scholarly journals Effect of the Presence of HCl on Simultaneous CO2 Capture and Contaminants Removal from Simulated Biomass Gasification Producer Gas by CaO-Fe2O3 Sorbent in Calcium Looping Cycles

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8167
Author(s):  
Forogh Dashtestani ◽  
Mohammad Nusheh ◽  
Vilailuck Siriwongrungson ◽  
Janjira Hongrapipat ◽  
Vlatko Materic ◽  
...  

This study investigated the effect of HCl in biomass gasification producer gas on the CO2 capture efficiency and contaminants removal efficiency by CaO-Fe2O3 based sorbent material in the calcium looping process. Experiments were conducted in a fixed bed reactor to capture CO2 from the producer gas with the combined contaminants of HCl at 200 ppmv, H2S at 230 ppmv, and NH3 at 2300 ppmv. The results show that with presence of HCl in the feeding gas, sorbent reactivity for CO2 capture and contaminants removal was enhanced. The maximum CO2 capture was achieved at carbonation temperatures of 680 °C, with efficiencies of 93%, 92%, and 87%, respectively, for three carbonation-calcination cycles. At this carbonation temperature, the average contaminant removal efficiencies were 92.7% for HCl, 99% for NH3, and 94.7% for H2S. The outlet contaminant concentrations during the calcination process were also examined which is useful for CO2 reuse. The pore structure change of the used sorbent material suggests that the HCl in the feeding gas contributes to high CO2 capture efficiency and contaminants removal simultaneously.

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4379
Author(s):  
Paula Teixeira ◽  
Auguste Fernandes ◽  
Filipa Ribeiro ◽  
Carla I. C. Pinheiro

The use of wastes of marble powder (WMP) and dolomite as sorbents for CO2 capture is extremely promising to make the Ca-looping (CaL) process a more sustainable and eco-friendly technology. For the downstream utilization of CO2, it is more realistic to produce a concentrated CO2 stream in the calcination step of the CaL process, so more severe conditions are required in the calciner, such as an atmosphere with high concentration of CO2 (>70%), which implies higher calcination temperatures (>900 °C). In this work, experimental CaL tests were carried out in a fixed bed reactor using natural CaO-based sorbent precursors, such as WMP, dolomite and their blend, under mild (800 °C, N2) and realistic (930 °C, 80% CO2) calcination conditions, and the sorbents CO2 carrying capacity along the cycles was compared. A blend of WMP with dolomite was tested as an approach to improve the CO2 carrying capacity of WMP. As regards the realistic calcination under high CO2 concentration at high temperature, there is a strong synergetic effect of inert MgO grains of calcined dolomite in the blended WMP + dolomite sorbent that leads to an improved stability along the cycles when compared with WMP used separately. Hence, it is a promising approach to tailor cheap waste-based blended sorbents with improved carrying capacity and stability along the cycles under realistic calcination conditions.


2020 ◽  
Vol 59 (41) ◽  
pp. 18447-18459
Author(s):  
Forogh Dashtestani ◽  
Mohammad Nusheh ◽  
Vilailuck Siriwongrungson ◽  
Janjira Hongrapipat ◽  
Vlatko Materic ◽  
...  

2013 ◽  
Author(s):  
Saeed Danaei Kenarsari ◽  
Yuan Zheng

A lab-scale CO2 capture system is designed, fabricated, and tested for performing CO2 capture via carbonation of very fine calcium oxide (CaO) with particle size in micrometers. This system includes a fixed-bed reactor made of stainless steel (12.7 mm in diameter and 76.2 mm long) packed with calcium oxide particles dispersed in sand particles; heated and maintained at a certain temperature (500–550°C) during each experiment. The pressure along the reactor can be kept constant using a back pressure regulator. The conditions of the tests are relevant to separation of CO2 from combustion/gasification flue gases and in-situ CO2 capture process. The inlet flow, 1% CO2 and 99% N2, goes through the reactor at the flow rate of 150 mL/min (at standard conditions). The CO2 percentage of the outlet gas is monitored and recorded by a portable CO2 analyzer. Using the outlet composition, the conversion of calcium oxide is figured and employed to develop the kinetics model. The results indicate that the rates of carbonation reactions considerably increase with raising the temperature from 500°C to 550°C. The conversion rates of CaO-carbonation are well fitted to a shrinking core model which combines chemical reaction controlled and diffusion controlled models.


Author(s):  
Ghulamullah Maitlo ◽  
Rasool Bux Mahar ◽  
Zulfiqar Ali Bhatti ◽  
Imran Nazir

The interest in the thermochemical conversion of biomass for producer gas production since last decade has increased because of the growing attention to the application of sustainable energy resources. Application of biomass resources is a valid alternative to fossil fuels as it is a renewable energy source. The valuable gaseous product obtained through thermochemical conversion of organic material is syngas, whereas the solid product obtained is char. This review deals with the state of the art of biomass gasification technologies and the quality of syngas gathered through the application of different gasifiers along with the effect of different operating parameters on the quality of producer gas. Main steps in gasification process including drying, oxidation, pyrolysis and reduction effects on syngas production and quality are presented in this review. An overview of various types of gasifiers used in lignocellulosic biomass gasification processes, fixed bed and fluidized bed and entrained flow gasifiers are discussed. The effects of various process parameters such as particle size, steam and biomass ratio, equivalence ratio, effects of temperature, pressure and gasifying agents are discussed. Depending on the priorities of several researchers, the optimum value of different anticipated productivities in the gasification process comprising better quality syngas production improved lower heating value, higher syngas production, improved cold gas efficiency, carbon conversion efficiency, production of char and tar have been reviewed.


