Article
Engineering, Environmental
Shiliang Yang, Shuai Wang, Hua Wang
Summary: The study on biomass pyrolysis in a spouted bed reactor reveals that the heat transfer coefficient of particles varies with bed height and shows significant distribution differences in different regions. The temperature and heat transfer coefficient of biomass increase with the rise of pyrolysis temperature, while the effect of gas velocity on the heat transfer coefficient is insignificant.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Engineering, Chemical
Yi Ouyang, Manuel Nunez Manzano, Ruben Wetzels, Siyuan Chen, Xiaojun Lang, Geraldine J. Heynderickx, Kevin M. Van Geem
Summary: The gas-liquid hydrodynamics in a gas-liquid vortex reactor (GLVR) have been investigated by high-speed imaging and digital image analysis, revealing that a high turbulent kinetic energy dissipation rate contributes to a high mixing and mass transfer efficiency in the GLVR.
CHEMICAL ENGINEERING SCIENCE
(2021)
Article
Agricultural Engineering
Yuanyu Tian, Jie Li, Wei Wei, Peijie Zong, Di Zhang, Yanan Zhu, Yingyun Qiao
Summary: The study revealed that adding hydrogen in fast partial hydropyrolysis of biomass can significantly increase volatile matter generation and the yields of CH4 and light tar. Alkali and alkaline earth metals play a significant catalytic role in the reactions, while operating temperature and gas flow rate also impact product yields.
BIORESOURCE TECHNOLOGY
(2021)
Review
Energy & Fuels
Yongnan Zhang, Yunyi Liang, Suiyi Li, Yan Yuan, Daihui Zhang, Yingji Wu, Huan Xie, Kathirvel Brindhadevi, Arivalagan Pugazhendhi, Changlei Xia
Summary: Biomass energy has become the fourth largest energy source due to its abundant availability. The main products of biomass pyrolysis are pyrolysis oil and biochar. However, there is still untapped potential in biomass products that deserves further exploration. Research on biomass pyrolysis gas is progressing and reaching a commercial level. It is possible to purify and decoke pyrolysis gas according to demand, and its components can be extracted for other purposes. Therefore, biomass pyrolysis gas has great potential for development.
Article
Engineering, Chemical
Yi Ouyang, Manuel Nunez Manzano, Siyuan Chen, Ruben Wetzels, Tom Verspeelt, Kevin M. Van Geem, Geraldine J. Heynderickx
Summary: The capabilities of a gas-liquid vortex reactor (GLVR) as novel process intensification equipment were evaluated and found to have the ability to generate large interfacial area in a small reactor volume, resulting in superior mass transfer efficiency and energetic efficiency.
Article
Thermodynamics
Shiliang Yang, Ruihan Dong, Yanxiang Du, Shuai Wang, Hua Wang
Summary: The study investigates the physical and thermochemical characteristics of biomass pyrolysis in a lab-scale spouted bed reactor using a reactive multiphase particle-in-cell approach. Results show that the distribution of biomass particles affects the spatial distributions of gas thermochemical properties. Intensive turbulent flow of gas phase exists in the spout region, which is enhanced with increasing gas inlet velocity and pyrolysis temperature.
Article
Engineering, Environmental
Zheng-hao Yang, Zhen He, Xiang-gang Zhang, Xia Jiang, Zi-heng Jin, Jian-ping Li, Liang Ma, Hua-lin Wang, Yu-long Chang
Summary: The circulating fluidized bed (CFB) reactor, commonly used in biomass fast pyrolysis, faces challenges in separating biochar from the heat carrier. To address this, a novel in-situ gas flow bed separator was designed, enabling efficient separation of biochar and the heat carrier. The separation efficiency was studied under different operational conditions, revealing the significant influence of bubble activity and the density and size disparities of binary particles. With the optimal conditions, a separation efficiency of 99% was achieved. This innovative technology holds great potential for enhancing product yields and competitiveness in fast pyrolysis applications.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Analytical
Jaroslav Mosko, Michal Jeremias, Siarhei Skoblia, Zdenek Beno, Vineet Singh Sikarwar, Matej Husek, Hailong Wang, Michael Pohorely
Summary: Residual moisture in pyrolyzed fuel affects the distribution and properties of pyrolysis products due to the concentration of steam in the primary pyrolysis gas. Using steam as a carrier gas results in significantly different product distribution and properties, especially at high temperatures. This approach offers a simplified way to predict and optimize pyrolysis products in large-scale units.
