scholarly journals Simultaneous Removal of SO2 and NOx From Flue Gas by Low-temperature Adsorption Over Activated Carbon

2020 ◽  
Author(s):  
Shiqing Wang ◽  
Qixiang Fan ◽  
Shisen Xu ◽  
Shiwang Gao ◽  
Ping Xiao ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Low Temperature ◽  
Flue Gas ◽  
Adsorption Process ◽  
Co Adsorption ◽  
Nitrogen Monoxide ◽  
Space Velocity ◽  
Pilot Scale ◽  
Breakthrough Time ◽  
Cold Temperatures

Abstract An exceptional phenomenon has been observed that nitrogen monoxide can be effectively adsorbed over activated carbon at cold temperatures with the presence of oxygen. Based on this finding, a novel low temperature adsorption process is developed to simultaneously remove SO2 and NOx from flue gas with a target of near-zero emission. In this study, the adsorption characteristics of NO and SO2 over activated carbon at various temperatures (-20, 0, 20 and 80℃) are experimentally investigated. For NO-O2 co-adsorption, NO-NO2 equilibriums with increasing NO2 concentration along the the adsorption bed are established due to the catalytic oxidation of NO over activated carbon. Co-adsorption of NO-NO2 occurs at each cross section of the adsorption bed and the adsorption capability increases along the adsorption bed with increasing NO2 concentrations. The oxidation rate of NO can be significantly enhanced at cold temperatures, which leads to an extraordinary improvement of NO adsorption. At a space velocity of 5000h-1 and an initial NO concentration of 200 ppmv, the breakthrough time increases from 3.49 to 1591.75 minutes when the temperature decreases from 80 to -20℃. In addition, the adsorption capacity of SO2 is also dramatically increased at cold temperatures. At a space velocity of 5000h-1 and an initial SO2 concentration of 1000 ppmv, the breakthrough time increase from 20 to 265 minutes when the temperature decreases from 80 to -20℃. A pilot-scale testing platform with a flue gas flowrate of 3600 Nm3/h is developed to validate this novel adsorption process for simultaneous desulfurization and denitrification. Emission of both SO2 and NOx is less than 1mg/Nm3, and the predicted energy penalty is about 3% of the net generation.

scholarly journals Simultaneous removal of SO2 and NOx from flue gas by low-temperature adsorption over activated carbon

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shiqing Wang ◽  
Shisen Xu ◽  
Shiwang Gao ◽  
Ping Xiao ◽  
Minhua Jiang ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Low Temperature ◽  
Adsorption Capacity ◽  
Flue Gas ◽  
Co Adsorption ◽  
Specific Capacity ◽  
Space Velocity ◽  
Oxygen Adsorption ◽  
Cold Temperatures ◽  
Initial Concentration

AbstractAn exceptional phenomenon has been observed that SO2 and NOx in flue gas can be effectively adsorbed over activated carbon with a surprising capacity at cold temperatures with the presence of oxygen. In this study, the adsorption characteristics of NO and SO2 over activated carbon at 80, 20, 0, and − 20 is experimentally investigated. Without the presence of oxygen, adsorption of NO is negligible. In the presence of oxygen, NO can be oxidized to NO2 over activated carbon which leads to the co-adsorption of NO/NO2 within the adsorption bed. Catalytic oxidation of NO over activated carbon can be significantly enhanced at cold temperatures, leading to an extraordinary increase of adsorption capacity of NO. With an initial concentration of NO = 200 ppmv and a space velocity of 5000 h−1, the average specific capacity increases from 3.8 to 169.1 mg/g when the temperature decreases from 80 to – 20 ℃. For NO–O2 co-adsorption, the specific capacity increases along the adsorption bed due to the increasing NO2 concentrations. The adsorption capacity of SO2 is also significantly enhanced at cold temperatures. With an initial concentration of SO2 = 1000 ppmv, the specific capacity increases from 12.9 to 123.1 mg/g when the temperature decreases from 80 to – 20 ℃. A novel low-temperature adsorption (LAS) process is developed to simultaneously remove SO2 and NOx from flue gas with a target of near-zero emission. A pilot-scale testing platform with a flue gas flowrate of 3600 Nm3/h is developed and tested. Emission of both SO2 and NOx is less than 1 ppmv, and the predicted energy penalty is about 3% of the net generation.

