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