PSA simulation and adsorption separation of CH4-N2 by self-supporting pellets Silicalite-1

doi:10.11949/0438-1157.20191357

Abstract

Abstract:

Pure-silica zeolite Silicalite-1 powder was pressed at 6 MPa pressure to form self-supporting pellets. By characterization of powder X-ray diffraction and 77 K nitrogen adsorption-desorption, there was no change in crystalline and specific surface area after pelletization. Single component adsorption equilibrium isotherm of CH₄ and N₂ on the self-supporting pellets Silicalite-1 at 273/298/313 K were measured by static gravimetric method. Selectivity of CH₄/N₂ mixtures on the adsorbent were calculated from Ideal Adsorbed Solution Theory (IAST). Separation effects of CH₄/N₂ mixtures on the adsorbent were investigated by dynamic mixtures breakthrough experiments, which show it is more suitable for enrichment and nitrogen removal from low concentration coal-bed methane. Separation and enrichment of methane from low concentration coal-bed methane by pressure swing adsorption (PSA) on the particle-shaped Silicalite-1 were predicted using total mass-transfer model by numerical simulation based on abovementioned data. The simulation results show that once the 20% / 80% CH₄ / N₂ mixture is concentrated, the CH₄ concentration can be increased to 37%—41%, and the recovery rate can be 60%—92%; 30%/70% CH₄/N₂ mixture is once concentration, CH₄ concentration can be increased to 50%—53%, and the recovery rate is 58%—92%.

Key words: methane, nitrogen, pressure swing adsorption, Silicalite-1

摘要：

纯硅分子筛Silicalite-1原粉（Si/Al>470）在6 MPa压力下制成自支撑颗粒状吸附剂，经XRD和77 K氮气吸脱附表征表明自支撑颗粒型的Silicalite-1保留了原粉的晶体结构和比表面。静态重量法测试了273/298/313 K下CH₄和N₂在其上的吸附等温线，利用理想吸附溶液理论（IAST）法计算了吸附剂对CH₄/N₂的选择性。动态气体穿透实验测试了颗粒型Silicalite-1吸附剂对不同浓度CH₄/N₂混合气的分离效果，结果表明该吸附剂更适合于低浓度甲烷（20%/80% CH₄/N₂）的富集脱氮。通过总传质模型利用数值模拟预测了颗粒型Silicalite-1吸附剂的变压吸附分离（PSA）富集低浓度煤层气中甲烷的效果。模拟结果显示20%/80%的CH₄/N₂混合气经一次提浓，CH₄浓度可以提升至37%~41%，回收率达到60%~92%；30%/70%的CH₄/N₂混合气经一次提浓，CH₄浓度可以提升至50%~53%，回收率达到58%~92%。

关键词: 甲烷, 氮气, 变压吸附, 纯硅分子筛

CLC Number:

TQ 028.1

Hua SHANG, Honghao BAI, Jiaqi LIU, Jiangfeng YANG, Jinping LI. PSA simulation and adsorption separation of CH₄-N₂ by self-supporting pellets Silicalite-1[J]. CIESC Journal, 2020, 71(5): 2088-2098.

尚华, 白洪灏, 刘佳奇, 杨江峰, 李晋平. CH₄-N₂在自支撑颗粒型Silicalite-1上的吸附分离及PSA模拟[J]. 化工学报, 2020, 71(5): 2088-2098.

Figures/Tables 18

Fig.1 Schematic representation of procedure of densification particle-shaped Silicalite-1

Fig.2 Silicalite-1 adsorbent particles prepared by compression, crushing and sieving