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
(2022)
Article
Engineering, Chemical
Sanaa Hafeez, Maarten Van Haute, Achilleas Constantinou, Sultan M. Al-Salem
Summary: A comprehensive process simulation was developed to study the pyrolysis of LLDPE in an FBR, with the focus on the pyrolytic oil and wax yields. The simulation showed a decrease in oil yield with increasing temperature, due to the vibration of the polymer matrix and absorbed thermal energy. A higher gas yield and negligible wax formation at 700 degrees C were observed, which is beneficial for controlling plastic waste. The simulation was validated with experimental data, showing less than 10% discrepancy.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Engineering, Environmental
Mudasir Akbar Shah, N. S. Khan, Vimal Kumar, Ahsanulhaq Qurashi
Summary: Bio-yields obtained from pyrolysis of different types of walnut shells showed potential for use as fuel, lubricant, and value-added products after modifications.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2021)
Article
Engineering, Environmental
Florian Wery, Laurien A. Vandewalle, Guy B. Marin, Geraldine J. Heynderickx, Kevin M. Van Geem
Summary: Process intensification in gas-solid fluidization processes can be achieved by working in a centrifugal rather than a gravitational field. The gas-solid vortex unit (GSVU) is an ideal candidate for heterogeneously catalyzed processes. A four-way coupled CFD-DEM model describing the hydrodynamics in the GSVU with an unprecedented level of detail is validated using experimental data, and it demonstrates enhanced heat and mass transfer rates and a narrow gas-phase residence time distribution.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Environmental
Xiaojun Lang, Yi Ouyang, Laurien A. Vandewalle, Bahman Goshayeshi, Siyuan Chen, Sepehr Madanikashani, Patrice Perreault, Kevin M. van Geem
Summary: The gas-solid vortex reactor (GSVR) has great potential for process intensification, but its high gas consumption can be a disadvantage. In this study, a novel design called stator-rotor vortex chamber (STARVOC) was demonstrated to decouple the rotation of solids bed and gas. The hydrodynamics of gas-solid fluidization were investigated using air and monosized aluminum balls. It was found that the bed can only be fluidized within a certain range of rotation speed, and increasing the air flow rate or rotation speed can resolve axial nonuniformity. The study provides design guidelines and potential applications for further development of the STARVOC concept.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Green & Sustainable Science & Technology
Alok Dhaundiyal, Divine Atsu
Summary: A pilot size reactor was tested to examine its design suitability for effective gas generation. The thermal efficiency and chemical exergy of the reactor were calculated for different temperature ranges, showing higher efficiency for higher temperatures and dried biomass. The study aims to provide a clean energy generation method by improving the exergetic content of the reactor.
JOURNAL OF CLEANER PRODUCTION
(2021)
Review
Energy & Fuels
Huan Zhang, Naijian Song, Tao Yu, Chengtun Qu
Summary: Process intensification is one way to meet the increasing global energy demand and solve energy and environmental problems in the chemical industry. This article provides an overview of the development in gas-liquid mass transfer enhancement, analyzing classical mass transfer models and summarizing major enhancement methods. It also presents the most recent accomplishments in gas-liquid mass transfer engineering and offers suggestions for further enhancement.
Article
Engineering, Environmental
Lionel J. J. Catalan, Braeden Roberts, Ebrahim Rezaei
Summary: Due to its abundance and relatively low cost, natural gas will continue to be a common feedstock for methanol production. This study proposes a new method using natural gas pyrolysis in a catalytic liquid metal bubble reactor, combined with CO2 utilization. The process shows lower carbon emissions compared to traditional steam reforming processes, with the potential for negative emissions when using low-emission supply chains for natural gas and captured CO2. The estimated carbon production cost is well below the market price of carbon black in the United States.
CHEMICAL ENGINEERING JOURNAL
(2023)
Review
Engineering, Chemical
Laurens Van Hoecke, Dieter Boeye, Arturo Gonzalez-Quiroga, Gregory S. Patience, Patrice Perreault
Summary: Computational fluid dynamics (CFD) is the application of numerical methods to solve fluid flow problems. It is widely used in chemical engineering for various applications such as heat transfer, mass transfer, and combustion. This article reviews the basic theoretical concepts of CFD and demonstrates a simulation example using the open-source software OpenFOAM. The simulation results can be improved by increasing the number of cells.
