Journal of The Energy Institute最新文献

{"title":"Biomass & coal co-milling: Old hat or the route to decarbonization for coal power dependent economies via novel particle size partitioning analysis","authors":"Orla Williams ,&nbsp;Fatih Gulec ,&nbsp;Ho Kwong Lau ,&nbsp;Joseph Perkins ,&nbsp;Graham O'Brien ,&nbsp;Edward Lester","doi":"10.1016/j.joei.2025.102402","DOIUrl":"10.1016/j.joei.2025.102402","url":null,"abstract":"<div><div>Despite the global push towards net zero, coal remains a dominant energy source in many economies. Biomass co-firing offers coal powered dependent economies a transitional decarbonization pathway, yet co-milling remains a critical barrier due to the contrasting fracture mechanics of coal and biomass and lack of understanding in the partitioning of milled blends. This study aims to overcome some of these challenges by investigating the co-milling behaviour of wood pellets and palm kernel shell (PKS), with 7 coals (5 Australian, 1 Indonesian and 1 Colombian) using a ball and race mill with pneumatic classification. These two biomasses were blended with each coal at 10 % and 40 % wt/wt. The milling performance was evaluated using particle size distribution (PSD) statistical analysis, novel application of thermal characterisation on the milled size fractions, and application of Von Rittinger's comminution theory to rank grindability. Results demonstrate that while PKS exhibits mill choking when milled alone, co-milling enables complete milling, indicating a synergistic effect. Thermogravimetric analysis of size fractions enables the first reported estimation of biomass and coal partitioning within co-milled products. The Von Rittinger constant ranking revealed that softer coals require disproportionately higher energy when blended with biomass, particularly at higher blend ratios. Predictive models based on parent material PSD and thermal composition were developed to estimate co-milled particle size and specific energy consumption, showing good agreement at low blend ratios and highlighting synergistic effects at higher biomass contents. This study provides new insights into the physical and thermal partitioning of co-milled biomass and coal blends, demonstrating that co-milling can mitigate biomass milling limitations and improve throughput. The findings support the development of predictive models for PSD and energy consumption based on the parent material properties, offering practical guidance for the transition towards lower-carbon energy systems.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"125 ","pages":"Article 102402"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839048","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":"TG-FTIR-MS and Py-GC/MS analysis on co-pyrolysis characteristics of municipal solid waste and sewage sludge","authors":"Meijun Fan ,&nbsp;Nan Xing ,&nbsp;Jinwei Zhu ,&nbsp;Xuanhao Zhang ,&nbsp;Yongqiang Chen ,&nbsp;Guan Wang ,&nbsp;Xuebin Wang ,&nbsp;Zhicheng Pan ,&nbsp;Tedla Medhane Embaye","doi":"10.1016/j.joei.2026.102448","DOIUrl":"10.1016/j.joei.2026.102448","url":null,"abstract":"<div><div>Co-pyrolysis of municipal solid waste (MSW) and sewage sludge (SS) represents a promising strategy for simultaneous waste reduction and energy recovery in pyrolysis-based power systems. This study investigated the pyrolytic behavior, synergistic mechanisms, and product evolution of MSW, SS, and their blends (SS10 %, SS20 %, and SS35 %) using thermogravimetric analysis coupled with Fourier transform infrared and mass spectrometry (TG-FTIR-MS) and pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) at a heating rate of 20 °C·min⁻¹. Thermogravimetric results revealed a clear positive synergistic effect during co-pyrolysis that intensified as SS content increased, and the 35 % SS blend exhibited the strongest enhancement in thermal decomposition. MSW showed higher mass loss due to its lower ash content and higher volatility, while SS decomposed slightly earlier. Blending effectively intensified interactions during the second and third decomposition stages. TG-FTIR-MS analysis demonstrated that co-pyrolysis effectively suppressed the evolution of nitrogen and sulfur containing pollutants, including SO₂, HCNO, Pyrrole, Pyridine, and CO₂. Py-GC/MS analysis of condensable vapors indicated that synergistic interactions enhanced the yield of aliphatic hydrocarbons and alcohols while substantially reducing aromatic hydrocarbons and nitrogen compounds. These effects are attributed to hydrogen donation from SS and the catalytic action of sludge minerals, which stabilize MSW-derived radicals and shift product selectivity toward aliphatic hydrocarbons. Overall, the results demonstrate the feasibility of integrating SS treatment into MSW waste to energy systems to improve resource recovery efficiency. Although the SS35 % blend showed the most favorable performance within the investigated range, further studies at higher SS ratios, along with detailed bio-char and bio-oil characterization and upgrading, is necessary to support higher value energy applications.