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Articles 391 - 420 of 834

Full-Text Articles in Chemical Engineering

Comparison Between Measurements And Numerical Simulation Of Particle Flow And Combustion A The Cfbc Plant Duisburg, M. Weng, J Plackmeyer May 2011

Comparison Between Measurements And Numerical Simulation Of Particle Flow And Combustion A The Cfbc Plant Duisburg, M. Weng, J Plackmeyer

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

The article presents the 3-dimensional numerical simulation of combustion and particle flow as an efficient engineering tool for analysis and optimization of fluidized bed combustion chambers. The comparison with measurements that were carried out within a European Research Project and with operational experience shows very good agreement and provides recommendations for future optimization.


Elutriation From Fluidized Beds: Comparison Between Experimental Measurements And 3d Simulation Results, Renaud Ansart, Herve Neau, Olivier Simonin, Philippe Accart, Alain De Ryck May 2011

Elutriation From Fluidized Beds: Comparison Between Experimental Measurements And 3d Simulation Results, Renaud Ansart, Herve Neau, Olivier Simonin, Philippe Accart, Alain De Ryck

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

This paper presents comparisons between experimental measurements and unsteady threedimensional numerical simulations performed by an unstructured parallelized CFD multiphase flow code of elutriation and transport of mono-dispersed glass beads type B and A/B in a fluidized bed. These comparisons show a satisfactory agreement between experimental measurements and numerical predictions. The numerical results also show a strong dependence on the mesh size, especially for fine particles. A model accounting for influences of mesoscales structures on overall bed hydrodynamics, which are not resolved by coarse mesh simulations, is applied. Results obtained with the model show improvements for the dense fluidized bed and …


Hydrodynamics Of A Cluster Descending At The Wall Of A Cfb Riser - Numerical Study, John R. Grace, Subhashini Vashisth May 2011

Hydrodynamics Of A Cluster Descending At The Wall Of A Cfb Riser - Numerical Study, John R. Grace, Subhashini Vashisth

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

The incompressible hydrodynamics of a single parabolic cluster descending at the wall of a CFB riser was numerically simulated using a 2-D Eulerian-Granular model and a segregated time-dependent unsteady solver. Numerical predictions of the velocity of descent and the evolution of cluster shape are in reasonable agreement with experimental results available in the literature.


High Sulfur Lignite Fired Large Cfb Boilers-Design And Operating Experience, M. Lakshminarasimhan, B. Ravikumar, A. Lawrence, M. Muthukrishnan May 2011

High Sulfur Lignite Fired Large Cfb Boilers-Design And Operating Experience, M. Lakshminarasimhan, B. Ravikumar, A. Lawrence, M. Muthukrishnan

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

One of the measures of the prosperity of a nation is per capita consumption of electricity. In developing countries like India the gap between supply and demand is strongly increasing. The demand for all forms of energy is expected to increase substantially in the foreseeable future and is forecasted to double by 2020. Although coal would continue to be a major energy source in India due to its availability, lignite is fast emerging as an alternate source of fuel for electricity generation. In India the total lignite potential is 4177 million tonnes. The varieties found in India (Gujarat & Rajasthan …


Research On Heat Transfer Inside The Furnace Of Large Scale Cfb Boilers, Ruiqing Zhang, Hairui Yang, Hai Zhang, Qing Liu, Junfu Lu, Yuxin Wu May 2011

Research On Heat Transfer Inside The Furnace Of Large Scale Cfb Boilers, Ruiqing Zhang, Hairui Yang, Hai Zhang, Qing Liu, Junfu Lu, Yuxin Wu

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

Field tests in one unit of 135MWe and two units of 300MWe commercial Circulating Fluidized bed (CFB) boilers (A&B) with different structures were carried out. The influence of operating conditions on the thermal boundary layer, local heat transfer coefficient and peripheral distribution of heat transfer coefficient were studied. It was found that, in the 135MWe and 300MWe-A CFB furnace, the thickness of the thermal boundary layer was almost constant, about 100mm, and independent of the height above the distributor and the boiler load. The local heat transfer coefficient increased with increasing load as well as the coal feeding rate and …


