Reuse of Spent FCC Catalyst for Removing Trace Olefins from Aromatics

Pu, Xin,Luan, Jin-Ning,Shi, Li Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.8

Pretreatment of spent FCC catalyst and its application in remove trace olefins in aromatics were investigated in this research. The most effective pretreatment route of spent FCC catalyst was calcining at $700^{\circ}C$ for 1 h, washing with 5% oxalic acid solution in ultrasonic reactor and dried. Treated spent FCC catalyst was modified with metal halides, then to prepare catalyst to remove trace olefins in aromatics. X-ray diffraction, Pyridine-FTIR, $N_2$ adsorption-desorption and inductively coupled plasma optical emission spectrometer (ICP-OES) were used to investigate the pretreatment process. The result showed that the performance of the treated spent FCC catalyst was much greater than that of the spent FCC catalyst, which indicted the possibility and improvement of this research.

Improvement of Enzymatic Stability and Catalytic Efficiency of Recombinant Fusariumoxysporum Trypsin with Different N-Terminal Residues Produced by Pichiapastoris

( Ning Yang ),( Zhenmin Ling ),( Liang Peng ),( Yanlai Liu ),( Pu Liu ),( Kai Zhang ),( Aman ),( Juanjuan Shi ),( Xiangkai Li ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 Journal of microbiology and biotechnology Vol.28 No.9

Fusarium oxysporum trypsin (FOT) is a fungal serine protease similar to mammal trypsin. The FOT could be successfully expressed in Pichiapastoris by engineering the natural propeptide APQEIPN. In this study, we constructed two recombinant enzymes with engineered amino acid sequences added to the N-terminus of FOT and expressed in P. pastoris. The N-terminal residues had various effects on the structural and functional properties of trypsin. The FOT, and the recombinants TE (with peptide YVEF) and TS (with peptide YV) displayed the same optimum temperature (40°C) and pH (8.0). However, the combinants TE and TS showed significantly increased thermal stability at 40°C and 50°C. Moreover, the combinants TE and TS also showed enhanced tolerance of alkaline pH conditions. Compared with those of wildtype FOT, the intramolecular hydrogen bonds and the cation π-interactions of the recombinants TE and TS were significantly increased. The recombinants TE and TS also had significantly increased catalytic efficiencies (referring to the specificity constant, k_cat/K_m), 1.75- fold and 1.23-fold than wild-type FOT. In silico modeling analysis uncovered that the introduction of the peptides YVEF and YV resulted in shorter distances between the substrate binding pocket (D174, G198, and G208) and catalytic triad (His42, Asp102, and Ser180), which would improve the electron transfer rate and catalytic efficiency. In addition, N-terminal residues modification described here may be a useful approach for improving the catalytic efficiencies and characteristics of other target enzymes.

Multi-objective intelligent cooperative design for interference fit of the conical sleeve

Ke Ning,Jianmei Wang,Pu Li,Dan Xiang,Dingbang Hou 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.8

This paper deals with the multi-objective intelligent cooperative optimization for interference fit of conical sleeve. The influence of various factors on contact pressure of conical sleeve was quantitatively analyzed, and the relationship among multi-objectives and multivariables was comprehensively built. Take the cone sleeve of oil film bearing as the research object, the key factors of the cone sleeve were determined with a combination of actual situations, and its sample data was obtained by central composite test design. Considering the multi-objective involving yield strength, torque and mass, the approximate model of the response surface based on the kriging algorithm was given. Then, a multi-objective intelligent cooperative design method for interference fit of the cone sleeve was established by solving the NSGA-II algorithm. Example analysis has shown that such a method makes up for the deficiency of theoretical design to ignore the stress concentration problem, and its accuracy is 32 times that of the BP neural network algorithm. Finally, the experiments verified the correctness of this method.

Reuse of Spent FCC Catalyst for Removing Trace Olefins from Aromatics

Xin Pu,Jin-ning Luan,Li Shi 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.8

Pretreatment of spent FCC catalyst and its application in remove trace olefins in aromatics were investigated in this research. The most effective pretreatment route of spent FCC catalyst was calcining at 700 oC for 1 h, washing with 5% oxalic acid solution in ultrasonic reactor and dried. Treated spent FCC catalyst was modified with metal halides, then to prepare catalyst to remove trace olefins in aromatics. X-ray diffraction, Pyridine- FTIR, N2 adsorption-desorption and inductively coupled plasma optical emission spectrometer (ICP-OES) were used to investigate the pretreatment process. The result showed that the performance of the treated spent FCC catalyst was much greater than that of the spent FCC catalyst, which indicted the possibility and improvement of this research.

Amphiphilically modified chitosan copolymer for enhanced oil recovery in harsh reservoir condition

Wan-Fen Pu,Rui Liu,Qin Peng,Dai-Jun Du,Qi-Ning Zhao 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.37 No.-

A novel amphiphilically grafting natural chitosan copolymer (PAMCS) was prepared by using one stepwater-free radical polymerization strategy and the basic parameters for PAMCS were systematicallycharacterized. The rigid D-glucosamine unit, intermolecular association and hydrogen bondingsynergistically endowed PAMCS solution with rheological properties, super-high salt resistance andtemperature tolerance in harsh reservoir condition. PAMCS solution exhibited viscoelastic behaviorand formulated the unique displacement mechanism in comparison to that for partially hydrolyzedpolyacrylamide. Moreover, the mass concentration, injective rate and polymer solution slug related to oilrecovery efficiency for PAMCS were investigated from the economic point.

