{"title":"Performance evaluation of helical tangential porous tube-in-tube microchannel mixer: Effect of cross-sectional area ratio and volumetric flow rate ratio","authors":"Xiao Xu , Jinfeng Zhang , Jia Chen , Dongbo Zhao , Shaodong Qin","doi":"10.1016/j.cep.2025.110296","DOIUrl":"10.1016/j.cep.2025.110296","url":null,"abstract":"<div><div>The tube-in-tube microchannel mixer (TMM) is a passive micromixer primarily applied in chemical engineering and pharmaceutical fields. This study investigates the performance optimization of a helical tangential porous tube-in-tube microchannel mixer (HTP-TMM) using computational fluid dynamics (CFD) simulations. A critical structural parameter, the cross-sectional area ratio (<em>R</em><sub>a</sub>), defined as the ratio of the annular microchannel cross-sectional area to the total micropore cross-sectional area, was introduced. The effects of various <em>R</em><sub>a</sub> and volumetric flow rate ratios (<em>R</em><sub>f</sub>) on mixing efficiency, turbulent kinetic energy, pressure drop, and mixing energy cost were evaluated across flow rates ranging from 10 to 300 mL/min. Results indicate that <em>R</em><sub>a</sub> = 1.5 demonstrates higher mixing efficiency and turbulent kinetic energy at low flow rates. Decreasing <em>R</em><sub>f</sub> improves mixing efficiency and turbulent kinetic energy, with optimal mixing performance occurring at <em>R</em><sub>f</sub> = 1. Additionally, larger <em>R</em><sub>a</sub> and smaller <em>R</em><sub>f</sub> values induce higher pressure drops, with maximum recorded values of 23,449 Pa for <em>R</em><sub>a</sub> = 2 and 19,990 Pa for <em>R</em><sub>f</sub> = 1, both within acceptable ranges for practical applications. Moreover, varying <em>R</em><sub>a</sub> minimally affects mixing energy cost, while increasing <em>R</em><sub>f</sub> raises mixing energy cost. These findings provide valuable guidance for TMM design and application in chemical engineering.</div></div>","PeriodicalId":9929,"journal":{"name":"Chemical Engineering and Processing - Process Intensification","volume":"213 ","pages":"Article 110296"},"PeriodicalIF":3.8,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thi Be Ta Truong , Do Tuong Ha , Hien Duy Tong , Thuat T. Trinh
{"title":"Molecular investigation of pyrolysis and thermal gasification pathways in polyethylene microplastics degradation","authors":"Thi Be Ta Truong , Do Tuong Ha , Hien Duy Tong , Thuat T. Trinh","doi":"10.1016/j.cep.2025.110285","DOIUrl":"10.1016/j.cep.2025.110285","url":null,"abstract":"<div><div>Polyethylene (PE) microplastics are a persistent environmental threat due to their widespread presence and potential for long-range transport. This study uses reactive molecular dynamics (ReaxFF) simulations to explore the atomic-level thermal degradation mechanisms of PE microplastics through pyrolysis and thermal gasification (TG). A key finding of the research is the comparison of activation energies for pyrolysis and TG. Results show that pyrolysis begins with chain scission, producing volatile compounds, while TG generates hydrogen, carbon monoxide, water, and small hydrocarbons. Oxygen plays a key role in controlling gas fractions during TG. The activation energy for pyrolysis is 315 kJ/mol, higher than TG, which ranges from 197 to 262 kJ/mol depending on oxygen content, indicating TG is a more efficient degradation pathway. These findings offer molecular insights into PE microplastic degradation, aiding the development of targeted remediation strategies and advancing research on microplastic waste treatment.</div></div>","PeriodicalId":9929,"journal":{"name":"Chemical Engineering and Processing - Process Intensification","volume":"213 ","pages":"Article 110285"},"PeriodicalIF":3.8,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143734537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lucas Schaare , Alexander Rave , Rafael Kuwertz , Georg Fieg , Mirko Skiborowski
{"title":"Axial dispersion modelling of the residence time distribution in a millistructured plate reactor","authors":"Lucas Schaare , Alexander Rave , Rafael Kuwertz , Georg Fieg , Mirko Skiborowski","doi":"10.1016/j.cep.2025.110295","DOIUrl":"10.1016/j.cep.2025.110295","url":null,"abstract":"<div><div>Micro- and millistructured reactors offer significant advantages compared to conventional batch reactors in terms of heat and mass transfer as well as process safety. Especially in case of fast and exothermic reactions, the space-time-yield of batch reactors is often limited by poor heat transfer and slow mixing. The use of millistructured reactors, such as the ART plate reactor PR37 of Ehrfeld Mikrotechnik, can overcome heat and mass transfer limitations and significantly extend applicable process windows, while providing sufficient capacity for industrial applications. Previous investigations showed that the reactor offers high heat transfer coefficients as well as short micromixing times at moderates Reynolds numbers. In order to further characterize the performance of the reactor and the possible