A new environmental friendly catalyst, H_4SiW_(12)O_(40)/PAn was prepared andidentified by means of FT-IR, XRD and TG/DTA. Cyclohexanone 1,2-propanediol ketal was synthesizedfrom cyclohexanone and 1,2-propanediol in t...A new environmental friendly catalyst, H_4SiW_(12)O_(40)/PAn was prepared andidentified by means of FT-IR, XRD and TG/DTA. Cyclohexanone 1,2-propanediol ketal was synthesizedfrom cyclohexanone and 1,2-propanediol in the presence of H_4SiW_(12)O_(40)/PAn The factorsinfluencing tlie synthesis were discussed and the best conditions were found out. The optimumconditions are: molar ratio of cyclohexanone to 1,2-propanediol is 1:1.4, the quantity of catalystis equal to 1.0 percent of feed stocks, and the reaction time is 40 min. H_4SiW_(12)O_(40)/PAn is anexcellent catalyst for synthesizing cyclohexanone 1,2-propanediol ketal and its yield can reachover 96.5 percent.展开更多
The production of propylene carbonate (PC) from urea and 1,2-propanediol (PG) was investigated in a batch process. The catalytic performances of zinc chloride and magnesium chloride were investigated for this reac...The production of propylene carbonate (PC) from urea and 1,2-propanediol (PG) was investigated in a batch process. The catalytic performances of zinc chloride and magnesium chloride were investigated for this reaction system. The influences of various operation conditions on the PC yield were explored. In this work, MgCl2 and ZnCl2 showed the excellent catalytic activity toward PC synthesis, and the yields of propylene carbonate reached 96.5% and 92.4%, respectively. The optimum reaction conditions were as follows: ethanol/urea molar ratio of 4, catalyst concentration of 1.5%, reaction temperature of 160 ℃, reaction time of 3 h, respectively. The route from urea and 1,2-propanediol shows advantages, such as mild reaction condition and safe operation. The catalytic system is environmentally benign.展开更多
MnOx-promoted Ni-based catalyst supported by ZnO was developed to selectively hydrogenate glucose into polyols in water at 523 K with a yield of 64.9%. Using glucose, sorbitol, glycerol and LA as the rawmaterials, the...MnOx-promoted Ni-based catalyst supported by ZnO was developed to selectively hydrogenate glucose into polyols in water at 523 K with a yield of 64.9%. Using glucose, sorbitol, glycerol and LA as the rawmaterials, the roles of nickel, ZnO and MnOx were investigated. The results show that nickel provided a new pathway of glucose to sorbitol and played an important role in the hydrogenation of C3 intermediates to 1,2-propanediol(1,2-PDO). The high yield of 1, 2-PDO was attributed to effective C–C bond cleavage performance of ZnO support promoted by MnOx. ZnO and MnOx contribute to the conversion of glycerol to lactic acid(LA) and LA to 1, 2-PDO, respectively. A concise pathway for hydrogenation of glucose over Ni-based catalyst was proposed.展开更多
Cu-x-Fe-y/SiO2 catalysts were prepared using urea-assisted sol-gel method. The structure and physicochemical properties of the catalysts were characterized using N-2 adsorption-desorption, transmission electron micros...Cu-x-Fe-y/SiO2 catalysts were prepared using urea-assisted sol-gel method. The structure and physicochemical properties of the catalysts were characterized using N-2 adsorption-desorption, transmission electron microscopy, H-2-temperature-programmed reduction, powder X-ray diffraction, and X-ray photoelectron spectroscopy. Compared with monometallic Cu or Fe catalysts, the bimetallic Cu-x-Fe-y/SiO2 catalysts exhibited enhanced catalytic performance for the selective hydrogenation of diethyl malonate to 1,3-propanediol. The bimetallic catalyst with an optimal Cu/Fe atomic ratio of 2 exhibited the highest activity, which yielded 96.3% conversion to diethyl malonate and 93.3% selectivity to 1,3-propanediol under the optimal reaction conditions. Characterization results revealed that interactions between Cu and Fe contributed to the improvement of diethyl malonate conversion and selectivity to 1,3-propanediol. The X-ray photoelectron spectroscopy