Thiobacillus denitrificans, a kind of autotrophic facultative bacteria, can oxidize sulfide into elemental sulfur or sulfate when nitrate was adopted as its electron accepter and carbon dioxide as its carbon resource ...Thiobacillus denitrificans, a kind of autotrophic facultative bacteria, can oxidize sulfide into elemental sulfur or sulfate when nitrate was adopted as its electron accepter and carbon dioxide as its carbon resource under anoxic or anaerobic environment. In this way, nitrate is converted into nitrogen. In addition, Thiobacillus denitrificans can accumulate sulfur extracellularly. In this study, in a process of simultaneous desulfurization and denitrification, a strain of Thiobacillus denitrificans is employed as sulfur-producer in the treatment of wastewater containing sulfide and nitrate. The key factors affecting this process are investigated through batch tests. The experimental results indicate that the sulfide concentration and the ratio of sulfide to nitrate (S^2-/NO3^-) in the influent are the key factors, and their suitable values are suggested to be 5/3 and no more than 300mg·L^-1, respectively, in order to achieve high conversion of sulfur.展开更多
The optimum conditions for sulfur removal from coal by electrochemical reduction flotation in an aqueous NaCl solution were determined from orthogonal experiments. The effect of electrolytic conditions on the desulfur...The optimum conditions for sulfur removal from coal by electrochemical reduction flotation in an aqueous NaCl solution were determined from orthogonal experiments. The effect of electrolytic conditions on the desulfurization ratio was also studied. The electrochemical-reduction processed coal was examined by X-ray diffraction, Fourier transform infrared spectroscopy and wet chemical analysis. The results show that electrochemical reduction converts hydrophobic pyrite in Nantong coal into hydrophilic FeS and S2- and leads to an increase in the concentration of hydroxyl groups and aliphatic moieties and a corresponding decrease in carboxyl and carbonyl groups, which enhances the flotation desulfurization of the coal.展开更多
A new combined desulfarizatinn/denitraticon (DeSOx/DeNOx) procees was teeted in this study. The procees uses the so-called powder-partlcle fluidized bed (PPFB) as the major reactor in which a coarse DeNOx catalyst, se...A new combined desulfarizatinn/denitraticon (DeSOx/DeNOx) procees was teeted in this study. The procees uses the so-called powder-partlcle fluidized bed (PPFB) as the major reactor in which a coarse DeNOx catalyst, several hundrsd micrometers in size, is fluidized by flue gas as the fluidization medium particles while a contlnuogsly supplied fine DeSOx sorbent, several to tens of micrometers in dianteter, is entrained with the flue gas. Ammonin for NOx reduction is fed to the bottom of the bed, thus, SOx and NOx are simultaneously removed in the single reactor.By adopting a model gas, SO2-NO-HaO-N2-air, to simulate actual flue gas in a laboratory-scale PPFB, simultaneous SO2 and NO removals were explored with respect to various gas components of flue gas. It was found that the vaxlations of SO2 removal with concentrations (fractions) of oxygen, water vapor, SO2 and NO in flue gas are little affected by the simultaneous NOx reduction. However,the dependencles of NO removal upon such gas components are clveely related to the inter-actions between DeSOx sorbent and DeNOx catalyst.展开更多
Different two-equation k-ε models were used to simulate the gas flow field generated by a new type of circulating fluidized bed reactor with venturi gas distributor. The numerical results were compared with the exp...Different two-equation k-ε models were used to simulate the gas flow field generated by a new type of circulating fluidized bed reactor with venturi gas distributor. The numerical results were compared with the experimental data. It has been shown that the simulation results from the standard k-ε model have the best match with the experimental data. Based on this model, the gas flow field in the venturi diffuser and riser was analyzed by the concept of velocity nonuniformity and dead zone percentage. Both the nonuniformity of gas velocity and the dead zone percentage reach the maximum at the venturi outlet due to the effect of the vortex. At the same time, it provides a good platform for the further optimization of the inlet configuration of circulating fluidized bed reactor.展开更多
