Article
Physics, Multidisciplinary
Etienne Jambon-Puillet, Pier Giuseppe Ledda, Francois Gallaire, P-T Brun
Summary: When the substrate is slightly tilted, the conventional growth of pendant drops is unexpectedly reversed, leading to drops that move too fast to grow and shrink. Through experiments and numerical simulations, the transition between the conventional growth regime and the previously unknown decay regime can be rationalized, with the critical inclination angle for the transition quantitatively predicted using analytical treatment of the Landau-Levich meniscus connecting the drop to the film.
PHYSICAL REVIEW LETTERS
(2021)
Article
Agricultural Engineering
Yuan Liu, Shiliang Wu, Huiyan Zhang, Rui Xiao
Summary: Combining torrefaction with fast pyrolysis is a feasible method for producing long-chain ether precursors. Structural characterization results showed that torrefaction led to a decrease in crystallinity index and the elimination of hydroxyls, ether bonds, etc., but an increase in carbonyls. The production of small-molecule gases was reduced after torrefaction, while the yield of targeted compounds in bio-oil significantly improved, with 240CS providing the highest carbon yield.
BIORESOURCE TECHNOLOGY
(2021)
Article
Green & Sustainable Science & Technology
Athanasios Dimitriadis, Loukia P. Chrysikou, George Meletidis, George Terzis, Milos Auersvald, David Kubicka, Stella Bezergianni
Summary: This study investigated the upgrading of pyrolysis bio-oil through mild hydrotreatment, finding that the longest catalyst life was achieved under specific operating conditions. Furthermore, several properties of the initial bio-oil were improved during the upgrading process.
Article
Energy & Fuels
Harsha Mysore Prabhakara, Eddy A. Bramer, Gerrit Brem
Summary: The study showed that hydrotalcite had the best catalytic effect, forming moderately deoxygenated compounds, followed by dolomite. The Na2CO3 loading on gamma-alumina had a noticeable effect on reducing acids.
Article
Thermodynamics
Erwei Leng, Ben He, Jingwei Chen, Gaoliang Liao, Yinjie Ma, Feng Zhang, Shuai Liu, E. Jiaqiang
Summary: By establishing regression prediction models, this study shows that the random forest algorithm is suitable for predicting three-phase product distribution and bio-oil heating value, with significant impacts from factors such as pyrolysis temperature, carbon, and hydrogen content.
Article
Thermodynamics
Wasel-Ur Rahman, Madhumita Patel, Vinoj Kurian, Amit Kumar
Summary: The conversion of municipal solid waste to transportation fuels through thermochemical conversion processes has the potential to reduce greenhouse gas emissions. Different production configurations and upgrading techniques result in different production costs for gasoline, diesel, and jet fuel. The study provides valuable information for the development and investment in these technologies to address the barriers and opportunities.
ENERGY CONVERSION AND MANAGEMENT
(2022)
Article
Engineering, Marine
A. A. Boryaev
Summary: This paper presents a mathematical model for water flow around a ship, taking into account the presence of gas bubbles. The study shows that the presence of gas bubbles leads to a reduction in liquid pressure and an increase in ship subsidence, which is directly related to flow velocity.
Review
Energy & Fuels
Anja Oasmaa, Jani Lehto, Yrjo Solantausta, Sirpa Kallio
Summary: The review summarizes VTT's development efforts in fast pyrolysis over the past 40 years, showcasing a wide range of feedstocks and products tested. Plastic wastes are currently seen as the most promising industrial opportunity in this field.
Article
Chemistry, Applied
A. A. Smirnov, M. Alekseeva, A. N. Grachev, O. O. Zaikina, S. A. Selishcheva, O. A. Bulavchenko, M. Shashkov, Yu A. Chesalov, V. A. Yakovlev
Summary: Hydrotreatment of birch wood pyrolysis liquid was conducted using Ni-based catalysts stabilized by SiO2, with the addition of Cu, Mo, Cr, and P additives for modification. MoCr-containing system showed higher yield of the aqueous phase and lower O/C ratio, while P-modified catalysts exhibited more intense CO2 formation and reduced oxygen content in the organic phase. The catalysts were characterized by various methods to evaluate their performance and stability.
