scholarly journals Optimal design of extractive dividing-wall column using an efficient equation-oriented approach

2020 ◽  
Author(s):  
Yingjie Ma ◽  
Nan Zhang ◽  
Jie Li ◽  
Cuiwen Cao
Keyword(s):  
Optimal Design ◽  
Hybrid Algorithm ◽  
Chemical Engineering ◽  
Integration Method ◽  
Integration Time ◽  
Literature Report ◽  
Dividing Wall Column ◽  
Feasible Path ◽  
Analysis Mode ◽  
First Time

AbstractThe extractive dividing-wall column (EDWC) is one of the most efficient technologies for separation of azeotropic or close boiling-point mixtures, but its design is fairly challenging. In this paper we extend the hybrid feasible path optimisation algorithm (Ma Y, McLaughlan M, Zhang N, Li J. Computers & Chemical Engineering, 2020, 143: 107058) for such optimal design. The tolerances-relaxation integration method is refined to allow for long enough integration time that can ensure the solution of the pseudo-transient continuation simulation close to the steady state before the required tolerance is used. To ensure the gradient and Jacobian information available for optimisation, we allow a relaxed tolerance for the simulation in the sensitivity analysis mode when the simulation diverges under small tolerance. In addition, valid lower bounds on purity of the recycled entrainer and the vapour flow rate in column sections are imposed to improve computational efficiency. The computational results demonstrate that the extended hybrid algorithm can achieve better design of the EDWC compared to those in literature. The energy consumption can be reduced by more than 20% compared with existing literature report. In addition, the optimal design of the heat pump assisted EDWC is achieved using the improved hybrid algorithm for the first time.

scholarly journals Analysis of Natural Gas Consumption by the Industrial Sector of Bangladesh

2013 ◽  
Vol 27 ◽  
pp. 1-7
Author(s):  
Mahbubur Rahman ◽  
Mohammad Tamin ◽  
Lutfar Rahman
Keyword(s):  
Natural Gas ◽  
Chemical Engineering ◽  
Industrial Sector ◽  
Policy Makers ◽  
Usual Practice ◽  
Consumption Data ◽  
Depth Analysis ◽  
Gas Consumption ◽  
Natural Gas Consumption ◽  
First Time

The natural gas consuming sectors in Bangladesh are: i) Power, ii) Fertilizer, iii) Industry, iv) Captive power, v) Domestic, vi) Commercial, and vii) Transportation (CNG). Broad sectoral consumptions are reported in various literatures and reports, however, further breakdown of the data are difficult to find, and neither reported. The combined consumption of fertilizer, industry and captive power sectors is a significant portion of national gas consumption. This paper presents for the first time an in-depth analysis of the industrial sector gas consumption. Data were collected for each type of industry, and grouped according to the United Nations Framework Convention for Climate Change (UNFCCC). Captive generation is included in the industrial sector consumption, unlike the usual practice of considering it under the power generation. It is noticed that garments, textile and leather industries together have shown remarkable growth in the last decade. All the industries are more or less related to the national GDP growth. Some are export oriented while others address the internal market. Therefore analysis presented here should be helpful for policy makers to prioritize the sectors in case preferential supply and tariff adjustments become necessary.DOI: http://dx.doi.org/10.3329/jce.v27i1.15846 Journal of Chemical Engineering, IEB Vol. ChE. 27, No. 1, June 2012: 1-7

scholarly journals Heat Capacities and Thermodynamic Properties of Hungchaoite and Mcallisterite

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4470
Author(s):  
Jiangtao Song ◽  
Fei Yuan ◽  
Long Li ◽  
Yafei Guo ◽  
Tianlong Deng
Keyword(s):  
Phase Transition ◽  
Thermodynamic Properties ◽  
Thermodynamic Functions ◽  
Process Design ◽  
Chemical Engineering ◽  
Heat Capacities ◽  
Salt Lakes ◽  
Engineering Process ◽  
Thermal Anomalies ◽  
First Time