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
(2023)
Article
Thermodynamics
Kevin De Ras, Marvin Kusenberg, Joris W. Thybaut, Kevin M. Van Geem
Summary: Oxymethylene ethers (OMEs) are synthetic compounds that can replace fossil fuels and contribute to a circular carbon economy. However, little is known about their thermal decomposition behavior. In this study, new insights into the pyrolysis chemistry of oxymethylene ether-2 (OME-2) and the role of carbenes were obtained through high-temperature experiments. The major products of OME-2 pyrolysis included dimethoxymethane, formaldehyde, methyl formate, methane, CO2, CO, and H2. A kinetic model was developed to simulate the experimental results and predict the major product trends.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Engineering, Chemical
Yannick Ureel, Florence H. Vermeire, Maarten K. Sabbe, Kevin M. Van Geem
Summary: Carbenium ions play important roles as intermediates in zeolite and plasma chemistry. Thermodynamic properties of these ions need to be incorporated into kinetic models, resulting in more accurate and general models for zeolite design and plasma process development.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Energy & Fuels
Liang Li, Ruben van de Vijver, Kevin M. Van Geem
Summary: The gas-phase pyrolysis kinetics of syringol, an abundant component in hardwood lignin, were studied using experimental and theoretical approaches. The experimental results revealed that 2,3-dihydroxybenzaldehyde is the most important phenolic product, along with the formation of significant pyrolytic water. The proposed decomposition pathways and the findings from the kinetic model provide new insights into the chemistry of syringyl species during pyrolysis.
Article
Engineering, Chemical
Hamed Mohamadzadeh Shirazi, Arezoo Ghanbari, Florence Vermeire, Marie-Francoise Reyniers, Kevin M. Van Geem
Summary: This study compared the coking tendencies of recently developed alloys to a conventional material at a higher temperature. The results showed that aluminum-containing alloys exhibited less coke formation and better stability against aging compared to non-aluminum-containing alloys. The protective oxide surface layer of the aluminum-containing alloys remained durable and showed no signs of carburization even at high temperatures. In contrast, the conventional alloy exhibited the highest coking rate and carburization.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Green & Sustainable Science & Technology
Waheed Zeb, Martijn Roosen, Pieter Knockaert, Sven Janssens, Daniel Withoeck, Marvin Kusenberg, Joel Hogie, Pieter Billen, Serge Tavernier, Kevin M. Van Geem, Steven De Meester
Summary: Valorisation of post-consumer plastic pyrolysis oil in steam crackers and their application as precursors to chemicals is hindered by the complexity of these oils, such as boiling range, fouling risk, and contaminations. Vacuum distillation effectively improved most properties of the distilled fractions, making it an essential downstream process step for the application of post-consumer plastic pyrolysis oils as feedstock in steam crackers and precursors to chemicals.
JOURNAL OF CLEANER PRODUCTION
(2023)
Review
Thermodynamics
Mehrdad Seifali Abbas-Abadi, Yannick Ureel, Andreas Eschenbacher, Florence H. Vermeire, Robin John Varghese, Jogchum Oenema, Georgios D. Stefanidis, Kevin M. Van Geem
Summary: Is full recyclability of polyolefins via chemical recycling a dream, or can it become a reality? The main problem in recycling plastic waste is its complexity and the need for large investments in sorting and purifying solutions. Novel chemical recycling processes can offer solutions to overcome these challenges and achieve higher value products. Thermal pyrolysis and catalytic pyrolysis have shown promise in this regard, but further research is needed to optimize the process and improve the purification and catalyst stability.
PROGRESS IN ENERGY AND COMBUSTION SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Dieter Ruijten, Thomas Narmon, Korneel Van Aelst, Hanne De Weer, Robbe van der Zweep, Tessy Hendrickx, Claude Poleunis, Lingfeng Li, Kevin M. Van Geem, Damien P. Debecker, Bert F. Sels
Summary: Functionalization of bio-based aromatics offers a renewable way of fulfilling chemical and materials needs. A Cu-catalyzed hydrogen borrowing strategy successfully functionalizes aliphatic alcohols in aromatic monomers and dimers derived from lignin. The stable lignin-derived tertiary amines display excellent antioxidant activity, highlighting the value of the hydrogen borrowing upgrading strategy.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Patrice Perreault, Laurens Van Hoecke, Hesam Pourfallah, Nithin B. Kummamuru, Cristian-Renato Boruntea, Patrick Preuster
Summary: This article discusses recent developments in the storage and release of hydrogen from liquid organic hydrogen carriers (LOHCs). It focuses on three areas: the application and development of alternative LOHC systems, process development and integration, and the electrochemical conversion of LOHCs. The article highlights the importance of reaction enthalpy, storage capacity, and power density in evaluating these systems. Further development is needed to improve energy efficiency, flexibility, and overall research maturity for commercial impact.