Article
Thermodynamics
Hengwei Zhang, Yao Xiao, Xu Yan, Hanyang Gu
Summary: This paper introduces a novel model for fast prediction of void fraction distribution in two-phase pipe flow. The model simplifies the N-S equations and calculates the void fraction distribution by balancing interfacial forces, providing both practical applications and fast computing time.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Energy & Fuels
Zheng Qiao, Yu Lv, Jean-Pierre Hickey
Summary: The study focuses on the single-phase instability of high-pressure, steady, laminar counterflow diffusion flame, with specific emphasis on the middle branch solutions characteristic of intermediary combustion states. The combustion states are influenced by operating pressure and inlet temperature, while the size and location of instability regions in the flame are determined by water vapor concentration and temperature.
Article
Chemistry, Analytical
Mario Sanchez, Juan C. Maya, Brennan Pecha, Farid Chejne, Adriana M. Quinchia-Figueroa
Summary: A low computational cost model was used to study the effect of various factors on biomass anisotropic particle pyrolysis. The model considered shrinking anisotropic particles with biomass pseudo-components, liquid intermediates, and secondary reactions. The results showed that considering the change of particle thermal conductivity anisotropy and the temperature dependency of thermal conductivities improved the accuracy of mass loss prediction. The CRECK pyrolysis reaction scheme provided insights into the evolution of liquid intermediates. Secondary intraparticle vapor phase reactions had a negligible effect on volatiles conversion, while heterogeneous reactions slightly overestimated its conversion. Heats of reaction and product advection were important for accurate prediction of particle mass loss.
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
(2022)
Article
Chemistry, Multidisciplinary
Jungjae Park, Hyeongseop Jeong, Namgyu Noh, Ji Su Park, Sanghyeon Ji, Sung Kang, Yoon Huh, Jaekyung Hyun, Jong Min Yuk
Summary: Single-molecule techniques, such as graphene liquid cell transmission electron microscopy (GLC-TEM), provide new insights into biological processes by offering unprecedented resolution and extended observation periods. GLC-TEM allows for the real-time investigation of structural perturbations in intact amyloid fibrils, revealing the role of these perturbations in the formation of different amyloid polymorphs. The ability to observe structural behavior in real time makes GLC-TEM a complementary approach to other single-molecule techniques.
ADVANCED MATERIALS
(2023)
Article
Optics
Linpei Xue, Yihan Jin, Steve J. Elston, Stephen M. Morris
Summary: This paper investigates the optical phase modulation potential of a nematic liquid crystal (LC) π-cell in the symmetric H (Hs) state. Experimental results of optical phase modulation using a phase-shifting Michelson interferometer are compared with simulation results using the Ericksen-Leslie continuum theory. The stability of the Hs state is studied by adjusting the applied voltage and the voltage burst duration. The LC pi-cell driven into the Hs state using a short burst voltage shows excellent phase modulation capability in achieving full 2n phase modulation with a 1 ms timescale in a reflective geometry.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Engineering, Environmental
Chuan Ma, Xie Shengyu, Shogo Kumagai, Yusuke Takahashi, Yuko Saito, Tomohito Kameda, Toshiaki Yoshioka
Summary: The co-pyrolysis of biomass and waste plastics can enhance the production of fuels and valuable chemicals, with PE and PP blends showing different behaviors in terms of weight loss and decomposition. The GP mode of the co-pyrolysis process resulted in significantly increased yields of gasoline and kerosene by enhancing cracking of PE intermediates, while the LSP mode inhibited rearrangement reactions of PP intermediates, leading to more wax products being converted into liquid.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Engineering, Chemical
Jader Alean, Farid Chejne, Say Ramirez, Edgar Rincon, Andres F. Alzate-Arbelaez, Benjamin Rojano
Summary: In this study, the oxidation of polyphenols during the drying of cocoa beans using microwaves was investigated. Quantitative analysis and color level measurement were performed to study the degradation of polyphenols during drying, revealing that the process is due to in-situ oxidative reactions rather than a transport mechanism.