The microwave technology was introduced for the desulfurization of diesel fuel. The atmosphericsecond side-cut diesel fraction, which was supplied by Liaohe Petrochemical Company, was desulfurized by anoxidation proce...The microwave technology was introduced for the desulfurization of diesel fuel. The atmosphericsecond side-cut diesel fraction, which was supplied by Liaohe Petrochemical Company, was desulfurized by anoxidation process under microwave irradiation. Hydrogen peroxide (H2O2), can oxidize the sulfur compounds indiesel fuel selectively and convert them into sulfones. Based on the rule of dissolution by similar substances,these sulfones are removed from diesel fuel because they could be dissolved in solvent phase. So the sulfurcontent of diesel fuel is decreased. The influence of the concentration of oxidizing reagent, solvent phase to oilphase volume ratio (S/O), irradiation pressure, irradiation time, and the irradiation power have been investigated.The optimum conditions for the refining process was determined. The sulfur removal rate was 59.7% under theoptimum conditions of 8%H2O2, S/O=0.25, 0.05MPa, 6 min, and 375W, respectively. When no microwave irradia-tion was applied, the removal rate was 11.5% only.展开更多
We prepared an SbSn intermetallic compound powder with a mixture of equal molar amounts of antimony (Sb) and tin (Sn) by melt-annealing and high-energy ball milling,and characterized the obtained substance with XRD (X...We prepared an SbSn intermetallic compound powder with a mixture of equal molar amounts of antimony (Sb) and tin (Sn) by melt-annealing and high-energy ball milling,and characterized the obtained substance with XRD (X-ray diffraction),DSC (differential scanning calorimetry),SEM (scanning electron microscopy),and XPS (X-ray photoelectron spectroscopy). The prepared SbSn has a hexagonal structure with a melting point of 425 °C. The particles have a dendritic appearance in micromorphology images. More Sb atoms are enriched on the surface than Sn atoms. A desulfurization efficiency of up to 33.92% can be obtained when applying this powder as a medium in the electric desulfurization of crude oil under the following conditions: an emulsion with a volumetric ratio of water to oil at 20:80,a surfactant mass fraction in the emulsion of 0.18%,a processing time of 17 h,and a voltage of 9.68 V. SbSn could be a promising catalyst for desulfurizing crude oil. The desulfurization performance is ascribed to the electron cavities formed by current induction.展开更多
Increasingly high requirement driven by environmental concern leads to more rigorous standards for sulfur dosage in fuel. Natural gas desulfurization is an important unit for industrial natural gas process. Catalytic ...Increasingly high requirement driven by environmental concern leads to more rigorous standards for sulfur dosage in fuel. Natural gas desulfurization is an important unit for industrial natural gas process. Catalytic membrane reactor for sulfur compounds removal is a newly emerged and integrated membrane technology. We reviewed the current progress for desulfurization of natural gas with membrane process, and predicted that the process combined with catalytic membrane reactor and microwave irradiation for desulfurization of natural gas might be an integrated and promising unit for large scale desulfurization with high efficiency.展开更多
Two Zn-based sorbents, L-991 and L-992 used for hot gas desulfurization (HGD) were introduced. Zn/Ti ratio of the two sorbent was 1:1 and 2:3 resptively and a certain proportion of Cu and Mn metal oxide were added int...Two Zn-based sorbents, L-991 and L-992 used for hot gas desulfurization (HGD) were introduced. Zn/Ti ratio of the two sorbent was 1:1 and 2:3 resptively and a certain proportion of Cu and Mn metal oxide were added into L-992, which provided better performance than L-991 in aspects of suitable work temperature, sulfur capacity and agglomeration on the surface of sorbent particles. The evaluation tests were done on both sorbents include multi cycles tests. ARD and SEM analysis were done on fresh and post tests sorbent. During continuous sulfidation/regeneration, the H2S concentra- tion can be reduced from about 10 g/m3 to less than 20 mg/m3, the H2S removal effi- ciency >99 %.展开更多
The DDA-II process aimed at manufacture of diesel fuel meeting the Euro-IV emission standard from inferior diesel feedstock has been developed and tested in pilot scale. This technology adopts non-noble metal catalyst...The DDA-II process aimed at manufacture of diesel fuel meeting the Euro-IV emission standard from inferior diesel feedstock has been developed and tested in pilot scale. This technology adopts non-noble metal catalysts and a highly integrated two-stage process scheme featuring low investment and operating cost and convenience in operation. Under an appropriate process regime the DDA-II technology can process FCC LCO, a blend of straight-run diesel and FCC LCO, or the SR diesel to yield the diesel product streams meeting the Euro-IV or even higher emission standards.展开更多
基金Supported by the National Natural Science Foundation of China (No. 50208006).
