Journal of The Energy Institute最新文献

{"title":"Volatile-char interactions during co-pyrolysis of sewage sludge and poplar wood","authors":"","doi":"10.1016/j.joei.2024.101820","DOIUrl":"10.1016/j.joei.2024.101820","url":null,"abstract":"<div><p>Pyrolysis is a thermo-chemical conversion method for harmless and resource utilization of sewage sludge, which gives carbon-containing products with high added value and benefits for GHG reduction towards “carbon peaking and carbon neutrality” goals. In this work, co-pyrolysis of sewage sludge and poplar wood was studied to investigate the effects of the wood blend ratio and the volatile-char interactions on the pyrolysis product characteristics. It was found that the synergistic effect during co-pyrolysis could enhance the production of aromatic hydrocarbons but inhibit the formation of nitrogen-containing and phenolic compounds. Meanwhile, the aromaticity of the char increased with increasing the wood blend ratio, resulting in an enhanced quality of the char. The volatile-char interactions could facilitate the cracking of large molecules in volatiles into small-molecule gases, leading to an increase in the gas yield of 0.6–14.6 %, and especially the H₂ yield of 16.2–53.8 %, as compared to the case without interaction in the experiment. The char yields hold fairly constant but the physicochemical structure of the char changed significantly with the interactions. Specifically, the O-containing functional groups on the char surface decreased significantly with increasing aromaticity and stability. More importantly, the total phosphorus content of char was increased by 11.3–33.6 %, as compared to the case without interaction, with the enhanced conversion of non-hydroxyapatite phosphorus to hydroxyapatite phosphorus. The interaction can increase bio-availability of the phosphorus and make biochar to be a better organic fertilizer in application.</p></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142149487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A pilot study on a 30 t/h biomass gasification-combustion plant","authors":"","doi":"10.1016/j.joei.2024.101822","DOIUrl":"10.1016/j.joei.2024.101822","url":null,"abstract":"<div><p>As a renewable energy with zero carbon emission, the utilization of biomass has attracted widely studied. One of the most effective methods is to gasify the biomass into high-quality gas fuel. In the recent years, the majority of research on biomass gasification is conducted in the laboratory. However, it lacks the research in engineering application scale. In this work, a biomass gasification-combustion plant was designed and built to provide the industrial steam with a rate of 30 t/h for a food industrial park. The agricultural and forestry waste biomass was gasified in a gasifier, and then the product gas combusted in a boiler to supply the steam. The characteristics of the product gas from the gasifier were studied. The corrosion and pollutants in the combustion process were investigated. In the gasification process, the main components of the product gas are CO, H₂ and CH₄. CO and H₂ account for 29.55 vol%-30.56 vol% and 11.65 vol%-15.35 vol%, respectively. The calorific value of the product gas is 5.88–6.29 MJ/m³. The tar concentration is 110.58–155.07 g/Nm³. At the outlet of the boiler, the concentration of the filterable particulate matter is 300.25 mg/Nm³, and the particle size is concentrated at 1.00–2.50 μm. The concentration of the condensable particulate matter (CPM) is 157.14 mg/Nm³, and the proportion of water-soluble ions in CPM is 86.36 wt%. The concentration of Cl⁻, SO₄^2-, NH₄⁺ and Na⁺ in CPM is relatively high, with the values of 28.83 mg/Nm³, 10.29 mg/Nm³, 7.46 mg/Nm³, and 5.06 mg/Nm³, respectively. During the half-year running, the ash deposition and corrosion were detected in the boiler heating surface and the economizer. The ash deposit in the boiler is mainly composed of the sulfate and silicate, such as CaSO₄, Zn₂SO₄, Na₂SO₄ and K₃Na(SO₄)₂. The ash deposit in the economizer is primarily composed of the sulfate and a small amount of alkali metal chloride. The flue gas reaches the emission requirement after passing through the pollution control devices and can be discharged into the atmosphere.