Co-Gasification Of Biomass And Coal In An 8mw Dual Fluidized Bed Steam Gasifier, Christoph Pfeifer, Isabella Aigner, Hermann Hofbauer May 2011

Co-Gasification Of Biomass And Coal In An 8mw Dual Fluidized Bed Steam Gasifier, Christoph Pfeifer, Isabella Aigner, Hermann Hofbauer

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

Gasification of biomass is an attractive technology for combined heat and power production. Co-gasification of biomass and coal was tested in an 8 MW dual fluidized bed steam gasifier with coal ratios up to 22% on an energy basis. Hydrogen levels in the producer gas increased with the addition of coal as well as ammonia, hydrogen sulfide and tars. Addition of coal to the system stabilized the process and improved gas quality.


Operating Experience And Latest Developments Of Alstom Power's 300 Mwe Class Cfb Boilers, Iqbal Abdulally, Bruce Wilhelm, Christian Enault, Pierre Gauville May 2011

Operating Experience And Latest Developments Of Alstom Power's 300 Mwe Class Cfb Boilers, Iqbal Abdulally, Bruce Wilhelm, Christian Enault, Pierre Gauville

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

Fuel flexibility combined with low emissions, particularly with high sulphur fuels, are the key drivers for installing a Circulating Fluidised Bed (CFB) Boiler. Taking into account the global drive for more efficient and clean combustion, and the development of CFB combustion and emission reduction technologies accordingly, worldwide applications for CFB Boilers are increasing. Accordingly, Alstom Power continues the evolutionary development of its CFB Boiler portfolio, based on the experience gained with operating units. This paper focuses on Alstom Power’s 300 MWe Class CFB Boiler products. East Kentucky Power Cooperative's (EKPC) Spurlock unit 4 is one of the large Alstom’s 300 …


Coal And Biomass Co-Gasification In A Circulating Fluidized Bed Reactor, Andrzej Czaplicki, Marek Sciazko May 2011

Coal And Biomass Co-Gasification In A Circulating Fluidized Bed Reactor, Andrzej Czaplicki, Marek Sciazko

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

Co-gasification tests of subbituminous coal with biomass were performed. A rape straw blended with coal was used in a mass ratios of coal/biomass of 25%, 50% and 75%. The gasification process was conducted in a circulating fluid bed reactor at atmospheric pressure with air and steam addition was applied to the reaction. The addition of biomass to coal resulted in a higher conversion to gas and increased the gas calorific value due to higher content of carbon oxide


Design And Operation Of Biomass Circulating Fluidized Bed Boiler With High Steam Parameter, Li Shiyuan, Lu Qinggang, Teng Haipeng, Shaolin Bao, Dongyu Wang May 2011

Design And Operation Of Biomass Circulating Fluidized Bed Boiler With High Steam Parameter, Li Shiyuan, Lu Qinggang, Teng Haipeng, Shaolin Bao, Dongyu Wang

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

Two circulating fluidized bed(CFB) boilers with capacity of 12 MWe and 25 MWe, respectively, with biomass as fuel, adopting the basic technology independently developed by Institute of Engineering Thermophysics (IET), Chinese Academy of Sciences, have been in commercial operation since March 2010 in China. This paper focuses on the design principles, the design specifications and operating results of the two CFB boilers.


Commissioning Of A 0.8 Mwth Cfbc For Oxy-Fuel Combustion, L. Jia, D. Mccalden, Y. Tan, Y. Wu, I. He, R. Symmonds, E.J. Anthony May 2011

Commissioning Of A 0.8 Mwth Cfbc For Oxy-Fuel Combustion, L. Jia, D. Mccalden, Y. Tan, Y. Wu, I. He, R. Symmonds, E.J. Anthony

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

Oxy-fuel fluidized bed combustion (FBC) is a new technology being developed for power production from carbonaceous fuels while producing a nearly pure steam of CO2 ready for sequestration or storage. Unlike oxy-fuel pulverized fuel combustion technology, oxy-fuel FBC offers the opportunity to use poor quality coals, hydrocarbon residues and a range of other materials including biomass. In Canada, pitches, tars and bottoms, in particular, are available in large quantities in western Canada, and this technology offers an opportunity to deal with many of these waste feedstocks in an environmentally benign manner. In addition, oxy-fuel circulating FBC (CFBC) can be fired …


Particle To Gas Heat Transfer In A Circulating Fluidized Bed Riser, Yassir Makkawi May 2011

Particle To Gas Heat Transfer In A Circulating Fluidized Bed Riser, Yassir Makkawi

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

The main objective of this study was to measure the heat transfer from particle to gas in a dilute CFB riser (  0.8 ) and to derive a predictive equation for the local particle-gas heat transfer coefficient. This coefficient was found to be a strong function of the particle velocity, concentration and length of the heat transfer section. Accordingly, a new correlation in terms of these parameters is proposed.


