The effect of thermal pretreatment on the active sites and catalytic performances of PtSn/SiO2 catalyst in acetic acid （AcOH） hydrogenation was investigated in this article. The catalysts were characterized by N2 ph...The effect of thermal pretreatment on the active sites and catalytic performances of PtSn/SiO2 catalyst in acetic acid （AcOH） hydrogenation was investigated in this article. The catalysts were characterized by N2 physical adsorption, X-ray diffraction, transmission electron microscopy, pyridine Fourier-transform infrared spectra, and H2-O2 titration on its physicochemical properties. The results showed that Pt species were formed primarily in crystalline structure and no PtSnx alloy was observed. Meanwhile, with the increment of thermal pretreatrnent temperature, Pt dispersion showed a decreas- ing trend due to the aggregation of Pt particles. Simultaneously, the amount of Lewis acid sites was remarkably influenced by such thermal pretreatment owning to the consequent physicochemical property variation of Sn species. Interestingly, the catalytic activity showed the similar variation trend with that of Lewis acid sites, confirming the important roles of Lewis acid sites in AcOH hydrogenation. Moreover, a balancing effect between exposed Pt and Lewis acid sites was obtained, resulting in the superior catalytic performance in AcOH hydrogenation.展开更多
对三球悬铃木(俗称法国梧桐)落叶酸碱预处理及其同步糖化发酵产氢工艺进行实验研究,利用修正的冈珀茨模型(Gompertz model)对产氢曲线加以拟合,以累积产氢量和产氢速率为考察指标,研究不同酸碱预处理方法(添加质量分数为2%、4%、6%、8%...对三球悬铃木(俗称法国梧桐)落叶酸碱预处理及其同步糖化发酵产氢工艺进行实验研究,利用修正的冈珀茨模型(Gompertz model)对产氢曲线加以拟合,以累积产氢量和产氢速率为考察指标,研究不同酸碱预处理方法(添加质量分数为2%、4%、6%、8%的H2SO4和Ca(OH)2)对三球悬铃木落叶光合生物产氢性能的影响规律,优化出最佳酸碱预处理工艺条件为:稀酸预处理后的落叶试样的产氢性能优于氢氧化钙预处理后的落叶试样,其中H2SO4质量分数为4%时处理效果最佳,发酵产气中的氢气最大体积分数达66.34%,累积产氢量为369 m L,最高产氢速率11.03 m L/h。稀酸处理液可以实现3次有效回收利用。展开更多
The effects of acid hydrolysis pretreatment of corn cob on saccharification efficiency and fermentation bio-hydrogen production were investigated by orthogonal test design.The hydrolysis pretreatment of corn cob with ...The effects of acid hydrolysis pretreatment of corn cob on saccharification efficiency and fermentation bio-hydrogen production were investigated by orthogonal test design.The hydrolysis pretreatment of corn cob with dilute sulfuric acid was essential for adequately converting substrate into soluble saccharides and bio-hydrogen.The experimental results showed that acid hydrolysis pretreatment of corn cob was found most effective at hydrolysis temperature of 115℃,sulfuric acid concentration of 1.0%,hydrolysis time of 1.5 h and solid-liquid mass ratio 1∶10,in which both maximum saccharification efficiency of 0.5433 g·(g TVS)-1 and bio-hydrogen yield of 85.8 ml H2·(g TVS)-1 were observed.In addition,the mechanisms of degrading corn cob by acid hydrolysis and hydrogen fermentation were also discussed by means of X-ray diffraction(XRD)analysis and crystallinity calculation.展开更多
The aim of this study was to investigate the biohydrogen production from thermal(T),alkaline(A)or thermal-alkaline(TA)pretreated sludge fermentation liquid(SFL)in a microbial electrolysis cells(MECs)without buffer add...The aim of this study was to investigate the biohydrogen production from thermal(T),alkaline(A)or thermal-alkaline(TA)pretreated sludge fermentation liquid(SFL)in a microbial electrolysis cells(MECs)without buffer addition.Highest hydrogen yield of 36.87±4.36 mgH_(2)/gVSS(0.026 m^(3)/kg COD)was achieved in TA pretreated SFL separated by centrifugation,which was 5.12,2.35 and 43.25 times higher than that of individual alkaline,thermal pretreatment and raw sludge,respectively.Separating SFL from sludge by centrifugation eliminated the negative effects of particulate matters,was more conducive for hydrogen production than filtration.The accumulated short chain fatty acid(SCFAs)after pretreatments were the main substrates for MEC hydrogen production.The maximum utilization ratio of acetic acid,propionic acid and n-butyric acid was 93.69%,90.72%and 91.85%,respectively.These results revealed that pretreated WAS was highly efficient to stimulate the accumulation of SCFAs.And the characteristics and cascade bioconversion of complex substrates were the main factor that determined the energy efficiency and hydrogen conversion rate of MECs.展开更多
基金Acknowledgements We are grateful to the financial support from the National Natural Science Foundation of China （Grant Nos. 21276186, 21325626, 91434127, U1510203） and the Tianjin Natural Science Foundation （13JCZDJC33000）.