Fig.3 Apparatus of gas mixture breakthrough experiment

Table 1 Equations used in breakthrough simulation

Parameter	Expression
mass balance	$- ε b D a x ? 2 c i ? z 2 + ? (v g c i) ? z + ε b + 1 - ε b ε p ? c i ? t + ρ s 1 - ε b ? q i ? t = 0$
energy balance	$- k g ? 2 T g ? z 2 + c v, g v g ρ g ? T g ? t + ε b c v, g ρ g + P ? v g ? z + h f T g - T s + 4 h w D b T g - T 0 = 0$
	$- k s ? 2 T s ? z 2 + c p s ρ s ? T s ? t + ρ s ∑ i = 1 n (c p s, i w i) ? T s ? t + ρ s ∑ i = 1 n (? H i ? q i ? t) = h f T g - T s$
	$c p w ρ w ? T w ? z = h w 4 D b D b + W t 2 - D b 2 T g - T w + U 4 D b + W t 2 D b + W t 2 - D b 2 T w - T a m b$
gas phase momentum	$? P ? z = - 1.5 × 10 - 3 1 - ε i 2 2 r p τ 2 ε i 3 μ v g + 1.75 × 10 - 5 M ρ g 1 - ε i 2 r p τ ε i 3 v g 2$
Langmuir isotherm	$q i q ∞ = b i P i 1 + ∑ i = 1 n b i P i$
	$b i = b 0 e x p ? - ? H i R T$
linear driving force model	$? q i ? t = k n q i * - q i$

Table 1 Equations used in breakthrough simulation

Parameter	Expression
mass balance	$- ε b D a x ? 2 c i ? z 2 + ? (v g c i) ? z + ε b + 1 - ε b ε p ? c i ? t + ρ s 1 - ε b ? q i ? t = 0$
energy balance	$- k g ? 2 T g ? z 2 + c v, g v g ρ g ? T g ? t + ε b c v, g ρ g + P ? v g ? z + h f T g - T s + 4 h w D b T g - T 0 = 0$
	$- k s ? 2 T s ? z 2 + c p s ρ s ? T s ? t + ρ s ∑ i = 1 n (c p s, i w i) ? T s ? t + ρ s ∑ i = 1 n (? H i ? q i ? t) = h f T g - T s$
	$c p w ρ w ? T w ? z = h w 4 D b D b + W t 2 - D b 2 T g - T w + U 4 D b + W t 2 D b + W t 2 - D b 2 T w - T a m b$
gas phase momentum	$? P ? z = - 1.5 × 10 - 3 1 - ε i 2 2 r p τ 2 ε i 3 μ v g + 1.75 × 10 - 5 M ρ g 1 - ε i 2 r p τ ε i 3 v g 2$
Langmuir isotherm	$q i q ∞ = b i P i 1 + ∑ i = 1 n b i P i$
	$b i = b 0 e x p ? - ? H i R T$
linear driving force model	$? q i ? t = k n q i * - q i$

Table 2 Parameters of adsorption bed and adsorbent

Parameter	Value
bed height, z/m	0.15
bed radius, D_b/m	9×10^-3
bed void fraction, ε_b	0.43
particle void fraction, ε_p	0.35
adsorbent particle radius, r_p/m	4×10^-4
adsorbent particle density, ρ_p/(kg/m³)	1.21
CH₄ mass transfer coefficient, $k L D F, C H 4$ /s^-1	0.66
N₂ mass transfer coefficient, $k L D F, N 2$ /s^-1	0.31

Table 2 Parameters of adsorption bed and adsorbent

Parameter	Value
bed height, z/m	0.15
bed radius, D_b/m	9×10^-3
bed void fraction, ε_b	0.43
particle void fraction, ε_p	0.35
adsorbent particle radius, r_p/m	4×10^-4
adsorbent particle density, ρ_p/(kg/m³)	1.21
CH₄ mass transfer coefficient, $k L D F, C H 4$ /s^-1	0.66
N₂ mass transfer coefficient, $k L D F, N 2$ /s^-1	0.31

Fig.4 XRD patterns of Silicalite-1 powder and particles

Fig.5 N2 adsorption-desorption isotherm at 77 K on Silicalite-1 of powder and pellets

Table 3 Porosity data and related density of Silicalite-1 powder and particle

Form

Applied pressure/MPa

BET surface area/(m2/g)

Langmuir surface area/(m2/g)

Total pore volume/(cm3/g)

Micropore volume/(cm3/g)