Study Of Recarbonation In Circulating Fluidized Bed Combustion, Marko Palonen, Irina Hyyatiäinen, Anna Mahlamäki, Mikko Varonen May 2011

Study Of Recarbonation In Circulating Fluidized Bed Combustion, Marko Palonen, Irina Hyyatiäinen, Anna Mahlamäki, Mikko Varonen

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

Oxy-fuel circulating fluidized bed combustion (CFBC) can use calcium based sorbents, primarily limestone, for the in-situ capture of much of the sulfur dioxide in the fuel. Under oxy-fuel CFBC conditions, the CO2 content is usually high, and at high combustor temperatures sulfur capture can occur in two steps, calcination and then sulfation. The typical Ca utilization ratio in oxy-fuel CFBCs is less than half. When temperature is below the calcination temperature while remaining exposed to a high CO2 environment, recarbonation of unused CaO may occur. This reaction between calcium oxide and carbon dioxide has the potential to create serious operational …


Uop Fcc Innovations Developed Using Sophisticated Engineering Tools, Lisa Wolschlag, Keith Couch May 2011

Uop Fcc Innovations Developed Using Sophisticated Engineering Tools, Lisa Wolschlag, Keith Couch

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

Fluid Catalytic Cracking (FCC) technology has been a part of the petroleum industry since the 1940’s. Yet, despite being a very mature technology, continued development is vital, especially as many refiners move their FCC operations from fuels production to higher value products. Advanced diagnostic and design tools are accelerating process developments and have resulted in several innovations. Through the development and commercialization of world record scale FCC units, technical discoveries have emerged, which have provided opportunities for improvements across all units, independent of size. Through the development and use of sophisticated engineering tools such as Computational Fluid Dynamic (CFD) modeling, …


Investigation On The Hydrodynamic Properties In The External Loop Of Circulating Fluidized Bed With A Loop Seal, Hairui Yang, Xuan Yao, Tao Wang, Hai Zhang, Qing Liu, Junfu Lv, Guangxi Yue May 2011

Investigation On The Hydrodynamic Properties In The External Loop Of Circulating Fluidized Bed With A Loop Seal, Hairui Yang, Xuan Yao, Tao Wang, Hai Zhang, Qing Liu, Junfu Lv, Guangxi Yue

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

The pressure balance and mass balance are influenced by the characteristics of different components in the loop of a circulating fluidized bed (CFB). Experiments were conducted in a 4.3 m high cold laboratory CFB test rig with a loop seal. With a fixed bed inventory and superficial gas velocity, the pressure drop of the loop seal decreased with increasing aeration, thus causing an increase in the solid circulation flux (Gs). Correspondingly, the pressure drop in the riser became higher with increasing Gs; the pressure drop of the cyclone had a non-linear relationship with Gs, and the transition point was determined …


A Generalized Flow Regime Diagram For Fluid-Solid Vertical Transport, Xiaotao T. Bi May 2011

A Generalized Flow Regime Diagram For Fluid-Solid Vertical Transport, Xiaotao T. Bi

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

An ideal generalized flow regime diagram was proposed for fluid-solids vertical transport systems with no bottom and top restrictions. Such an ideal flow regime diagram was further extended to shed light onto the understanding of the flow regimes and instabilities encountered in bottom- restricted bubbling and circulating fluidized bed systems.


