We prepared a kind of metal oxide-modified walnut-shell activated carbon(MWAC) by KOH chemical activation method and used for PH_3 adsorption removal. Meanwhile, the PH_3 adsorption equilibrium was investigated experi...We prepared a kind of metal oxide-modified walnut-shell activated carbon(MWAC) by KOH chemical activation method and used for PH_3 adsorption removal. Meanwhile, the PH_3 adsorption equilibrium was investigated experimentally and fitted by the Toth equation, and the isosteric heat of PH_3 adsorption was calculated by the Clausius-Clapeyron Equation. The exhausted MWAC was regenerated by water washing and air drying. Moreover, the properties of five different samples were characterized by N_2 adsorption isotherm, SEM/EDS, XPS, and FTIR. The results showed that the maximum PH_3 equilibrium adsorption capacity was 595.56 mg/g. The MWAC had an energetically heterogeneous surface due to values of isosteric heat of adsorption ranging from 43 to 90 kJ/mol. The regeneration method provided an effective way for both adsorption species recycling and exhausted carbon regeneration. The high removal efficiency and big equilibrium adsorption capacity for PH_3 adsorption on the MWAC were related to its large surface area and high oxidation activity in PH_3 adsorption-oxidation to H_3 PO_4 and P_2 O_5. Furthermore, a possible PH_3 adsorption mechanism was proposed.展开更多
Walnut-shellactivated carbons（WSACs）were prepared by the KOH chemicalactivation.The effects of carbonization temperature,activation temperature,and ratio of KOH to chars on the pore development of WSACs were investi...Walnut-shellactivated carbons（WSACs）were prepared by the KOH chemicalactivation.The effects of carbonization temperature,activation temperature,and ratio of KOH to chars on the pore development of WSACs were investigated.Fourier transform infrared spectroscopy（FTIR）,X-ray powder diffraction（XRD）,and scanning electron microscopy（SEM）were employed to characterize the microstructure and morphology of WSACs.Methanoladsorption performance onto the optimalWSAC and the coal-based AC were also investigated.The results show that the optimalpreparation conditions are a carbonization temperature of 700 ℃,an activation temperature of 700 ℃,and a mass ratio of 3.The BET surface area,the micropore volume,and the micropore volume percentage of the optimalWASC are 1636 m^2/g,0.641 cm^3/g and 81.97%,respectively.There are a lot of micropores and a certain amount of meso-and macropores.The characteristics of the amorphous state are identified.The results show that the optimalWSAC is favorable for methanoladsorption.The equilibrium adsorption capacity of the optimalWSAC is 248.02mg/g.It is shown that the equilibrium adsorption capacity of the optimalWSAC is almost equivalent to that of the common activated carbon.Therefore the optimalWSAC could be a potentialadsorbent for the solar energy adsorption refrigeration cycle.展开更多
Hydrothermal carbon（HC） was prepared from walnut shells, which are abundant in Northeastern China. The prepared HC was used as a precursor to produce mtric acid modified carbon（MC）. The hydrothermal carbonization ...Hydrothermal carbon（HC） was prepared from walnut shells, which are abundant in Northeastern China. The prepared HC was used as a precursor to produce mtric acid modified carbon（MC）. The hydrothermal carbonization included dehydration and decarboxylation processes wherein the hemicellulose was completely decomposed and the celhilose was partly decomposed, with some oxygen-containing functional groups being produced. The aromati- city, specific surface area and pore content of the HC increased, but its polarity decreased. With 6 mol/L nitric acid and a modification time of 15 min, the specific surface area and pore content decreased, but the proportion of oxy- gen-containing fimctional groups on the surface increased significantly, thereby improving the dye adsorption performance. The adsorption of methylene blue and malachite green was best desclibed by the pseudo-second-order kinetic and Langmuir isotherm models. The adsorption capacity of MC was determined to be much larger than that of HC.展开更多
Walnut-shell activated carbon（WSAC） supported ferric oxide was modified by non-thermal plasma（NTP）, and the removal efficiency for hydrogen sulfide over Fe/WSAC modified by dielectric barrier discharge（DBD） was ...Walnut-shell activated carbon（WSAC） supported ferric oxide was modified by non-thermal plasma（NTP）, and the removal efficiency for hydrogen sulfide over Fe/WSAC modified by dielectric barrier discharge（DBD） was significantly promoted. The sample modified for10 min and 6.8 k V output（30 V input voltage） maintained 100% H2 S conversion over a long reaction time of 390 min. The surface properties of adsorbents modified by NTP under different conditions were evaluated by the methods of X-ray photoelectron spectroscopy（XPS）, Brunauer–Emmett–Teller（BET） analysis and in-situ Fourier transform infrared spectroscopy（FTIR）, to help understand the effect of the NTP treatment. NTP treatment enhanced the adsorption capacity of Fe/WSAC, which could due to the formation of micro-pores with sizes of0.4, 0.5 and 0.75 nm. XPS revealed that chemisorbed oxygen changed into lattice oxygen after NTP treatment, and lattice oxygen is beneficial for H2 S oxidation. From the in-situ FTIR result,transformation of the reaction path on Fe/WSAC was observed after NTP modification. The research results indicate that NTP is an effective method to improve the surface properties of the Fe/WSAC catalyst for H2 S adsorption-oxidation.展开更多
