Low-Temperature Pyrolysis and Gasification of Biomass: Numerical Evaluation of the Process Intensification Potential of Rotating- and Circulating Rotating Fluidized Beds in a Static Fluidization Chamber

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
Nicolas Staudt ◽  
Axel De Broqueville ◽  
Waldo Rosales Trujillo ◽  
Juray De Wilde
Keyword(s):  
Low Temperature ◽  
Fluidized Beds ◽  
Circulating Fluidized Bed ◽  
Plug Flow ◽  
Process Intensification ◽  
High Heat ◽  
Continuity Equations ◽  
Particle Bed ◽  
Low Temperature Pyrolysis ◽  
Shift Reaction

The process intensification potential of rotating- and circulating rotating fluidized beds in a static fluidization chamber when used for the low-temperature pyrolysis and gasification of biomass is numerically evaluated. The species continuity equations and energy balance equations are based on complete mixing for the particles within given zones of the particle bed and plug flow for the gas. The reaction mechanism accounts for pyrolysis of biomass and tar, gas-phase combustion, the water gas shift reaction, and combustion and gasification of char. A comparison with current circulating fluidized bed riser technology is made. The circulation of inert solid with a high heat capacity and the separation of the flue gas from the production gas are also studied.

Low-Temperature Pyrolysis Characteristics of Inner Mongolia Lignite

2013 ◽  
Vol 805-806 ◽  
pp. 1455-1460
Author(s):  
Zhen Xin Zhao ◽  
Bu Wei Ma ◽  
Shu Quan Zhu ◽  
Hai Jin Zheng
Keyword(s):  
Low Temperature ◽  
Inner Mongolia ◽  
Heat Content ◽  
Calorific Value ◽  
Product Yield ◽  
High Heat ◽  
Holding Time ◽  
Low Rank ◽  
Pyrolysis Characteristics ◽  
Low Temperature Pyrolysis

The utilization of high moisture, high volatile low rank coals such as lignite is gaining importance day by day to meet the growing demands of coal for the energy sectors. For the combustion of pulverized material it appears essential to dry lignite. Further, lowest possible ash and moisture as well as high heat content are desired for combustion. The present work gives the details of the preparation of a product of higher calorific value by thermal treatment of Inner Mongolia lignite. The low-temperature pyrolysis characteristics were carried out on the regularities of pyrolysis temperature and holding time on the product yield of dry distillation of lignite by using aluminium retort method. The result shows that the suitable pyrolysis condition of lignite is 450 ~ 510 °C, holding time for 30 min. The ratio of aliphatic and aromatic groups of 400°C semi-coke obviously decrease 53.1% and 11.8% compared with raw coal. The degree of aromatization of semi-coke is gradually increased and aromatic nucleus condensation degree increases. The retort process of lignite is a dehydrogenation, deoxidization and carbon-rich process.

Analysis of a Vortexing Circulating Fluidized Bed for Process Intensification Via High-G Flows

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Michael Bobek ◽  
Steve Rowan ◽  
Jingsi Yang ◽  
Justin Weber ◽  
Frank Shafer ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Fluidized Bed ◽  
Dynamic Models ◽  
Circulating Fluidized Bed ◽  
Fluid Dynamic ◽  
Process Intensification ◽  
Operating Regime ◽  
High Heat ◽  
Angular Velocities ◽  
Solids Mixing

Fluidized beds are used in many industries where gas–solid reactions are present for their favorable characteristics of good solids mixing, high heat, and mass transfer rates, and large throughputs. In an attempt to increase throughput, reduce reactor footprints, and reduce costs, process intensification by unconventional reactor designs is being pursued. Specifically, this work focuses on the development of high-G reactors where the particles are experiencing a centripetal force typically on the order of ten times the force of gravity. This operating regime provides intensified gas–solids contact providing higher mass transfer, heat transfer, and gas throughput than a typical fluidized bed. This work focuses analysis of a cold flow vortexing circulating fluidized bed (CFB). Through mapping the pressure distributions in the riser, insights into the behavior of the system were made and compared to CPFD Barracuda computational fluid dynamic models. The simulation results outlined the working envelope of the system and provided a baseline to compare the experimental results. The experimental pressure data determined angular velocities of the gas in the range of 30–40 m/s, with corresponding particle velocities around 15 m/s.

