Unsteady state behavior of multicomponent distillation columns: Part I: Simulation

AIChE Journal ◽  
1970 ◽  
Vol 16 (6) ◽  
pp. 1022-1029 ◽  
Author(s):  
G. Michael Howard
Keyword(s):  
Unsteady State ◽  
State Behavior ◽  
Distillation Columns ◽  
Multicomponent Distillation

Evolution of Pinch-Point Zones in Multicomponent Distillation Columns. 1. Rectifying Section

1996 ◽  
Vol 35 (8) ◽  
pp. 2777-2781
Author(s):  
Yang Zhicai ◽  
Wu Di ◽  
Yang Zhaoxia ◽  
Zhang Ronglan
Keyword(s):  
Pinch Point ◽  
Distillation Columns ◽  
Multicomponent Distillation

Dynamic and control behavior of multicomponent distillation columns

SIMULATION ◽  
1990 ◽  
Vol 54 (4) ◽  
pp. 201-209 ◽  
Author(s):  
Y.S. Yiu ◽  
G.A. Carling ◽  
R.K. Wood
Keyword(s):  
Distillation Columns ◽  
Control Behavior ◽  
Multicomponent Distillation ◽  
And Control

Unsteady-State Behavior of Naturally Fractured Reservoirs

1965 ◽  
Vol 5 (01) ◽  
pp. 60-66 ◽  
Author(s):  
A.S. Odeh
Keyword(s):  
Fractured Reservoirs ◽  
Naturally Fractured Reservoirs ◽  
Unsteady State ◽  
Fractured Reservoir ◽  
State Behavior ◽  
Naturally Fractured ◽  
Matrix Blocks ◽  
The Matrix ◽  
Porosity And Permeability ◽  
Bulk Volume

Abstract A simplified model was employed to develop mathematically equations that describe the unsteady-state behavior of naturally fractured reservoirs. The analysis resulted in an equation of flow of radial symmetry whose solution, for the infinite case, is identical in form and function to that describing the unsteady-state behavior of homogeneous reservoirs. Accepting the assumed model, for all practical purposes one cannot distinguish between fractured and homogeneous reservoirs from pressure build-up and/or drawdown plots. Introduction The bulk of reservoir engineering research and techniques has been directed toward homogeneous reservoirs, whose physical characteristics, such as porosity and permeability, are considered, on the average, to be constant. However, many prolific reservoirs, especially in the Middle East, are naturally fractured. These reservoirs consist of two distinct elements, namely fractures and matrix, each of which contains its characteristic porosity and permeability. Because of this, the extension of conventional methods of reservoir engineering analysis to fractured reservoirs without mathematical justification could lead to results of uncertain value. The early reported work on artificially and naturally fractured reservoirs consists mainly of papers by Pollard, Freeman and Natanson, and Samara. The most familiar method is that of Pollard. A more recent paper by Warren and Root showed how the Pollard method could lead to erroneous results. Warren and Root analyzed a plausible two-dimensional model of fractured reservoirs. They concluded that a Horner-type pressure build-up plot of a well producing from a factured reservoir may be characterized by two parallel linear segments. These segments form the early and the late portions of the build-up plot and are connected by a transitional curve. In our analysis of pressure build-up and drawdown data obtained on several wells from various fractured reservoirs, two parallel straight lines were not observed. In fact, the build-up and drawdown plots were similar in shape to those obtained on homogeneous reservoirs. Fractured reservoirs, due to their complexity, could be represented by various mathematical models, none of which may be completely descriptive and satisfactory for all systems. This is so because the fractures and matrix blocks can be diverse in pattern, size, and geometry not only between one reservoir and another but also within a single reservoir. Therefore, one mathematical model may lead to a satisfactory solution in one case and fail in another. To understand the behavior of the pressure build-up and drawdown data that were studied, and to explain the shape of the resulting plots, a fractured reservoir model was employed and analyzed mathematically. The model is based on the following assumptions:1. The matrix blocks act like sources which feed the fractures with fluid;2. The net fluid movement toward the wellbore obtains only in the fractures; and3. The fractures' flow capacity and the degree of fracturing of the reservoir are uniform. By the degree of fracturing is meant the fractures' bulk volume per unit reservoir bulk volume. Assumption 3 does not stipulate that either the fractures or the matrix blocks should possess certain size, uniformity, geometric pattern, spacing, or direction. Moreover, this assumption of uniform flow capacity and degree of fracturing should be taken in the same general sense as one accepts uniform permeability and porosity assumptions in a homogeneous reservoir when deriving the unsteady-state fluid flow equation. Thus, the assumption may not be unreasonable, especially if one considers the evidence obtained from examining samples of fractured outcrops and reservoirs. Such samples show that the matrix usually consists of numerous blocks, all of which are small compared to the reservoir dimensions and well spacings. Therefore, the model could be described to represent a "homogeneously" fractured reservoir. SPEJ P. 60ˆ

Transient behaviour of multicomponent distillation columns

1960 ◽  
Vol 1 (1) ◽  
pp. 1816-1824
Author(s):  
H.H. Rosenbrock ◽  
A.B. Tavendale ◽  
C. Storey ◽  
J.A. Challis
Keyword(s):  
Distillation Columns ◽  
Transient Behaviour ◽  
Multicomponent Distillation

scholarly journals CFD Modeling to Predict Mass Transfer in Multicomponent Mixtures

2019 ◽  
Vol 14 (4) ◽  
Author(s):  
Mitra Sadat Lavasani ◽  
Rahbar Rahimi ◽  
Mortaza Zivdar ◽  
Mohammad Kalbassi
Keyword(s):  
Mass Transfer ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Ternary Mixtures ◽  
Cfd Modeling ◽  
Multicomponent Mixtures ◽  
Distillation Columns ◽  
Multicomponent Distillation ◽  
Interactive Nature ◽  
Two Phases

Abstract A novel three-dimensional computational fluid dynamics mass transfer (CMT) model in Eulerian–Eulerian frame work is deploys for investigating the concentration profiles, and trays efficiencies in multicomponent distillation columns. The proposed model is based on Maxwell Stefan equations, and CFD was employed as a powerful tool to model the hydrodynamics and mass transfer. The two phases are modelled as two interpenetrating phases with interphase momentum, heat and mass transfer. The Closure model is developed for mass interphase transfer rate in ternary mixtures. The predictability of the mass transfer behaviours of multicomponent can result in a more efficient and predictable design of distillation trays. Two non-ideal ternary mixtures were studied. The tray geometry and operating conditions are based on the experimental works of Kalbassi and the composition profiles, tray efficiencies, and point efficiencies of mixtures were presented. The obtained results were confirmed by the experimental data. The results indicate that the values of individual component tray efficiencies and point efficiencies for these multicomponent systems were considerably different which confirm the interactive nature of the mass transfer in multicomponent mixtures. These mixtures also illustrated different point efficiencies across the tray because of the composition dependency of these mixtures. The average relative error for the prediction of efficiencies is about 8 %, which indicates the accuracy of the model.

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