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"125 ","pages":"Article 102448"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145978027","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":"Experimental investigation on ammonia/coal co-firing of Zhundong coal and anthracite: a comparative study of combustion performance, fuel-N conversion and ash deposition","authors":"Qiwei Wu ,&nbsp;Naixin Wu ,&nbsp;Ziqi Wang ,&nbsp;Liansheng Ding ,&nbsp;Chongru Wang ,&nbsp;Jiaqing Chen ,&nbsp;Jingwen Liu ,&nbsp;Kunquan He ,&nbsp;Hao Zhou","doi":"10.1016/j.joei.2026.102471","DOIUrl":"10.1016/j.joei.2026.102471","url":null,"abstract":"<div><div>Under the dual-carbon strategy, ammonia/coal co-firing has emerged as a promising decarbonization pathway for coal-fired power units. This study investigated the co-firing characteristics of Zhundong coal (ZD) and anthracite (AN) at ammonia blending ratios of 0%-30% in a 0.2 MW one-dimensional furnace, with a focus on combustion performance, pollutant emissions, fuel-N conversion, and ash deposition behavior. Results indicate that co-firing performance is synergistically governed by inherent coal properties and ammonia blending ratios. Specifically, ZD showed higher combustion intensity and lower unburned carbon content. Co-firing will help improve the combustion performance of high-rank coal AN, but increased flue gas heat capacity and reduced fly ash concentration lowered furnace temperatures. The fly ash was identified as the primary carrier of unreacted ammonia. Ammonia co-firing notably optimized fuel-N conversion pathways, reducing ZD's fuel-N to NOx conversion rate from 12.36% to 1.73%. In terms of ash deposition, ZD deposits featured a double-layer structure, while AN deposits presented as loose accumulations. At 15% ammonia blending, ZD-15 achieved a peak deposit collection efficiency of 6.09% and a relative heat flux of 0.6732. Notably, ammonia co-firing does not alter the mineral composition of ash deposits but accelerates the growth of initial deposition layers, consequently impairing heat transfer efficiency on heating surfaces in the furnace's high-temperature zone. These insights are expected to contribute to the demonstration project for ammonia/coal co-firing power generation.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"125 ","pages":"Article 102471"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146188702","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":"Co nanoparticles embedded Co-phyllosilicate/ZSM-5 catalyst for boosting hydrogen production from ethanol steam reforming","authors":"Chunsheng Wang,&nbsp;Hongxia Cao,&nbsp;Dejin Zhang","doi":"10.1016/j.joei.2026.102465","DOIUrl":"10.1016/j.joei.2026.102465","url":null,"abstract":"<div><div>A catalyst supported on kaolin-derived ZSM-5 was designed to immobilize cobalt species for ethanol steam reforming (ESR), demonstrating enhanced activity and stability compared to its counterpart on commercial ZSM-5. The introduction of a Co-phyllosilicate phase grafted onto the ZSM-5 surface resulted in enhanced metal-support interaction within the Co-PS/ZSM-5 catalyst, which provided the active sites with high accessibility and sintering resistance. In contrast to the significant aggregation of Co⁰ nanoparticles observed in the Co/ZSM-5 and Co/CZSM-5 catalysts, the homogeneous Co active sites formed via exsolution from the Co-phyllosilicate precursor effectively suppressed metal sintering and coke deposition. Physicochemical characterization of the catalysts revealed that the Si-O-Co bonds in the residual Co-phyllosilicate played a key role in stabilizing the dispersed Co active sites and suppressing the competing reaction pathway of ethanol dehydration versus dehydrogenation. Consequently, the catalyst avoided the marked decline in H₂ yield associated with the formation and encapsulation of carbon nanotubes on Co sites. Among all tested catalysts, Co-PS/ZSM-5 demonstrated optimal performance, achieving near-complete conversion (∼100%), a high H₂ yield (∼76%), and stable operation over 50 h at 600 °C. This work presents a strategy for utilizing kaolin-derived ZSM-5 as a support for Co-based catalysts, demonstrating their potential for long-term, commercially viable ESR operation.