Author(s):  
Khanh-Quang Tran ◽  
M. Kristiina Iisa ◽  
Britt-Marie Steenari ◽  
Oliver Lindqvist ◽  
Magnus Hagstro¨m ◽  
...  

Alkali metals present in biomass fuels may cause increased bed agglomeration during fluidized bed combustion. In worst case this may lead to complete defluidization of the bed. Other problems caused by alkali metals include increased fouling and slagging. One possibility to reduce the impact of alkali metals is to add sorbents, e.g. aluminosilicates, to the bed for the capture of alkali metals. In the current investigation, the capture of vapor phase potassium compounds by kaolin was investigated in a fixed bed reactor. The reactor consisted of an alkali metal source placed at a variable temperature from which gaseous potassium compounds were generated, a fixed bed holding the kaolin, and an on-line detector for the alkali metal concentration. The on-line alkali metal detector was based on ionization of alkali metals on hot surfaces and is capable of detecting alkali metals down to ppb levels. This makes it possible to perform experiments at alkali metal concentrations relevant to fluidized bed combustion of biomass fuels. In the experiments, KCl was used as the alkali metal source with inlet concentrations of 0.5–3.5 ppm. The experiments were performed at reactor temperatures of 800–900°C and a contact time of 0.26 s. The capture efficiencies of KCl were always above 97%. The capture efficiency was somewhat higher in oxidizing than in reducing gas atmospheres. In the oxidizing gas atmosphere, the conversion was slightly higher with H2O addition than without. The capture efficiency decreased slightly as temperature or KCl concentration was increased.


Fuel ◽  
2015 ◽  
Vol 153 ◽  
pp. 202-209 ◽  
Author(s):  
Firas N. Ridha ◽  
Dennis Lu ◽  
Arturo Macchi ◽  
Robin W. Hughes

Fuel ◽  
2021 ◽  
Vol 295 ◽  
pp. 120586
Author(s):  
F. Dashtestani ◽  
M. Nusheh ◽  
V. Siriwongrungson ◽  
J. Hongrapipat ◽  
V. Materic ◽  
...  

2013 ◽  
Vol 634-638 ◽  
pp. 479-489 ◽  
Author(s):  
Shuang Hui Deng ◽  
Jian Hang Hu ◽  
Hua Wang ◽  
Juan Qin Li ◽  
Wei Hu

Biomass gasification was separated from catalytic pyrolysis in a two-stage fixed bed reactor with precalcined copper slag catalysts placed in a secondary reactor. The effects of gasification temperature (720-950°C), steam to biomass (S/B) mass ratio (0-2g/g), precalcined copper slag to biomass (C/B) mass ratio (0-2g/g) and copper slag precalcined at different temperatures (800-1000°C) on characteristics of biomass gasification were investigated. The experimental results show that the increase of gasification temperature, S/B mass ratio, C/B mass ratio and precalcination temperature are all favorable for raising gasification efficiency and enhancing the H2 production. With copper slag precalcined at 1000°C for 5 hours as catalyst under the experimental conditions examined, the H2 content, the hydrogen yield, the gas yield and the gasification efficiency reach the maximum of 59.16%, 0.72 Nm3/kg, 1.22 Nm3/kg and 77.56%,respectively.


2019 ◽  
Vol 8 (3) ◽  
pp. 215-224 ◽  
Author(s):  
Poramate Sittisun ◽  
Nakorn Tippayawong ◽  
Sirivatch Shimpalee

This work studied generation of producer gas using oxygen-enriched air and steam mixture as gasifying medium. Corn residues consisting of cobs and stover were used as biomass feedstock. Both corn residues were pelletized and gasified separately with normal air, oxygen enriched air and steam mixture in a fixed bed reactor. Effects of oxygen concentration in enriched air (21-50%), equivalence ratio (0.15-0.35), and steam to biomass ratio (0-0.8) on the yield of product gas, the combustible gas composition such as H2, CO, and CH4, the lower heating value (LHV), and the gasification efficiency were investigated. It was found that the decrease in nitrogen dilution in oxygen enriched air increased proportion of combustible gas components, improved the LHV of producer gas, but gasification efficiency was not affected. The increase in equivalence ratio favoured high product gas yield but decreased combustible gas components and LHV. It was also observed that introduction of steam enhanced H2 production but excessive steam degraded fuel gas quality and decreased gasification efficiency. The highest gasification efficiency of each oxygen concentration was at equivalence ratio of 0.3 and steam to biomass ratio of 0.58 for cob, and 0.22 and 0.68 for stover, respectively. ©2019. CBIORE-IJRED. All rights reserved


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