The heat capacities on two minerals of hungchaoite (MgB4O7·9H2O, Hu) and mcallisterite (MgB6O10·7.5H2O, Mc) have been measured with a precision calorimeter at temperatures ranging from 306.15 to 355.15 K, experimentally. It was found that there are no phase transition and thermal anomalies, and the molar heat capacities against temperature for the minerals of hungchaoite and mcallisterite were fitted as C p , m , Hu   =   − 27019.23675 + 229.55286 T   −   0.63912 T   2   +   ( 5.95862   ×   10   − 4 )   T   3 and C p , mMc   =   − 9981.88552   +   84.10964 T   −   0.22685 T   2   +   ( 2.0593   ×   10   − 4 )   T   3 , respectively. The molar heat capacities and thermodynamic functions of (HT-H298.15), (ST-S298.15), and (GT-G298.15) at intervals of 1 K for the two minerals were obtained for the first time. These results are significant in order to understand the thermodynamic properties of those minerals existing in nature salt lakes, as well as applying them to the chemical engineering process design.

scholarly journals Morphology of z ~ 1 galaxies from deep K-band AO imaging

2006 ◽  
Vol 2 (S235) ◽  
pp. 405-405
Author(s):  
Marc Huertas-Company ◽  
Daniel Rouan ◽  
Geneviève Soucail ◽  
Olivier Le Fèvre ◽  
Lidia Tasca
Keyword(s):  
Adaptive Optics ◽  
Spatial Resolution ◽  
Near Infrared ◽  
High Spatial Resolution ◽  
Integration Time ◽  
Early Type ◽  
Distant Galaxies ◽  
First Time ◽  
Concentration Asymmetry ◽  
Adaptive Optics System

AbstractWe present the results of observations of distant galaxies (z ~ 0.8) at high spatial resolution (~0.1"). We observed 7 fields of 1' × 1' with the NACO Adaptive Optics system (VLT) in Ks (2.2μm) band with typical V ~ 14 guide stars and 3h integration time per field. Observed fields are selected within the COSMOS survey area. We analyze the morphologies by means of B/D (Bulge/Disk) decomposition with GIM2D and CAS (Concentration-Asymmetry) estimators for 79 galaxies with magnitudes between Ks = 17 − 23 and classify them in three main morphological types (Late Type, Early Type and Irregulars). We obtain for the first time an estimate of the distribution of galaxy types at redshift z ~ 1 as measured from the near infrared at high spatial resolution.

Optimal Design of NPP Containment Protection Against Fuel Container Drop

2013 ◽  
Vol 688 ◽  
pp. 213-221 ◽  
Author(s):  
Juraj Králik
Keyword(s):  
Optimal Design ◽  
Nuclear Power ◽  
Soil Structure ◽  
Integration Method ◽  
Free Fall ◽  
Dynamic Equations ◽  
Impact Loads ◽  
Building Structure ◽  
Reinforced Concrete Structure ◽  
The Impact

This paper presents a optimal design of a damping devices for the protection of the reinforced concrete structure of a nuclear power plant (NPP) against the impact loads from a container of nuclear fuel of the type TK C30 drop. The finite element idealization of the building structure is used in space. The interaction of the soil-structure, as well as the fluid-structure of the deactivated basin is considered in space. A steel pipe damper system is proposed for the dissipation of the kinetic energy of the container is free fall. The Newmark’s integration method is used for the solution of the dynamic equations.