results revealed that the addition of appropriate amount of Fe species enhanced the reduction of Cu2+ species, thereby increasing the Cu-0 species on the surface of bimetallic catalyst. It led to a better chemisorption capacity of hydrogen and further promoted of the activation of hydrogen molecule. The ethyl acetate temperature-programmed desorption results indicated that the FeOx species provided the additional adsorption sites for substrate molecules, and they activated the C=O bond. The improved catalytic performance of bimetallic Cu-x-Fe-y/SiO2 catalyst was mainly attributed to the synergistic effect between Cu-0 and FeOx species. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.展开更多
[ Objective ] The paper was to investigate the content of 1,2-propanediol in silage feed. [ Method ] Whole-crop corn was stored in laboratory bag silos and outdoor bunker silos. Bag silos were stored for 3, 7, 14, 28,...[ Objective ] The paper was to investigate the content of 1,2-propanediol in silage feed. [ Method ] Whole-crop corn was stored in laboratory bag silos and outdoor bunker silos. Bag silos were stored for 3, 7, 14, 28, 56 and 120 d, respectively, and fermentation products were analyzed after opening; the fermentation products, which were from three 500 t above-ground outdoor bunker silos stored for 120 d, were detected. Eight sampling points were selected for each bunker silo. [ Result] No 1,2-propanediol was detected out in laboratory bag silos, and lactic acid was dominant in fermentation products. The acetic acid content significantly increased ( P 〈 0.05 ) with the extension of storage time, whereas the acetic acid content was kept below one-third of the lactic acid content ; 1,2-propanediol and a small amount of 1-propanol were detected out in three bunker silos, and lactic acid was dominant in fermentation products, whereas the content of acetic acid was slightly lower than that of lactic acid. The differences in fermentation products from different silos and different sites in silos presented heterogeneity; except to propanediol, lactic acid bacteria and yeast, there was no significant difference in fermentation products at the top and bottom layers of silos ( P 〉0.05 ) ; there were significant differences in contents of lactic acid, acetic acid, 1,2-propanediol, and yeast between the outer and inner parts of silos (P 〈 0.05 ) ; except to pH values and acetic acid, there were significant differences in fermentation products between hunker silos (P 〈0. 05). [ Conclusion] No 1,2-propanediol is detected out in laboratory bag silos due to relatively simple fermentation products. However, 1,2-propanediol can be detected in the bunker silos due to complex outdoor environment for silage, and the microorganisms producing 1,2-propanediol exist in silos.展开更多
As the biodiesel production is rapidly enhanced, the crude glycerol, which is by-product of biodiesel processes, is state of surplus. 1,3-PDO (1,3-propanediol), a valuable monomer of poly(trimethylene terephthalate) (...As the biodiesel production is rapidly enhanced, the crude glycerol, which is by-product of biodiesel processes, is state of surplus. 1,3-PDO (1,3-propanediol), a valuable monomer of poly(trimethylene terephthalate) (PTT), can be produced from the fermentation process using crude glycerin as a carbon source. For the economic biological production of 1,3-PDO, the low cost and high efficient separation processes is essential. In this study, aqueous two-phase system composed of various hydrophilic alcohols and salt was used as a primary separation step for 1,3-PDO. It was found that the aqueous two-phase systems are easily formed with decreasing of the polarity of alcohols. The extraction efficiency is proportional to the polarity of alcohols. In case of methanol or ethanol/K2HPO4, the extraction efficiency was more than 90%.? It was concluded that the aqueous two-phase extraction using methanol or ethanol/K2HPO4 can be applied? for the primary separation of 1,3-PDO? as an alternative to a conventional primary separation processes.展开更多
