Kinetic Analysis of H2S Removal over Mesoporous CuâMn Mixed

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Kinetic Analysis of H2S Removal over Mesoporous Cu(La)Mn Mixed Oxide /SBA-15(KIT-6) Sorbents during Hot Coal Gas Desulfurization by Using Deactivation Kinetics Model Yong-Son Hong, Kye-Ryong Sin, Chol-Jin Kim, Jong-Su Pak, and Bingsi Liu Energy Fuels, Just Accepted Manuscript • DOI: 10.1021/acs.energyfuels.7b00048 • Publication Date (Web): 28 Jul 2017 Downloaded from http://pubs.acs.org on August 3, 2017

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Kinetic Analysis of H2S Removal over Mesoporous Cu(La)-Mn Mixed Oxide /SBA-15(KIT-6) Sorbents during Hot Coal Gas Desulfurization by Using Deactivation Kinetics Model Yong-Son Hong1, Kye-Ryong Sin2*, 1

Jong-Su Pak1, Chol-Jin Kim1,

Bing-Si Liu3

Department of Chemistry, Kim Hyong Jik Normal University，Pyongyang，DPR of Korea 2

Department of Chemistry, Kim Il Sung University，Pyongyang，DPR of Korea

3

Department of Chemistry, School of Science, Tianjin University, Tianjin, China

ABSTRACT: Kinetic analysis was investigated by using the deactivation kinetics model where the reaction order of each species based on the experimental data was estimated for H2S removal over mesoporous Cu-Mn mixed oxide/SBA-15 and La-Mn mixed oxide/KIT-6 sorbent during hot coal gas desulfurization in a fixed-bed reactor. The reaction orders, rate constants, the apparent activation energy (Ea) and deactivation energy (Ed) were calculated as the kinetic parameters. The calculated reaction orders (α, β, γ) were (1, 1, 1) for Cu-Mn mixed oxide /SBA-15 and (0.6, 1.2, 1) for La-Mn mixed oxide /KIT-6. The obtained Ea and Ed for Cu1Mn9 mixed oxide/SBA-15 were 33.02 kJ·mol−1, 46.34kJ·mol−1, and they are 48.98 kJ·mol−1, 56.10 kJ·mol−1 for La3Mn97 mixed oxide/KIT-6, respectively. This model offered the H2S breakthrough curves for the whole duration of the desulfurization reaction with errors less than 5% between calculated and experimental data. Keywords: deactivation kinetics model; hot coal gas desulfurization; H2S removal; mesoporous mixed oxide, fixed-bed reactor 1. INTRODUCTION Desulfurization, the conventional removal of sulfur compounds, such as the desulfurization of the fuel gases and coal gasification, requires severe conditions to produce ultralow sulfur compounds.1,2 However, the hot coal gases from gasification processes always contain H2S, which can cause acid rain and severe corrosion of downstream equipments, and hence need to be removed prior to the utilization. The conventional desulfurization techniques were conducted at low temperature with a loss of sensible heat. Therefore, the removal of H2S at high temperature over metal oxides has received considerable attention in the past decades.3-7 Mesoporous zeolites, for instance, MCM-41, SBA-15 (hereafter referred to as simply S15) and KIT-6 (hereafter referred to as simply K6) with high specific surface area and regular pore structure were used as support and promoted the diffusion of H2S molecules and attrition resistance.8,9 The effective utilization of active components in supported sorbents was considered to be the main reason for the improvement of desulfurization performance. There were some reports on the desulfurization performance of supported oxide sorbents, which exhibited good regeneration stability and mechanical strength.10-14 Many kinetic models have been proposed to describe the kinetics of non-catalytic heterogeneous

