Article
Energy & Fuels
Huifang Feng, Jingli Sun, Hui Jin, Jiajing Kou, Liejin Guo
Summary: The study found that adding phenol can increase coal gasification efficiency and inhibit char formation, leading to an increased hydrogen yield. Phenol effectively suppresses char formation and enhances char reactivity.
Article
Environmental Sciences
Chenyu Wang, Chaoyue Wu, Ursel Hornung, Wei Zhu, Nicolaus Dahmen
Summary: This study investigated the feasibility of inhibiting char and tar formation during supercritical water gasification of sewage sludge by additive addition. The results showed that different additives had varying effects on the formation of char and tar, with NaOH being the most effective inhibitor. Additionally, the addition of additives also had an impact on the hydrogen yield and gasification efficiency.
Article
Engineering, Environmental
Chenyu Wang, Wei Zhu, Xihui Fan
Summary: Supercritical water gasification (SCWG) is a promising technology for sewage sludge (SS) treatment, but char production has been a bottleneck. This study compared chars produced by SCWG and hydrothermal carbonization (HTC) to explore the feasibility of using char as an additional product in SCWG. Experimental results showed that humus is related to char formation, providing insights for further treatment or utilization of chars generated during SCWG of SS.
Article
Energy & Fuels
Chao Fan, Hui Jin
Summary: This study developed a 2D transient CFD-based model to investigate the conversion of char particles in supercritical water. The results showed that the conversion of char particles was restricted by particle size and temperature, and convection promoted the conversion by enhancing heat and mass transfer while causing irregular particle shape development.
Article
Engineering, Environmental
Lei Pang, Yingjuan Shao, Wenqi Zhong, Hao Liu
Summary: Pressurized oxy-coal combustion has potential for high efficiency and low cost CO2 capture. Increased pressure and oxygen concentration reduce burnout time of char particles and improve their reactivity and temperature. A combustion model shows pressure's impact on char burnout time.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Green & Sustainable Science & Technology
Weijing Ding, Hui Jin, Panpan Sun
Summary: This article investigates the diffusion behavior of free radicals in supercritical water using molecular dynamics simulation. The results show that higher temperatures promote free radical diffusion under supercritical water conditions, while lower pressure has a positive impact on diffusion coefficients for hydrocarbon radicals.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Thermodynamics
Yunan Chen, Lei Yi, Jiarong Yin, Hui Jin, Liejin Guo
Summary: The study investigated the supercritical water gasification of sewage sludge in a fluidized bed reactor, focusing on the effects of temperature on product distribution and gas compositions. It was found that increasing temperature enhanced the dissolution and hydrolysis of organic matter in the sludge, leading to increased gas production. Furthermore, temperature elevation also induced dehydrogenation and polymerization reactions, which could be explained by the Diels-Alder mechanism.
Article
Energy & Fuels
Aekjuthon Phounglamcheik, Markus Backebo, Ryan Robinson, Kentaro Umeki
Summary: This study investigates the influences of intraparticle and interparticle diffusions on the reaction rates of char gasification in a packed bed without forced convective flows. It was found that at the particle scale, gasification rate decreased with the increase of particle size when the reaction was controlled by intraparticle diffusion, while at the bed scale, void fraction and tortuosity of the packed bed were influential parameters on diffusivity of CO2 through the bed channels. The diffusion resistances at particle and bed scales are sensitive to different size fractions in the PSD.
Article
Thermodynamics
Mohammed N. Asheruddin, Anand M. Shivapuji, Srinivasaiah Dasappa
Summary: This work presents experimental and numerical investigations on the conversion of biomass char in a thermal environment dominated by H2O. The study establishes that a temperature above 730°C is when char conversion becomes practically relevant, with a rate of 0.4 mg min-1 °C-1. The mass loss rate of char particles with different sizes is studied under various temperatures, H2O concentrations, and their combinations, showing that increasing temperature and reactant concentration reduces conversion time scales. The presence of H2 is found to inhibit the char-steam reaction, and the CO+H2O reaction plays a pivotal role in controlling char conversion.
Article
Green & Sustainable Science & Technology
Cui Wang, Chao Zhu, Jianbing Huang, Linfeng Li, Hui Jin
Summary: This study investigates the efficiency improvement strategies for supercritical water gasification of depolymerization slag, showing that adding oxidants and increasing reaction temperature can significantly enhance hydrogen yield and gasification efficiency.
Article
Chemistry, Applied
Lin Li, Shuai Tong, Lunbo Duan, Changsui Zhao, Zhipeng Shi
Summary: By comparing chars produced under different atmospheres, it was found that the pore structure and specific surface area of chars are significantly affected by the gasification environment, while the presence of chemical groups has a minor impact on the chars. The best gasification reactivities were obtained on the chars produced under 50%CO2/50%N2 and 50%H2O/50%N2 atmospheres, largely influenced by the porosity of the chars.
FUEL PROCESSING TECHNOLOGY
(2021)
Article
Energy & Fuels
Robert Schwarz, Stefan DeYoung, Hartmut Spliethoff
Summary: Accurate knowledge of reaction rate, diameter, and density is crucial for CFD simulations of gasifiers. The study compared a new shell model approach with the common modeling method based on power law relations, showing that modifications may be needed for better accuracy in certain cases.
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.