</p></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142149524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of peak Laminar Burning Velocity of several syngas compositions at different temperatures","authors":"","doi":"10.1016/j.joei.2024.101816","DOIUrl":"10.1016/j.joei.2024.101816","url":null,"abstract":"&lt;div&gt;&lt;p&gt;In the context of the current energy transition, the use of biomass-derived syngas (BDS) is often recognized as a fundamental path towards decreasing fossil fuel dependency and greenhouse gas emissions. However, hydrogen-containing BDS are prone to flame instability problems. More efforts are being carried out aiming at efficiently adopting BDS in industrial combustors with CH&lt;sub&gt;4&lt;/sub&gt; co-firing or inert gas dilutions by exploring accurate knowledge of burning velocity. To do so, a deeper knowledge of the syngas combustion behaviour is strictly necessary. The objective of this study fits in this framework: in particular, a computational study has been carried out to evaluate kinetic models and present fresh insights on the effects of varying syngas mixtures such as CO/H&lt;sub&gt;2&lt;/sub&gt;, CO/H&lt;sub&gt;2&lt;/sub&gt;/CO&lt;sub&gt;2&lt;/sub&gt; and CO/H&lt;sub&gt;2&lt;/sub&gt;/CH&lt;sub&gt;4&lt;/sub&gt; on Laminar Burning Velocity (LBV) and peak LBV location &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;msub&gt;&lt;mi&gt;Φ&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;L&lt;/mi&gt;&lt;mi&gt;B&lt;/mi&gt;&lt;mi&gt;V&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mi&gt;max&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;. In-detail chemical kinetic simulations of equimolar (CO: H&lt;sub&gt;2&lt;/sub&gt; = 1:1) forestry waste syngas were systematically carried out taking advantage of the open-source CANTERA solver. Three detailed kinetic models i.e., newly released FFCM-2, USC mech II, and modified GRI mech III were implemented to report accurate flame parameters at 1 bar and different temperature levels (from 300 K up to 450 K). On comparing the results with experiments, FFCM-2 proved to be a good kinetic model for the considered syngas mixtures CO/H&lt;sub&gt;2&lt;/sub&gt;, CO/H&lt;sub&gt;2&lt;/sub&gt;/CO&lt;sub&gt;2&lt;/sub&gt; and especially for CO/H&lt;sub&gt;2&lt;/sub&gt;/CH&lt;sub&gt;4&lt;/sub&gt; for mixtures containing a limited share of 30 % methane at normal and moderately elevated temperature at 0.4 ≤ &lt;strong&gt;&lt;em&gt;Φ&lt;/em&gt;&lt;/strong&gt; ≤ 2.1. The USC mech II performed very well for CO/H&lt;sub&gt;2&lt;/sub&gt;, and CO/H&lt;sub&gt;2&lt;/sub&gt;/CO&lt;sub&gt;2&lt;/sub&gt;, while the modified GRI mech III model also gave agreeable predictions for CO/H&lt;sub&gt;2&lt;/sub&gt;/CH&lt;sub&gt;4&lt;/sub&gt; mixture having rich methane content. Additionally, when varying syngas composition analysis was conducted at different temperatures, the progressive CO&lt;sub&gt;2&lt;/sub&gt; dilution and CH&lt;sub&gt;4&lt;/sub&gt; addition of up to 30 % reduced the peak LBV and moved the peak LBV locations &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;msub&gt;&lt;mi&gt;Φ&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;L&lt;/mi&gt;&lt;mi&gt;B&lt;/mi&gt;&lt;mi&gt;V&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mi&gt;max&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; towards lean ER conditions with 9 % and 40 % reductions, respectively; however, only the latter effect was enhanced at the elevated initial temperature. Furthermore, sensitivity analysis of respective syngas mixtures is reported at normal and elevated temperatures to explore the most sensitive intermediate reactions relative to LBV. The shift of peak LBV locations and their enhancement at elevated temperatures also open the research path to study the underlying impacts on the flame modes/regimes and stru","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1743967124002940/pdfft?md5=dc41ff5f8d5fb107f29d56f1c1edab04&pid=1-s2.0-S1743967124002940-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142168747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stepwise dechlorination and co-pyrolysis of poplar wood with dechlorinated polyvinyl chloride: Synergistic effect and products