Article
Energy & Fuels
Dan Gall, Jan Viljanen, Ivan Gogolev, Thomas Allguren, Klas Andersson
Summary: This study rigorously calibrated and assessed a surface ionization detector (SID) for alkali monitoring in industrial process gases and compared it to an in situ laser diagnostic method called collinear photofragmentation and atomic absorption spectroscopy (CPFAAS). Findings showed good agreement between SID and CPFAAS in detecting KCl concentration, with significant differences in sensitivity towards different alkali salts. The results demonstrated the capability and limitations of the SID in monitoring KCl levels in process gases.
Article
Thermodynamics
Emil Thorin, Alexey Sepman, Yngve Ogren, Charlie Ma, Markus Carlborg, Jonas Wennebro, Markus Brostrom, Henrik Wiinikka, Florian M. Schmidt
Summary: Photofragmentation tunable diode laser absorption spectroscopy (PF-TDLAS) was used to simultaneously measure the concentrations of gas phase atomic potassium (K), potassium hydroxide (KOH) and potassium chloride (KCl) in the reactor core of a gasifier. The results showed differences in the behavior of K species between gasification and combustion processes, with gasification being dominated by hydrogen reactions. Short-term variations in K species concentrations were observed due to fuel feeding, and a gradual increase in KOH(g) over time. The comparison between different fuel types revealed higher total K in the gas phase for the FR/WS mixture.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
Wubin Weng, Marcus Alden, Zhongshan Li
Summary: Two-dimensional laser-induced photofragmentation fluorescence (LIPF) was used to visualize the vapor of potassium hydroxide (KOH) and potassium chloride (KCl) in the plume above burning wood and straw pellets. Different techniques were employed to measure the potassium concentration, elemental potassium concentration, and surface temperature during combustion. The results showed that the release of potassium species depended on the combustion stage and the composition of the fuel. Evaluating the importance and relevance of identifying the release behavior of potassium during biomass combustion is critical for understanding the formation of alkali-related problems and optimizing combustion processes.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Review
Chemistry, Applied
Juntao Wei, Miao Wang, Deliang Xu, Lei Shi, Bin Li, Yonghui Bai, Guangsuo Yu, Weina Bao, Jie Xu, Hong Zhang, Shu Zhang
Summary: This paper provides a detailed summary of the main detection methods for the migration and transformation of alkali/alkaline earth metal species (AAEMs) during biomass and coal co-gasification. It systematically reviews the influencing factors and proposes pathways for the migration and transformation of AAEMs. Furthermore, it discusses the relationship between AAEMs migration and transformation and the synergy of co-gasification.
FUEL PROCESSING TECHNOLOGY
(2022)
Article
Energy & Fuels
Saiman Ding, Yaxin Ge, Efthymios Kantarelis, Xiangrui Kong, Jan B. C. Pettersson, Klas Engvall
Summary: This study investigates time-resolved char conversion and alkali release under steam gasification conditions using a fixed bed reactor. The study finds that woody chars exhibit increased gasification reactivity and notable alkali release as gasification approaches completion, while straw chars show decreased conversion rate and alkali release throughout the gasification process.
Review
Chemistry, Applied
Junqin Yu, Qinghua Guo, Yan Gong, Lu Ding, Jiajian Wang, Guangsuo Yu
Summary: The effects of alkali and alkaline earth metals on the component and distribution of products, gasification reactivity, catalytic mechanism, and char-ash/slag transition during biomass gasification were reviewed. Studies show that the catalytic role of AAEM in biomass gasification is significant, impacting product distribution, gasification reactivity, and char-ash/slag transition.
FUEL PROCESSING TECHNOLOGY
(2021)
Article
Thermodynamics
Wubin Weng, Marcus Alden, Zhongshan Li
Summary: In this study, a species-specified quantitative measurement of potassium hydroxide (KOH) in combustion environments was conducted using laser-induced photofragmentation fluorescence (LIPF) technique. The most proper light source, the fourth-harmonic of Nd:YAG laser at 266 nm, was found after direct comparison. The detection limit of the LIPF planar imaging system was determined to be about 3 ppm, and the technique was applied to quantitatively measure KOH concentration in hot flue gases and visualize the distribution of KOH vapor.
