Skip to main content

Advertisement

SpringerLink
Log in

Theoretical and experimental investigation on improvement of magnesium oxide sorbent by acetic acid washing for enhancing flue gas desulfurization performance

  • Original Paper
  • Published:
Chemical Papers Aims and scope Submit manuscript

Abstract

Flue gas desulfurization (FGD) technologies are applied to minimize SO2 emission to the atmosphere and prevention of acid rains. Magnesium oxide (MgO) is one of the common sorbents to capture sulfur dioxide in FGD. Pore blockage and incomplete conversion are the main problems of sorbents such as CaO and MgO. In this study, acid-washed technique as a modification method was applied to enhance SO2 adsorption capacity of MgO. The tests were carried out in thermogravimeter (TG) and packed bed reactor to compare the performance of the acid-washed sorbents with the initial natural samples. The results showed that the acid-washed sorbents has more adsorption capacity than the natural samples. Finally, the single pellet conversion–time profiles and packed bed reactor breakthrough curves for both sorbents were predicted by random pore model (RPM) with fairly good agreements.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5

Similar content being viewed by others

Abbreviations

a = CA/CAb :

Dimensionless gas concentration in the pellet

b = CB/CB0 :

Dimensionless solid concentration

C A :

Gas concentration in the pellet, kmol m–3

C Ab :

Bulk gas concentration, kmol m–3

C Ab0 :

Inlet bulk gas concentration to the bed, kmol m–3

C B :

Solid reactant concentration, kmol m–3

C B 0 :

Initial solid reactant concentration, kmol m–3

D AK :

Knudsen diffusivity, m2 s–1

D AM :

Molecular diffusivity of gas A in the pellet, m2 s–1

D e :

Effective diffusivity of gas A in the pellet, m2 s–1

D e0 :

Initial effective diffusivity of gas A in pores, m2 s–1

D p :

Diffusivity of gas A in product layer, m2 s–1

D L :

Axial dispersion coefficient in bed, m2 s−1

k m :

External mass-transfer coefficient, m s–1

k s :

Surface rate constant, m s–1

L :

Packed bed length, m

L 0 :

Pore length per unit volume, m–2

M B :

Molecular weight of solid reactant, kg kmol–1

M D :

Molecular weight of solid product, kg kmol–1

n :

Reaction order

r :

Pore radius, m

r p :

Each point position in the spherical pellet, m

\(\overline{r}\) :

Average pore radius of the pellet, m

R :

Spherical pellet radius, m

S 0 :

Reaction surface area per unit volume, m–1

\({\text{Sh}} = \frac{{k_{{\text{m}}} L}}{{2D_{{{\text{AM}}}} }}\) :

Sherwood number for external mass transfer

t :

Time, s

T :

Temperature, K

\(\upsilon_{0} (r)\) :

Pore volume distribution function, m2 kg–1

V p :

Total pore volume, m3 kg−1

\(w = C_{{\text{A}}} /C_{{{\text{Ab0}}}}\) :

Dimensionless gas concentration in the bed

x :

Axial distance from beginning of bed, m

\(X\) :

Solid local conversion in the bed at each time

\(\overline{X}(\theta )\) :

Solid average conversion at each time

\(y = r_{{\text{p}}} /R\) :

Dimensionless position in the spherical pellet

Z :

Molar volume ratio of solid product to solid reactant

\(\beta = 2k_{{\text{s}}} (1 - \varepsilon_{0} )/(\upsilon_{{\text{B}}} D_{{\text{p}}} S_{0} )\) :

Product layer resistance

\(\varepsilon\) :

Pellet porosity

\(\varepsilon_{0}\) :

Initial pellet porosity

\(\delta = \frac{{D_{{\text{e}}} }}{{D_{{{\text{e0}}}} }}\) :

Variation ratio of the pore diffusion

\(\beta = 2k_{{\text{s}}} (1 - \varepsilon_{0} )/(\nu_{{\text{B}}} D_{{\text{p}}} S_{0} )\) :

Product layer resistance

\(\varepsilon\) :

Pellet porosity

\(\varepsilon_{0}\) :

Initial pellet porosity

\(\delta = \frac{{D_{e} }}{{D_{e0} }}\) :

Variation ratio of the pore diffusion

\(\theta = k_{{\text{s}}} S_{0} C_{{{\text{Ab}}}}^{{}} t/[C_{{{\text{B0}}}} (1 - \varepsilon_{0} ] = t/\tau\) :

Dimensionless time

\(\nu_{{\text{B}}}\) :

Stoichiometric coefficient of the solid reactant

\(\nu_{{\text{D}}}\) :

Stoichiometric coefficient of the solid product

\(\rho_{{\text{B}}}\) :

True density of the solid reactant, kg m–3

\(\rho_{{\text{D}}}\) :

True density of the solid product, kg m–3

\(\phi = (L/2)(k_{{\text{s}}} S_{0} C_{{{\text{Ab}}}}^{n - 1} /\upsilon_{{\text{B}}} D_{{{\text{e0}}}} )^{1/2}\) :

Thiele modulus for the pellet

\(\psi\) :

Random pore model main parameter

\(\zeta = x/R\) :

Dimensionless reactor length

References

Download references

Author information

Authors and Affiliations

  1. Department of Chemical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran

    A. Bakhshi Ani & H. Ale Ebrahim

Authors
  1. A. Bakhshi Ani
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. H. Ale Ebrahim
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to H. Ale Ebrahim.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Ani, A.B., Ebrahim, H.A. Theoretical and experimental investigation on improvement of magnesium oxide sorbent by acetic acid washing for enhancing flue gas desulfurization performance. Chem. Pap. 74, 2471–2479 (2020). https://doi.org/10.1007/s11696-020-01093-6

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11696-020-01093-6

Keywords

Search

Navigation