1,3-Propanediol is a promising renewable resource produced by microbial production. It is mainly used in many synthetic reactions, particularly applied to the polymer synthesis and cosmetics industry. We described her...1,3-Propanediol is a promising renewable resource produced by microbial production. It is mainly used in many synthetic reactions, particularly applied to the polymer synthesis and cosmetics industry. We described here the isolation of strain ZH-1, which has the ability of high production with 1,3-propanediol, from Fenhe River in China. It was classified as a member of K. pneumoniae after the study of phenotypic, physio-logical, biochemical and phylogenetic (16S rDNA). The initial glycerol concentration, fermentation time and pH value of strain ZH-1 were determined to be 50 g·L<sup>-1</sup>, 36 h and 8.0. Under these conditions, the practical yield of 1,3-PD was 18.53 g·L<sup>-1</sup> and a molar yield (mol<sub>1,3-PD</sub> mol<sub>Glycerol</sub>-1</sup> of 1,3-propanediol to glycerol of 0.497. In addition, we found that for the strain ZH-1, the optimum grown pH was 9.0, so we can deter-mine that it is a new member of alkali-resistant strains.展开更多
1,3-Propanediol,traditionally obtained from fossils,has numerous industrial applications,including use in the production of high performance polymers.The microbial production of 1,3-propanediol presents several opport...1,3-Propanediol,traditionally obtained from fossils,has numerous industrial applications,including use in the production of high performance polymers.The microbial production of 1,3-propanediol presents several opportunities,and the final purity grade determines its price and commercial viability.The development of novel separation technology could improve the economic viability of the bioproduction of 1,3-propanediol.Thus,we investigated salting-out extraction as a novel process for 1,3-propanediol recovery from fermentation broth.Initially,a screening for the best salt/solvent combination was conducted and then optimized using the response surface methodology.The solvents studied were methanol,ethanol,isopropanol and acetone,and the salts examined were K_2HPO_4,Na_2CO_3,K_2CO_3,(NH_4)_2SO_4,NaHPO_4,K_3PO_4 and C_6H_5NaO_7.The optimal extraction system consisted of 34 wt%K_3PO_4,28 wt% ethanol,and 38 wt% fermentation broth containing 23.0 g·L^(-1)1,3-propanediol,which gave the highest partition coefficient of 33 and recovery yield of 97%.The results demonstrated that salting-out extraction was a promising method for 1,3-propanediol recovery from fermentation broth.展开更多
An efficient conversion of biomass-derived ethyl lactate to 1,2-propanediol(1,2-PDO) over CuO was investigated.Among the catalysts we tested, CuO, Cu2 O and Co showed excellent catalytic activity for the conversion of...An efficient conversion of biomass-derived ethyl lactate to 1,2-propanediol(1,2-PDO) over CuO was investigated.Among the catalysts we tested, CuO, Cu2 O and Co showed excellent catalytic activity for the conversion of ethyl lactate to 1,2-PDO in water, and CuO was more active and gave the best result. The 1,2-PDO yield of 93.6% was achieved when Zn acted as a reductant. The results indicated that in situ formed hydrogen by the oxidation of Zn in water is more effective than gaseous hydrogen, which failed to produce the 1,2-PDO from ethyl lactate.From a practical point of view, the present method may provide a useful route for the production of 1,2-PDO from ethyl lactate.展开更多
