Process Modelling of the Calcium Looping Process and Validation Against 1 MWth Pilot Testing

Haaf, Martin; Stroh, Alexander; Hilz, Jochen; Helbig, Martin; Ströhle, Jochen; Epple, Bernd

doi:10.1016/j.egypro.2017.03.1159

Cited by 20 publications

(5 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It can be widely applied in carbon capture, adsorption-enhanced steam methane reforming (SE-SMR), integrated CO 2 capture and conversion, and thermochemical heat storage [3][4][5][6][7]. CaL technology typically involves the use of dual interconnected circulating fluidized bed (CFB) reactors [8,9]. In the first reactor, lime (CaO) reacts with CO 2 in the temperature range of 600-700 • C to form CaCO 3 .…”

Section: Introductionmentioning

confidence: 99%

Limestone Calcination Kinetics in Microfluidized Bed Thermogravimetric Analysis (MFB-TGA) for Calcium Looping

Wang

2022

Catalysts

View full text Add to dashboard Cite

Limestone calcination is an important part of calcium looping (CaL) technology and is critical to the design and operation optimization of fluidized bed reactors. However, obtaining a method of measuring the fast calcination kinetics in a fluidizing environment with isothermal conditions is still a challenge in the field of calcium looping. We address this challenge in this work and develop a new method of obtaining limestone calcination kinetics by injecting limestone particles into the hot fluidizing sands in a microfluidized bed thermogravimetric analysis (MFB-TGA) with a mass measurement resolution of 1 mg. The calcination characteristics of limestone are investigated at different particle sizes (150–1250 μm), temperatures (750–920 °C), and CO2 concentrations (0–30 vol.%). The experimental data measured from MFB-TGA were analyzed using a detailed model including surface reaction and intraparticle and external diffusion. The results show that the kinetics of limestone calcination measured by MFB-TGA are faster than those measured via regular TGA. This particle-injecting method of MFB-TGA provides a new experimental idea for measuring fast calcination kinetics occurring inside fluidized bed reactors and provides guidance on the application of CaL technology.

show abstract

Section: Introductionmentioning

confidence: 99%

Limestone Calcination Kinetics in Microfluidized Bed Thermogravimetric Analysis (MFB-TGA) for Calcium Looping

Wang

2022

Catalysts

View full text Add to dashboard Cite

show abstract

“…(b) and (c), a shift to the highest binding energy of Ca 2p and O 1s in C‐Mn‐CaO was found, which was not observed in the original CaO. It means that it was easier for the Ca atom and O atom in C‐Mn‐CaO to give electrons to CO 2 than the original CaO, which assisted the fast formation of CO 3 . The doping of Mn in CaO was beneficial to the electron transport from CaO to CO 2 , which accelerated the carbonation rates of CaO.…”

Section: Resultsmentioning

confidence: 93%

“…Usually, the carbonation duration in the carbonator is very short in industrial applications . It is necessary to improve the carbonation rates of calcium‐based sorbents.…”

Section: Resultsmentioning

confidence: 99%

A study of the synergistic effects of Mn/steam on CO₂ capture performance of CaO by experiment and DFT calculation