Denitrification Activities of Mo-V-Ti Catalysts Prepared by Dipping Method at Low Temperature

2018 ◽  
Vol 913 ◽  
pp. 900-906
Author(s):  
Dong Zhu Ma ◽  
Jian Li ◽  
Di Yin ◽  
Yuan Huang ◽  
Rui Min Wang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Conversion Efficiency ◽  
Flue Gas ◽  
Catalytic Reduction ◽  
Fixed Bed ◽  
Space Velocity ◽  
Fixed Bed Reactor ◽  
Optimum Ratio ◽  
Denitrification Activity ◽  
Gas Space

Mo-V-Ti catalysts of low temperature denitrification were prepared by dipping method. In order to study the activity of selective catalytic reduction, the catalyst was placed in a fixed bed reactor. Industrial flue gas was simulated with cylinder gas. The experimental condition is NO: 500ppm, NH3:500ppm, O2:8%, SO2:100ppm, N2: equilibrium gas, space velocity: 36000h-1. Results indicate that the catalyst prepared by dipping method had good denitrification activity and sulfur resistance at low temperature. The optimum ratio of catalyst was 3V2O5-6MoO3-91TiO2 (wt %). The conversion efficiency of NO was 80~93%, and the conversion efficiency of SO2 was less than 1% at 180~260 °C.

Denitrification Activities of Mg-Mo-V-Ti Catalysts Prepared by Dipping Method at Low Temperature

2018 ◽  
Vol 913 ◽  
pp. 893-899
Author(s):  
Dong Zhu Ma ◽  
Jian Li ◽  
Ling Zhang ◽  
Peng Guo ◽  
Zi Qiang Wen ◽  
...  
Keyword(s):  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
Oxygen Content ◽  
Oxygen Concentration ◽  
Flue Gas ◽  
Catalytic Reduction ◽  
Fixed Bed ◽  
Space Velocity ◽  
Fixed Bed Reactor ◽  
Sulfur Resistance

Mg-Mo-V-Ti catalysts of low temperature denitrification were prepared by dipping method. In order to study the activity of selective catalytic reduction, the catalyst was placed in a fixed bed reactor. Industrial flue gas was simulated with cylinder gas. Results indicate that the 0.1wt% content of MgO catalyst has good performance on denitration activity and sulfur resistance. The effects of oxygen content, space velocity and reaction temperature on the activity of the 0.1MgO-6MoO3-3V2O5-TiO2 wt% catalyst were investigated. With the increase of oxygen concentration, the denitrification efficiency increases when the oxygen concentration is less than 8%. When the oxygen content is greater than 8%, the denitrification efficiency is almost the same. The denitrification efficiency decreases with the increase of space velocity. The removal efficiency of NO 0.1MgO-6MoO3-3V2O5-TiO2 wt% catalyst over increases first and then becomes stable with the increase of temperature, and the conversion efficiency of SO2 is less than or equal to 2.2% at 120~240 °C.

scholarly journals Nitric oxide removal by zinc chloride activated oil palm empty fruit bunch fibre

2021 ◽  
Vol 17 (1) ◽  
pp. 84-89
Author(s):  
Cha Soon Lin ◽  
Naimah Ibrahim ◽  
Norhidayah Ahmad ◽  
Muhammad Adli Hanif ◽  
Sureena Abdullah
Keyword(s):  
Nitric Oxide ◽  
Activated Carbon ◽  
Kinetic Model ◽  
Zinc Chloride ◽  
Flue Gas ◽  
Adsorption Process ◽  
Waste Materials ◽  
Empty Fruit Bunch ◽  
No Adsorption ◽  
No Removal