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reaction and adsorption. The unreacted shrinking core model (SCM)15,16 assumes that the reaction occurs at a sharp interface between the reacted outer surface and the unreacted interior core. Mass transfer of gaseous reactant from the bulk to the pellet exterior surface is followed by diffusion through a sulfidation layer before contacting with fresh sorbent and the desulfurization reaction can occur. However, the SCM is suitable mainly for solid sorbents with low porosity. In order to describe the kinetics of CaO sulfation, Wen and Ishida17 and Hartman and Coughlin18 employed the grain model19 and expressed the porosity as a function of conversion. Ramachandran and Smith20 proposed the single-pore model and took into account the change of pore structure. Georgakis et al21 presented the changing grain size model focusing on the change of grain size. Bhatia and Perlmutter22,23 proposed a random pore model (RPM) for fluid-solid reaction with unsupported solid24,25 and utilized a pore structure parameter (ψ) to characterize solid reactivity, and correlated this parameter with the grain shape factor. A large amount of work has been done on kinetics model for hot coal gas desulfurization,26-29 and there appeared some adsorption kinetics models such as the pseudo-first-order (PFO),30 the pseudo-second-order (PSO),30,31 the modified pseudo-n-order (MPnO),32 the mixed-order (MOE)33 rate equations, and the fractal-like kinetics model.34 Yasyerli et al35-39 applied the deactivation model (DM) to predict the H2S breakthrough curves over a variety of sorbents, which was consistent with the experimental results. According to this model, the effects of the textural variation (pore structure, active surface area and activity per unit area) of the solid sorbent and formation of a dense sulfide (or sulfate) layer over the sorbent on activity of the solid sorbent were expressed in terms of deactivation rate (Eq. 1), da = k d0 C A a dt dC A −Q − k0 C A a = 0 dW −

(1)

where the meaning of parameters was explained in NOMENCLATURE at the end of this paper. The results revealed that if breakthrough time of sorbents varied greatly with operating conditions, such as different weight hourly space velocity (WHSV), the model would make large deviation for the evaluation of initial reaction rate constants k0 and deactivation rate constant kd0. Because the order of the reaction between H2S and sorbent is assumed to be 1 and all these factors, such as pore structure and active surface areas of sorbent, are combined in an activity of the solid reactant (a), the deactivation model is not suitable for all of the complicated desulfurization reactions in hot coal gas. Dahlan et al.40and Ficicilar et al.41 reported similarly that the deactivation rate of solid reactant (sorbent) was considered to be independent of the concentration of gaseous reactant; that is, the deactivation rate was zero order with respect to gaseous reactant in the deactivation model. Recently, we presented the deactivation kinetics model (DKM, Eq. 2)43 for non-catalytic heterogeneous reaction and adsorption and applied it to the kinetics analysis on H2S removal over mesoporous LaFeO3/MCM-41 sorbent during hot coal gas desulfurization in the fixed bed reactor12, where LaxFeyO/MCM-41 sorbents (mesopore volume 50~150mm3/g, WHSV=9 L•h−1•g−1) had different La/Mn atomic ratios and the temperature range was 450-600 °C. k  ∂C = − a C A (1 − X ) α  ∂z u  X ∂  = k d ⋅ C Aγ (1 − X ) β  ∂t


(2)