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"125 ","pages":"Article 102465"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146188705","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":"Coal-derived nanoparticles as nanofuel additives in combustion engines: Synthesis, characterization, and engine test","authors":"Abdülvahap Çakmak ,&nbsp;Hakan Özcan","doi":"10.1016/j.joei.2025.102418","DOIUrl":"10.1016/j.joei.2025.102418","url":null,"abstract":"<div><div>As demand for cleaner and more efficient engine combustion grows, metallic nanofuel additives have emerged as promising solutions due to their ability to enhance combustion performance and lower emissions. However, high production costs, restricted availability, and toxicity concerns limit their adoption in real-world applications. To address these challenges, this study investigates the use of coal nanoparticles (CNPs) as a novel fuel additive for diesel fuel in diesel engines, presenting findings that have not been previously reported in the literature. CNPs were synthesized through a mechanical wet ball milling process and characterized using Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and particle size analysis. A milling duration of 6 h produced nearly spherical CNPs with an average particle size of 50 nm, which were then blended with diesel at concentrations of 100, 200, and 300 ppm. The fuel properties of the blends were measured, and engine tests were conducted on a four-stroke research diesel engine under various operating conditions. Results showed that among the concentrations, 300 ppm yielded the best outcomes, with a 3.58 % reduction in brake-specific fuel consumption and a 3.72 % increase in brake thermal efficiency compared to pure diesel. CNPs improved combustion by advancing cylinder pressure and net heat release rate while reducing total combustion duration. Also, HC, CO, and NO emissions decreased by up to 15.61 %, 35.22 %, and 20.28 %, respectively. However, smoke opacity increased by as much as 32.40 %. The findings indicate that CNPs can replace metallic nanoparticles, providing comparable improvements in engine combustion, performance, and emissions.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"125 ","pages":"Article 102418"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145789966","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":"Experimental and numerical investigation of high-flow-rate injection focusing on improved thermal efficiency and output performance in low-pressure direct-injection hydrogen engines","authors":"Nobuhiro Shimmura ,&nbsp;Masakuni Oikawa ,&nbsp;Seiya Yamada ,&nbsp;Yuji Mihara ,&nbsp;Yasuo Takagi","doi":"10.1016/j.joei.2026.102463","DOIUrl":"10.1016/j.joei.2026.102463","url":null,"abstract":"<div><div>Direct hydrogen injectors are actively being developed today to enable high-flow-rate injection of hydrogen into the engine cylinders at low pressure to promote opportunities for hydrogen application to internal combustion engines. In this study, the effect of high-flow-rate injection by direct hydrogen injectors on engine performance was evaluated under low hydrogen supply pressure. Combustion tests of a spark-ignition hydrogen engine were combined with a computational fluid dynamics analysis of jet and mixture formation behavior using large eddy simulation (LES). The results of this study revealed that a reduction of cooling losses accompanying attenuation of in-cylinder gas flow and changes in mixture location due to high-flow-rate injection contributed to a large improvement of thermal efficiency by 2–3%. This indicates that high-flow-rate injection in low-pressure direct-injection hydrogen engines is not only essential for achieving high power output through supercharging, but it is also effective in improving thermal efficiency by optimizing the injection timing.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"125 ","pages":"Article 102463"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146188711","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":"Machine learning aids co-hydrothermal liquefaction of algae and waste: Prediction of synergistic effect and bio-oil yield","authors":"Yamin Hu ,&nbsp;Yuke Ma ,&nbsp;Zhen Liu ,&nbsp;Hongjun Zhang ,&nbsp;Ding Jiang ,&nbsp;Lili Qian ,&nbsp;Sirong He ,&nbsp;Shuang Wang ,&nbsp;Qian Wang","doi":"10.1016/j.joei.2025.102340","DOIUrl":"10.1016/j.joei.2025.102340","url":null,"abstract":"<div><div>Algal biomass co-hydrothermal liquefaction (co-HTL) is an efficient biofuel production method where the synergistic effect (SE) critically improves biofuel quality and yield, but predicting SE and bio-oil yield (Yield_oil) remains challenging due to complex reaction conditions and feedstock variability. This study integrated algal co-HTL operational parameters, biochemical/elemental compositions, and atomic ratios (using 187 literature + 63 proprietary experimental data points, differing from prior single-source data) to develop six machine learning (ML) models (including eXtreme Gradient Boosting (XGBoost), Random Forest (RF)), optimized via five-fold cross-validation and grid search, while systematically comparing single-task (separate Yield_oil/SE prediction) and