operating window, the current work provides a thorough study of the residence time distribution on the basis of pulse experiments and a model-based evaluation of the deviation from ideal plug flow on the basis of the axial dispersion model. The results demonstrate that the reactor closely resembles the ideal plug flow even for Reynolds numbers of just about <em>Re</em> <span><math><mo>≈</mo></math></span> 100. Due to its meandering, periodically diverging/converging process channels, the formation of secondary flow is promoted resulting in an increased cross-mixing and thus a considerably reduced axial dispersion compared straight channels. For further analysis, as well as model-based assessment and design of the reactor, a correlation for the axial dispersion coefficient is derived which is applicable for a wide process window.</div></div>","PeriodicalId":9929,"journal":{"name":"Chemical Engineering and Processing - Process Intensification","volume":"213 ","pages":"Article 110295"},"PeriodicalIF":3.8,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143748331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhishan Zhang, Jinyu Wang, Kunao Zhu, Siyuan Li, Min Li, Xing Fan, Jun Gao
{"title":"An efficient heat-pump extractive distillation process for recovering lower alcohols from bioethanol fusel oil","authors":"Zhishan Zhang, Jinyu Wang, Kunao Zhu, Siyuan Li, Min Li, Xing Fan, Jun Gao","doi":"10.1016/j.cep.2025.110291","DOIUrl":"10.1016/j.cep.2025.110291","url":null,"abstract":"<div><div>Fusel oil is a common mixture of several alcohols produced as a by-product of alcoholic fermentation. After removing the main ingredient (amyl alcohol), it also contains lower alcohols such as ethanol (EtOH), n-propanol (NPA) and isobutanol (IBA), each of which forms an azeotrope with water and has a similar boiling point. In order to efficient recover high purity products from the EtOH/NPA/IBA/water mixture, this article investigates different extractive distillation processes with heat pump in terms of economic, environment and thermodynamic properties. Firstly, 1,4-butanediol is screened as the best dehydration solvent based on the thermodynamic and molecular quantization analysis; Next, a conventional extractive distillation sequence (CED) is proposed and optimized using total annual costs (TAC) and CO<sub>2</sub> emissions as dual objectives. Finally, introducing heat integration, vapor recompressed heat pump and bottom flash heat pump into the CED process, three energy-saving processes (i.e., HICED, DVRHPs-HICED and BFVRHPs-HICED) are designed. The results show that compared with the CED process, the DVRHPs-HICED process reduces TAC by 17.5 %, exergy loss by 42.2 %, and gas emissions (CO<sub>2</sub>, SO<sub>2</sub>, NO<sub>x</sub>) by 49.2 % while the BFVRHPs-HICED process reduce TAC by 17.8 %, exergy loss by 40.8 %, and gas emissions (CO<sub>2</sub>, SO<sub>2</sub>, NO<sub>x</sub>) by 48.5 %.</div></div>","PeriodicalId":9929,"journal":{"name":"Chemical Engineering and Processing - Process Intensification","volume":"213 ","pages":"Article 110291"},"PeriodicalIF":3.8,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"CFD analysis of the intensification mechanism of bubble breakup by perforated plates in a bubble column","authors":"Rongtao Wang, Xinya Guo, Mengqin Zhan, Yefei Liu","doi":"10.1016/j.cep.2025.110288","DOIUrl":"10.1016/j.cep.2025.110288","url":null,"abstract":"<div><div>Conventional bubble column reactors suffer from some drawbacks like severe backmixing and poor heat/mass transfer performance. The process intensification by the utilization of perforated plates has been an important strategy to overcome these problems. However, a fundamental understanding of the bubble breakup by perforated plates is still very limited. CFD simulations are carried out to reveal the interaction between the rising bubbles and perforated plates. It is found that no bubbles break up when they just pass through the hole. A bubble can be broken into three small daughter bubbles when it collides with the bridge connecting three holes. The bubble breakup is mainly attributed to the bridge cutting, whereas it is not sensitive to large hole diameters. A large bubble cap is formed underneath the plate due to very small hole diameter. The plate thickness has no significant influence on bubble breakup. When the inclined angle of a perforated plate is larger than 45°, the bubbles slide beneath the plate more readily and no bubbles pass through it. The perforated plate with large inclined angle fails to induce bubble breakup. This study would provide deep insights into bubble breakup mechanism related to process intensification by perforated plates.</div></div>","PeriodicalId":9929,"journal":{"name":"Chemical Engineering and Processing - Process Intensification","volume":"213 ","pages":"Article 110288"},"PeriodicalIF":3.8,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Raphael Lucas Jacinto Almeida , Newton Carlos Santos , Waleska Rayane Dantas Bezerra de Medeiros , Anna Paula Rocha de Queiroga , Nathália Saraiva Rios , Everaldo Silvino dos Santos