Nitric oxide (NO) emission is known to pose detrimental effects towards the environment and human beings. Low-temperature NO removal by activated carbon from agricultural waste materials is affordable due to the use of low-cost materials as precursor and elimination of the need for flue gas reheating. The use of chemical agents in activated carbon production improves the performance of waste materials in NO removal. The performance of NO removal was investigated via breakthrough experiment using oil palm empty fruit bunch (EFB) activated with zinc chloride (ZnCl2) at different concentrations (0.1, 0.5, and 1.5 M). Activation of EFB with 0.5 M ZnCl2 resulted in the formation of well-defined micropores, but the use of higher concentration of ZnCl2 resulted in widening of developed pores and intense pore blockage which reduce the accessibility of NO molecules to the adsorption sites. An adsorption isotherm study conducted using 0.5 M ZnCl2/EFB sample with varying NO concentration between 300-1000 ppm indicated that the adsorption process was best defined by Langmuir isotherm model. In addition, adsorption kinetic was investigated at different temperatures; i.e. 100, 150, 200, 250 and 300 °C. NO removal was found to follow Avrami kinetic model at T=100 °C, while upon further increase in temperature, the process was better fitted to the pseudo-second order kinetic model. NO adsorption capacity increases significantly beyond 250 °C up to 1000 mg/g. The activation energy of NO adsorption fell into two distinct regions: -4.73 kJ/mol at 100-200 °C and 84.04 kJ/mol at 200-300 °C. At lower temperature, the adsorption process was exothermic and followed physisorption path, while the increase in reaction temperature led to slower rate of reaction. It was concluded that the removal of NO using EFB modified with ZnCl2 at optimized condition could be a promising alternatives for treating NO-containing flue gas.

scholarly journals Pilot scale study on medium/low temperature SCR denitration technology for industrial flue gas

2019 ◽  
Vol 267 ◽  
pp. 022035
Author(s):  
Xiang Xiao ◽  
Ping Fang ◽  
Jianhang Huang ◽  
Haiwen Wu ◽  
Zhixiong Tang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Flue Gas ◽  
Pilot Scale ◽  
Low Temperature Scr

Experimental Study of Breakthrough Adsorption on Activated Carbon for CO2 Capture

2011 ◽  
Vol 356-360 ◽  
pp. 1139-1144
Author(s):  
Qi Gang Cen ◽  
Meng Xiang Fang ◽  
Jia Ping Xu ◽  
Zhong Yang Luo
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Flow Rate ◽  
Flue Gas ◽  
Fixed Bed ◽  
Column Efficiency ◽  
Breakthrough Time ◽  
Fixed Bed Column ◽  
Temperature Changes ◽  
Adsorbent Capacity

In this study, a commercial activated carbon was assessed as adsorbent for post-combustion CO2 capture. The breakthrough adsorption experiments were conducted in a fixed-bed column with simulated flue gas of 12% CO2. The effects of feed flow rate and adsorption pressure on breakthrough time and CO2 adsorption capacity were evaluated. The column efficiency was introduced to estimate the percentage of the utilization of the bed adsorbent capacity. At a higher flow rate, the breakthrough time, breakthrough capacity and column efficiency decreased. Conversely, increasing adsorption pressure was favorable to CO2 adsorption by the increase in breakthrough time, CO2 adsorption capacity and the column efficiency. During the experiments, temperature changes were detected at three positions inside the column to track the movement of breakthrough front.

Adsorption CO2 on Activated Carbon with Surface Modification

2013 ◽  
Vol 634-638 ◽  
pp. 746-750 ◽  
Author(s):  
Cheng Lin ◽  
Hui Yun Zhang ◽  
Xiao Ying Lin ◽  
Yun Fei Feng
Keyword(s):  
Surface Modification ◽  
Activated Carbon ◽  
Activate Carbon ◽  
Adsorption Capacity ◽  
Flue Gas ◽  
Adsorption Process ◽  
Low Cost ◽  
Solid Sorbent ◽  
Adsorption Capacities ◽  
New Type

The success of CO2 capture from flue gas with solid sorbent is dependent of a low cost sorbent with high CO2 adsorption capacity and selectivity. Modifying surface texture of activated carbon with impregnating amines is expected to offer the benefits of liquid amines in the typical adsorption process routes. In this work, cocoanut activate carbon (AC) is firstly alkalified by KOH solution, then modified by impregnation of tetraethylenepentamine (TEPA), triethylenetetramine (TATA), and triethanolamine (TEA) to form a new type of sorbents. The effects of alkalifying treatment and temperature on CO2 adsorption capacities of the sorbents are investigated. Results indicate that the activate carbons modified by combining alkalification pretreatment firstly and then impregnated amines at low temperature are profitable for CO2 adsorption. The adsorption capacities of CO2 are enhanced with TEPA and TETA impregnation on the activate carbon pretreated by KOH solution. And CO2 adsorption capacity of new sorbents is stable after many adsorption and desorption cycles.

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