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The aim of this work is to verify the validity of DKM through the kinetic analysis on the previous experimental data on H2S removal over mesoporous Cu-Mn mixed oxide/S1513 and La-Mn mixed oxide /K644 sorbent during hot coal gas desulfurization in a fixed bed reactor. According to the previous report from Zhang et al13, a series of mesoporous xCuyMn/SBA-15 sorbents with different Cu/Mn atomic ratios were prepared by wet impregnation method and their desulfurization performance in hot coal gas was investigated in a fixed-bed quartz reactor in the range of 700–850℃(WHSV=19.8 L•h−1•g−1). The successive nine desulfurization–regeneration cycles at 800◦C revealed that 1Cu9Mn/SBA-15 presented high performance with durable regeneration ability due to the high dispersion of Mn2O3 particles incorporated with a certain amount of copper oxides. The breakthrough sulfur capacity of 1Cu9Mn/SBA-15 observed 800℃ was 13.8 g S/100 g sorbents, which is remarkably higher than these of 40 wt%LaFeO3/SBA-15 (4.8 g S/100 g sorbents) and 50 wt%LaFe2Ox/MCM-41 (5.58 g S/100 g sorbents) used only at 500–550 ◦C. Xia et al44 reported that a series of mesoporous xLayMn/KIT-6 sorbents with different La/Mn atomic ratios were fabricated by a sol-gel method and their desulphurization properties in hot coal gas were investigated at 700-850℃(WHSV=21.6 L•h−1•g−1). 3La97Mn/KIT-6 performed the best at 800℃ with breakthrough sulfur capacity of 11.56 g sulfur/100 g sorbent. The eight successive desulphurization (800 ℃ )-regeneration (600 ℃ ) cycles revealed that 3La97Mn/ KIT-6 with endurable regeneration ability could obtain 80% of initial sulfur capacity. It indicated better desulphurization performance compared to pure 3La97Mn and 3La97Mn/MCM-41. DKM has not considered the detailed characteristic parameters of the solid sorbent in such microscopic way as SCM15,16 or GRM22,23, but in macroscopic way. Therefore, DKM can be applied to kinetics analysis on two sets of hot coal gas desulfurization system13,44 in spite of differences of some specific conditions like the composition of solid sorbent and gases, reaction temperature, and space velocity of gaseous reactant. 2. ESTIMATION OF REACTION ORDERS 2.1. Calculation process. Introducing dimensionless variables (C*=C/C0, Z*=Z/L0), the deactivation kinetics model (Eq. 2) yields Eq. 3.  ∂C * k a ⋅ L0 * C (1 − X ) α  * = − ∂z u   ∂X = k ⋅ C γ C *γ (1 − X ) β d 0  ∂t

(3)

Both partial differential equations (Eq. 3) were solved simultaneously by using forward finite differential method. The initial and boundary conditions for Eq. 3, such as the fractional conversion (X) of fresh solid sorbent, the inlet concentration of gas reactant (C0) and the outlet concentration variation with position (z) and time (t) were chosen as follows: (4) X ( z ∗ ,0) = 0 , C A * (0, t ) = 1 , ∂C A * / ∂z ∗ (1, t ) = 0 The corresponding concentration of H2S in gas phase and the fractional conversion of sorbent can be estimated as follows (Eq. 5):


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 * * k a ⋅ L0 C i,j* (1 − X i,j ) α + C i,j* C i +1,j = − ∆z ⋅ u  r ∗γ β X  i +1,j = ∆t ⋅ k d C 0 C i,j (1 − X i,j ) + X i,j

(5)

The reaction rate constants and reaction orders were calculated using the nonlinear least-squares fitting of the H2S concentration, which was obtained by solving partial differential equations, to the previous experimental data of H2S removal over mesoporous Cu-Mn mixed oxide/S1513 and La-Mn mixed oxide /K644 sorbent during hot coal gas desulfurization in a fixed bed reactor. The object function of least-squares fitting for the kinetic parameters calculation was described as follows (Eq. 6). ni

(

min f (k a , k d ,α , β , γ ) = ∑ C * i

cal

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* − Cexp

)

2

(6)