Article
Energy & Fuels
Shirish Kumar Sharma, Anand M. Shivapuji, S. Dasappa
Summary: This study focuses on char gasification in steam for generating syngas in a two-stage gasification technology for high-ash coal. Controlled experiments were conducted to investigate the dependence of char reactivity on temperature, gas composition, flow rate, and carbon conversion rate. The results showed that small particles have higher reactivity compared to bigger particles, making them suitable for pilot-scale operations. Pilot-scale experiments were also carried out in an oxy-steam environment, and the results were compared to simulated experiments for small particles. The addition of oxygen with steam improved the reactivity of char gasification, but led to a decrease in the calorific value of the gas.
Article
Chemistry, Applied
Yaxin Ge, Saiman Ding, Xiangrui Kong, Efthymios Kantarelis, Klas Engvall, Marcus Ohman, Jan B. C. Pettersson
Summary: Online alkali measurements using surface ionization were conducted to investigate alkali release during heating of industrial fluidized bed materials and gasification of biomass-based char and bed material mixtures. The results indicate that alkali release from the bed materials starts at 820 C and increases with temperature, time, and the presence of CO2. It was also observed that the char absorbs significant amounts of alkali from the used bed material. Furthermore, the migration of other important inorganic elements enhances initial alkali release and char reactivity, but reduces during the final stage of gasification.
FUEL PROCESSING TECHNOLOGY
(2022)
Article
Energy & Fuels
Nattacha Paksung, Junichi Kato, Yutaka Nakashimada, Yukihiko Matsumura
JOURNAL OF THE JAPAN PETROLEUM INSTITUTE
(2018)
Article
Multidisciplinary Sciences
Hirokazu Takahashi, Masahiko Ohkawachi, Kyohei Horio, Toshiro Kobori, Tsunehiro Aki, Yukihiko Matsumura, Yutaka Nakashimada, Yoshiko Okamura
SCIENTIFIC REPORTS
(2018)
Article
Chemistry, Physical
Shuhei Inoue, Yoshihiro Tomita, Takuya Kokabu, Yukihiko Matsumura
CHEMICAL PHYSICS LETTERS
(2018)
Article
Energy & Fuels
Yukihiko Matsumura, Satoshi Goto, Yusuke Takase, Shuhei Inoue, Takahito Inoue, Yoshifumi Kawa, Takashi Noguchi, Hiroaki Tanigawa
Article
Energy & Fuels
Apip Amrullah, Yukihiko Matsumura
Article
Chemistry, Physical
Shuhei Inoue, Yoshihiro Tomita, Yukihiko Matsumura
CHEMICAL PHYSICS LETTERS
(2019)
Article
Chemistry, Physical
Hidetaka Takaki, Keita Shinzato, Shuhei Inoue, Hiroki Miyaoka, Takayuki Ichikawa, Yukihiko Matsumura
CHEMICAL PHYSICS LETTERS
(2020)
Article
Energy & Fuels
Rahmat Iman Mainil, Yukihiko Matsumura
Article
Chemistry, Physical
Mengli Zhang, Shuhei Inoue, Yukihiko Matsumura
CHEMICAL PHYSICS LETTERS
(2020)
Article
Chemistry, Multidisciplinary
Pattraporn Changsuwan, Shuhei Inoue, Yukihiko Matsumura
Article
Environmental Sciences
Takashi Amemiya, Masato Denou, Hiroshi Enomoto, Takuya Ito, Kenji Kaibe, Naomi Sawada, Miyuki Tomari, Yukihiko Matsumura
Summary: This study clarified the feasibility of generating heat and electricity from woody biomass based on biomass unit price and productivity, with heat production feasible for small-scale biomass use and electricity generation feasible for large-scale biomass use.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2021)
Article
Chemistry, Multidisciplinary
Puji Rahmawati Nurcahyani, Yukihiko Matsumura
Summary: Effluents from SCWG process mixed with Bristol Medium at 600 degrees C showed improvement in growth rate for cultivating Chlorella vulgaris. The low non-purgeable organic carbon content indicated that inhibiting materials were decomposed at the high temperature of 600 degrees C. Furthermore, phosphorus accumulation in C. vulgaris was significantly higher in the SCWG mixed medium, suggesting the potential for nutrient recycling processes using a combination of C. vulgaris and SCWG effluents.
Article
Nanoscience & Nanotechnology
Yutaro Suzuki, Hidetaka Takaki, Shuhei Inoue, Yukihiko Matsumura
Summary: The photochromic phenomenon does not occur independently in MTO films, but rather in the interface between the prepared MTO layer and the indium tin oxide layer. To clarify this phenomenon, analysis of the MTO layer is crucial, and investigation under environmental conditions is necessary.
Article
Chemistry, Multidisciplinary
Yukihiko Matsumura, Yuito Suganuma, Takayuki Ichikawa, Wookyung Kim, Yutaka Nakashimada, Keiya Nishida
Summary: This study treated chicken manure under hydrothermal reaction conditions to effectively produce ammonia, achieving a nitrogen yield as high as 0.8, indicating the potential for chicken manure to be a favorable feedstock for ammonium production.
Article
Chemistry, Physical
Shuhei Inoue, Kento Tobinaga, Kou Suzuki, Yukihiko Matsumura
CHEMICAL PHYSICS LETTERS
(2020)