{"title":"Dual modification of red rice starch: Combining hydrothermal pretreatment with acid hydrolysis for the production of nanomaterials","authors":"Raphael Lucas Jacinto Almeida , Newton Carlos Santos , Waleska Rayane Dantas Bezerra de Medeiros , Anna Paula Rocha de Queiroga , Nathália Saraiva Rios , Everaldo Silvino dos Santos","doi":"10.1016/j.cep.2025.110292","DOIUrl":"10.1016/j.cep.2025.110292","url":null,"abstract":"<div><div>This study evaluated the combination of acid hydrolysis with hydrothermal pretreatment (HPT) for the production of nanomaterials using red rice starch. Native red rice starch (A0) was subjected to HPT in an autoclave at 121°C/10 min (A3) or cooked at 100°C/10 min (A4) and then hydrolyzed with 3.16M sulfuric acid at 25°C for a period of 5 days. The A3 treatment enhanced acid diffusion, leading to the efficient production of starch nanomaterials with a diameter of 106.97 nm. This process resulted in a crystallinity of 31.94%, a higher degree of polymerization of amylopectin (DP ≥ 37: 31.39–34.98%), and a yield of 33.48% on the third day, surpassing A0′s 10.12%. These characteristics classify A3 as starch nanocrystals (SNC). In contrast, A4 exhibited an increased diameter of 260.81 nm, and crystallinity remained in the range of 15%. It is classified as starch nanoparticles (SNP) and displayed higher gelatinization temperatures due to amorphous regions. DP was most affected by A4 with lower values DP ≥ 37 (25.68-30.16%) throughout acid hydrolysis, confirming the lower crystallinity. Finally, it was found that autoclaving was efficient as a pretreatment for native red rice starch to produce SNC through acid hydrolysis in a reduced time.</div></div>","PeriodicalId":9929,"journal":{"name":"Chemical Engineering and Processing - Process Intensification","volume":"213 ","pages":"Article 110292"},"PeriodicalIF":3.8,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143777473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L.M. Marques , S.M. Mota , P. Teixeira , M. Mateus , C.I.C. Pinheiro
{"title":"Decarbonisation of cement industry: Calcium looping with white mud and limestone as CaO-based sorbents for industrial flue gas treatment","authors":"L.M. Marques , S.M. Mota , P. Teixeira , M. Mateus , C.I.C. Pinheiro","doi":"10.1016/j.cep.2025.110290","DOIUrl":"10.1016/j.cep.2025.110290","url":null,"abstract":"<div><div>This study investigates the potential of CaO-based sorbents from white mud and limestone for CO<sub>2</sub> capture in the Calcium-looping (CaL) process, employing both dry synthetic gas and real industrial flue gas (FG) from a cement plant (<0.3 % moisture). Exploring white mud as a CO<sub>2</sub> sorbent offers a novel way to valorise waste, aiding waste reduction. The CO<sub>2</sub> capture capacity was evaluated in a laboratory scale Fluidized Bed Reactor over ten carbonation-calcination cycles (calcination: 930 °C, 70 % CO<sub>2</sub>; carbonation: 700 °C, 15 % CO<sub>2</sub>). Sorbents carbonated with FG demonstrated improved performance and stability, emphasizing moisture's role. These conditions generally improved sorbent textural properties after cycling. Results also showed that higher CO<sub>2</sub> capture was associated with fresh sorbents having lower SiO<sub>2</sub> content (<0.73 wt. %), whereas higher SiO<sub>2</sub> content led to decreased performance. In conclusion, white mud offers potential for greener CO<sub>2</sub> capture. The research further examines the potential for reducing calcination temperature when steam is used in both calcination-carbonation stages. Adding 15 vol. % steam was found to improve CO<sub>2</sub> capture capacity at a lower calcination temperature (910 °C), achieving 0.29 g CO<sub>2</sub>/g sorbent in the first cycle. Our preliminary approach revealed that using steam during both stages is promising at low calcination temperatures.</div></div>","PeriodicalId":9929,"journal":{"name":"Chemical Engineering and Processing - Process Intensification","volume":"213 ","pages":"Article 110290"},"PeriodicalIF":3.8,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143737963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Muhammad Zubair Shahid , Ahmad Salam Farooqi , Mohammad Mozahar Hossain , Usama Ahmed , Medhat A. Nemitallah