以核桃壳为原料,采用微波辐照磷酸法制备活性炭.探讨了磷酸浓度、微波功率、辐照时间及对产品活性炭的亚甲基蓝脱色力、碘吸附值及得率的影响.确定了微波辐照磷酸法制备活性炭的工艺条件:微波功率460 W,活化时间10 m in,磷酸质量分数50%...以核桃壳为原料,采用微波辐照磷酸法制备活性炭.探讨了磷酸浓度、微波功率、辐照时间及对产品活性炭的亚甲基蓝脱色力、碘吸附值及得率的影响.确定了微波辐照磷酸法制备活性炭的工艺条件:微波功率460 W,活化时间10 m in,磷酸质量分数50%.在此条件下制得的活性炭碘吸附值为809.06 mg/g,亚甲基蓝脱色率108 mL/g,得率52.96%.活化时间是传统工艺水蒸汽活化核桃壳制活性炭的1/9,得率是传统工艺的2.6倍.展开更多
基金Funded by the National Natural Science Foundation of China(51566017)
文摘We prepared a kind of metal oxide-modified walnut-shell activated carbon(MWAC) by KOH chemical activation method and used for PH_3 adsorption removal. Meanwhile, the PH_3 adsorption equilibrium was investigated experimentally and fitted by the Toth equation, and the isosteric heat of PH_3 adsorption was calculated by the Clausius-Clapeyron Equation. The exhausted MWAC was regenerated by water washing and air drying. Moreover, the properties of five different samples were characterized by N_2 adsorption isotherm, SEM/EDS, XPS, and FTIR. The results showed that the maximum PH_3 equilibrium adsorption capacity was 595.56 mg/g. The MWAC had an energetically heterogeneous surface due to values of isosteric heat of adsorption ranging from 43 to 90 kJ/mol. The regeneration method provided an effective way for both adsorption species recycling and exhausted carbon regeneration. The high removal efficiency and big equilibrium adsorption capacity for PH_3 adsorption on the MWAC were related to its large surface area and high oxidation activity in PH_3 adsorption-oxidation to H_3 PO_4 and P_2 O_5. Furthermore, a possible PH_3 adsorption mechanism was proposed.
基金Funded by the National Natural Science Foundation of China(Nos.U1137605,51366014,51466017,and 51566017)the General Program of Yunnan Provincial Applied Fundamental Research(No.2011FZ076)the Scientific Research Training Foundation of Undergraduate(No.ky2014-179)
文摘Walnut-shellactivated carbons（WSACs）were prepared by the KOH chemicalactivation.The effects of carbonization temperature,activation temperature,and ratio of KOH to chars on the pore development of WSACs were investigated.Fourier transform infrared spectroscopy（FTIR）,X-ray powder diffraction（XRD）,and scanning electron microscopy（SEM）were employed to characterize the microstructure and morphology of WSACs.Methanoladsorption performance onto the optimalWSAC and the coal-based AC were also investigated.The results show that the optimalpreparation conditions are a carbonization temperature of 700 ℃,an activation temperature of 700 ℃,and a mass ratio of 3.The BET surface area,the micropore volume,and the micropore volume percentage of the optimalWASC are 1636 m^2/g,0.641 cm^3/g and 81.97%,respectively.There are a lot of micropores and a certain amount of meso-and macropores.The characteristics of the amorphous state are identified.The results show that the optimalWSAC is favorable for methanoladsorption.The equilibrium adsorption capacity of the optimalWSAC is 248.02mg/g.It is shown that the equilibrium adsorption capacity of the optimalWSAC is almost equivalent to that of the common activated carbon.Therefore the optimalWSAC could be a potentialadsorbent for the solar energy adsorption refrigeration cycle.
文摘Hydrothermal carbon（HC） was prepared from walnut shells, which are abundant in Northeastern China. The prepared HC was used as a precursor to produce mtric acid modified carbon（MC）. The hydrothermal carbonization included dehydration and decarboxylation processes wherein the hemicellulose was completely decomposed and the celhilose was partly decomposed, with some oxygen-containing functional groups being produced. The aromati- city, specific surface area and pore content of the HC increased, but its polarity decreased. With 6 mol/L nitric acid and a modification time of 15 min, the specific surface area and pore content decreased, but the proportion of oxy- gen-containing fimctional groups on the surface increased significantly, thereby improving the dye adsorption performance. The adsorption of methylene blue and malachite green was best desclibed by the pseudo-second-order kinetic and Langmuir isotherm models. The adsorption capacity of MC was determined to be much larger than that of HC.
基金supported by National Natural Science Foundation of China(Nos.21667015,51408282 and 21367016)
文摘Walnut-shell activated carbon（WSAC） supported ferric oxide was modified by non-thermal plasma（NTP）, and the removal efficiency for hydrogen sulfide over Fe/WSAC modified by dielectric barrier discharge（DBD） was significantly promoted. The sample modified for10 min and 6.8 k V output（30 V input voltage） maintained 100% H2 S conversion over a long reaction time of 390 min. The surface properties of adsorbents modified by NTP under different conditions were evaluated by the methods of X-ray photoelectron spectroscopy（XPS）, Brunauer–Emmett–Teller（BET） analysis and in-situ Fourier transform infrared spectroscopy（FTIR）, to help understand the effect of the NTP treatment. NTP treatment enhanced the adsorption capacity of Fe/WSAC, which could due to the formation of micro-pores with sizes of0.4, 0.5 and 0.75 nm. XPS revealed that chemisorbed oxygen changed into lattice oxygen after NTP treatment, and lattice oxygen is beneficial for H2 S oxidation. From the in-situ FTIR result,transformation of the reaction path on Fe/WSAC was observed after NTP modification. The research results indicate that NTP is an effective method to improve the surface properties of the Fe/WSAC catalyst for H2 S adsorption-oxidation.