High-Flux Triple Bed Circulating Fluidized Bed (Tbcfb) Gasifier For Exergy Recuperative Igcc/Igfc, Chihiro Fushimi, Guoqing Guan, Masanori Ishizuka, Yu Nakamura, Atsushi Tsutsumi, Yoshizo Suzuki, Eldin Wee, Yong Cheng, Chi-Hwa Wang May 2011

High-Flux Triple Bed Circulating Fluidized Bed (Tbcfb) Gasifier For Exergy Recuperative Igcc/Igfc, Chihiro Fushimi, Guoqing Guan, Masanori Ishizuka, Yu Nakamura, Atsushi Tsutsumi, Yoshizo Suzuki, Eldin Wee, Yong Cheng, Chi-Hwa Wang

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

The flow behavior of silica sand, of average particle size 128 μm, was investigated using a large-scale triple-bed combined circulating fluidized bed (TBCFB) cold model, which was composed of a 0.1 m I.D. ×16.6 m tall riser, a solids distributor, a 0.1m I.D. × 6.5 m long downer, a gas-solids separator, a 0.75 m × 0.27 m × 3.4 m bubbling fluidized bed and a 0.158 m I.D. × 5.0 m tall gas-sealing bed (GSB) with a high solids mass flux. The main focus of this study is to determine effect of riser secondary air injection on solids mass flux …


Process Decoupling Of Plasma Enhanced Synthesis Of Chlorinated Polyvinyl Chloride (Cpvc) Particles In A Circulating Fluidized Bed, Wei Lu, Teng Cao, Yong Jin, Yi Cheng May 2011

Process Decoupling Of Plasma Enhanced Synthesis Of Chlorinated Polyvinyl Chloride (Cpvc) Particles In A Circulating Fluidized Bed, Wei Lu, Teng Cao, Yong Jin, Yi Cheng

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

Plasma enhanced synthesis of CPVC particles in a gas-solid plasma circulating fluidized bed reactor (PCFBR) is proposed as a novel CPVC synthesizing method. The chlorination process is decoupled into a fast initiation step in a plasma riser and a slow chlorination process in the accompanying bed. The CPVC product has good properties in terms of chlorine content and microstructure.


Flow Rate Of Solids In L-Valves, Duvvuri Subbarao May 2011

Flow Rate Of Solids In L-Valves, Duvvuri Subbarao

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

Movement of solids in a L-valve by fluid drag due to external aeration is opposed by frictional resistance at the wall/non-moving solids. Model equations developed for the threshold aeration rate and solids flow rate as a function of aeration rate compare well with the literature data.


Cold Model Investigations Of A High Temperature Looping Process In A Dual Circulating Fluidized Bed System, Ajay R. Bidwe, Miguel A.M Dominguez, Craig Hawthorne, Heiko Dieter, Alexander Charitos, Anjia Schuster, Güenter Scheffknecht May 2011

Cold Model Investigations Of A High Temperature Looping Process In A Dual Circulating Fluidized Bed System, Ajay R. Bidwe, Miguel A.M Dominguez, Craig Hawthorne, Heiko Dieter, Alexander Charitos, Anjia Schuster, Güenter Scheffknecht

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

The Calcium Looping process is a promising post-combustion CO2 capture technology. A 200 kWth Dual Circulating Fluidized Bed has been built at IFK, University of Stuttgart. Tests were carried out on a hydrodynamically scaled cold model. Operating parameters have been varied, while the suitability of the 200 kWth design has been proven


Bio-Gasoline From Jatropha Oil: New Applications For The Fcc- Process, Alexander Weinert, Alexander Reichhold, Peter Bielansky, Christoph Schönberger, Bettina Schumi May 2011

Bio-Gasoline From Jatropha Oil: New Applications For The Fcc- Process, Alexander Weinert, Alexander Reichhold, Peter Bielansky, Christoph Schönberger, Bettina Schumi

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

Jatropha curcas L. is a very drought-resistant plant, and jatropha oil can be ex-tracted from its seeds. Whilst not suitable for human consumption, we found that it is a promising feedstock for producing (bio)-gasoline. The oil was cracked in an inter-nally circulating FCC-reactor using a Grace Davison Ultima® catalyst. The total con-version was around 65%, with ca. 40% gasoline and ca. 25% crack gas (exact num-bers varied with reactor temperature). The gasoline has a RON > 95 and oxy-gen < 0.3% m. The crack-gas consisted of ca. 35% propylene, ca. 13% 1-butene and ca. 6% ethylene.