文摘Thiobacillus denitrificans, a kind of autotrophic facultative bacteria, can oxidize sulfide into elemental sulfur or sulfate when nitrate was adopted as its electron accepter and carbon dioxide as its carbon resource under anoxic or anaerobic environment. In this way, nitrate is converted into nitrogen. In addition, Thiobacillus denitrificans can accumulate sulfur extracellularly. In this study, in a process of simultaneous desulfurization and denitrification, a strain of Thiobacillus denitrificans is employed as sulfur-producer in the treatment of wastewater containing sulfide and nitrate. The key factors affecting this process are investigated through batch tests. The experimental results indicate that the sulfide concentration and the ratio of sulfide to nitrate (S^2-/NO3^-) in the influent are the key factors, and their suitable values are suggested to be 5/3 and no more than 300mg·L^-1, respectively, in order to achieve high conversion of sulfur.
基金supported by the Special Fund for Major State Basic Research Program of China (Project 2004CB217601).
文摘The optimum conditions for sulfur removal from coal by electrochemical reduction flotation in an aqueous NaCl solution were determined from orthogonal experiments. The effect of electrolytic conditions on the desulfurization ratio was also studied. The electrochemical-reduction processed coal was examined by X-ray diffraction, Fourier transform infrared spectroscopy and wet chemical analysis. The results show that electrochemical reduction converts hydrophobic pyrite in Nantong coal into hydrophilic FeS and S2- and leads to an increase in the concentration of hydroxyl groups and aliphatic moieties and a corresponding decrease in carboxyl and carbonyl groups, which enhances the flotation desulfurization of the coal.
文摘A new combined desulfarizatinn/denitraticon (DeSOx/DeNOx) procees was teeted in this study. The procees uses the so-called powder-partlcle fluidized bed (PPFB) as the major reactor in which a coarse DeNOx catalyst, several hundrsd micrometers in size, is fluidized by flue gas as the fluidization medium particles while a contlnuogsly supplied fine DeSOx sorbent, several to tens of micrometers in dianteter, is entrained with the flue gas. Ammonin for NOx reduction is fed to the bottom of the bed, thus, SOx and NOx are simultaneously removed in the single reactor.By adopting a model gas, SO2-NO-HaO-N2-air, to simulate actual flue gas in a laboratory-scale PPFB, simultaneous SO2 and NO removals were explored with respect to various gas components of flue gas. It was found that the vaxlations of SO2 removal with concentrations (fractions) of oxygen, water vapor, SO2 and NO in flue gas are little affected by the simultaneous NOx reduction. However,the dependencles of NO removal upon such gas components are clveely related to the inter-actions between DeSOx sorbent and DeNOx catalyst.
文摘Different two-equation k-ε models were used to simulate the gas flow field generated by a new type of circulating fluidized bed reactor with venturi gas distributor. The numerical results were compared with the experimental data. It has been shown that the simulation results from the standard k-ε model have the best match with the experimental data. Based on this model, the gas flow field in the venturi diffuser and riser was analyzed by the concept of velocity nonuniformity and dead zone percentage. Both the nonuniformity of gas velocity and the dead zone percentage reach the maximum at the venturi outlet due to the effect of the vortex. At the same time, it provides a good platform for the further optimization of the inlet configuration of circulating fluidized bed reactor.