Article
Energy & Fuels
Carlos F. Valdes, Jorge Montoya, Carlos A. Gomez, Hernando Chaquea, M. Brennan Pecha, Farid Chejne
Summary: The gasification of pelletized and dry-ground EFB can achieve autothermal operating conditions at certain ER values, while wet EFB can achieve this condition at any ER value. The average composition of the syngas from pelletized EFB showed the best performance when the ER values were between 0.25 and 0.40.
Review
Energy & Fuels
Carlos F. Valdes, Carlos A. Gomez, Michel Ortiz, David Mena, Ricardo Ruiz, Kevin Cogollo, John Mira, Farid Chejne
Summary: This study evaluates the energy value of fique bagasse waste through combustion and gasification, demonstrating its potential as a fuel source. The combustion process shows high thermal efficiency and energy utilization, while gasification produces high-quality synthesis gas suitable for power generation or as a heat source.
BIOMASS CONVERSION AND BIOREFINERY
(2023)
Article
Energy & Fuels
Carlos F. Valdes, Carlos A. Gomez, Farid Chejne, Alfredo Marin-Jaramillo, Jorge Franco-Ocampo, Liliana Norena-Marin
Summary: This study analyzes the impact of agro-industrial waste pellets and pine bark chips on energy performance and identifies synergistic effects through co-processing. These effects improve performance indicators commonly used for waste energy assessment and contribute to environmental and operational improvements.
BIOMASS CONVERSION AND BIOREFINERY
(2023)
Article
Biotechnology & Applied Microbiology
Matthew R. Wiatrowski, Abhijit Dutta, M. Brennan Pecha, Meagan Crowley, Peter N. Ciesielski, Daniel Carpenter
Summary: The study investigated the impact of feedstock attributes of lignocellulosic biomass on fast pyrolysis-based conversion processes. It was found that variations in ash content had the biggest impact on the minimum fuel selling price, which could be mitigated by controlling ash levels and increasing extractives in forest residues. Other inputs such as particle size, moisture content, and reactor temperature had relatively negligible effects on process economics within the ranges analyzed considering particle-scale effects alone.
BIOFUELS BIOPRODUCTS & BIOREFINING-BIOFPR
(2022)
Article
Food Science & Technology
Myriam Rojas, Arne Hommes, Hero Jan Heeres, Farid Chejne
Summary: The quality of cocoa depends on its origin and processing, and the roasting process plays a critical role in developing its aroma and flavor. Various factors, such as heating rate, particle size, and inert atmospheres, have unknown effects on cocoa quality. Further research is needed to understand the energy, mass, and chemical kinetic transfer phenomena in roasting and their impact on process parameters.
FOOD ENGINEERING REVIEWS
(2022)
Review
Engineering, Mechanical
Javier Ordonez-Loza, Carlos Gomez, Farid Chejne
Summary: This work presents a mathematical model for ignition delay time using a zero-dimensional reactor under adiabatic and isochoric assumptions. The model reveals the impact of CO2 on the combustion of syngas and examines the role of H and O radicals in oxidation under oxy-fuel conditions. The study provides insights into the thermal and chemical characteristics, as well as the reaction pathway, and shows good agreement with experimental data.
JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING
(2022)
Article
Engineering, Chemical
Omar Estrada, Farid Chejne Janna
Summary: This article introduces a novel polymer melting mechanism and model called mechanically induced transition layer removal, which explains the enhanced behavior in terms of melting capacity, output, and energy efficiency of single screw Grooved Plasticating Extruders (GPE). The proposed model shows a considerable improvement in plasticizing speed and describes the phenomenology of the plasticization process in GPE. This mechanism has the potential to accurately describe how this type of technology operates and help improve and design new plasticizing units.