Effects Of Particle Properties On Cluster Characteristics In A 2-D Cfb Riser, Jesse Zhu, Jing Xu May 2011

Effects Of Particle Properties On Cluster Characteristics In A 2-D Cfb Riser, Jesse Zhu, Jing Xu

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

The characteristic of particle clusters was studied in a 2-D circulating fluidized bed riser by using a digital image system and optical fiber probes. A new parameter, cluster number fraction, was proposed to characterize the clusters. The results indicated the smaller and lighter particles have higher potential to aggregate, while the effects of particle sphericity were less significant than those of particle density and size.


Hydrodynamics Of A Loop-Seal Operated In A Circulating Fluidized Bed: Influence Of The Operating Conditions On Gas And Solid Flow Patterns, Roberto Solimene, Riccardo Chirone, Piero Bareschino, Piero Salatino May 2011

Hydrodynamics Of A Loop-Seal Operated In A Circulating Fluidized Bed: Influence Of The Operating Conditions On Gas And Solid Flow Patterns, Roberto Solimene, Riccardo Chirone, Piero Bareschino, Piero Salatino

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

Hydrodynamic features of a loop-seal operated as solids re-injection device in a labscale cold CFB apparatus are studied. Gas flow patterns are characterized by means of gas tracing experiments with continuous injection of CO2 in the loop-seal chambers. Solids flow patterns are characterized by impulsive injection of dyecoloured particles into the supply chamber, followed by particle tracking.


Manufacture Of Granular Polysilicon From Trichlorosilane In An Internally Circulating Fluidized Bed Reactor, Chenjing Wang, Tiefeng Wang, Zhanwen Wang May 2011

Manufacture Of Granular Polysilicon From Trichlorosilane In An Internally Circulating Fluidized Bed Reactor, Chenjing Wang, Tiefeng Wang, Zhanwen Wang

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

A lab scale internally circulating fluidized bed (ICFB) with a centrally located draft tube was designed to make polysilicon from trichlorosilane. Experimental results and evaluations showed that particle circulation could carry enough heat for reaction and effectively decrease wall deposition. Well grown granular polysilicon was obtained in a stable fluidization state and particle circulation rate.


Studies On Propane Dehydrogenation To Propylene In A Gas-Solid-Sold Fluidized Bed Reactor, Yue Chu, Tongwei Wu, Yunxin Li, Zeeshan Nawaz, Yao Wang, Fei Wei May 2011

Studies On Propane Dehydrogenation To Propylene In A Gas-Solid-Sold Fluidized Bed Reactor, Yue Chu, Tongwei Wu, Yunxin Li, Zeeshan Nawaz, Yao Wang, Fei Wei

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

Platinum and tin deposited on mixed support of SAPO-34 and alumina oxide at certain proportion constitute a new catalyst of good catalytic performance. The catalyst was tested in a Gas-Solid-Solid fluidized bed reactor. Cold model experiment was carried on to obtain fluidization curves and characteristic velocities. Reaction results in the GSS-FBR showed that propylene yield was improved by 5 % compared with that in micro fixed bed reactor.


Waste Wood Gasification: Distribution Of Nitrogen, Sulphur And Chlorine In A Dual Fluidised Bed Steam Gasifier, Veronika Wilk, C. Aichernig, H. Hofbauer May 2011

Waste Wood Gasification: Distribution Of Nitrogen, Sulphur And Chlorine In A Dual Fluidised Bed Steam Gasifier, Veronika Wilk, C. Aichernig, H. Hofbauer

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

Waste wood was gasified in a dual fluidised bed gasifier in order to investigate the behaviour of waste fuels in this technology. The distribution of nitrogen, sulphur and chlorine between the gasifier and combustor of the dual bed system was studied to identify the requirements for gas cleaning devices. The gasification system is suitable for the use of waste wood. A slight adaption of the gas cleaning equipment was necessary compared to gasification of natural woody biomass.