CURRENT OPINION IN GREEN AND SUSTAINABLE CHEMISTRY
(2023)
Article
Thermodynamics
Daniel A. Quintero-Coronel, Adalberto Salazar, Oscar R. Pupo-Roncallo, Antonio Bula, Lesme Corredor, German Amador, Arturo Gonzalez-Quiroga
Summary: Syngas from biomass-coal co-gasification has the potential to be used as a viable energy source for electricity production and industrial heating. This study evaluates the inter-changeability of syngas-natural gas blends in atmospheric burners and high-pressure combustion. The results show that syngas-natural gas blends with up to 15 vol % syngas can be used in atmospheric natural gas burners without modifications, and the methane number for these blends is higher than that of natural gas. This research highlights the potential of using syngas-natural gas blends in thermal applications and identifies areas for further research.
Article
Engineering, Environmental
Evangelos Delikonstantis, Panagiotis Vettas, Fabio Cameli, Marco Scapinello, Anton Nikiforov, Guy B. Marin, Kevin M. Van Geem, Georgios D. Stefanidis
Summary: The conversion of CO2 in steel mill off-gases to syngas using nanosecond pulsed discharges at atmospheric pressure is an effective way to reduce the environmental impact of the steelmaking process. Experimental results show that CO2 conversion is affected by H2 excess, interelectrode distance, and specific energy input (SEI). It is recommended to use a stoichiometric H2:CO2 feed ratio for higher energy efficiency.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Thermodynamics
L. dos S. Vargette, N. D. Ristic, M. Geerts, G. J. Heynderickx, G. B. Marin, K. M. Van Geem
Summary: The use of heavier feedstocks presents challenges in the steam cracking process due to severe fouling. The Fouling Assessment SeTup (FAST) was developed to understand fouling phenomenon and its relation to feedstock composition. The experimental unit determined fouling tendency in different sections of a steam cracker and tested a mitigation concept using paraffinic fluid injection in the transfer line heat exchanger (TLE) section, which substantially reduced fouling.
HEAT AND MASS TRANSFER
(2023)
Article
Engineering, Chemical
Siyuan Chen, Paulien Malego, Kevin M. Van Geem, Yi Ouyang, Geraldine J. Heynderickx
Summary: Gas-liquid vortex units (GLVUs) have potential for solvent-based applications due to their exceptional multiphase mixing and mass transfer performance. Computational fluid dynamics (CFD) simulations are used to optimize the design of GLVU geometry and operating conditions. The optimized designs show significant improvement in gas-liquid contact time and energy consumption efficiency.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Green & Sustainable Science & Technology
Oleksii Mynko, Mike Bonheure, Ismael Amghizar, David J. Brown, Lin Chen, Guy B. Marin, Rodrigo Freitas de Alvarenga, Didem Civancik Uslu, Jo Dewulf, Kevin M. Van Geem
Summary: In the Chemical Process Industry (CPI), hydrogen production from steam methane reforming is the only process that emits more greenhouse gases than light olefins production. Various solutions have been proposed to reduce CO2 emissions from olefins production, but it is unclear which solution is the best. In this study, we conducted a life cycle assessment (LCA) to compare three highly promising solutions: a low-emission steam cracking furnace, an electrically driven RotoDynamic reactor (RDR), and a blue hydrogen-fired furnace.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Engineering, Chemical
Michiel Van Melkebeke, Tobias De Somer, Tine Van Laere, Thien Nguyen Luu Minh, Hamed Mohamadzadeh Shirazi, Hilde Poelman, Kevin Van Geem, Steven De Meester
Summary: This study explores the potential of using adsorption in a non-aqueous environment as a novel approach for plastic waste dissolution recycling. The results suggest that activated charcoal can effectively remove dyes but has weak adsorption capacity for polystyrene. The adsorption process is predominantly driven by physical forces and is an endothermic process.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Chemistry, Analytical
Guanshuai Zhang, Shanjian Liu, Dongmei Bi, Zhisen He, Jia Liu, Yinjiao Liu
Summary: Hydrogen peroxide pretreatment was applied for fast pyrolysis of corn stalks, and it was found that the pretreatment effectively promoted lignin depolymerization and decreased the reaction activation energy. The pretreatment also increased the cellulose content and removed alkali and alkaline earth metals from the biomass. The pH of the hydrogen peroxide solution affected the removal of lignin and ash by the pretreatment, and the composition of bio-oil changed significantly, with a significant increase in the relative content of levoglucosan after pretreatment.
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
(2024)