COMBUSTION AND FLAME
(2022)
Article
Energy & Fuels
Lei Deng, Xiaole Huang, Yuan Tie, Jiahao Jiang, Kai Zhang, Shihao Ma, Defu Che
Summary: A fixed-bed reactor was used to simulate CO2 gasification and examine the transformation of alkali and alkaline earth metals (AAEMs) in biomass. The study found that the release of AAEMs followed a specific sequence and the alkali metals mainly appeared as water-soluble inorganic salts. Higher temperatures led to the formation of compounds with other elements. Larger particle sizes were beneficial for the transformation of potassium from water-soluble to organic forms, particularly in candlenut wood.
JOURNAL OF THE ENERGY INSTITUTE
(2022)
Article
Energy & Fuels
Wei Yi, Xianhua Wang, Kuo Zeng, Haiping Yang, Jingai Shao, Shihong Zhang, A. Paul Watkinson, Hanping Chen
Summary: In this study, the effect of medium temperature devolatilization (MTD) on biomass gasification kinetics was investigated. Isothermal steam gasification experiments were performed on corn stalk and its MTD-chars. It was found that the influences of alkali and alkaline earth metal (AAEM) on the gasification process varied under different conversion rates, which resulted in fitting errors for the random pore model. Therefore, a semi-empirical kinetic model called RPM+ was developed to accurately describe the catalytic effects of AAEMs on biomass gasification. This study is significant for the simulation and design of biomass staged gasification processes, as well as the high-value utilization of biomass with high AAEMs content through gasification.
Article
Agricultural Engineering
Muhammad Mahmood Khan, Shaoping Xu, Chao Wang
Summary: In this study, gasification of biomass using a decoupled dual loop gasification system was investigated. The effects of process variables on product gas composition, heating value, tar content, yield, conversion, and efficiency were studied. It was found that controlling temperature, S/B, and ER could improve the quality and efficiency of gasification.
BIOMASS & BIOENERGY
(2022)
Article
Chemistry, Applied
Liqun Ma, Syed Shatir A. Syed-Hassan, Junbo Zhou, Wei Deng, Yimin Xiong, Xuepeng Wang, Xun Hu, Jun Xu, Long Jiang, Sheng Su, Song Hu, Yi Wang, Jun Xiang
Summary: Stable free radicals are long-lived macromolecule radicals formed in pyrolysis and play a crucial role in biochar formation. The presence of alkali and alkaline earth metals (AAEMs) in biomass can affect the reactions of stable free radicals during pyrolysis. This study used in-situ electron paramagnetic resonance (EPR) spectroscopy to analyze the effect of AAEMs on stable free radicals in cocoanut pyrolysis, and found that AAEMs enhanced the activity of stable free radicals and promoted radical-radical coupling.
FUEL PROCESSING TECHNOLOGY
(2023)
Article
Green & Sustainable Science & Technology
Ruihan Dong, Shiliang Yang, Jianhang Hu, Fangjun Chen, Guirong Bao, Hua Wang
Summary: This study numerically investigates the gas-solid reactive flow in the biomass gasification of the fuel reactor in a chemical looping combustion system. The results show that the distribution of solid phase is non-uniform, the residence time of biomass is skewed, and the gas products exhibit a wide range of variations.
