for preparing the casting solution for the blended membranes) significantly influences the morphological and thermal properties of the resultant membranes. The blended membranes exhibited a transition from a finger-like pore structure to a dense substructure in the presence of macrovoids. Similarly, thermal analysis confirmed the improved residual weight (up to 7%) and higher onset degradation temperature (up to 10 °C) of the synthesized membranes. Finally, spectral analysis confirmed that the blending of both polymers was physical only.","PeriodicalId":12796,"journal":{"name":"Greenhouse Gases: Science and Technology","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134886936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wilfred Emori, Inime I. Udoh, Okpo O. Ekerenam, Alexander I. Ikeuba, IniIbehe N. Etim, Chigoziri N. Njoku, Enobong F. Daniel, Demian I. Njoku, Paul C. Uzoma, Sharafadeen K. Kolawole, Olajire S. Olanrele
{"title":"CO2-Induced alterations due to thermal maturation in shale: Implications for CO2 utilization and storage","authors":"Chioma Onwumelu, Oladoyin Kolawole, Imene Bouchakour, Ogochukwu Ozotta, Stephan Nordeng, Moones Alamooti","doi":"10.1002/ghg.2243","DOIUrl":"10.1002/ghg.2243","url":null,"abstract":"<p>Shales have low to ultra-low porosity and permeability, which makes them an attractive candidate for CO<sub>2</sub> utilization during CO<sub>2</sub>-enhanced oil recovery (CO<sub>2</sub>-EOR) or for geologic CO<sub>2</sub> storage (GCS). Shale are source rocks, and thus, there is a continuous induced diagenetic process that can alter their properties as they reaches maturity at greater in situ temperature. However, there are significant knowledge gaps in the possibility of CO<sub>2</sub> utilization during this diagenetic process (thermal maturation) to achieve long-term CO<sub>2</sub> storage. This experimental study investigates the potential for CO<sub>2</sub> utilization in shale due to induced thermal maturation at in situ conditions, and the implications of pre-maturation CO<sub>2</sub> injection in shale for GCS and CO<sub>2</sub>-EOR. Here, we used subsurface hydrocarbon-rich Bakken and Green River shales exposed to CO<sub>2</sub> for a specific period. This is followed by inducing the unexposed and CO<sub>2</sub>-exposed shales to thermal maturity. Subsequently, we evaluated the total organic carbon (TOC), liberated hydrocarbons (<i>S</i><sub>2</sub>), and the mineralogical and mechanical properties of the mature and CO<sub>2</sub>-exposed mature shales. We further assessed the implications of CO<sub>2</sub> utilization and storage in thermally matured Bakken and Green River shales for long-term storage or CO<sub>2</sub>-EOR. The results indicate that if CO<sub>2</sub> is injected into shales before attaining maturity, higher hydrocarbon production and more significant mechanical weakness can be expected when they attain maturity in Bakken shales (+30% liberated hydrocarbons; −31% Young's modulus; −34% hardness) and Green Rivers shales (+8% liberated hydrocarbons; −40% Young's modulus; −30% hardness), and this is relative to Bakken and Green River shales without CO<sub>2</sub> injection before attaining thermal maturity. Further, CO<sub>2</sub>-exposed mature Bakken and Green River shales can alter the minerals in shales with the dissolution of dolomite and precipitation of calcite, which promotes mineral trapping and achieve a lower TOC (Bakken shale = −24%; Green River shale = −26%), and this is relative to Bakken and Green River shales without CO<sub>2</sub> injection before attaining maturity. Analyses of the results suggest that the application of this proposed CO<sub>2</sub> injection and utilization in immature shales could access more excellent CO<sub>2</sub>-storage reservoirs in Bakken and Green River shales without waiting for a more extended period for the shales to become viable and mature, which is the case with the present GCS and CO<sub>2</sub>-EOR operations in shale reservoirs globally. Also, our proposed pre-maturation CO<sub>2</sub> injection could rejuvenate mature shales for increased hydrocarbon production through CO<sub>2</sub>-EOR, yield a greater sealing efficiency, and mitigate leakage risks for long-term C","PeriodicalId":12796,"journal":{"name":"Greenhouse Gases: Science and Technology","volume":"13 6","pages":"797-813"},"PeriodicalIF":2.2,"publicationDate":"2023-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42611171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sustainable forages for net zero in livestock production","authors":"Annie Williams","doi":"10.1002/ghg.2241","DOIUrl":"10.1002/ghg.2241","url":null,"abstract":"","PeriodicalId":12796,"journal":{"name":"Greenhouse Gases: Science and Technology","volume":"13 5","pages":"613-615"},"PeriodicalIF":2.2,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42072988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. V. Solovtsova, I. Men’shchikov, A. Shkolin, A. E. Grinchenko, E. Khozina, A. Fomkin
{"title":"Experimental Study and Thermodynamic Analysis of Carbon Dioxide Adsorption onto Activated Carbons Prepared from Biowaste Raw Materials","authors":"O. V. Solovtsova, I. Men’shchikov, A. Shkolin, A. E. Grinchenko, E. Khozina, A. Fomkin","doi":"10.3390/gases3030008","DOIUrl":"https://doi.org/10.3390/gases3030008","url":null,"abstract":"Nutshells are regarded as cost-effective and abundant raw materials for producing activated carbons (ACs) for CO2 capture, storage, and utilization. The effects of carbonization temperature and thermochemical KOH activation conditions on the porous structure as a BET surface, micropore volume, micropore width, and pore size distribution of ACs prepared from walnut (WNS) and hazelnut (HNS) shells were investigated. As a result, one-step carbonization at 900/800 °C and thermochemical KOH activation with a char/KOH mass ratio of 1:2/1:3 were found to be optimal for preparing ACs from WNS/HNS: WNS-AC-3 and HNS-AC-2, respectively. The textural properties of the WNS/HNS chars and ACs were characterized by low-temperature nitrogen vapor adsorption, XRD, and SEM methods. Dubinin’s theory of volume filling of micropores was used to evaluate the microporosity parameters and to calculate the CO2 adsorption equilibrium over the sub- and supercritical temperatures from 216.4 to 393 K at a pressure up to 10 MPa. The CO2 capture capacities of WNS- and HNS-derived adsorbents reached 5.9/4.1 and 5.4/3.9 mmol/g at 273/293 K under 0.1 MPa pressure, respectively. A discrepancy between the total and delivery volumetric adsorption capacities of the adsorbents was attributed to the strong binding of CO2 molecules with the adsorption sites, which were mainly narrow micropores with a high adsorption potential. The high initial differential heats of CO2 adsorption onto ACs of ~32 kJ/mol confirmed this proposal. The behaviors of thermodynamic functions (enthalpy and entropy) of the adsorption systems were attributed to changes in the state of adsorbed CO2 molecules determined by a balance between attractive and repulsive CO2–CO2 and CO2–AC interactions during the adsorption process. Thus, the chosen route for preparing ACs from the nutshells made it possible to prepare efficient carbon adsorbents with a relatively high CO2 adsorption performance due to a substantial volume of micropores with a size in the range of 0.6–0.7 nm.","PeriodicalId":12796,"journal":{"name":"Greenhouse Gases: Science and Technology","volume":"46 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77858644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}