Article
Thermodynamics
Selin Armakan, Mihriban Civan, Sema Yurdakul
Summary: This study investigated the combustion characteristics and kinetics of various mixtures of raw and torrefied rose pulp and red pine sawdust with Elbistan lignite. The study found that the torrefaction process improves the fuel/combustion performance of the mixtures, and lignite addition further enhances the combustion behavior. The activation energy of the samples decreased with the torrefaction process.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Thermodynamics
D. Vamvuka, M. Diamantaki, S. Sfakiotakis
Summary: The study found that torrefaction delayed ignition and reduced the reactivity of biomass fuels, while blending with lignite improved the reactivity of lignite. The developed parallel reactions model accurately fitted the experimental results, indicating a higher similarity in mechanism of combustion and thermal behavior between torrefied biomass blends and lignite.
INTERNATIONAL JOURNAL OF GREEN ENERGY
(2022)
Article
Energy & Fuels
Jingkun Han, Dunxi Yu, Jianqun Wu, Xin Yu, Fangqi Liu, Minghou Xu
Summary: Torrefaction has different effects on the ash slagging behavior during biomass and coal co-combustion. Co-firing biomass with high-Ca coal reduces the ash slagging rate, while co-firing biomass with high-Si/Al coal exacerbates the slagging tendency. Torrefaction can reduce the ash slagging rate of sawdust but increase it for other fuels. Measures such as optimizing operation conditions, co-firing with high-Ca coals, and using additives are suggested to alleviate the ash slagging during torrefied herbaceous biomass combustion.
Article
Energy & Fuels
Jingkun Han, Dunxi Yu, Jianqun Wu, Xin Yu, Fangqi Liu, Minghou Xu
Summary: Torrefaction technology has positive effects on ash fouling during biomass combustion and co-combustion. The interactions between fuels during co-combustion inhibit the formation of inside fouling deposits while the incorporation of alkalis in aluminosilicates promotes the growth of outside deposits. Torrefaction reduces the formation of chlorides and sulfates, thus inhibiting the inside deposition. However, the elemental repartitioning during torrefaction leads to more retention of alkalis, which aggravates the formation of mixed aluminosilicates and favors the outside deposition.
Article
Agricultural Engineering
Xudong Yang, Zhongyang Luo, Bichen Yan, Yinchen Wang, Chunjiang Yu
Summary: This study investigated the migration and transformation of nitrogen during biomass torrefaction combined with coal co-combustion. The XPS analysis showed that torrefaction in CO2 suppressed the conversion of nitrogen components. Additionally, torrefaction in a N2/O2 atmosphere at a lower temperature improved biomass properties and reduced NO emissions during co-combustion.
BIORESOURCE TECHNOLOGY
(2021)
Article
Engineering, Environmental
Jinhao Zheng, Lei Liao, Rui Liu, Chongcong Li, Yan Zhang
Summary: This study explored a promising approach to co-manage torrefaction condensates (TCs) and carbon-rich fly ash (FA), finding that the blending of FA and TC improved CO2 gasification reactivity and combustion performance of the resulting mixtures.
Article
Energy & Fuels
Yanquan Liu, Wenyi Tan, Shaohua Liang, Xiaolong Bi, Rongyue Sun, Xiaojun Pan
Summary: Co-combustion of torrefied cornstalk with different rank coals can decrease the ignition temperatures of coals and exhibit both synergistic and anti-synergistic interactions. The coal/torrefied cornstalk blends show better combustion performance and lower NOx and SO2 emissions than pure coals.
BIOMASS CONVERSION AND BIOREFINERY
(2022)
Article
Energy & Fuels
Kun Dong, Zhongfa Hu, Yuan Xue, Yuegui Zhou, Tingzhou Lei, Zhanjun Cheng
Summary: This study investigated the combustion characteristics of lignite after torrefaction treatment using non-isothermal thermogravimetric analysis. The results showed that increasing the torrefaction temperature reduced the volatile content and increased the fixed-carbon. Torrefaction treatment significantly improved the combustion performance of lignite.
Article
Green & Sustainable Science & Technology
N. T. Sibiya, B. Oboirien, A. Lanzini, M. Gandiglio, D. Ferrero, D. Papurello, S. O. Bada
Summary: Wet torrefaction showed significant improvement in gasification properties of grass biomass with higher reactivity index and lower activation energy, likely due to the enhancement of pore structure and pore volume in the treated biomass.
Article
Energy & Fuels
Jingkun Han, Dunxi Yu, Jianqun Wu, Xin Yu, Fangqi Liu, Minghou Xu
Summary: Torrefaction is a promising technology for biomass utilization, but its effects on ash-related issues during combustion and co-combustion are seldom concerned. In this study, the authors conducted experiments to investigate the particulate matter (PM) emission during combustion of torrefied biomass. The results showed that torrefaction effectively reduced the release of sulfur and chlorine, and promoted the transformation of alkaline and alkaline earth metals (AAEMs) into less-reactive forms, leading to a reduction in PM1 emission.
Article
Engineering, Chemical
Artemy Nebyvaev, Dmitry Klimov, Artem Ryzhenkov, Mathieu Brule
Summary: This article proposes an innovative two-stage technology for biomass torrefaction to generate high-quality biochar as solid fuel, providing a promising solution for biomass combustion challenges. The technology reduces the build-up of deposits on fired surfaces and improves the efficiency of biomass boilers. Experimental results demonstrate the potential of this two-stage torrefaction process to enhance the solid fuel characteristics of biomass and promote the sustainability of biomass-fired power plants.
Article
Energy & Fuels
Sinem Ozsoy Aydemir, Hanzade Haykiri-Acma, Serdar Yaman
Summary: This study investigates co-combustion effects of coal and biochar, and finds that the properties and addition rate of biochar affect the combustion performance of coal, resulting in additive or synergistic interactions.