Chemical yields from low-temperature pyrolysis of CCA-treated wood

2009 ◽  
Author(s):  
Qirong Fu ◽  
Dimitris Argyropolous ◽  
Lucian Lucia ◽  
David Tilotta ◽  
Stan Lebow
Keyword(s):  
Low Temperature ◽  
Treated Wood ◽  
Low Temperature Pyrolysis

Preparation of Organic/Inorganic Membrane by PDMS Low-temperature Pyrolysis

2014 ◽  
Vol 29 (2) ◽  
pp. 137-142
Author(s):  
Jiao-Zhu YU ◽  
Lin LI ◽  
Xin JIN ◽  
Ling-Hua DING ◽  
Tong-Hua WANG
Keyword(s):  
Low Temperature ◽  
Inorganic Membrane ◽  
Low Temperature Pyrolysis

The reverse water gas shift reaction: a process systems engineering perspective

2021 ◽  
Author(s):  
Miriam González-Castaño ◽  
Bogdan Dorneanu ◽  
Harvey Arellano-García
Keyword(s):  
Systems Engineering ◽  
Process Design ◽  
Process Intensification ◽  
Industrial Applications ◽  
Catalytic Systems ◽  
Process Systems ◽  
Reverse Water Gas Shift ◽  
Reaction Thermodynamics ◽  
Rwgs Reaction ◽  
Shift Reaction

RWGS reaction thermodynamics, mechanisms and kinetics. Process design and process intensification – from lab scale to industrial applications and CO2 value chains. Pathways for further improvement of catalytic systems, reactor and process design.

scholarly journals Pre-Reduction of Au/Iron Oxide Catalyst for Low-Temperature Water-Gas Shift Reaction Below 150 °C

Catalysts ◽  
2011 ◽  
Vol 1 (1) ◽  
pp. 175-190 ◽  
Author(s):  
Shinji Kudo ◽  
Taisuke Maki ◽  
Takashi Fukuda ◽  
Kazuhiro Mae
Keyword(s):  
Iron Oxide ◽  
Low Temperature ◽  
Oxide Catalyst ◽  
Water Gas Shift ◽  
Water Gas Shift Reaction ◽  
Iron Oxide Catalyst ◽  
Shift Reaction ◽  
Water Gas ◽  
Temperature Water

scholarly journals High- and low-temperature pyrolysis profiles describe volatile organic compound emissions from western US wildfire fuels

2018 ◽  
Author(s):  
Kanako Sekimoto ◽  
Abigail R. Koss ◽  
Jessica B. Gilman ◽  
Vanessa Selimovic ◽  
Matthew M. Coggon ◽  
...  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Biomass Burning ◽  
Ponderosa Pine ◽  
Fine Particles ◽  
Voc Emissions ◽  
Western Us ◽  
Volatile Organic ◽  
Low Temperature Pyrolysis ◽  
Pyrolysis Processes

Abstract. Biomass burning is a large source of volatile organic compounds (VOCs) and many other trace species to the atmosphere, which can act as precursors to the formation of secondary pollutants such as ozone and fine particles. Measurements collected with a proton-transfer-reaction time-of-flight mass spectrometer during the FIREX 2016 laboratory intensive were analyzed with Positive Matrix Factorization (PMF), in order to understand the instantaneous variability in VOC emissions from biomass burning, and to simplify the description of these types of emissions. Despite the complexity and variability of emissions, we found that a solution including just two emission profiles, which are mass spectral representations of the relative abundances of emitted VOCs, explained on average 85 % of the VOC emissions across various fuels representative of the western US (including various coniferous and chaparral fuels). In addition, the profiles were remarkably similar across almost all of the fuel types tested. For example, the correlation coefficient r of each profile between Ponderosa pine (coniferous tree) and Manzanita (chaparral) is higher than 0.9. We identified the two VOC profiles as resulting from high-temperature and low-temperature pyrolysis processes known to form VOCs in biomass burning. High-temperature and low-temperature pyrolysis processes do not correspond exactly to the commonly used flaming and smoldering categories as described by modified combustion efficiency (MCE). The average atmospheric properties (e.g. OH reactivity, volatility, etc.) of the high- and low-temperature profiles are significantly different. We also found that the two VOC profiles can describe previously reported VOC data for laboratory and field burns. This indicates that the high- and low-temperature pyrolysis profiles could be widely useful to model VOC emissions from many types of biomass burning in the western US, with a few exceptions such as burns of duff and rotten wood.

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