Article
Environmental Sciences
Wei Su, Miaomiao Zhao, Yi Xing, Hongzhi Ma, Ping Liu, Xinyan Li, Hongshuo Zhang, Yingji Wu, Changlei Xia
Summary: The high moisture content and heavy metal concentration of hyperaccumulator plants pose challenges for resource utilization. This study applied supercritical water gasification technology to convert a hyperaccumulator plant, Sedum plumbizincicola, into hydrogen gas and immobilize heavy metals in biochar. The addition of alkali metal catalysts, such as NaOH, Na2CO3, and Ca(OH)(2), improved the experimental conditions. The results showed that NaOH effectively captured CO2 and enhanced hydrogen production. Additionally, the alkali catalyst promoted heavy metal stabilization. The study highlights the potential of SCWG with alkali catalyst for hydrogen production and heavy metal immobilization.
ENVIRONMENTAL RESEARCH
(2022)
Article
Chemistry, Applied
Dongxu Cui, Shiliang Wu, Sang Jun Yoon, Youn-Sang Bae, Bugae Park, Rui Xiao
Summary: This study found that a light potassium carbonate load can improve the peak power density of a solid oxide fuel cell, but the peak power density gradually decreases with increasing load time. Through electrochemical impedance spectroscopy and characterization methods, it was observed that potassium carbonate loads affect the anode catalytic reaction.
FUEL PROCESSING TECHNOLOGY
(2022)
Article
Engineering, Chemical
Feng Cheng, Xiuwei Li
Summary: This study investigated the temperature-programmed reduction of NiO/Al2O3 by in situ generated biochar from citric acid pyrolysis. The results showed that the reduction of NiO could be divided into two parts and the presence of Al2O3 support resulted in different reduction mechanisms.
Article
Thermodynamics
A. Vandersickel, W. G. Wedel, H. Spliethoff
APPLIED THERMAL ENGINEERING
(2020)
Article
Green & Sustainable Science & Technology
S. Eyerer, C. Schifflechner, S. Hofbauer, W. Bauer, C. Wieland, H. Spliethoff
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2020)
Article
Energy & Fuels
Bastian Alt, Daniel Klueh, Matthias Gaderer
Summary: Combustion plants using wooden biomass can help reduce the need for fossil energy, decreasing carbon emissions, but require separators like ESP to handle increased particulate matter. The study proposes a method using current and voltage data to calculate ESP efficiency, ensuring continuous functionality without high costs. It proves to be effective in calculating particle separation efficiency and helps operators meet legal requirements.
BIOMASS CONVERSION AND BIOREFINERY
(2021)
Article
Energy & Fuels
Katharina Koch, Bastian Alt, Matthias Gaderer
Article
Energy & Fuels
Bastian Alt, Daniel Klueh, Katharina Koch, Bernhard Huber, Matthias Gaderer
Summary: This paper discusses the importance of using biomass as a fuel in energy production to reduce CO(2) emissions. It also highlights the need for continuous monitoring of electrostatic precipitators (ESPs) to prevent increased particulate matter emissions. The paper presents an alternative methodology to define the effectiveness of the ESP using threshold values for current and voltage. The study aims to help legislative authorities determine reasonable threshold values through statistical evaluations and also explores the possibility of verifying the operation of the combustion system through flue gas temperature.
BIOMASS CONVERSION AND BIOREFINERY
(2022)
Article
Energy & Fuels
Florian Julian Lugauer, Josef Kainz, Matthias Gaderer
Summary: Storage technologies are crucial for the expansion of renewable energy production, with micro-hydro storage using a pump as a turbine offering promising potential for extending existing PV systems and enabling economically beneficial self-consumption. Simulation models and optimizers are used to determine the optimal economic operation of the pump-turbine system in combination with PV, leading to precise calculations of energy quantities and efficiency values critical to each operating strategy.
Article
Chemistry, Multidisciplinary
Bernd Gamisch, Matthias Gaderer, Belal Dawoud
Summary: This study investigates the redox reaction kinetics on iron oxide pellets under different operating conditions of thermochemical hydrogen storage. The iron oxide pellets showed stable redox performance, demonstrating potential for applications in urban areas as day-night or seasonal storage for green hydrogen.