{"title":"Effects of CaO/MgO compositions on the performances of sorption enhanced water gas shift reaction: A thermodynamic analysis","authors":"Muhammad Zubair Shahid , Ahmad Salam Farooqi , Mohammad Mozahar Hossain , Usama Ahmed , Medhat A. Nemitallah","doi":"10.1016/j.cep.2025.110287","DOIUrl":"10.1016/j.cep.2025.110287","url":null,"abstract":"<div><div>The CO<sub>2</sub> sorption-enhanced water gas shift reaction (SE-WGSR) is a promising approach that facilitates in-situ CO<sub>2</sub> capture and promotes hydrogen yields by shifting the equilibrium of the WGSR towards higher CO conversion. Developing an effective sorbent/catalyst is one of the key challenges for industrial-scale applications of SE-WGSR technology. The present study investigated mixed CaO/MgO as a sorbent material for an SE-WGSR process. The performances of the SE-WGSR with various concentrations of CaO/MgO mixtures were analyzed by using the Gibbs free energy minimization method. The ultimate objective was to secure a high CO conversion and a low energy requirement for sorbent regeneration. The results showed that the increasing CaO in the CaO/MgO mixture significantly increased the CO conversion, while the increase in MgO decreased the total sorbent regeneration enthalpy. A CaO/MgO mixture of 20 mol % CaO was identified as the optimal sorbent composition, achieving a 29.3 % higher CO conversion in comparison to 100 % MgO sorbent at 40 bar pressure and 350 °C, requiring 14.1 % less regeneration enthalpy than a 100 mol % CaO sorbent. Therefore, the optimal sorbent mixture composition can result in the realization of an efficient SE-WGS process to achieve high CO conversion at the appropriate regeneration energy cost.</div></div>","PeriodicalId":9929,"journal":{"name":"Chemical Engineering and Processing - Process Intensification","volume":"212 ","pages":"Article 110287"},"PeriodicalIF":3.8,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143705601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fuxing Jia , Haibin Zhang , Changliang Wang , Shanwei Li , Min Wei
{"title":"Study on internal circulation patterns and heat transfer characteristics of gas-liquid Taylor flow in a gradually expanding microchannel","authors":"Fuxing Jia , Haibin Zhang , Changliang Wang , Shanwei Li , Min Wei","doi":"10.1016/j.cep.2025.110283","DOIUrl":"10.1016/j.cep.2025.110283","url":null,"abstract":"<div><div>The internal circulation within the gas-liquid Taylor flow slug promotes radial fluid mixing, which is a key factor in enhancing heat and mass transfer rates. The present study investigates numerically the internal circulation patterns of gas-liquid Taylor flow slugs in a gradually expanding microchannel and their effect on heat transfer characteristics. The flow field structure and heat transfer performance of slugs in straight and gradually expanding channels under different flow velocity conditions are compared and analyzed. The results show that secondary vortices within the slug significantly enhance the mixing in the liquid phase, thus improving local heat transfer efficiency. In the expanding channel, the gradual increase in hydraulic diameter promotes the formation and development of secondary vortices, leading to the further intensification of heat transfer. Under these conditions, the secondary circulation zone significantly impacts the main circulation zone, and its contribution to strengthening heat transfer cannot be ignored. This study provides a theoretical basis for optimizing the design of microchannel heat sinks with broad engineering applications, particularly in device cooling and efficient heat dissipation.</div></div>","PeriodicalId":9929,"journal":{"name":"Chemical Engineering and Processing - Process Intensification","volume":"212 ","pages":"Article 110283"},"PeriodicalIF":3.8,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143679806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. González Pérez, M.J. Vilchez, T. Burgos, J.M. Bisang
{"title":"Mass-transfer study in a swirling flow electrochemical reactor with structured counter electrodes under single-phase and two-phase (gas-evolving) flows","authors":"O. González Pérez, M.J. Vilchez, T. Burgos, J.M. Bisang","doi":"10.1016/j.cep.2025.110286","DOIUrl":"10.1016/j.cep.2025.110286","url":null,"abstract":"<div><div>This paper analyses the effect of two kinds of structures as counter electrodes on the mass-transfer performance of an electrochemical reactor under swirling flow. The arrangements used as counter electrodes were either helical-shaped structures or an expanded metal sheet. The former presents a more uniform mass-transfer distribution as the main advantage compared to a decaying swirling flow system. The best uniformity was achieved when the number of turns in the helix was higher than 9 for a 257.5 mm reactor length. The latter structured counter electrode can only be vindicated by its high value of specific surface area, increasing the space-time yield of the reactor, but with a poor performance in the mass-transfer behaviour regarding the decaying swirling flow. The effect of the volumetric flow rate on the mass-transfer distribution is scarce for both structured counter electrodes. The operation with a two-phase system showed a slightly more ineffective behaviour in comparison to the single-phase case. The use of a helical structure as a counter electrode can be recognised as an improvement in the reactor performance under swirling flow from the standpoint of the mass-transfer distribution.</div></div>","PeriodicalId":9929,"journal":{"name":"Chemical Engineering and Processing - Process Intensification","volume":"212 ","pages":"Article 110286"},"PeriodicalIF":3.8,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143697972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}