Numerical Simulations Of A Circulating Fluidized Bed With A Square Cross-Section, Tingwen Li, S Pannala, C. Guenther May 2011

Numerical Simulations Of A Circulating Fluidized Bed With A Square Cross-Section, Tingwen Li, S Pannala, C. Guenther

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

In this study, both 2D and 3D numerical simulations of a well-documented circulating fluidized bed with a square cross-section were conducted. With some assumptions, a series of 2D simulations was first carried out to study the influence of grid resolution, initial flow field, and boundary condition on the flow hydrodynamics. It was found that 2D simulations under-predicted the solids inventory even with the finest grid (10-particle-diameter grid size). On the other hand, a 3D simulation with relatively coarse grid was found in better agreement with the experimental data. Differences between 2D and 3D simulations were briefly discussed.


Effects Of Gas Velocity And Solid Hold-Up On The Sub-Grid Behavior Of Riser Flows, Christian Costa Milioli, Fernando Eduardo Milioli May 2011

Effects Of Gas Velocity And Solid Hold-Up On The Sub-Grid Behavior Of Riser Flows, Christian Costa Milioli, Fernando Eduardo Milioli

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

Two-fluid highly resolved sub-grid simulations (SGS) of riser flows were developed under realistic gas velocities and solid hold-ups, for a solid phase derived from high Stokes number particles. The results showed that both gas velocity and solid hold-up considerably affect the effective hydrodynamics of the solid phase.


Co2 Looping Cycle For Co2 Separation, Tadaaki Shimizu, Takayuki Takahashi, Hiroko Narisawa, Yasuyuki Murakami, Liuyun Li, Heejon Kim May 2011

Co2 Looping Cycle For Co2 Separation, Tadaaki Shimizu, Takayuki Takahashi, Hiroko Narisawa, Yasuyuki Murakami, Liuyun Li, Heejon Kim

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

A dual fluidized bed process using CaO-based solid sorbent is considered to be a promising technology to separate CO2 from flue gas with low energy penalty. As reactor for CaO-looping cycle, both bubbling fluidized bed and “fast” fluidized bed are available, thus four possible combinations, (bubbling or fast absorber)x(bubbling or fast regenerator), are conceivable for this process. In this work, the authors discuss favorable combination of reactor type from viewpoints of heat removal from carbonation reactor and on energy penalty associated with dilution of pure oxygen by CO2 in the regenerator. As conclusion, suitable combination was found to be bubbling …


Energetic Optimization Of The Lignin Pyrolysis For The Production Of Aromatic Hydrocarbons, Miika Franck, Ernst-Ulrich Hertge, Stefan Heinrich, Bea Lorenz, Joachim Werther May 2011

Energetic Optimization Of The Lignin Pyrolysis For The Production Of Aromatic Hydrocarbons, Miika Franck, Ernst-Ulrich Hertge, Stefan Heinrich, Bea Lorenz, Joachim Werther

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

The energy supply of the endothermic lignin pyrolysis process in a circulating fluidized bed is to be achieved by recirculation of bed material, which is heated by combustion of the by-products char and permanent gases in a separate combustor. The feasibility of this concept is examined by the investigation of the yield of the byproducts in pyrolysis experiments, char combustion kinetics, the pyrolysis energy demand and the combustion energy of the char and the non-condensable gases. It is shown that the integrated pyrolysis-combustion process is feasible and even produces an energy surplus of 4 MJ/kg raw lignin, which can be …


Effect Of Wall Boundary Conditions And Mesh Refinement On Numerical Simulation Of Pressurized Dense Fluidized Bed For Polymerization Reactor, Pascal Fede, Olivier Simonin, Renaud Ansart, Herve Neau, I. Ghouila May 2011

Effect Of Wall Boundary Conditions And Mesh Refinement On Numerical Simulation Of Pressurized Dense Fluidized Bed For Polymerization Reactor, Pascal Fede, Olivier Simonin, Renaud Ansart, Herve Neau, I. Ghouila

10th International Conference on Circulating Fluidized Beds and Fluidization Technology - CFB-10

The effect of the mesh refinement and the solid phase boundary condition are investigated for numerical simulation of dense pressurized fluidized bed. Two fluidized beds have been considered: a laboratory-scale device and a pilot-scale facility. A relation is proposed to scale-up the numerical simulation and preserving the spatial resolution accuracy. As expected the boundary condition of the solid phase modifies the behaviour of the fluidized bed. Compared to free-slip wall boundary condition, a no-slip condition improves the numerical predictions with respect to available experimental data.