Cheolwoong Park, Yonghun Jang, Seonyeob Kim, Yongrae Kim, Young Choi
Because ammonia is easier to store and transport over long distances than hydrogen, it is a promising research direction as a potential carrier for hydrogen. However, its low ignition and combustion rates pose challenges for running conventional ignition engines solely on ammonia fuel over the entire operational range. In this study, we attempted to identify a stable engine combustion zone using a high-pressure direct injection of ammonia fuel into a 2.5 L spark ignition engine and examined the potential for extending the operational range by adding hydrogen. As it is difficult to secure combustion stability in a low-temperature atmosphere, the experiment was conducted in a sufficiently-warmed atmosphere (90 ± 2.5 °C), and the combustion, emission, and efficiency results under each operating condition were experimentally compared. At 1500 rpm, the addition of 10% hydrogen resulted in a notable 20.26% surge in the maximum torque, reaching 263.5 Nm, in contrast with the case where only ammonia fuel was used. Furthermore, combustion stability was ensured at a torque of 140 Nm by reducing the fuel and air flow rates.
{"title":"Influence of Hydrogen on the Performance and Emissions Characteristics of a Spark Ignition Ammonia Direct Injection Engine","authors":"Cheolwoong Park, Yonghun Jang, Seonyeob Kim, Yongrae Kim, Young Choi","doi":"10.3390/gases3040010","DOIUrl":"https://doi.org/10.3390/gases3040010","url":null,"abstract":"Because ammonia is easier to store and transport over long distances than hydrogen, it is a promising research direction as a potential carrier for hydrogen. However, its low ignition and combustion rates pose challenges for running conventional ignition engines solely on ammonia fuel over the entire operational range. In this study, we attempted to identify a stable engine combustion zone using a high-pressure direct injection of ammonia fuel into a 2.5 L spark ignition engine and examined the potential for extending the operational range by adding hydrogen. As it is difficult to secure combustion stability in a low-temperature atmosphere, the experiment was conducted in a sufficiently-warmed atmosphere (90 ± 2.5 °C), and the combustion, emission, and efficiency results under each operating condition were experimentally compared. At 1500 rpm, the addition of 10% hydrogen resulted in a notable 20.26% surge in the maximum torque, reaching 263.5 Nm, in contrast with the case where only ammonia fuel was used. Furthermore, combustion stability was ensured at a torque of 140 Nm by reducing the fuel and air flow rates.","PeriodicalId":12796,"journal":{"name":"Greenhouse Gases: Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136142572","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}
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.
{"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":null,"pages":null},"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
Shales have low to ultra-low porosity and permeability, which makes them an attractive candidate for CO2 utilization during CO2-enhanced oil recovery (CO2-EOR) or for geologic CO2 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 CO2 utilization during this diagenetic process (thermal maturation) to achieve long-term CO2 storage. This experimental study investigates the potential for CO2 utilization in shale due to induced thermal maturation at in situ conditions, and the implications of pre-maturation CO2 injection in shale for GCS and CO2-EOR. Here, we used subsurface hydrocarbon-rich Bakken and Green River shales exposed to CO2 for a specific period. This is followed by inducing the unexposed and CO2-exposed shales to thermal maturity. Subsequently, we evaluated the total organic carbon (TOC), liberated hydrocarbons (S2), and the mineralogical and mechanical properties of the mature and CO2-exposed mature shales. We further assessed the implications of CO2 utilization and storage in thermally matured Bakken and Green River shales for long-term storage or CO2-EOR. The results indicate that if CO2 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 CO2 injection before attaining thermal maturity. Further, CO2-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 CO2 injection before attaining maturity. Analyses of the results suggest that the application of this proposed CO2 injection and utilization in immature shales could access more excellent CO2-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 CO2-EOR operations in shale reservoirs globally. Also, our proposed pre-maturation CO2 injection could rejuvenate mature shales for increased hydrocarbon production through CO2-EOR, yield a greater sealing efficiency, and mitigate leakage risks for long-term C
{"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":null,"pages":null},"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}