multi-task (joint prediction) models. The XGBoost model showed superior performance (Yield_oil R² (Prediction Determination Coefficients) = 0.88, SE R² = 0.86), with the multi-task model achieving R² = 0.83 and RMSE (Root Mean Square Error) = 3.40; feature analysis identified temperature as the key Yield_oil driver, residence time as a major SE influencer, and revealed high ash/lignin inhibited SE while ash promoted SE via potential catalytic effects (e.g., alkali metals), with validation confirming prediction errors &lt;5 %. This work is innovative given algal feedstocks' unique composition and distinct co-HTL conditions, and scientifically addressed the lack of joint SE-Yield_oil prediction in algal co-HTL (a prior single-target model limitation) and industrially reduced trial-and-error costs via rapid parameter optimization for algal biocrude production. These findings highlight ML's value in deciphering complex process-outcome relationships, laying groundwork for efficient algal biomass conversion and offering a novel framework to optimize co-HTL parameters and modulate SE.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"125 ","pages":"Article 102340"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839045","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":"Nitrogen-sulfur transport, products, and synergistic effects in co-pyrolysis of the CaO/K2FeO4 conditioned sludge and chlorella","authors":"Guiying Xu,&nbsp;Xiaoxuan Yang,&nbsp;Jie Zhang,&nbsp;Haojie Chen,&nbsp;Chunxia Zhao","doi":"10.1016/j.joei.2025.102421","DOIUrl":"10.1016/j.joei.2025.102421","url":null,"abstract":"<div><div>The purpose of this study is to evaluate the synergistic mechanism and the impacts of co-pyrolysis between chlorella (CV) and CaO/K₂FeO₄ conditioned sludge (CSS) on the regulation of pollutants to be produced. Thermogravimetric analysis reveals that there is a non-linear synergistic effect that occurs during their co-pyrolysis. The fitting of the Coats-Redfern kinetic model indicated that the activation energy (E_m) for pyrolysis decreased with decreasing CV content. This study demonstrated that the high reactivity of CSS significantly promotes CV pyrolysis. Experiments on pollutant release revealed that adding CSS most effectively reduced nitrogen- and sulfur-containing gas emissions at a 75 % loading, with the suppression being most apparent at this level. The analysis of pyrolysis products revealed that the co-pyrolyzed oil included reduced amounts of carboxylic acids and nitrogen-containing compounds, with the carboxylic acids and nitrogen-containing compounds amounting to 24.68 % and the latter to 7.66 %, respectively. This was the case when the CSS addition rate was 25 %. The purpose of this work is to present kinetic data and control mechanisms for the utilization of resources through the co-pyrolysis of microalgae and municipal sewage sludge.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"125 ","pages":"Article 102421"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839101","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":"Ash fusion and migration characteristics of municipal solid waste and sewage sludge co-firing in power plants","authors":"Ao Zhou ,&nbsp;Zhongfa Hu ,&nbsp;Muhammad Bilal Ahmad ,&nbsp;Zhaotianyi Zhang ,&nbsp;Wei Yu ,&nbsp;Yiming Zhu ,&nbsp;Jingjie Li ,&nbsp;Xuebin Wang ,&nbsp;Houzhang Tan","doi":"10.1016/j.joei.2025.102430","DOIUrl":"10.1016/j.joei.2025.102430","url":null,"abstract":"<div><div>With the municipal sludge production increasing annually, co-disposal of municipal sewage sludge (SS) has become the choice of more and more power plants. In this paper, municipal solid waste (MSW), sewage sludge as well as fly ash and slag were sampled from a power plant that actually co-disposed municipal sludge. The ash fusion characteristics and compositions of MSW and SS at different mixing ratios were investigated and analyzed. The simulation of mineral evolution under different sludge mixing ratios was also carried out using Factsage software. The experimental results showed that the ash melting temperature of MSW was lower than that of sludge. When SS was mixed at a low ratio (SS10 %), the ash melting temperature of the ash samples decreased significantly. When the mixing ratio gradually increased, the fly ash melting temperature gradually increased. XRD analysis results showed that when SS mixing ratio was small, the Fe content in the ash samples was low, and Fe mainly existed in the form of FeO, which led to the decline of the ash melting point of SS10 %. When the sludge mixing ratio was gradually increased to 20 %, the Fe content in the ash samples increased. The reaction of Fe with SiO₂ and Al₂O₃ generated high melting point Fe-containing minerals such as Ca₄FeO₃, CaFeO₄ and Ca₄Fe₉O₁₇, which led to an increase in the ash melting point of the ash