distribution","authors":"","doi":"10.1016/j.joei.2024.101819","DOIUrl":"10.1016/j.joei.2024.101819","url":null,"abstract":"<div><p>With the combination of stepwise dechlorination and co-pyrolysis techniques, this study conducted polyvinyl chloride (PVC) dechlorination experiments and co-pyrolysis experiments of poplar wood (PW) with dechlorinated polyvinyl chloride (DPVC) by thermogravimetric analysis and a fixed bed reactor. Stepwise pyrolysis effectively removed Cl from PVC with a dechlorination efficiency of 99.84 % at 360 °C for 30 min. Thermogravimetric tests and thermokinetic variables were employed to describe the co-pyrolysis process's thermodynamic behavior, where co-pyrolysis significantly diminished the activation energy of the initial pyrolysis stage (9.65–21.62 kJ/mol) and increased the reaction rate (0.02–0.09 %/°C). The synergistic effect of co-pyrolysis enhanced the yield and quality of liquid oil and reduced the solid residue rate, with the maximum change in solid residue rate (−2.36 wt%) occurring at PW:DPVC = 3:7. The optimal conditions for the synergistic effect are a raw material ratio of 3:7 at 500 °C. Co-pyrolysis efficiently reduced the content of oxygen-containing compounds of phenols, ketones, and acids in oil, and elevated the selectivity of aromatics. The research methods avoid the drawbacks of bio-oil and plastic oil and improve the quality of pyrolysis oil in a concise and efficient manner, which provides some new ideas for the resource and clean utilization of municipal waste.</p></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142149486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ceria-boosted Ni/Al2O3 catalysts for enhanced H2 production via acetic acid dry reforming","authors":"","doi":"10.1016/j.joei.2024.101821","DOIUrl":"10.1016/j.joei.2024.101821","url":null,"abstract":"<div><p>Acetic acid dry reforming (ADR) is a promising route for sustainable H₂ generation. However, coke inhibition during ADR is the main challenge and not resolved by using suitable promoted catalysts. In this work, Ce promotion on 10%Ni/Al₂O₃ catalysts with 1-5 wt%Ce was evaluated for ADR at varied temperatures of 923–998 K and stoichiometric feed in a fixed-bed rig. CeO₂ addition of 1–3% enhanced metal dispersion, and surface area whilst basic CeO₂ character significantly boosted the concentration and density of basic sites on catalysts. Particularly, the CO₂ uptake of promoted catalysts was about 2.49–3.73 times greater than that of counterpart sample. CH₃COOH and CO₂ conversions were enhanced with rising Ce loading and the highest reactant conversions were observed at 3 wt%Ce. The improved adsorption of acidic CH₃COOH and CO₂ molecules due to increasing amount of basic sites as well as redox attributes of CeO₂ promoter could be responsible for the enhancement in ADR activity and yield of H₂ and CO. The mechanistic two-step pathway for coke suppression induced by CeO₂ promotion was elaborated in this work. Generally, carbonaceous species formation on 3%Ce–10%Ni/Al₂O₃ was considerably reduced about 1.6–2.0 times. H₂/CO ratio varied from 0.59 to 0.65 relying on ADR temperature over 3%Ce–10%Ni/Al₂O₃. These H₂/CO values, two times higher than theoretical H₂/CO ratio in ADR, are compatible for downstream gas-to-liquid processes to selectively yield high molecular weight olefins. Water formation rate increased from 8.67 × 10⁻⁶ to 4.71 × 10⁻⁵ <span><math><mrow><msub><mtext>mol</mtext><mrow><msub><mi>H</mi><mn>2</mn></msub><mi>O</mi></mrow></msub></mrow></math></span> g_cat⁻¹ s⁻¹ with rising temperature within 923–998 K on 3%Ce–10%Ni/Al₂O₃.</p></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142149443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Entrainment rate predictions of axis-symmetric non-swirling jets using free-jet-theory, Reynolds-averaged Navier-Stokes modelling and large-eddy-simulations resolved up to Kolmogorov scale","authors":"","doi":"10.1016/j.joei.2024.101806","DOIUrl":"10.1016/j.joei.2024.101806","url":null,"abstract":"<div><div>Jet entrainment - relevant to mixers, sprays and combustion technologies - has been the subject of this work. We limit our considerations to air jets issued from convergent nozzles of diameter smaller than 25.4 mm, the nozzle exit Reynolds number in the range 30,000 to 100,000 and Mach numbers not exceeding 0.4. The emphasis is on jet self-similarity region (60 &lt; x/d₀ &lt; 210) and the key question is with which accuracy can Computational Fluid Dynamics (RANS and LES) and free-jet theory predict jet entrainment. Seven jets have been considered.