The industrially important organic compound 1,3-propanediol(1,3-PDO) is mainly used as a building block for the production of various polymers. In the present study, response surface methodology protocol was followed ...The industrially important organic compound 1,3-propanediol(1,3-PDO) is mainly used as a building block for the production of various polymers. In the present study, response surface methodology protocol was followed to determine and optimize fermentation conditions for the maximum production of 1,3-PDO using marine-derived Klebsiella pneumoniae HSL4. Four nutritional supplements together with three independent culture conditions were optimized as follows: 29.3 g/L glycerol, 8.0 g/L K 2 HPO 4, 7.6 g/L(NH 4) 2 SO 4, 3.0 g/L KH 2 PO 4, pH 7.1, cultivation at 35°C for 12 h. Under the optimal conditions, a maximum 1,3-PDO concentration of 14.5 g/L, a productivity of 1.21 g/(L·h) and a conversion of glycerol of 0.49 g/g were obtained. In comparison with the control conditions, fermentation under the optimized conditions achieved an increase of 38.8% in 1,3-PDO concentration, 39.0% in productivity and 25.7% in glycerol conversion in flask. This enhancement trend was further confirmed when the fermentation was conducted in a 5-L fermentor. The optimized fermentation conditions could be an important basis for developing lowcost, large-scale methods for industrial production of 1,3-PDO in the future.展开更多
Benzaldehyde 1,2-propanediol acetal was synthesized from benzaldehyde and 1,2-propanediol in the presence of SO42-/TiO2-MoO3-La2O3.The factors influencing the synthesis were discussed and the best conditions were foun...Benzaldehyde 1,2-propanediol acetal was synthesized from benzaldehyde and 1,2-propanediol in the presence of SO42-/TiO2-MoO3-La2O3.The factors influencing the synthesis were discussed and the best conditions were found out.The optimum conditions are:molar ratio of benzaldehyde to 1,2-propanediol is 1:1.8,the quantity of catalyst is equal to 1.0% feed stock,and the reaction time is 1.0 h.SO42-/TiO2-MoO3-La2O3 is an excellent catalyst for synthesizing benzaldehyde 1,2-propanediol acetal and its yield can reach over 77.2%.展开更多
The catalytic oxidation of biomass-derived polyhydroxyl compounds provides an efficient and green route for biomass resource utility.Gold nanocrystals supported on Mg(OH)2 were synthesized by sol-immobilization method...The catalytic oxidation of biomass-derived polyhydroxyl compounds provides an efficient and green route for biomass resource utility.Gold nanocrystals supported on Mg(OH)2 were synthesized by sol-immobilization method,characterized by XRD,TEM,UV-vis DRS,and tested in the selective oxidation of 1,2-propanediol to lactic acid.The gold particle size and the ratio of Au to 1,2-propanediol strongly influenced the catalytic activity.Over Au/Mg(OH)2 with the majority of gold particles concentrated in 14-18 nm,excellent catalytic performance with 94.4% conversion and 89.3% selectivity to lactic acid has been achieved under 0.3 MPa O2 at 60°C for 6 h.展开更多
文摘A new environmental friendly catalyst, H_4SiW_(12)O_(40)/PAn was prepared andidentified by means of FT-IR, XRD and TG/DTA. Cyclohexanone 1,2-propanediol ketal was synthesizedfrom cyclohexanone and 1,2-propanediol in the presence of H_4SiW_(12)O_(40)/PAn The factorsinfluencing tlie synthesis were discussed and the best conditions were found out. The optimumconditions are: molar ratio of cyclohexanone to 1,2-propanediol is 1:1.4, the quantity of catalystis equal to 1.0 percent of feed stocks, and the reaction time is 40 min. H_4SiW_(12)O_(40)/PAn is anexcellent catalyst for synthesizing cyclohexanone 1,2-propanediol ketal and its yield can reachover 96.5 percent.
基金supported by the National Natural Science Fund for Distinguished Young Scholars of China(No.20625308).
文摘The production of propylene carbonate (PC) from urea and 1,2-propanediol (PG) was investigated in a batch process. The catalytic performances of zinc chloride and magnesium chloride were investigated for this reaction system. The influences of various operation conditions on the PC yield were explored. In this work, MgCl2 and ZnCl2 showed the excellent catalytic activity toward PC synthesis, and the yields of propylene carbonate reached 96.5% and 92.4%, respectively. The optimum reaction conditions were as follows: ethanol/urea molar ratio of 4, catalyst concentration of 1.5%, reaction temperature of 160 ℃, reaction time of 3 h, respectively. The route from urea and 1,2-propanediol shows advantages, such as mild reaction condition and safe operation. The catalytic system is environmentally benign.