It was very difficult to optimize 5 parameters simultaneously by non-linear LSQ optimization (especially, setting the initial value of parameters is the most difficult). This problem was solved step by step like follows: at first, every parameter was calculated by non-linear LSQ optimization one by one and used as its initial value for the 5 parameters’ optimization by the nonlinear least-squares fitting with “fminsearch” and “fminunc” (MATLAB functions). 2.2. Estimated reaction orders. To calculate the reaction orders, the experimental points over CuxMny mixed oxides (hereafter referred to as simply CuxMny)/S15 sorbents and LaxMny mixed oxides(hereafter referred to as simply LaxMny)/K6 sorbents with different Cu(or La)/Mn ratios were used. As shown in the calculated results (Table 1), the deviation of reaction orders for CuxMny/S15 sorbents was very small and those average values of the reaction orders were α=0.9672, β=1.0253, γ=1.0098, respectively, where all the reaction orders were around 1. On the other hand, the deviation of the reaction orders for LaxMny/K6 sorbents was very small and those average reaction orders were α=0.6271≈0.6, β=1.1928≈1.2, and γ=1.0154≈1.0, respectively. The obtained correlation coefficients (R2) between the experimental and calculated breakthrough values are nearly 1. It can be noticed that all reaction orders for the desulfurization reaction of hot coal gas over Cu-Mn/S15 sorbents were nearly 1 and the reaction orders for La-Mn/K6 sorbents were 0.6, 1.2, and 1, respectively. As shown in Table 1, the kinetic parameters depended strongly on the channel structure (Table 2) of SBA-1513 or KIT-644 support and Cu/Mn or La/Mn molar ratios of active species under the same reaction conditions. It is interesting to note that the rate constants for LaxMny/K6 sorbents were increased according to the increase of La amount, but ka and kd for CuxMny/S15 sorbents raised with the decrease of Cu amount, and the rate constants for CuxMny/S15 sorbents without Cu (x=0) were the lowest. The rate constants for LaxMny/K6 sorbents were higher than those for CuxMny/S15 sorbents. The higher values of ka and kd are consistent with the previous observation where the experimental breakthrough curves over the LaxMny/K6 sorbents were sharper.44 Figures 1 and 2 show the relationship of the calculated desulfurization curves with the experimental points for different CuxMny/S15 and LaxMny/K6 sorbents. It can be seen that the breakthrough curves calculated by Eq. 3 represent good prediction of the experimental breakthrough curves. The breakthrough curves of mixed oxides/S15 shifted to longer breakthrough time and sharper than pure Mn oxide/S15, indicating its higher reactivity. Table 1. Calculated kinetic parameters for sorbents with different Cu/Mn and La/Mn ratios. sorbents

Mn10/S15*

Cu5Mn5/S15*

Cu3Mn7/S15*


Cu1Mn9/S15*

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ka ×104 (min·g)-1 kd×10-1 (min-1 (mol·cm-3)-1)

(Mn10/K6) #

(La3Mn97/K6)#

(La5Mn95/K6)#

(La10Mn90/K6) #

0.80±0.11 (1.38±0.20)

1.08±0.08 (2.67±0.55)

2.37±0.16 (3.37±0.35)

3.36±0.16 (7.49±0.67)

0.47±0.06 (2.29±0.36)

0.84±0.07 (4.37±0.79)

1.44±0.11 (5.41±0.62)

1.96±0.35 (17.63±3.77)

Average

0.9670 0.9673 0.9671 0.9672 0.9672 (0.6258) (0.6277) (0.6274) (0.6276) (0.6271) 1.0255 1.0253 1.0252 1.0253 1.0253 β (1.1934) (1.1927) (1.1924) (1.1925) (1.1928) 1.0096 1.0097 1.0099 1.0098 1.0098 γ (1.0149) (1.0156) (1.0155) (1.0157) (1.0154) 0.9614 0.9912 0.9945 0.9867 R2 (0.9751) (0.9603) (0.9894) (0.9996) * Mn10, Cu5Mn5, Cu3Mn7 and Cu1Mn9 represent the molar ratio of Cu:Mn in sorbents are 0:10, 5:5, 3:7, 1:9 respectively. # Mn10, La3Mn97, La5Mn95 and La10Mn90 represent the molar ratio of La:Mn in sorbents are 0:10, 3:97, 5:95, 10:90 respectively, the data in parentheses are the rate constants and reaction orders for LaxMny/K6 sorbents. α

Table 2.

