Calculation of the Multiphase Equilibrium of the Reaction in Wet Flue Gas Desulfuration

2005 ◽  
Author(s):  
Qulan Zhou ◽  
Shi’en Hui ◽  
Tongmo Xu ◽  
Caihong Zhao ◽  
Zhenhai Shi
Keyword(s):  
Free Energy ◽  
Phase Equilibrium ◽  
Partial Pressure ◽  
Flue Gas ◽  
Initial Conditions ◽  
Equilibrium Line ◽  
Energy Minimum ◽  
Computational Code ◽  
Flue Gas Desulfuration ◽  
Phase Equilibrium Line

A computational code, which can be used to calculate gas-liquid-solid 3-phase equilibrium line, has been developed based on the principle of free energy minimum. Then the equilibrium lines of dissolution of SO2 and CaCO3 in water are obtained using the code. The results satisfy the mass and charge conservation and match well with the data in the references. Finally, multiphase equilibrium lines of the reaction in WFGD are calculated in different conditions. The results show that temperature, concentration of SO2, CO2, have different effects on the solubility of SO2 under initial conditions given in the paper. Temperature and concentration of SO2 have great effects, and the concentration of CO2 has a small effect. The solubility of SO2 increases as the partial pressure of SO2 increases, temperature decreases or the concentration of CO2 decreases. These conclusions have a great guidance on designing the tower of wet flue gas desulphurization.

scholarly journals Description of the liquid-vapor phase equilibrium line of pure substances within the bounds of scale theory based on the Clapeyron equation

2021 ◽  
Vol 2057 (1) ◽  
pp. 012113
Author(s):  
S V Rykov ◽  
I V Kudryavtseva ◽  
V A Rykov ◽  
E E Ustyuzhanin
Keyword(s):  
Phase Equilibrium ◽  
Saturated Vapor ◽  
Average Diameter ◽  
Saturation Line ◽  
Equilibrium Line ◽  
Modern Theory ◽  
Clapeyron Equation ◽  
Scale Theory ◽  
Pure Substances ◽  
Phase Equilibrium Line

Abstract On the basis of the Clapeyron equation and the scale theory, expressions are developed for the “apparent” heat of vaporization r * = r * (T), vapor ρ- = ρ- (T) and liquid ρ+ = ρ+ (T) branches of the saturation line of individual substances for the range of state parameters from the triple point (pt,Tt,ρt ) to the critical (pc,Tc,ρc ). The peculiarity of the proposed approach to the description of the saturation line is that all exponents of the components of the equations ρ- = ρ- (T) and ρ+ = ρ+ (T) are universal up to the universality of the critical indices α, β and Δ. In this case, the order parameter ds = (ρ+ − ρ-)/(2ρc) and the average diameter df = (ρ+ + ρ-)/(2ρc) − 1 of the saturation line satisfy the saturation line model [2β,1−α], which follows from the modern theory of critical phenomena. The method is tested on the example of describing the phase equilibrium line of refrigerant R1233zd(E) in the range from Tt = 195.15 K to Tc = 439.57 K. It is found that in the temperature range [Tt,Tc ], the developed system of the mutually consistent equations ps = ps (T), r * = r * (T), ρ- = ρ- (T) and ρ+ = ρ+ (T) allows describing the data on the saturated vapor pressure ps and densities ρ- and ρ+ on the saturation line within the experimental uncertainty of these data.

scholarly journals R-245fa phase equilibrium line modeling method

2021 ◽  
Author(s):  
S.V. Rykov ◽  
◽  
I.V. Kudryavtseva ◽  
P.V. Popov ◽  
M. Nurysheva ◽  
...  
Keyword(s):  
Phase Equilibrium ◽  
Modeling Method ◽  
Equilibrium Line ◽  
Phase Equilibrium Line

scholarly journals Ethane phase equilibrium line

2021 ◽  
Vol 20 (2) ◽  
Author(s):  
S.V. Rykov ◽  
◽  
I.V. Kudryavtseva ◽  
V.A. Rykov ◽  
M. Nurysheva ◽  
...  
Keyword(s):  
Phase Equilibrium ◽  
Equilibrium Line ◽  
Phase Equilibrium Line