基金financially supported by the National Science Foundation of China (21671132)Shanghai Science and Technology Committee(16dz1207200)the Youth Innovation Promotion Association CAS(2015231)
文摘MnOx-promoted Ni-based catalyst supported by ZnO was developed to selectively hydrogenate glucose into polyols in water at 523 K with a yield of 64.9%. Using glucose, sorbitol, glycerol and LA as the rawmaterials, the roles of nickel, ZnO and MnOx were investigated. The results show that nickel provided a new pathway of glucose to sorbitol and played an important role in the hydrogenation of C3 intermediates to 1,2-propanediol(1,2-PDO). The high yield of 1, 2-PDO was attributed to effective C–C bond cleavage performance of ZnO support promoted by MnOx. ZnO and MnOx contribute to the conversion of glycerol to lactic acid(LA) and LA to 1, 2-PDO, respectively. A concise pathway for hydrogenation of glucose over Ni-based catalyst was proposed.
基金supported by the Natural Science Foundation of China (91545115,21473145,and 21403178)the Postgraduate Basic Innovative Research Program of Xiamen University (201412G001)the Program for Innovative Research Team in Chinese Universities (no.IRT_14R31)
文摘Cu-x-Fe-y/SiO2 catalysts were prepared using urea-assisted sol-gel method. The structure and physicochemical properties of the catalysts were characterized using N-2 adsorption-desorption, transmission electron microscopy, H-2-temperature-programmed reduction, powder X-ray diffraction, and X-ray photoelectron spectroscopy. Compared with monometallic Cu or Fe catalysts, the bimetallic Cu-x-Fe-y/SiO2 catalysts exhibited enhanced catalytic performance for the selective hydrogenation of diethyl malonate to 1,3-propanediol. The bimetallic catalyst with an optimal Cu/Fe atomic ratio of 2 exhibited the highest activity, which yielded 96.3% conversion to diethyl malonate and 93.3% selectivity to 1,3-propanediol under the optimal reaction conditions. Characterization results revealed that interactions between Cu and Fe contributed to the improvement of diethyl malonate conversion and selectivity to 1,3-propanediol. The X-ray photoelectron spectroscopy results revealed that the addition of appropriate amount of Fe species enhanced the reduction of Cu2+ species, thereby increasing the Cu-0 species on the surface of bimetallic catalyst. It led to a better chemisorption capacity of hydrogen and further promoted of the activation of hydrogen molecule. The ethyl acetate temperature-programmed desorption results indicated that the FeOx species provided the additional adsorption sites for substrate molecules, and they activated the C=O bond. The improved catalytic performance of bimetallic Cu-x-Fe-y/SiO2 catalyst was mainly attributed to the synergistic effect between Cu-0 and FeOx species. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.
基金Supported by National Natural Science Foundation of China(31402136)Research Project of Bureau of Reclamation in Heilongjiang Province(HNK135-04-02-03)+1 种基金Postdoctoral Fund in Heilongjiang Province(LBH-Z14029)Doctoral Fund in Heilongjiang Bayi Agricultural University(B2012-06)
文摘[ Objective ] The paper was to investigate the content of 1,2-propanediol in silage feed. [ Method ] Whole-crop corn was stored in laboratory bag silos and outdoor bunker silos. Bag silos were stored for 3, 7, 14, 28, 56 and 120 d, respectively, and fermentation products were analyzed after opening; the fermentation products, which were from three 500 t above-ground outdoor bunker silos stored for 120 d, were detected. Eight sampling points were selected for each bunker silo. [ Result] No 1,2-propanediol was detected out in laboratory bag silos, and lactic acid was dominant in fermentation products. The acetic acid content significantly increased ( P 〈 0.05 ) with the extension of storage time, whereas the acetic acid content was kept below one-third of the lactic acid content ; 1,2-propanediol and a small amount of 1-propanol were detected out in three bunker silos, and lactic acid was dominant in fermentation products, whereas the content of acetic acid was slightly lower than that of lactic acid. The differences in fermentation products from different silos and different sites in silos presented heterogeneity; except to propanediol, lactic acid bacteria and yeast, there was no significant difference in fermentation products at the top and bottom layers of silos ( P 〉0.05 ) ; there were significant differences in contents of lactic acid, acetic acid, 1,2-propanediol, and yeast between the outer and inner parts of silos (P 〈 0.05 ) ; except to pH values and acetic acid, there were significant differences in fermentation products between hunker silos (P 〈0. 05). [ Conclusion] No 1,2-propanediol is detected out in laboratory bag silos due to relatively simple fermentation products. However, 1,2-propanediol can be detected in the bunker silos due to complex outdoor environment for silage, and the microorganisms producing 1,2-propanediol exist in silos.