Chemical constituents of the stem bark of Acacia AuriculiformisA.Cunn ex. Benth. (fabaceae)

2020 ◽  
Vol 23 ◽  
pp. 88-91
Author(s):  
A.A. Ahmadu ◽  
B.A. Lawal ◽  
B. Olanipekun ◽  
A. Udobre ◽  
N. Tsafantakis ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Secondary Metabolites ◽  
Acid Ester ◽  
Spectroscopic Analysis ◽  
Chemical Constituents ◽  
Stem Bark ◽  
Acacia Auriculiformis ◽  
Compound I ◽  
Literature Report ◽  
First Time

The genus Acacia has been known to be a rich source of many secondary metabolites. This study was carried to isolate chemical constituents present in the stem bark of Acacia auriculiformis. The dichloromethane extract of the stem bark of Acacia auriculiformis was obtained by maceration. The extract obtained was subjected to silica gel column chromatography and preparative TLC. The isolated compounds were identified by spectroscopic analysis. This led to the isolation of ferulic acid ester (I), along with a steroid (II) and a triterpenoid (III). The structure of compound I was established using spectroscopic analysis (UV, IR, NMR and mass spectrometry) and identified to be dodecyl-4-hydroxy-3-methoxy-trans-cinnamate (I), compounds II and III were found to be á-spinasterol and lupenol respectively, based on the comparison of their spectral data NMR and MS with literature report. Compound I is being reported for the first time in the genus Acacia.

Performance and Spectral Response of Far-Infrared Pb1−xSnxTe(In) Photodetectors

1999 ◽  
Vol 607 ◽  
Author(s):  
I. Ivanchik ◽  
D. Khokilov ◽  
J. Pipher ◽  
N. Raines ◽  
D. Watson
Keyword(s):  
State Of The Art ◽  
Spectral Response ◽  
Far Infrared ◽  
Integration Time ◽  
First Time

AbstractDirect comparison of performance has been done for a Pb1−xSnxTe(In) photodetector, a Si(Sb) BIB structure and a state of the art Ge(Ga) photoconductor in the integration cavity. The PblSnTe(In) photodetector shows several orders of magnitude higher responsivity S, then the Si(Sb) BIB at the wavelength λ ∼ 14 µm. Persistent photoresponse with SI ∼ 103 A/W at 40 mV bias and 1 s integration time at the wavelengths of, λ = 90 and 116 µm has been observed for the first time for the Pb1−xSnxTe(In) photodetector. This value is by a factor of ∼ 100 higher than the respective parameters of the Ge(Ga) photoconductor in the same conditions.

scholarly journals Continuous isotopic composition measurements of tropospheric CO<sub>2</sub> at Jungfraujoch (3580 m a.s.l.), Switzerland: real-time observation of regional pollution events

2010 ◽  
Vol 10 (10) ◽  
pp. 24563-24593 ◽  
Author(s):  
B. Tuzson ◽  
S. Henne ◽  
D. Brunner ◽  
M. Steinbacher ◽  
J. Mohn ◽  
...  
Keyword(s):  
Particle Dispersion ◽  
Integration Time ◽  
High Temporal Resolution ◽  
Research Station ◽  
Mixing Ratios ◽  
Keeling Plot ◽  
Time Observation ◽  
First Time ◽  
Pollution Events

Abstract. A quantum cascade laser based absorption spectrometer (QCLAS) is applied for the first time to perform in situ, continuous and high precision isotope ratio measurements of CO2 in the free troposphere. Time series of the three main CO2 isotopologue mixing ratios (12C16O2, 12C16O2 and 12C18O16O) have simultaneously been measured at one second time resolution over two years (from August 2008 to present) at the High Altitude Research Station Jungfraujoch (3580 m a.s.l., Switzerland). This work focuses on periods in February 2009 only, when sudden and pronounced enhancements in the tropospheric CO2 were observed. These short-term changes were closely correlated with variations in CO mixing ratios measured at the same site, indicating combustion related emissions as potential source. The analytical precision of 0.046‰ (at 50 s integration time) for both δ13C and δ18O and the high temporal resolution allowed the application of the Keeling plot method for source signature identification. The spatial origin of these CO2 emission sources was then determined by backward Lagrangian particle dispersion simulations.

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