samples. The Factsage results also showed that MSW ash samples in the three-phase diagram moved gradually from the Ca₂P₂SiO₁₂ region to the CaAl₂Si₂O₈ region and the mullite region with the increase of sludge mixing ratio, so the ash melting point was higher. Through the slag and fly ash analysis of the power plant, it is found that the fly ash and slag are both dominated by silica-aluminate such as calcium feldspar and mullite, where slag also contains a small amount of iron-containing minerals such as Ca₄Fe₉O₁₇. The Fe in the sludge is mainly residual in the slag. It indicates that the mixing of sludge in small proportions mainly affects the fly ash of the power plant, and does not have much effect on the slag of the power plant. The experimental results can contribute to the actual waste power plant in terms of reasonable sludge mixing, avoiding boiler slagging and improving boiler efficiency.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"125 ","pages":"Article 102430"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927014","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":"Experimental study and process analysis on Co-production of hydrogen-rich gas and carbon nanotubes via catalytic pyrolysis of solid wastes","authors":"Zhongfa Hu ,&nbsp;Bixiu Lv ,&nbsp;Wenjing Ma ,&nbsp;Bin Liu ,&nbsp;Xuebin Wang ,&nbsp;Yili Zhang ,&nbsp;Zia ur Rahman ,&nbsp;Renhui Ruan","doi":"10.1016/j.joei.2026.102454","DOIUrl":"10.1016/j.joei.2026.102454","url":null,"abstract":"&lt;div&gt;&lt;div&gt;The decomposition of polyethylene into hydrogen and carbon nanotubes by pyrolysis not only enables the proper disposal of large amounts of waste plastic but also achieves the targeted production of hydrogen and high-value carbon nanotubes, thus it is widely applied in industry. In this paper, typical solid wastes, such as polyethylene (PE) and sawdust, were used as raw materials, and continuous pyrolysis-catalysis experiments were conducted on a two-stage pilot system (rotary kiln for pyrolysis and fixed-bed for catalysis).To overcome the limitations of traditional fixed-bed reactors in organic waste treatment, this study develops a continuous pyrolysis-catalytic co-production process for the simultaneous generation of high-value hydrogen gas and carbon nanotube (CNTs), aiming for system energy self-sufficiency. The core research encompasses experimental validation under specific conditions and simulation analysis of three process routes based on experimental results. Successful experimental validation was achieved under continuous operation at a feeding rate of 1 g min&lt;sup&gt;−1&lt;/sup&gt;, pyrolysis temperature of 500 °C, catalytic temperature of 750 °C, and using a coal gangue-based nickel catalyst (loading 10 %) for processing polyethylene (PE) and wood chips; significant PE conversion yielded a hydrogen concentration (H&lt;sub&gt;2&lt;/sub&gt;) in the gas product as high as 64.6 vol%, with a production rate reaching 27.4 mmol g&lt;sup&gt;−1&lt;/sup&gt; while substantial coking occurred on the catalyst surface achieving a yield of 32.5 wt%. Characterization of the PE-derived coke indicated that it primarily consisted of CNTs with hollow tubular structures confirmed by TEM images and high graphitization degree and good crystallinity indicated by Raman spectroscopy (&lt;em&gt;I&lt;/em&gt;&lt;sub&gt;D&lt;/sub&gt;/&lt;em&gt;I&lt;/em&gt;&lt;sub&gt;G&lt;/sub&gt; = 0.75) and TPO results where graphite carbon accounted for 38.8 wt%. Based on experimental data, three process routes were established using Aspen Plus software all utilizing partial pyrolysis oil/gas combustion to supply energy for the system balance but differing in the handling of pyrolyzed coke; simulation optimization showed that route I (coke combustion) performed best under optimal conditions (raw material moisture content 20 %, oil/gas ratio 25 %, gasification stage O&lt;sub&gt;2&lt;/sub&gt;/feedstock = 0.25, H&lt;sub&gt;2&lt;/sub&gt;O/feedstock = 0.5) achieving a hydrogen yield of 1102.6 Nm&lt;sup&gt;3&lt;/sup&gt;·t&lt;sup&gt;−1&lt;/sup&gt; and a CNTs yield of 43.9 kg t&lt;sup&gt;−1&lt;/sup&gt; whereas route II (coke gasification) had slightly lower target product yields compared to route I and route III (coke collection) collected pyrolyzed coke as solid products (biochar) without thermal treatment resulting in the lowest carbon emissions but also the lowest target product yields. Comprehensive analysis indicates that adopting a continuous pyrolysis-catalytic unit combined with the design of utilizing pyrolyzed coke for energy supply efficiently converts organic solid waste into high-value hydrogen and CNTs","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"125 ","pages":"Article 102454"},"PeriodicalIF":6.2,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146078403","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}