APPLIED SCIENCES-BASEL
(2021)
Article
Green & Sustainable Science & Technology
Peter Steininger, Matthias Gaderer, Belal Dawoud
Summary: The numerical parameter sensitivity analysis of the design parameters of the solar selective thermal insulation system (SATIS) revealed that reducing the length of the glass closure element can effectively enhance insulation properties, while increasing the area share of light conducting elements (LCEs) and decreasing their length-to-diameter (L/D) ratio are key parameters for improving solar gain. Additionally, a new methodology was developed for integrating computed solar gains of SATIS in 1D simulation tools, resulting in a radiant heat flow map for use as a heat source in 1D simulation models. Comparing the 1D and 3D models of inside wall heat fluxes showed a high yearly agreement of 98%.
Article
Energy & Fuels
Sebastian Gaertner, Daniel Rank, Michael Heberl, Matthias Gaderer, Belal Dawoud, Anton Haumer, Michael Sterner
Summary: The glass industry, as an energy-intensive sector, is facing challenges in meeting climate protection targets. This study investigates the integration of a Power-to-Hydrogen concept into established oxyfuel glass melting processes to reduce carbon dioxide emissions and increase energy demand. The results show promising potential for economic optimization of the proposed energy system in the future.
Article
Energy & Fuels
Bernd Gamisch, Lea Huber, Matthias Gaderer, Belal Dawoud
Summary: This work investigates the kinetic mechanisms of redox reactions of iron oxide/iron pellets and finds that the shrinking core model excellently describes the measured kinetic results. The oxidation reaction is less affected by temperature compared to the reduction process, while the concentration of the reacting gas has a significant impact on the oxidation reaction rate constant.
Article
Energy & Fuels
Sebastian Gaertner, Thomas Marx-Schubach, Matthias Gaderer, Gerhard Schmitz, Michael Sterner
Summary: The glass industry is facing the challenge of reducing CO2 emissions and integrating renewable energy sources due to the high demand for fossil energy. This paper presents a novel power-to-methane concept and focuses on methods for capturing CO2 from flue gases in the industry. Process simulation models are developed to investigate post-combustion CO2 capture, followed by a techno-economic evaluation. The results show that the designed CO2 capture plant has a smaller volume compared to absorption-based CO2 separation processes for power plants, and the cost of CO2 separation is lower than comparable industrial applications. However, there are technical restrictions related to solvent degradation and high oxygen content in flue gas compositions.
Article
Engineering, Chemical
Lingga Aksara Putra, Bernhard Huber, Matthias Gaderer
Summary: In a biogas plant, the concentration of acetic acid in the substrate plays a crucial role in determining the pH value and volume of biogas produced. However, it is not possible to measure the acetic acid concentration online due to the need for specialized laboratory equipment. This project aims to estimate the acetic acid concentration in a biogas substrate using NIR sensors and machine learning algorithms based on substrate intensities.
INTERNATIONAL JOURNAL OF CHEMICAL ENGINEERING
(2023)
Article
Green & Sustainable Science & Technology
Daniel Klueh, Wolfgang Waldmueller, Matthias Gaderer
Summary: The Kolbe electrolysis is a promising method to convert carboxylic acids into hydrocarbons for various applications. This study provides the first basic engineering design study on process development for continuously working processes, using thermophysical data for analysis.
CLEAN TECHNOLOGIES
(2021)
Article
Construction & Building Technology
Peter Steininger, Matthias Gaderer, Oliver Steffens, Belal Dawoud
Summary: The newly-developed solar active thermal insulation system (SATIS) achieves a highly-dependent total solar transmittance on the irradiation angle through the use of light-conducting elements and closing elements. Experimental and numerical investigations show that SATIS has different solar energy transmittances at various irradiation angles.
Article
Engineering, Environmental
Wolfgang Waldmuller, Szymon Herdzik, Matthias Gaderer
Summary: The combined filtration and phosphate leaching method enables efficient removal of phosphate and production of ash-reduced hydrochar for energetic utilization. Further development is needed for filtration performance and system integration to enable technical application.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2021)