Total pore volume (Vt), Mesopore volume (Vmeso), Micropore volume (Vm), Average pore

diameter (Da) and BET surface area (SBET) of

SBA-1513, CuxMny/SBA-1513, KIT-644 and

LaxMny/KIT-644 Sample

V t (mm3/g )

Vmeso(mm3/g)

Vm(mm3/g)

Da(nm)

SBET(m2/g)

S15

910

640

270

2.1

867

Cu5Mn5/S15

260

200

60

2.5

206

Cu3Mn7/ S15

290

220

70

2.5

239

Cu1Mn9/ S15

260

190

70

2.1

243

Mn10/ S15

270

210

60

3.0

181

K6

1093

762

331

2.33

938

La3Mn97/ K6

381

309

72

3.56

214

La5Mn95/ K6

395

308

87

3.11

254

La10Mn90/ K6

414

344

70

4.04

205

Mn10/ K6

336

262

74

3.57

188

5

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Figure 1. H2S breakthrough curves for CuxMny/S15 sorbents with different Cu/Mn ratios. (a,b,c,d: the previous experimental data13, a- Mn10/S15, b- Cu5Mn5/S15, c- Cu3Mn7/S15, and dCu1Mn9/S15; the curves were calculated by using DKM43; T=800oC, WHSV = 19.8 L·h-1·g-1, 0.33% H2S, 10.5% H2, 17.1% CO, N2 as balance gas).

Figure 2. H2S breakthrough curves for LaxMny/K6 sorbents with different La/Mn ratios. (a,b,c,d: the previous experimental data44, a-La3Mn97/K6, b- La5Mn95/K6, c- La10Mn90/K6 and d-Mn10/K6; the curves were calculated by using DKM43; T= 800oC, WHSV=21.6 L·h-1·g-1, 0.36% H2S, 13.84% H2, 19.36% CO, N2 as balance gas) In the same way, we also estimated the reaction orders based on chemical stoichiometric equation43 again.(Table 3) The calculated results were α=1.1029≈1.1, β=1.4677≈1.5 and γ=0.5946≈0.6, respectively. The rate constants43 based on chemical stoichiometric equation depend on WHSV, but the rate constants estimated by the model presented in this paper do not depend on it. Table 3. Calculated Rate Constants ka and kd for La1Fe2 mixed oxide/MCM41 sorbents at different WHSV WHSV (L·h−1·g−1) ka ×103 (min·g)-1

9 6.17±0.32

12 6.14±0.28

15 6.11±0.65 6


18 6.07±0.14

Standard deviation 0.0427

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(ka ×103 (min·g)-1) # kd×10-1(min-1 (mol·cm-3)-0.6) (kd×10-2(min-1 (mol·cm-3)-3/2)) #

(7.52±0.85)

(7.08±0.47)

(6.15±0.4)

(5.81±0.24)

(0.7109)

4.33±0.13 (5.41±0.74)

4.32±0.58 (5.39±0.91)

4.35±0.37 (6.14±0.82)

4.37±0.78 (6.16±0.69)

0.022 (0.5211)

0.9916 0.9971 0.9949 0.9995 (0.989) (0.998) (0.998) (0.999) # The data in parentheses are the rate constants based on reaction order α=2/3, β=1 and γ=3/2 for LaxFe y mixed oxide/MCM41 sorbents. 43 R2

3. EFFECTS OF TEMPERATURE ON DESULFURIZATION REACTION OVER Cu1Mn9/S15 AND La3Mn97/K6 SORBENTS, and ESTIMATION OF ACTIVATION ENERGIES The rate constants at different temperatures were calculated by Eq.7, and the obtained ka and kd values are listed in Table 4. ni

(

min f (k a , k d ) = ∑ C * i

cal

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* − C exp

)

(7)