POLYMER ENGINEERING AND SCIENCE
(2022)
Review
Energy & Fuels
Farid Chejne, Carlos Martinez-Smit, Marlon Bastidas-Barranco, Manuel Garcia-Perez
Summary: This paper reviews some aspects of the formation of carbon nanostructures from compounds produced during biomass gasification, where tars can decrease the efficiency of the process.
Article
Computer Science, Interdisciplinary Applications
Dario Serrano-Florez, Whady Felipe Florez, Carlos Andres Bustamante, Farid Chejne
Summary: This study models and simulates a one-dimensional reverse osmosis (RO) water desalination system and applies it to water sources from La Guajira, Colombia. The results show that electric power produced from renewable sources can meet the energy needs of remote areas and can be used for water desalination to improve the quality of life.
COMPUTERS & CHEMICAL ENGINEERING
(2023)
Article
Engineering, Electrical & Electronic
Clara Rojo Ceballos, Farid Chejne, Ernesto Perez, Andres Osorio, Alexander Correa
Summary: In order to study the behavior of low voltage ZnO varistors against Very Fast Transient Overvoltage (VFTO), the authors developed a complete VFTO(s) generation and measurement system based on magnetic pulse compression (MPC) and Transmission Line Transformer (TLT). The experimental methodology presented in this work allows observation of the response of low voltage ZnO varistors against VFTO, indicating their poor performance. This method can assist manufacturers and consumers in taking corrective measures in case of malfunction or damage.
ELECTRIC POWER SYSTEMS RESEARCH
(2023)
Article
Energy & Fuels
Raiza Manrique, Evan Terrell, Pavlo Kostetskyy, Farid Chejne, Mariefel Olarte, Linda Broadbelt, Manuel Garcia-Perez
Summary: This study evaluates the impact of the positions and bonding of guaiacyl (G) and syringyl (S) units in a hardwood lignin model on the oligomer structures. Dimer, trimer, and tetramer structures are proposed. The study suggests that homolytic cleavage of β-O-4 bonds can generate free radical fragments that can stabilize by combining with hydrogen radicals. Alternatively, intramolecular hydrogen bonding can stabilize the radicals. The calculated thermophysical properties and spectroscopic evaluation provide insights into the formation of lignin oligomers, which are valuable for the development of pyrolysis oil separation and upgrading equipment.
Article
Engineering, Chemical
Esteban Largo-Avila, Carlos H. Suarez-Rodriguez, Juan C. Maya, Hector J. Ciro-Velasquez, Farid Chejne
Summary: This study investigates the effects of solar drying and mechanical drying on the concentration of sucrose and fatty acids in coffee beans. It demonstrates that a shorter drying time leads to an increase in the concentration of these chemical compounds.
JOURNAL OF FOOD PROCESS ENGINEERING
(2023)
Article
Engineering, Chemical
Juan C. Maya, Farid Chejne, Carlos A. Gomez, Jorge Montoya, Hernando Chaquea, Brennan Pecha
Summary: This article analyzes the main variables related to the performance of a proton exchange membrane-type electrolyzer and the risk of explosion for different operating conditions. A novel mathematical model is developed that considers all mass transport phenomena in the membrane electrode assembly (MEA) and water evaporation in the anode and cathode channels. The findings show that the electrolyzer cannot function safely throughout the day under a solar energy supply operating at high pressure, due to low current densities favoring high hydrogen concentrations at the anode. Additionally, greater membrane thickness increases the explosion risk.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2023)
Article
Food Science & Technology
Myriam Rojas, Jessi Osorio, Hero Jan Heeres, Farid Chejne
Summary: This study aims to understand the kinetics and chemical composition of volatile compounds formed during cocoa roasting. By using thermogravimetric analysis and gas chromatography-mass spectrometry, the researchers identified the formation of various aromatic compounds at intermediate temperatures and established a reaction network for cocoa roasting.
ACS FOOD SCIENCE & TECHNOLOGY
(2022)
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)