文摘As the biodiesel production is rapidly enhanced, the crude glycerol, which is by-product of biodiesel processes, is state of surplus. 1,3-PDO (1,3-propanediol), a valuable monomer of poly(trimethylene terephthalate) (PTT), can be produced from the fermentation process using crude glycerin as a carbon source. For the economic biological production of 1,3-PDO, the low cost and high efficient separation processes is essential. In this study, aqueous two-phase system composed of various hydrophilic alcohols and salt was used as a primary separation step for 1,3-PDO. It was found that the aqueous two-phase systems are easily formed with decreasing of the polarity of alcohols. The extraction efficiency is proportional to the polarity of alcohols. In case of methanol or ethanol/K2HPO4, the extraction efficiency was more than 90%.? It was concluded that the aqueous two-phase extraction using methanol or ethanol/K2HPO4 can be applied? for the primary separation of 1,3-PDO? as an alternative to a conventional primary separation processes.
文摘1,3-Propanediol is a promising renewable resource produced by microbial production. It is mainly used in many synthetic reactions, particularly applied to the polymer synthesis and cosmetics industry. We described here the isolation of strain ZH-1, which has the ability of high production with 1,3-propanediol, from Fenhe River in China. It was classified as a member of K. pneumoniae after the study of phenotypic, physio-logical, biochemical and phylogenetic (16S rDNA). The initial glycerol concentration, fermentation time and pH value of strain ZH-1 were determined to be 50 g·L<sup>-1</sup>, 36 h and 8.0. Under these conditions, the practical yield of 1,3-PD was 18.53 g·L<sup>-1</sup> and a molar yield (mol<sub>1,3-PD</sub> mol<sub>Glycerol</sub>-1</sup> of 1,3-propanediol to glycerol of 0.497. In addition, we found that for the strain ZH-1, the optimum grown pH was 9.0, so we can deter-mine that it is a new member of alkali-resistant strains.
基金CNPq,FAPERJ and CAPES through the PDSE and Program and Human Resources Program 13 of the National Petroleum Agency (ANP-PRH 13)
文摘1,3-Propanediol,traditionally obtained from fossils,has numerous industrial applications,including use in the production of high performance polymers.The microbial production of 1,3-propanediol presents several opportunities,and the final purity grade determines its price and commercial viability.The development of novel separation technology could improve the economic viability of the bioproduction of 1,3-propanediol.Thus,we investigated salting-out extraction as a novel process for 1,3-propanediol recovery from fermentation broth.Initially,a screening for the best salt/solvent combination was conducted and then optimized using the response surface methodology.The solvents studied were methanol,ethanol,isopropanol and acetone,and the salts examined were K_2HPO_4,Na_2CO_3,K_2CO_3,(NH_4)_2SO_4,NaHPO_4,K_3PO_4 and C_6H_5NaO_7.The optimal extraction system consisted of 34 wt%K_3PO_4,28 wt% ethanol,and 38 wt% fermentation broth containing 23.0 g·L^(-1)1,3-propanediol,which gave the highest partition coefficient of 33 and recovery yield of 97%.The results demonstrated that salting-out extraction was a promising method for 1,3-propanediol recovery from fermentation broth.