JOURNAL OF ENERGY RESOURCES TECHNOLOGY-TRANSACTIONS OF THE ASME
(2022)
Article
Energy & Fuels
Zhongzheng Xiao, Shuzhong Wang, Ming Luo, Jianjun Cai
Summary: Co-combustion of lignocellulosic biomass and coal has been recognized as a promising route to achieve carbon neutrality. In this study, the combustion characteristics of lignocellulosic biomass main components and lignite were investigated under air and oxy-fuel conditions. Cellulose and hemicellulose showed better combustion reactivity than lignite, while lignin had worse reactivity. Wood components had positive synergies with lignite on char oxidation.
Article
Energy & Fuels
Despina Vamvuka, E. Loukakou, C. Avgoustidis, A. Stratakis, F. Pavloudakis, S. Sfakiotakis
Summary: This study aimed to investigate the combustion behavior of lignite/woody biomass blends and evaluate their impact on combustion performance and deposition problems. The results showed that blending lignite with woody fuels improved combustion performance and exhibited synergistic interactions between the component fuels.
ENERGY SOURCES PART A-RECOVERY UTILIZATION AND ENVIRONMENTAL EFFECTS
(2023)
Article
Energy & Fuels
Melek Yilgin, Bedriye Hos, Dursun Pehlivan
Summary: The torrefaction of furniture work dusts and lignite blends was studied, showing that blend pellets exhibited similar combustion behavior to lignite. Volatile matter and carbon combustion periods were significantly influenced by blending raw or torrefied furniture work dusts with lignite.
JOURNAL OF ENERGY RESOURCES TECHNOLOGY-TRANSACTIONS OF THE ASME
(2021)
Article
Engineering, Chemical
E. Petrakis, E. Stamboliadis, K. Komnitsas
PARTICULATE SCIENCE AND TECHNOLOGY
(2017)
Article
Chemistry, Multidisciplinary
Evangelos Petrakis, Konstantinos Komnitsas
APPLIED SCIENCES-BASEL
(2018)
Article
Geochemistry & Geophysics
Kostas Komnitsas, Evangelos Petrakis, Olga Pantelaki, Anna Kritikaki
Article
Green & Sustainable Science & Technology
Konstantinos Komnitsas, Georgios Bartzas, Vasiliki Karmali, Evangelos Petrakis, Witold Kurylak, Grzegorz Pietek, Jaroslaw Kanasiewicz
Article
Environmental Sciences
Kostas Komnitsas, Evangelos Petrakis, Georgios Bartzas, Vassiliki Karmali
SCIENCE OF THE TOTAL ENVIRONMENT
(2019)
Article
Geochemistry & Geophysics
Evangelos Petrakis, Vasiliki Karmali, Georgios Bartzas, Konstantinos Komnitsas
Article
Geochemistry & Geophysics
Evangelos Petrakis, Georgios Bartzas, Konstantinos Komnitsas
Article
Environmental Sciences
Konstantinos Komnitsas, Lourdes Yurramendi, Georgios Bartzas, Vasiliki Karmali, Evangelos Petrakis
SCIENCE OF THE TOTAL ENVIRONMENT
(2020)
Article
Metallurgy & Metallurgical Engineering
E. Petrakis, K. Komnitsas
Summary: The main objective of batch grinding modeling is to estimate the product particle size distribution over time or specific energy input to the mill. A simplified approach based on the population balance model was proposed in this study to reliably predict the complete product size distribution. Experimental data revealed non-first-order behavior in grinding and the deviation from linear theory depends on the material tested. The proposed model was validated using distribution modulus, breakage rate parameter, and optimum values.
MINING METALLURGY & EXPLORATION
(2021)
Article
Geochemistry & Geophysics
Evangelos Petrakis, Konstantinos Komnitsas
Summary: The aim of this study was to evaluate the impact of different sizes of grinding media on the efficiency and energy savings of ferronickel slag milling. The results showed that coarse particles are ground more effectively than fines and there is an optimal grinding time and ball size for maximizing the desired size class volume fraction. Compared to using small size balls, using 25.4 mm balls or a mixed load of balls with varying sizes resulted in significant energy savings.
Article
Geochemistry & Geophysics
Vasiliki Karmali, Evangelos Petrakis, Georgios Bartzas, Konstantinos Komnitsas
Summary: This study investigated the valorization potential of Polish laterite leaching residues through alkali activation using NaOH and Na2SiO3 solutions. The results showed that AAMs with sufficient compressive strength were only produced when metakaolin was added. Various analysis methods were used to characterize the raw materials and AAMs, and the structural integrity and toxicity of the AAMs were assessed.
Article
Environmental Sciences
Konstantinos Komnitsas, Georgios Bartzas, Vasiliki Karmali, Evangelos Petrakis
Summary: This experimental study investigates the alkali activation of laterite leaching residues using a mixture of sodium hydroxide and alkaline sodium silicate solution as activators. The addition of metakaolin significantly increased the compressive strength of the alkali activated materials, while calcination of the residues had little effect on activation. The study explores the potential of using these materials in construction applications to improve environmental sustainability in the metallurgical sector.
Article
Metallurgy & Metallurgical Engineering
Evangelos Petrakis, Kostas Komnitsas
MINING METALLURGY & EXPLORATION
(2019)
Article
Geosciences, Multidisciplinary
Antonios Stratakis, Evangelos Petrakis, Nikolaos Katzagiannakis, Georgios Alevizos
APPLIED EARTH SCIENCE-TRANSACTIONS OF THE INSTITUTIONS OF MINING AND METALLURGY
(2020)
