Co-reporter:Ye Li; Lei Zhong; Weisong Li; Long Zhang; Xubin Zhang; Chunjian Xu
Journal of Chemical & Engineering Data 2016 Volume 61(Issue 7) pp:2481-2492
Publication Date(Web):June 13, 2016
DOI:10.1021/acs.jced.6b00180
The isobaric vapor–liquid equilibrium (VLE) data for nine binary systems of cracking C5 fraction including n-pentane + cyclopentane, n-pentane + cyclopentene, isopentane + 2-methyl-2-butene, isopentane + cyclopentene, cyclopentane + 2-methyl-2-butene, cyclopentane + cyclopentene, cyclopentane + isoprene, isoprene + 2-methyl-2-butene, isoprene + cyclopentene at 250 kPa have been measured using a VLE recirculating still. All of the experimental data were checked with the Herington thermodynamic consistency test, which showed thermodynamic consistency. The experimental VLE data were correlated with the Wilson, nonrandom two-liquid (NRTL) and universal quasichemical (UNIQUAC) activity coefficient models. The results show that the calculated values of the vapor-phase mole fraction and boiling temperature by the Wilson, NRTL, and UNIQUAC models agree well with the experimental data. The ideal liquid model was also used to compare with experimental data, which showed a few small differences which indicated the small deviations of these systems from the ideal liquid. The universal quasichemical functional group activity coefficients (UNIFAC) model was also used to predict the VLE data for these systems, which agree well with the experimental data, except cyclopentane + isoprene system which shows a little bigger deviation.
Co-reporter:Zhiqun Pan;Xubin Zhang;Yunfeng Xie
Chemical Engineering & Technology 2014 Volume 37( Issue 3) pp:495-504
Publication Date(Web):
DOI:10.1002/ceat.201300354
Abstract
The mass transfer process under CO2-water Taylor flow was experimentally investigated in circular capillaries with different lengths. The measured volumetric mass transfer coefficient kLa was found to reduce with the increase of mass transfer time under the same operational conditions. With computational fluid dynamics simulations, the instantaneous kLa values decreased sharply at the initial stage of the mass transfer process. The effects of numerous experimental parameters on separated contribution of kLa were investigated for different dimensionless mass transfer times. The instantaneous kLa values for arbitary transfer times could be calculated and agreed well with experimental data.
Co-reporter:Z. Fan;X. Zhang;W. Cai;F. Wang
Chemical Engineering & Technology 2013 Volume 36( Issue 5) pp:829-839
Publication Date(Web):
DOI:10.1002/ceat.201200611
Abstract
Design and control of an extractive distillation system for tetrahydrofuran (THF) dehydration with ethylene glycol as entrainer is investigated. The main module is a two-column system containing an extractive distillation column, whose top stream is the desired product THF, and an entrainer recovery column. Economic analysis with total annual cost as the objective function is developed. Two kinds of control strategies are explored for THF dehydration. The responses reveal that the control structure with fixed reflux ratio cannot maintain the bottom liquid level of the entrainer recovery column, while the control scheme with fixed reboiler heat duty/feed flow ratio exhibits good control performance in spite of large deviations in feed flow rate and feed composition.
Co-reporter:Yiqing Chen, Zhidong Fan, Lixia Ma, Juan Yin, ... Wangfeng Cai
Saudi Journal of Biological Sciences (November 2014) Volume 21(Issue 5) pp:450-456
Publication Date(Web):1 November 2014
DOI:10.1016/j.sjbs.2014.05.008
Hydrogen sulfide (H2S) is a major malodorous compound emitted from wastewater treatment plants. In this study, the performance of three pilot-scale immobilized-cell biotrickling filters (BTFs) spacked with combinations of bamboo charcoal and ceramsite in different ratios was investigated in terms of H2S removal. Extensive tests were performed to determine the removal characteristics, pressure drops, metabolic products, and removal kinetics of the BTFs. The BTFs were operated in continuous mode at low loading rates varying from 0.59 to 5.00 g H2S m−3 h−1 with an empty bed retention time (EBRT) of 25 s. The removal efficiency (RE) for each BTF was >99% in the steady-state period, and high standards were met for the exhaust gas. It was found that a multilayer BTF had a slight advantage over a perfectly mixed BTF for the removal of H2S. Furthermore, an impressive amount >97% of the H2S was eliminated by 10% of packing materials near the inlet of the BTF. The modified Michaelis–Menten equation was adopted to describe the characteristics of the BTF, and Ks and Vm values for the BTF with pure bamboo charcoal packing material were 3.68 ppmv and 4.26 g H2S m−3 h−1, respectively. Both bamboo charcoal and ceramsite demonstrated good performance as packing materials in BTFs for the removal of H2S, and the results of this study could serve as a guide for further design and operation of industrial-scale systems.
