To determine fragrance character of Spirit “Bai” from Shandong. Spirit “Lu”was positive control, “Er”, egative control, three samples were extracted with either,then analyzed qualitatively and quantitatively wit...To determine fragrance character of Spirit “Bai” from Shandong. Spirit “Lu”was positive control, “Er”, egative control, three samples were extracted with either,then analyzed qualitatively and quantitatively with ISTD N-amyl acetate (EP) by gas chromatography-mass spectrometry (GC/MS). Fragranter components including ethyl acid ester(E),butanotic acid ester (B),lactic acid ester (L), pentoic acid ester(p), and hexanoic acid ester(H) were chosen. The result showed that the level of esters were higher in Bai close to “Lu”, so “Bai” can be called concentration fragrant type spirit.展开更多
A novel Mo/C catalyst, which are reduced in H2 after sulfidizaing ammonium heptamolybdate with （NH4）2S aqueous solution, has a high activity and selectivity for ethanol vapor phase carbonylation to ethyl propionate ...A novel Mo/C catalyst, which are reduced in H2 after sulfidizaing ammonium heptamolybdate with （NH4）2S aqueous solution, has a high activity and selectivity for ethanol vapor phase carbonylation to ethyl propionate without addition of any promoter in the feed. Ethanol carbonylation is carried out in a fixed bed reactor with a continuous flow system at atmospheric pressure. This catalyst has a higher initial activity and selectivity; the catalytic activity reaches steady state after carbonylation reaction for 30 min. Higher temperatures led to a sharp decrease of the carbonylation activity and to an increase of the selectivities of ethene and ether. The optimal reaction conditions are as follows: reaction temperature is 553 K; n（C2H5OH）/n（CO）=4/1; GHSV=4.0 L/（g cat·h）. Under these conditions, the conversion of ethanol is 80%, the selectivity of ethyl propionate is 80.6% and the space-time yield is 1.157×10 -2 mol/（g cat·h）. This result is surprisingly better than that of ethanol vapor phase carbonylation over Ni-Zn/C catalyst with addition of ethyl iodide promoter to the feed [n（C2H5OH）/n（C2H5I）=10/1], especially, this novel Mo/C catalyst has a significantly higher selectivity. No carbonylation product is found over Ni base catalyst without addition of the promoter. This research demonstrates that novel Mo/C catalyst may be promising for ethyl propionate production from the carbonylation of ethanol at atmospheric pressure, without requiring ethyl iodide as promoter. This novel catalyst is found to be a non-crystalline by X-ray diffraction. The Mo content in the catalyst is 10%.展开更多
研究了聚对苯二甲酸乙二醇酯固相缩聚动力学,发现前人提出的化学反应控制模型和副产物乙二醇扩散控制模型都存在某些缺陷。本文根据实验结果,参照 T.M.Pell 对 PET 熔融缩聚的研究,提出 PET 固相缩聚的反应-扩散综合模型。根据此模型所...研究了聚对苯二甲酸乙二醇酯固相缩聚动力学,发现前人提出的化学反应控制模型和副产物乙二醇扩散控制模型都存在某些缺陷。本文根据实验结果,参照 T.M.Pell 对 PET 熔融缩聚的研究,提出 PET 固相缩聚的反应-扩散综合模型。根据此模型所拟合出的反应速率常数 k,平衡常数 K、扩散系数 D 和样品表面乙二醇浓度 C_(?)基本上都是常数,理论动力学曲线与实验结果基本相符。展开更多
文摘To determine fragrance character of Spirit “Bai” from Shandong. Spirit “Lu”was positive control, “Er”, egative control, three samples were extracted with either,then analyzed qualitatively and quantitatively with ISTD N-amyl acetate (EP) by gas chromatography-mass spectrometry (GC/MS). Fragranter components including ethyl acid ester(E),butanotic acid ester (B),lactic acid ester (L), pentoic acid ester(p), and hexanoic acid ester(H) were chosen. The result showed that the level of esters were higher in Bai close to “Lu”, so “Bai” can be called concentration fragrant type spirit.
文摘A novel Mo/C catalyst, which are reduced in H2 after sulfidizaing ammonium heptamolybdate with （NH4）2S aqueous solution, has a high activity and selectivity for ethanol vapor phase carbonylation to ethyl propionate without addition of any promoter in the feed. Ethanol carbonylation is carried out in a fixed bed reactor with a continuous flow system at atmospheric pressure. This catalyst has a higher initial activity and selectivity; the catalytic activity reaches steady state after carbonylation reaction for 30 min. Higher temperatures led to a sharp decrease of the carbonylation activity and to an increase of the selectivities of ethene and ether. The optimal reaction conditions are as follows: reaction temperature is 553 K; n（C2H5OH）/n（CO）=4/1; GHSV=4.0 L/（g cat·h）. Under these conditions, the conversion of ethanol is 80%, the selectivity of ethyl propionate is 80.6% and the space-time yield is 1.157×10 -2 mol/（g cat·h）. This result is surprisingly better than that of ethanol vapor phase carbonylation over Ni-Zn/C catalyst with addition of ethyl iodide promoter to the feed [n（C2H5OH）/n（C2H5I）=10/1], especially, this novel Mo/C catalyst has a significantly higher selectivity. No carbonylation product is found over Ni base catalyst without addition of the promoter. This research demonstrates that novel Mo/C catalyst may be promising for ethyl propionate production from the carbonylation of ethanol at atmospheric pressure, without requiring ethyl iodide as promoter. This novel catalyst is found to be a non-crystalline by X-ray diffraction. The Mo content in the catalyst is 10%.
文摘研究了聚对苯二甲酸乙二醇酯固相缩聚动力学,发现前人提出的化学反应控制模型和副产物乙二醇扩散控制模型都存在某些缺陷。本文根据实验结果,参照 T.M.Pell 对 PET 熔融缩聚的研究,提出 PET 固相缩聚的反应-扩散综合模型。根据此模型所拟合出的反应速率常数 k,平衡常数 K、扩散系数 D 和样品表面乙二醇浓度 C_(?)基本上都是常数,理论动力学曲线与实验结果基本相符。