RASSF1A Gene Methylation is Associated with Nasopharyngeal Carcinoma Risk in Chinese

Wu, Kun,Xu, Xiao-Ning,Chen, Yu,Pu, Xiao-Lin,Wang, Bo-Yuan,Tang, Xiao-Dan Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.6

In order to explore the association between RASSF1A methylation and nasopharyngeal carcinoma (NPC) risk of Chinese, we carried out a meta-analysis with searches of PubMed, Web of Science, ProQest and Medline databases. Ultimately, 14 articles were identified and analysised using R Software (R version 3.1.2) including meta packages. Overall, we found a significant relationship between RASSF1A methylation and NPC risk (OR 30.7; 95 % CI, 16.71~56.23; z=11.0591; p<0.0001) in a fixed effects model and (OR 32.1; 95% CI, 14.27~72.01; z=8.3984; p<0.0001) in a random effects model pooled. In tissue and NP brushings groups, similar results were found. Hence, our study identified a strong association between RASSF1A methylation and NPC and highlighted a promising potential for RASSF1A methylation in NPC risk prediction of Chinese.

Crack-tip constraint analysis of two collinear cracks under creep condition

Guang-Chen Jiao,Wei-Zhe Wang,Pu-Ning Jiang 국제구조공학회 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.43 No.3

The higher-order asymptotic C(t) − A2(t) approach was employed to investigate the crack-tip stress of two collinear cracks in a power-law creeping material under the plane strain conditions. A comprehensive calculation was made of the single crack, collinear crack model with S/a = 0.4 and 0.8, by using the C(t) − A2(t) approach, HRR-type field and the finite element analysis; the latter two methods were used to check the constraint significance and the calculation accuracy of the C(t) − A2(t) approach,respectively. With increasing the creep time, the constraint A2 was exponentially increased in the smallscale creep stage, while no discernible dependency of the constraint A2 on the creep time was found at the extensive creep state. In addition, the creep time and the mechanical loads have no distinct influence on accuracy of the results obtained from the higher-order asymptotic C(t) − A2(t) approach. In comparison with the HRR-type field, the higher-order asymptotic C(t) − A2(t) solution matches well with the finite element results for the collinear crack model.

Crack-tip constraint analysis of two collinear cracks under creep condition

Jiao, Guang-Chen,Wang, Wei-Zhe,Jiang, Pu-Ning Techno-Press 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.43 No.3

The higher-order asymptotic C(t) - $A_2(t)$ approach was employed to investigate the crack-tip stress of two collinear cracks in a power-law creeping material under the plane strain conditions. A comprehensive calculation was made of the single crack, collinear crack model with S/a = 0.4 and 0.8, by using the C(t) - $A_2(t)$ approach, HRR-type field and the finite element analysis; the latter two methods were used to check the constraint significance and the calculation accuracy of the C(t) - $A_2(t)$ approach, respectively. With increasing the creep time, the constraint $A_2$ was exponentially increased in the small-scale creep stage, while no discernible dependency of the constraint $A_2$ on the creep time was found at the extensive creep state. In addition, the creep time and the mechanical loads have no distinct influence on accuracy of the results obtained from the higher-order asymptotic C(t) - $A_2(t)$ approach. In comparison with the HRR-type field, the higher-order asymptotic C(t) - $A_2(t)$ solution matches well with the finite element results for the collinear crack model.

Influence of rub groove on rotordynamics associated with leakage air flow through a labyrinth seal

Wei Zhe Wang,Ying Zheng Liu,Guang Meng,Pu Ning Jiang 대한기계학회 2010 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.24 No.8

An extensive investigation of influence of rub grooves on dynamics and stability of the rotor, which is subjected to aerodynamic forcing associated with the leakage flow through 44 straight-through seals, was performed by using numerical calculations based on the single control-volume method and the perturbation analysis. Three cases of different groove configurations were chosen for the comparative study, e.g., the seal without rub groove (case1), the seal with upstream shifting of the seal tooth in respect to the rub groove (case2) and the seal with location of the seal tooth in the middle station of the rub groove (case3). The orifice contract coefficient adopted in reduction of rotordynamic coefficients was provided by using Computational Fluid Dynamics (CFD). Influence of rub grooves on the leakage flow was obtained in terms of the close-up view of the flow pattern near the seal tooth, leakage flow rate, distributions of the mean pressure and circumferential velocity in cavities. In comparison to case 1, the leakage flow in case 3 is considerably intensified, while which in case 2 is slightly increased. Dynamics and instability of the rotor in all cases was discussed in terms of the rotordynamic coefficients and the logarithmic decrement, respectively. The results disclosed that the aerodynamic forcing in case 2 intensified the destabilization of the rotor system.