Simulation of continuous-contact separation processes: multicomponent, adiabatic absorption

Abstract

Malone, M. F. Ind. Eng. Chem. Process Des. Dev. 1984, 23, Gllnos, K.; Malone, M. F. Ind. Eng. Chem. Process Des, Dev. 1985, 24, Jafarey. A.; McAvoy, T. J.; Douglas, J. M. Ind. Eng. Chem. Fundem. 1979, King, C. J. "Separation Processes", 2nd ed.; McOlaw-Hlli: New York, 1980. Malone, M. F.; Glinos. K.; Marquez, F. E.; Douglas, J. M. AIChE J . 1085, 31, Underwood. A. J. V. J . Inst. Pet. 1848, 32, 598. VI/ w1 i in the side stream 784. 822. 18, 101. 083.

Simulation of continuous-contact separation processes: unsteady-state, multicomponent, adiabatic absorption

“…In addition, earlier model assumptions of Hitch et al (1986) were relaxed so that the effect of nonideal vaporliquid equilibrium relationships and nonlinear masstransfer expressions on simulation results could be observed. The only remaining major restrictions imposed on the system equations are as follows: (1) The absorption column is adiabatic.…”

“…The numerical method chosen for the unsteady-state simulation uses finite difference expressions to approximate the derivatives in the differential model equations, thereby reducing the system of partial differential equations to a coupled system of algebraic equations. Forward and backward difference approximations to the spatial derivative terms were described earlier (Hitch et al, 1986); a similar expression may be used to approximate the where Ck again represents some dependent variable and the designation (N) represents an arbitrary "position" in the finite difference grid associated with the time domain. Therefore, the rate of change of variable Ck with time is approximated by the difference between the value of Ck at some time N + 1 and its value at time N divided by the time step At.…”

“…Simulation predictions, both dynamic and final steady-state, compared favorably with experimental results.The numerical simulation of continuous-contact separation devices is a topic that has long been neglected. In a previous article (Hitch et al, 1986), we pointed out that until recently most research efforts in the area of the design and analysis of separation processes have concentrated on…”

“…Some of previous results for gas holdups that either were not well understood (e.g., the foam breakup reported by Farley and Ray (1964)) or appeared to be in a poor agreement (i.e., small vs. high gas holdup values obtained in different studies with different types of gas distributors) can be explained in terms of the existence of these two flow staged operations. Coincident with the development of our simcal algorithm, which is described by Hitch et al (1986), other workers also produced numerical simulations that can handle rigorously the process of steady-state, adiabatic absorption in a packed column. Chief among these are the "nonequilibrium stage model" algorithms of Krishnamurthy and Taylor (1985).…”

Performance improvement for chemical absorption of CO2 by global field synergy optimization

“…The process description of CO 2 capture was always kept an eye on, almost from the gas absorption birth period to presently furious investigation phase (Kohl and Riesenfeld, 1979;Tontiwachwuthikul et al, 1992;Bouhamra et al, 1999;Freguia and Rochelle, 2003;Abu-Zahra et al, 2007;Rochelle, 2009;Sanpasertparnich et al, 2010). The basic absorption model has been suggested for quite a period with latest development on the multi-dimensional and steady description (Hitch et al, 1986;Liu, 2001;Aboudheir et al, 2006;Plaza et al, 2010). However, necessary uniform intensification for the capture system was not developed in a deep-going way.…”