2

The reaction rates depended on temperatures, the rate constants of most reactions increase as the temperature is raised. As shown in Table 4, the rate constants for La3Mn97/K6 sorbents were raised uneventfully as expected, however, ones of 850℃ for Cu1Mn9/S15 sorbent was the lowest. It can be explained that higher reaction temperature could cause the evaporation of active species and the sintering of metal oxides and Cu1Mn9/S15 has less thermal stability than La3Mn97/K6. Figures 3 and 4 showed that the calculated H2S breakthrough curves related with desulfurization reaction temperature. As shown in Figure 3, the breakthrough curve after breakthrough points is very steep, it means that the deactivation rate ( kd ) at high temperature (800℃) is quick. According to the Arrhenius formula k = k0 exp(−E#/RT) the plots of reaction rate constants ka or kd estimated by the deactivation kinetics model to reaction temperature are shown in Figure 3 and 4. The apparent activation energy and deactivation energy can be calculated by linear regression of Arrhenius equation. The plots of ln ka or ln kd against 1/T are almost linear (Figures 3 and 4), and the obtained apparent activation energy (Ea) and deactivation energy (Ed) for Cu1Mn9/S15 are 33.02 kJ/mol and 46.34kJ/mol, and for La3Mn97/K6 48.98 kJ/mol and 56.10 kJ/mol, respectively. Table 4. Calculated Rate Constants ka and kd for Cu1Mn9/S15 and La3Mn97/K6 sorbents at different temperatures temperatures ka ×104 (min·g)-1 kd×10-1 (min-1 (mol·cm-3)-1)

700 oC 1.05±0.13 (1.96±0.40)#

750 oC 1.14±0.09 (2.24±0.56)

800 oC 3.36±0.52 (2.67±0.69)

850 oC 1.55±0.14 (4.06±0.42)

0.51±0.06 (2.34±0.74)

0.68±0.12 (3.29±0.91)

1.96±0.36 (4.37±0.82)

0.81±0.08 (5.96±0.69)

0.9616 0.9691 0.9849 0.9895 (0.9521) (0.9568) (0.9603) (0.9914) #: The data in parentheses are the rate constants for La3Mn97/K6 sorbents. R2

7


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Figure 3. H2S breakthrough curves for Cu1Mn9/S15 sorbents at different temperatures. (all the points are from the previous experimental data13; the curves were calculated by using DKM43; WHSV = 19.8L·h-1·g-1, 0.33% H2S, 10.5% H2, 17.1% CO, N2 as balance gas)

Figure 4. H2S breakthrough curves for La3Mn97/K6 sorbents at different temperatures. (all the points are from the previous experimental data44; the curves were calculated by using DKM43; WHSV=21.6 L·h-1·g-1, 0.36% H2S, 13.84% H2, 19.36% CO, N2 as balance gas) If the length of reactor is given (designed), the H2S breakthrough time can be predicted precisely, which is of great significance to obtain basic chemical engineering data for the design of new reactors without experimental data on a large scale. Also this kinetic model can be extensively applied to the kinetic analysis of non-catalytic heterogeneous reactions or adsorption processes in fixed-bed reactors without the additional data of structural property of sorbents and seems to have very good prediction ability for hot coal gas desulfurization. 4. RATE CONSTANTS OF SULFIDATION-REGENERATION PROCESS OVER Cu1Mn9/S15 AND La3Mn97/K6 SORBENT In order to investigate the prediction ability of the deactivation kinetic model and verify the reliability of the estimated kinetic parameters, we calculated sulfur contents in gas phase under the eight desulfurization-regeneration cycles reaction conditions with Cu1Mn9/S15 and La3Mn97/K6 sorbents, and the obtained results were compared to the experimental data (Figures 5 and 6). The average deviation between the calculated values and the experimental data is less than 5%, which 8


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shows that this kinetic model has a good prediction ability for hot coal gas desulfurization in a fixed-bed reactors. Figures 5 and 6 show the change of the rate constants during the successive sulfidation-regeneration cycles for Cu1Mn9/S15 and La3Mn97/K6 sorbent. The obtained rate constants ka and kd were declined slightly due to the sintering of the active species and the deterioration of mesoporous structure in Cu1Mn9/S15 and La3Mn97/K6 sorbents during the sulfidation- regeneration cycles. But it indicated that Cu1Mn9/S15 and La3Mn97/K6 sorbents have considerable structural stability and maintain their activity during desulfurization of coal gas at high temperatures.