基金Supported by the National Natural Science Foundation of China(21277091)the State Key Program of National Natural Science Foundation of China(21436007)+2 种基金Key Basic Research Projects of Science and Technology Commission of Shanghai Municipality(14JC1403100)the Program for Professor of Special Appointment(Eastern Scholar) at Shanghai Institutions of Higher Learning(ZXDF160002)the Project-sponsored by SRF for ROCS,SEM(BG1600002)
文摘An efficient conversion of biomass-derived ethyl lactate to 1,2-propanediol(1,2-PDO) over CuO was investigated.Among the catalysts we tested, CuO, Cu2 O and Co showed excellent catalytic activity for the conversion of ethyl lactate to 1,2-PDO in water, and CuO was more active and gave the best result. The 1,2-PDO yield of 93.6% was achieved when Zn acted as a reductant. The results indicated that in situ formed hydrogen by the oxidation of Zn in water is more effective than gaseous hydrogen, which failed to produce the 1,2-PDO from ethyl lactate.From a practical point of view, the present method may provide a useful route for the production of 1,2-PDO from ethyl lactate.
基金Supported by the Scientific Research Project of Marine Public Welfare Industry of China(No.201205020-4)the Knowledge Innovation Project of Chinese Academy of Sciences(No.KSCX2-EW-G-12B)the Administration of Ocean and Fisheries of Guangdong Province(No.GD2012-D01-002)
文摘The industrially important organic compound 1,3-propanediol(1,3-PDO) is mainly used as a building block for the production of various polymers. In the present study, response surface methodology protocol was followed to determine and optimize fermentation conditions for the maximum production of 1,3-PDO using marine-derived Klebsiella pneumoniae HSL4. Four nutritional supplements together with three independent culture conditions were optimized as follows: 29.3 g/L glycerol, 8.0 g/L K 2 HPO 4, 7.6 g/L(NH 4) 2 SO 4, 3.0 g/L KH 2 PO 4, pH 7.1, cultivation at 35°C for 12 h. Under the optimal conditions, a maximum 1,3-PDO concentration of 14.5 g/L, a productivity of 1.21 g/(L·h) and a conversion of glycerol of 0.49 g/g were obtained. In comparison with the control conditions, fermentation under the optimized conditions achieved an increase of 38.8% in 1,3-PDO concentration, 39.0% in productivity and 25.7% in glycerol conversion in flask. This enhancement trend was further confirmed when the fermentation was conducted in a 5-L fermentor. The optimized fermentation conditions could be an important basis for developing lowcost, large-scale methods for industrial production of 1,3-PDO in the future.
基金Supported by the Natural Science Foundation of Hubei Province(No2005ABA053)
文摘Benzaldehyde 1,2-propanediol acetal was synthesized from benzaldehyde and 1,2-propanediol in the presence of SO42-/TiO2-MoO3-La2O3.The factors influencing the synthesis were discussed and the best conditions were found out.The optimum conditions are:molar ratio of benzaldehyde to 1,2-propanediol is 1:1.8,the quantity of catalyst is equal to 1.0% feed stock,and the reaction time is 1.0 h.SO42-/TiO2-MoO3-La2O3 is an excellent catalyst for synthesizing benzaldehyde 1,2-propanediol acetal and its yield can reach over 77.2%.
基金supported by the National Natural Science Foundation of China (20803074)
文摘The catalytic oxidation of biomass-derived polyhydroxyl compounds provides an efficient and green route for biomass resource utility.Gold nanocrystals supported on Mg(OH)2 were synthesized by sol-immobilization method,characterized by XRD,TEM,UV-vis DRS,and tested in the selective oxidation of 1,2-propanediol to lactic acid.The gold particle size and the ratio of Au to 1,2-propanediol strongly influenced the catalytic activity.Over Au/Mg(OH)2 with the majority of gold particles concentrated in 14-18 nm,excellent catalytic performance with 94.4% conversion and 89.3% selectivity to lactic acid has been achieved under 0.3 MPa O2 at 60°C for 6 h.