</div><div>The realizable k-є model has outperformed the other models and provides the entrainment predictions within ±6 % margin from the measured data. The standard k-є and the Shear-Stress Transport (SST) k-ω models deliver entrainment figures which are larger than the measured data by 22 % – 24 % whilst predictions of either the Reynolds Stress Model (RSM) or Re-Normalization Group (RNG) k-є models can be off (too large) by as much as 34 % and 40 %, respectively. Such a clarity in classification of turbulence models has been obtained after minimization of numerical related errors to a degree which was not achievable in the past. The Panchapakesan&amp;Lumly's jet has been computed using the Large Eddy Simulations with the filter size of the order of Kolmogorov scale throughout the jet e.g. at the inlet, potential core and the far field. Excellent predictions of the jet spread rate, velocity profiles and the entrainment have been obtained at the expense of huge computational resources.</div><div>The well-known engineering correlation <span><math><mrow><msub><mover><mi>m</mi><mo>˙</mo></mover><mi>e</mi></msub><mo>/</mo><mover><msub><mi>m</mi><mn>0</mn></msub><mo>˙</mo></mover><mo>=</mo><mn>0.32</mn><mrow><mo>(</mo><mrow><mi>x</mi><mo>/</mo><msub><mi>d</mi><mn>0</mn></msub></mrow><mo>)</mo></mrow></mrow></math></span> provides entrainment figures that are by 10 % or less larger than the measured values.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insight into high-temperature fast pyrolysis characterization, product distribution and interaction effect of municipal solid waste and its components under steam-containing hydrogen-rich syngas atmosphere","authors":"","doi":"10.1016/j.joei.2024.101811","DOIUrl":"10.1016/j.joei.2024.101811","url":null,"abstract":"<div><p>This research delves into the field of fast hydropyrolysis of mixed municipal solid waste (MSW), with the goal of understanding product distribution and interactions in a hydrogen-rich condition. Through experimental investigations on MSW and its components, this study thoroughly examines the impact of pyrolysis temperature and gasification atmosphere (30 % H₂+30 % CO+20 % CO₂+20 % H₂O) on the yields and distribution of the three-phase products. As the temperature increases, the gas yield gradually increases, while the yields of tar and char gradually decrease. The introduction of a hydrogen source increases the methane content in the combustible gas, which generally reaches its maximum at 850 °C, and promotes aromatic formation in tar, making aromatics the main component of pyrolysis oil. Notably, aromatics have the highest-octane number in gasoline. This study highlights gasification as a promising technology for converting organic waste into valuable fuel, advancing waste management and energy recovery.</p></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142136651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of alkali and alkaline earth metals on agglomeration in biomass chemical looping gasification","authors":"","doi":"10.1016/j.joei.2024.101815","DOIUrl":"10.1016/j.joei.2024.101815","url":null,"abstract":"<div><p>By reasonably controlling the lattice oxygen of oxygen carrier (OC), the biomass chemical looping gasification (CLG) technology can convert biomass into syngas dominated by H₂ and CO, which is a prevalent topic in the world. However, in practical applications, the mechanism underlying OC agglomeration induced by alkali and alkaline earth metals (AAEMs), along with effective countermeasures, remain ambiguous. In this paper, AAEM elements were added to the biomass after pickling to explore the effects of K, Na, Ca, and Mg on agglomeration. The results indicated that with the increase of K and Na additions from 0.5 % to 18 %, the deformation temperature (DT) of spent OC decreased, leading to a marked intensification of agglomeration, with degree of agglomeration increases from 2.88 % and 1.74 % to 17.44 % and 13.91 %, respectively. In contrast, with the increase of Ca and Mg additions from 0.5 % to 18 %, the DT of spent OC increased, and the degree of agglomeration remained lower than that of K and Na, with values ranging only from 1.03 % and 0.95 % to 11.17 % and 2.66 %, respectively. Besides, with augmented alkali metal chloride addition, the amount of low melting point aluminosilicates formed from SiO₂ and Al₂O₃ increased, further exacerbating the OC agglomeration.