文摘The microwave technology was introduced for the desulfurization of diesel fuel. The atmosphericsecond side-cut diesel fraction, which was supplied by Liaohe Petrochemical Company, was desulfurized by anoxidation process under microwave irradiation. Hydrogen peroxide (H2O2), can oxidize the sulfur compounds indiesel fuel selectively and convert them into sulfones. Based on the rule of dissolution by similar substances,these sulfones are removed from diesel fuel because they could be dissolved in solvent phase. So the sulfurcontent of diesel fuel is decreased. The influence of the concentration of oxidizing reagent, solvent phase to oilphase volume ratio (S/O), irradiation pressure, irradiation time, and the irradiation power have been investigated.The optimum conditions for the refining process was determined. The sulfur removal rate was 59.7% under theoptimum conditions of 8%H2O2, S/O=0.25, 0.05MPa, 6 min, and 375W, respectively. When no microwave irradia-tion was applied, the removal rate was 11.5% only.
文摘We prepared an SbSn intermetallic compound powder with a mixture of equal molar amounts of antimony (Sb) and tin (Sn) by melt-annealing and high-energy ball milling,and characterized the obtained substance with XRD (X-ray diffraction),DSC (differential scanning calorimetry),SEM (scanning electron microscopy),and XPS (X-ray photoelectron spectroscopy). The prepared SbSn has a hexagonal structure with a melting point of 425 °C. The particles have a dendritic appearance in micromorphology images. More Sb atoms are enriched on the surface than Sn atoms. A desulfurization efficiency of up to 33.92% can be obtained when applying this powder as a medium in the electric desulfurization of crude oil under the following conditions: an emulsion with a volumetric ratio of water to oil at 20:80,a surfactant mass fraction in the emulsion of 0.18%,a processing time of 17 h,and a voltage of 9.68 V. SbSn could be a promising catalyst for desulfurizing crude oil. The desulfurization performance is ascribed to the electron cavities formed by current induction.
基金Funded by the Natural Science Fundation of China for Creative Research Groups (No. 50621403)the Visiting Scholar Foundation of Key Lab. of University Projects (KLVF-2006-5).
文摘Increasingly high requirement driven by environmental concern leads to more rigorous standards for sulfur dosage in fuel. Natural gas desulfurization is an important unit for industrial natural gas process. Catalytic membrane reactor for sulfur compounds removal is a newly emerged and integrated membrane technology. We reviewed the current progress for desulfurization of natural gas with membrane process, and predicted that the process combined with catalytic membrane reactor and microwave irradiation for desulfurization of natural gas might be an integrated and promising unit for large scale desulfurization with high efficiency.
基金Supported by China National "95" Project (96-A26-03-02-01) China National "863" Project (2002AA529080) and China-UK, BRICC, CCRI
文摘Two Zn-based sorbents, L-991 and L-992 used for hot gas desulfurization (HGD) were introduced. Zn/Ti ratio of the two sorbent was 1:1 and 2:3 resptively and a certain proportion of Cu and Mn metal oxide were added into L-992, which provided better performance than L-991 in aspects of suitable work temperature, sulfur capacity and agglomeration on the surface of sorbent particles. The evaluation tests were done on both sorbents include multi cycles tests. ARD and SEM analysis were done on fresh and post tests sorbent. During continuous sulfidation/regeneration, the H2S concentra- tion can be reduced from about 10 g/m3 to less than 20 mg/m3, the H2S removal effi- ciency >99 %.
文摘The DDA-II process aimed at manufacture of diesel fuel meeting the Euro-IV emission standard from inferior diesel feedstock has been developed and tested in pilot scale. This technology adopts non-noble metal catalysts and a highly integrated two-stage process scheme featuring low investment and operating cost and convenience in operation. Under an appropriate process regime the DDA-II technology can process FCC LCO, a blend of straight-run diesel and FCC LCO, or the SR diesel to yield the diesel product streams meeting the Euro-IV or even higher emission standards.