Study on Mechanism of Flue Gas Desulfuration by Using Liquid-Phase Biochemical Method

2011 ◽  
Vol 356-360 ◽  
pp. 1556-1560
Author(s):  
Zhi An Liu ◽  
Ying Chang ◽  
Peng Wang ◽  
Jlan Jun Jia ◽  
Qi Wang Liu
Keyword(s):  
Flue Gas ◽  
Rate Increase ◽  
The Self ◽  
Inlet Concentration ◽  
Critical Factors ◽  
Biochemical Method ◽  
Solution Ph ◽  
Flue Gas Desulfuration ◽  
Increasing Temperature ◽  
Flue Gas Desulphurization

Wet Biochemical Flue Gas Desulphurization technique (WB-FGD) is combined both catalyst of transition metal with microbial metabolize to achieve flue gas desulphurization. In the self-designed device of power plant flue gas desulphurization, study the desulphurization kinetics according to the absorption solution pH, Fe3+concentration, inlet concentration of SO2, temperature and other factors. The results show that: Concentration of Fe3+is the most critical factors in the desulphurization process, the desulphurization efficiency is decreased with the increasing of Fe3+concentration, which in the range of 0~0.01mol·L-1, and the desulphurization efficiency do not change significantly with the further increasing of the concentration of Fe3+.the desulphurization efficiency is decreased with the increasing concentration of H+when pH of the solution in the range of 1.5~3.5. The efficiency of desulphurization decrease with the increasing concentration of SO2, which in the range of 1145-3432mg·L-1. The oxidation rate increase with the increasing temperature at 20~40°C.The kinetic equation and controllable parameters of changes of Fe3+concentration are obtained according to the experimental data in WB-FGD.

scholarly journals Rapid, accurate, precise and reproducible ligand–protein binding free energy prediction

2020 ◽  
Vol 10 (6) ◽  
pp. 20200007 ◽  
Author(s):  
Shunzhou Wan ◽  
Agastya P. Bhati ◽  
Stefan J. Zasada ◽  
Peter V. Coveney
Keyword(s):  
Free Energy ◽  
Initial Conditions ◽  
Binding Free Energy ◽  
Computational Cost ◽  
Free Energy Calculations ◽  
Enhanced Sampling ◽  
Energy Prediction ◽  
Massive Scale ◽  
Chaotic Nature ◽  
High Level

A central quantity of interest in molecular biology and medicine is the free energy of binding of a molecule to a target biomacromolecule. Until recently, the accurate prediction of binding affinity had been widely regarded as out of reach of theoretical methods owing to the lack of reproducibility of the available methods, not to mention their complexity, computational cost and time-consuming procedures. The lack of reproducibility stems primarily from the chaotic nature of classical molecular dynamics (MD) and the associated extreme sensitivity of trajectories to their initial conditions. Here, we review computational approaches for both relative and absolute binding free energy calculations, and illustrate their application to a diverse set of ligands bound to a range of proteins with immediate relevance in a number of medical domains. We focus on ensemble-based methods which are essential in order to compute statistically robust results, including two we have recently developed, namely thermodynamic integration with enhanced sampling and enhanced sampling of MD with an approximation of continuum solvent. Together, these form a set of rapid, accurate, precise and reproducible free energy methods. They can be used in real-world problems such as hit-to-lead and lead optimization stages in drug discovery, and in personalized medicine. These applications show that individual binding affinities equipped with uncertainty quantification may be computed in a few hours on a massive scale given access to suitable high-end computing resources and workflow automation. A high level of accuracy can be achieved using these approaches.

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