Figure 5. Relationship of the rate constants and the calculated vs experimental dimensionless concentration of H2S during the eight desulfurization-regeneration cycles with Cu1Mn9/S15 sorbent (The experimental data are from the previous report13, Desulfurization: 800℃, WHSV = 19.8 L·h-1·g-1, : 0.33% H2S, 10.5% H2, 17.1% CO, N2 as balance gas, Regeneration: 800℃, WHSV = 19.8 L·h-1·g-1, : 5% O2, N2 as balance gas)

Figure 6. Relationship of the rate constants and the calculated vs experimental dimensionless concentration of H2S during the eight desulfurization-regeneration cycles with for La3Mn97/K6 sorbent (The experimental data are from the previous report44, Desulfurization: 800℃; WHSV=21.6 L·h-1·g-1; 0.36% H2S, 13.84% H2, 19.36% CO, N2 as balance gas, Regeneration: 600℃; WHSV= 9


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7.2L·h-1·g-1; : 6% O2, N2 as balance gas) 5. CONCLUSIONS In this work, kinetic analysis was investigated by the deactivation kinetics model where the reaction order of each species based on the experimental data was estimated for H2S removal over mesoporous Cu-Mn mixed oxide /SBA-15 and La-Mn mixed oxide/KIT-6 sorbent during hot coal gas desulfurization in a fixed-bed reactor. The reaction orders, rate constants, the apparent activation energy (Ea) and deactivation energy (Ed) were calculated as the kinetic parameters. The calculated reaction orders are (1, 1, 1) for Cu-Mn mixed oxide /SBA-15 and (0.6, 1.2, 1) for La-Mn mixed oxide /KIT-6, respectively. The obtained apparent activation energy (Ea) and the deactivation energy (Ed) for Cu1Mn9 mixed oxide/SBA-15 are 33.02 and 46.34kJ·mol−1, and for La3Mn97 mixed oxide/KIT-6, they are 48.98 and 56.10 kJ·mol−1, respectively. This method predicted successfully in the whole duration of the desulfurization reaction, when the relative errors between the calculated and experimental data were less than 5%. This deactivation kinetic model presented here for reaction orders can be used to analyze the experimental breakthrough curves of non-catalytic heterogeneous reactions or adsorption processes and has good prospect for application in kinetic analysis for fixed-bed reactors. ■ AUTHOR INFORMATION Corresponding Author * E-mail: [email protected] Notes The authors declare no competing ﬁnancial interest. ■ ACKNOWLEDGMENTS The work was supported by the National Training Programs of Innovation and Entrepreneurship for Undergraduates (201210056146) and the National Foundation of Science and Technology (201601043731). ■ NOMENCLATURE a = activity of the solid reactant C = H2S concentration in gaseous reactant, mol·cm-3 C0 = inlet H2S concentration, mol·cm-3 CA = outlet H2S concentration, mol·cm-3 C *= dimensionless H2S concentration (=C/C0) C *exp = experimental dimensionless H2S concentration C *cal = calculated dimensionless H2S concentration ka = the rate constant of apparent chemical reaction (in DKM), (min·g)-1 kd = deactivation rate constant (in DKM), min-1 (mol·cm-3)-1 kd0 = deactivation rate constant (in DM) min-1 ko = initial rate constant (in DM), cm3·g-1·min-1 i= distance step in forward finite differential method 10


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Kinetic Analysis of H2S Removal over Mesoporous CuâMn Mixed

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