Wan

et al. 2019

Greenhouse Gases

View full text Add to dashboard Cite

Novel Mn‐doped CaO was prepared by the combustion method. The CO2 capture performance of Mn‐doped CaO, carbonated in the presence of steam and under severe calcination conditions (950°C and 70% CO2/30% N2) during calcium looping cycles, was investigated in a dual fixed‐bed reactor. The intercoupling effects of Mn and steam on CO2 capture by CaO were also studied. Doping of Mn in CaO by the combustion method greatly improved the CO2 capture capacity of CaO. The carbonation conversions of Mn‐doped CaO increased with increasing steam concentration from 0 to 15%. When the molar ratio of Mn/Ca was 0.75 : 100, Mn‐doped CaO achieved the highest CO2 capture capacity. Under severe calcination conditions, the carbonation conversion of Mn‐doped CaO, where the molar ratio of Mn to Ca = 0.75 : 100 in the presence of 15% steam, was about 0.4 after ten cycles (carbonation for 5 min at 650°C under 15% CO2/15% steam/N2), which was 4.38 times as high as that of the original CaO in the absence of steam. The cyclic CO2 capture capacities of CaO were improved by Mn and steam. Synergistic enhancement effects of Mn and steam on the CO2 capture capacities of CaO were also found. The effect of steam on the carbonation conversion of Mn‐doped CaO was stronger than that of the original CaO. Mn in the presence of steam showed a more positive effect on CO2 capture by CaO. X‐ray photoelectron spectroscopy analysis showed that doping of Mn in CaO enhanced the transport of electrons in the carbonation of CaO, which helped to increase the carbonation rate. When steam was present in the carbonation, Mn‐doped CaO possessed a more porous structure and smaller CaO grains than the original CaO during the cycles. Simulation calculations using periodic density functional theory (DFT) showed that CO2 molecules were easier to absorb on CaO owing to the doping of Mn and the presence of steam. The synergistic enhancement effects of Mn and steam on CO2 captured the performance of CaO. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

show abstract

“…The 1 MW th CFB pilot plant of TUDA has been utilized in the past for various applications, including calcium and chemical looping (Ströhle et al, 2014;Haaf et al, 2017Haaf et al, , 2020Ohlemüller et al, 2017;Hilz et al, 2018), as well as CFB combustion. In this work, the pilot plant is utilized to carry out combustion tests with a low rank German lignite fuel.…”

Section: General Description Of the Boilermentioning

confidence: 99%

Simulation of a CFB Boiler Integrated With a Thermal Energy Storage System During Transient Operation

Stefanitsis¹,

Nesiadis²,

Koutita³

et al. 2020

Front. Energy Res.

View full text Add to dashboard Cite

In the current work, a transient/dynamic 1-dimensional model has been developed in the commercial software APROS for the pilot 1 MW th CFB boiler of the Technical University of Darmstadt. Experiments have been performed with the same unit, the data of which are utilized for the model validation. The examined conditions correspond to the steady-state operation of the boiler at 100, 80, and 60% heat loads, as well as for transient conditions for the load changes from 80 to 60% and back to 80%. Fair agreement is observed between the simulations and the experiments regarding the temperature profiles in the riser, the heat extracted by the cooling lances, as well as the concentration of the main species in the flue gases; a small deviation is observed for the pressure drop, which, however, is close to the results of a CFD simulation run. The validated model is extended with the use of a thermal energy storage (TES) system, which utilizes a bubbling fluidized bed to store/return the particles during ramp up/down operation. Simulations are performed both with and without the use of TES for the load path 100-80-60-80-100%, and the results showed that the TES concept proved to be superior in terms of changing load flexibility, since the ramp up and down times proved to be much faster, and lower temperature drops between the loads are observed in this case.

show abstract

Process Modelling of the Calcium Looping Process and Validation Against 1 MWth Pilot Testing

Cited by 20 publications

References 20 publications

Limestone Calcination Kinetics in Microfluidized Bed Thermogravimetric Analysis (MFB-TGA) for Calcium Looping

Limestone Calcination Kinetics in Microfluidized Bed Thermogravimetric Analysis (MFB-TGA) for Calcium Looping

A study of the synergistic effects of Mn/steam on CO₂ capture performance of CaO by experiment and DFT calculation

Simulation of a CFB Boiler Integrated With a Thermal Energy Storage System During Transient Operation

Contact Info

Product

Resources

About

Process Modelling of the Calcium Looping Process and Validation Against 1 MWth Pilot Testing

Cited by 20 publications

References 20 publications

Limestone Calcination Kinetics in Microfluidized Bed Thermogravimetric Analysis (MFB-TGA) for Calcium Looping

Limestone Calcination Kinetics in Microfluidized Bed Thermogravimetric Analysis (MFB-TGA) for Calcium Looping

A study of the synergistic effects of Mn/steam on CO2 capture performance of CaO by experiment and DFT calculation

Simulation of a CFB Boiler Integrated With a Thermal Energy Storage System During Transient Operation

Contact Info

Product

Resources

About

A study of the synergistic effects of Mn/steam on CO₂ capture performance of CaO by experiment and DFT calculation