文摘The effect of thermal pretreatment on the active sites and catalytic performances of PtSn/SiO2 catalyst in acetic acid （AcOH） hydrogenation was investigated in this article. The catalysts were characterized by N2 physical adsorption, X-ray diffraction, transmission electron microscopy, pyridine Fourier-transform infrared spectra, and H2-O2 titration on its physicochemical properties. The results showed that Pt species were formed primarily in crystalline structure and no PtSnx alloy was observed. Meanwhile, with the increment of thermal pretreatrnent temperature, Pt dispersion showed a decreas- ing trend due to the aggregation of Pt particles. Simultaneously, the amount of Lewis acid sites was remarkably influenced by such thermal pretreatment owning to the consequent physicochemical property variation of Sn species. Interestingly, the catalytic activity showed the similar variation trend with that of Lewis acid sites, confirming the important roles of Lewis acid sites in AcOH hydrogenation. Moreover, a balancing effect between exposed Pt and Lewis acid sites was obtained, resulting in the superior catalytic performance in AcOH hydrogenation.
文摘对三球悬铃木(俗称法国梧桐)落叶酸碱预处理及其同步糖化发酵产氢工艺进行实验研究,利用修正的冈珀茨模型(Gompertz model)对产氢曲线加以拟合,以累积产氢量和产氢速率为考察指标,研究不同酸碱预处理方法(添加质量分数为2%、4%、6%、8%的H2SO4和Ca(OH)2)对三球悬铃木落叶光合生物产氢性能的影响规律,优化出最佳酸碱预处理工艺条件为:稀酸预处理后的落叶试样的产氢性能优于氢氧化钙预处理后的落叶试样,其中H2SO4质量分数为4%时处理效果最佳,发酵产气中的氢气最大体积分数达66.34%,累积产氢量为369 m L,最高产氢速率11.03 m L/h。稀酸处理液可以实现3次有效回收利用。
文摘The effects of acid hydrolysis pretreatment of corn cob on saccharification efficiency and fermentation bio-hydrogen production were investigated by orthogonal test design.The hydrolysis pretreatment of corn cob with dilute sulfuric acid was essential for adequately converting substrate into soluble saccharides and bio-hydrogen.The experimental results showed that acid hydrolysis pretreatment of corn cob was found most effective at hydrolysis temperature of 115℃,sulfuric acid concentration of 1.0%,hydrolysis time of 1.5 h and solid-liquid mass ratio 1∶10,in which both maximum saccharification efficiency of 0.5433 g·(g TVS)-1 and bio-hydrogen yield of 85.8 ml H2·(g TVS)-1 were observed.In addition,the mechanisms of degrading corn cob by acid hydrolysis and hydrogen fermentation were also discussed by means of X-ray diffraction(XRD)analysis and crystallinity calculation.
基金This research was supported by the National Natural Science Foundation of China(Grant No.51778607)and the Natural Science Fundation of Heilongjiang Province,China(No.LH2019E071).
文摘The aim of this study was to investigate the biohydrogen production from thermal(T),alkaline(A)or thermal-alkaline(TA)pretreated sludge fermentation liquid(SFL)in a microbial electrolysis cells(MECs)without buffer addition.Highest hydrogen yield of 36.87±4.36 mgH_(2)/gVSS(0.026 m^(3)/kg COD)was achieved in TA pretreated SFL separated by centrifugation,which was 5.12,2.35 and 43.25 times higher than that of individual alkaline,thermal pretreatment and raw sludge,respectively.Separating SFL from sludge by centrifugation eliminated the negative effects of particulate matters,was more conducive for hydrogen production than filtration.The accumulated short chain fatty acid(SCFAs)after pretreatments were the main substrates for MEC hydrogen production.The maximum utilization ratio of acetic acid,propionic acid and n-butyric acid was 93.69%,90.72%and 91.85%,respectively.These results revealed that pretreated WAS was highly efficient to stimulate the accumulation of SCFAs.And the characteristics and cascade bioconversion of complex substrates were the main factor that determined the energy efficiency and hydrogen conversion rate of MECs.
