Binderless zeolite is considered to be a potential alternative for binder-containing zeolite in the industrial applications of adsorptive separation process. Synthesized binderless zeolite and commercial binder-contai...Binderless zeolite is considered to be a potential alternative for binder-containing zeolite in the industrial applications of adsorptive separation process. Synthesized binderless zeolite and commercial binder-containing product were used in adsorptive separation of n-paraffins from a model oil, with their performance compared. It is indicated that the binderless zeolite exhibits by 25%-35% higher in saturated adsorption capacity and by 115%-130% more adsorption amount at the breakthrough point with much shorter length of mass-transfer zone. Adsorptive separation of n-paraffins from naphtha was carried out in a fixed-bed adsorber containing the synthesized binderless zeolite 5 A under the operating conditions covering a feed space velocity of 90 h-1 and an adsorption temperature of 573 K. As compared to original naphtha, the raffinate shows by 34 units more in research octane number and by around 10% more of potential aromatic content, while the desorption oil exhibits by 13.3% more ethylene yield and by 11.7% higher in total olefins yield.展开更多
The improvement of the Cold Filter Plugging Point (CFPP) by an additive will depend on either the characteristics of the diesel or the additive itself. The ways in which cold flow improver interacts with the constitue...The improvement of the Cold Filter Plugging Point (CFPP) by an additive will depend on either the characteristics of the diesel or the additive itself. The ways in which cold flow improver interacts with the constituents of the fuels and the reasons for their efficiencies are far from fully elucidated. In this work , the contents of the n-paraffin in five kinds of diesels were tested by urea adduction, and the carbon distribution of n-paraffins was tested by temperature programmed gas chromatograph GC-14A and computed by the software for simulating distillation. Maximum likelihood method is applied to obtain μ and σ2 of the carbon distribution, and the deviation χ2 is computed. When the degrees of freedom is 4 and significance level (α) is 0.10, χ2_ 0.90(4)=7.779. If deviation χ2 is smaller than χ2_ 0.90(4), the hypothesis that the population is normal is accepted. The results show that the distributions of n-paraffin in these five kinds of diesels are normal. It can be found that the susceptibility of the diesel DQCH is weak and the variance σ2 of the carbon distribution in n-paraffin is only 1076.21 smaller than that for other diesels. The smaller the variance σ2 is, the weaker the susceptibility is. The susceptibility of the diesel LYL is also weak. The value of the statistic test quantity χ2 on the normal distribution of the n-paraffin in the diesel LYL is 4.112 bigger than other diesels . Statistic test quantity χ2 could reflect whether the carbon distribution of n-paraffin fits the normal distribution. When the carbon distribution of n-paraffin does not fit normal well, the wax settling does not match the agglomeration of flow improver. In this situation, the flow improver can’t interact with more wax crystal so that the CFPP of diesel can not be decreased.展开更多
基金financially supported by the Natural Science Foundation of Shanghai(Grant 16ZR1408100)the National Natural Science Foundation of China(Grant 91634112 and 21878097)the Open Project of State Key Laboratory of Chemical Engineering(SKL-ChE-16C01)
文摘Binderless zeolite is considered to be a potential alternative for binder-containing zeolite in the industrial applications of adsorptive separation process. Synthesized binderless zeolite and commercial binder-containing product were used in adsorptive separation of n-paraffins from a model oil, with their performance compared. It is indicated that the binderless zeolite exhibits by 25%-35% higher in saturated adsorption capacity and by 115%-130% more adsorption amount at the breakthrough point with much shorter length of mass-transfer zone. Adsorptive separation of n-paraffins from naphtha was carried out in a fixed-bed adsorber containing the synthesized binderless zeolite 5 A under the operating conditions covering a feed space velocity of 90 h-1 and an adsorption temperature of 573 K. As compared to original naphtha, the raffinate shows by 34 units more in research octane number and by around 10% more of potential aromatic content, while the desorption oil exhibits by 13.3% more ethylene yield and by 11.7% higher in total olefins yield.
文摘The improvement of the Cold Filter Plugging Point (CFPP) by an additive will depend on either the characteristics of the diesel or the additive itself. The ways in which cold flow improver interacts with the constituents of the fuels and the reasons for their efficiencies are far from fully elucidated. In this work , the contents of the n-paraffin in five kinds of diesels were tested by urea adduction, and the carbon distribution of n-paraffins was tested by temperature programmed gas chromatograph GC-14A and computed by the software for simulating distillation. Maximum likelihood method is applied to obtain μ and σ2 of the carbon distribution, and the deviation χ2 is computed. When the degrees of freedom is 4 and significance level (α) is 0.10, χ2_ 0.90(4)=7.779. If deviation χ2 is smaller than χ2_ 0.90(4), the hypothesis that the population is normal is accepted. The results show that the distributions of n-paraffin in these five kinds of diesels are normal. It can be found that the susceptibility of the diesel DQCH is weak and the variance σ2 of the carbon distribution in n-paraffin is only 1076.21 smaller than that for other diesels. The smaller the variance σ2 is, the weaker the susceptibility is. The susceptibility of the diesel LYL is also weak. The value of the statistic test quantity χ2 on the normal distribution of the n-paraffin in the diesel LYL is 4.112 bigger than other diesels . Statistic test quantity χ2 could reflect whether the carbon distribution of n-paraffin fits the normal distribution. When the carbon distribution of n-paraffin does not fit normal well, the wax settling does not match the agglomeration of flow improver. In this situation, the flow improver can’t interact with more wax crystal so that the CFPP of diesel can not be decreased.