</p></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142128763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of banana peel waste biomass ratio in Co-pyrolysis of waste plastics to regulate aromatic content and oxygenated compounds: A study of liquid product characterization and its CI engine performance","authors":"","doi":"10.1016/j.joei.2024.101803","DOIUrl":"10.1016/j.joei.2024.101803","url":null,"abstract":"<div><p>We have reported the importance of biomass ratio in the co-pyrolysis of waste plastics to regulate the aromatic content and oxygenated compounds in hydrocarbon-rich fuels for enhancing engine performance. The study revealed that changing biomass to plastic ratio can control aromatic compositional change. The obtained product was characterized using different instrumentation techniques, such as NMR, FTIR, GCMS, etc., to identify the hydrocarbon types in the liquid product. Results revealed that it contains C₈-C₂₄ range carbon compounds with dominating aromatics compounds, as confirmed by ¹H NMR and FTIR analysis. The pyro-oils contain different hydrocarbons: olefins, paraffin, aromatics, esters, and alcohols. It was observed that the presence of biomass in co-pyrolysis produces oxygenated compounds up to ∼12.08 % and also enhances calorific value up to 55.4 MJ/kg from 48.3 MJ/kg due to the presence of longer hydrocarbon chains of esters in pyro-oil. Biomass co-pyrolysis also improved the fuel properties such as pour point (&lt;-25°C) and 4°C increment in flash point. Engine performance showed that blending biomass pyro-oil obtained from B25PS75 reduced fuel consumption and increased BTE.</p></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142163250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on the mechanism of CO chemical looping combustion over Fe-Based oxygen carriers with unsaturated coordination environments","authors":"","doi":"10.1016/j.joei.2024.101809","DOIUrl":"10.1016/j.joei.2024.101809","url":null,"abstract":"<div><p>It is crucial to study the Fe-O coordination environment due to oxygen defects for elucidating the dynamic active center during CO chemical looping combustion with hematite. In this work, Fe-based oxygen carriers with varying oxygen vacancy concentrations were firstly synthesized by direct thermal decomposition of ferric nitrate and subsequently evaluated through fixed-bed experimentation. It was showed that the reactivity of oxygen carriers produced by calcination at 700 °C exhibited a higher CO conversion rate due to the moderate oxygen vacancy concentration. Then, density-functional theory (DFT) calculations were conducted to examine the impact of oxygen vacancies. The results indicated that the formation of oxygen vacancies exhibited a proximity effect, resulting in the emergence of various Fe-O coordination environments. The low coordination number of Fe-O enhances the reactivity of the lattice oxygen and significantly lowers the activation energy barrier for the oxidation of CO to CO₂. Furthermore, the effect of oxygen vacancies on the migration of bulk phase oxygen was also investigated. It was shown that the migration barriers of bulk oxygen increased with the concentration of oxygen vacancies, resulting in a reduction in the oxygen supply rate. Moderate concentration of oxygen vacancies facilitates CO oxidation by aligning surface catalysis with the oxygen migration rate. This evidence suggests that the Fe-O coordination environment and oxygen vacancy concentration serve as key factors in controlling in controlling CO oxidation over Fe-based oxygen carriers.</p></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":null,"pages":null},"PeriodicalIF":5.6,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142117610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}