Crystal density/(g/cm³)

Bulk density/

(g/cm³)

Fig.6 Water vapor adsorption isotherms for particle-shaped Silicalite-1 at 298 K

Fig.7 Pure gas adsorption isotherms of CH4 and N2 on particle-shaped Silicalite-1 at different temperature

Table 4 Langmuir model fitting parameters based on CH4 and N2 adsorption isotherm at different temperature

Gas	T/K	Langmuir model
Gas	T/K	q_m,L/(cm³/g)	B_L/bar^-1	R²
CH₄	273	61.11	0.50	0.9999
	298	60.24	0.31	0.9999
	313	80.69	0.12	0.9999
N₂	273	57.41	0.13	0.9999
	298	62.00	0.07	0.9999
	313	101.68	0.03	0.9999

Table 5 Comparison of adsorption capacities with literature data

Adsorbate	Condition	Capacity/(cm³/g)
Adsorbate	Condition	Ref.[27]	This work
CH₄	298 K,1 bar	11.42	16.82
N₂	298 K,1 bar	3.58	4.30

Fig.8 Adsorption selectivity of CH4/N2 mixtures on particle-shaped Silicalite-1

Fig.9 Adsorption heat of CH4 and N2 on particle-shaped Silicalite-1

Fig.10 Experimental and simulated breakthrough for 20% and 50% CH4/N2 mixtures on particle-shaped Silicalite-1

Table 6 Effect of content and flow on breakthrough time, retention time, adsorbed amount and selectivity for CH4/N2

Content/%	Flow/ (ml/min)	CH₄ breakthrough time/s	N₂ breakthrough time/s	Retention time/s	CH₄adsorption amount/(mmol/g)	N₂adsorption amount/(mmol/g)	CH₄/N₂ selectivity
20	3	1420	683	737	0.154	0.222	2.77
	5	720	350	370	0.124	0.206	2.41
	10	380	190	190	0.113	0.190	2.37
50	3	1500	1140	360	0.397	0.234	1.70
	5	750	470	280	0.389	0.210	1.85
	10	510	310	200	0.306	0.159	1.92

Fig.11 Schematic diagram of PSA cycle process

Fig.12 Prediction of enrichment effect of particle-shaped Silicalite-1 on methane in low concentration coalbed methane

References 41

1	Águeda V I, Delgado J A, Álvarez S, et al. Modeling and simulation of the efficient separation of methane/nitrogen mixtures with [Ni₃(HCOO)₆] MOF by PSA[J]. Chemical Engineering Journal, 2019, 361: 1007-1018.
2	Effendy S, Xu C, Farooq S. Optimization of a pressure swing adsorption process for nitrogen rejection from natural gas[J]. Industrial & Engineering Chemistry Research, 2017, 56(18): 5417-5431.
3	Kim J, Maiti A, Lin L C, et al. New materials for methane capture from dilute and medium-concentration sources[J]. Nature Communications, 2013, 4: 1694.
4	郑德志. 我国煤层气产业政策评价研究[J]. 煤炭经济研究, 2019, 39(1): 62-65.
	Zheng D Z. Research on China's coalbed methane industry policy evaluation[J]. Coal Economic Research, 2019, 39(1): 62-65.
5	Bhadra S, Farooq S. Separation of methane-nitrogen mixture by pressure swing adsorption for natural gas upgrading[J]. Industrial & Engineering Chemistry Research, 2011, 50(24): 14030-14045.
6	杨颖, 曲冬蕾, 李平, 等. 低浓度煤层气吸附浓缩技术研究与发展[J]. 化工学报, 2018, 69(11): 4518-4529.
	Yang Y, Qu D L, Li P, et al. Research and development on enrichment of low concentration coal mine methane by adsorption technology[J]. CIESC Journal, 2018, 69(11): 4518-4529.
7	吕秋楠, 李小森, 徐纯刚, 等. 低浓度煤层气分离提纯的研究进展[J]. 化工进展, 2013, 32(6): 1267-1272.
	Lyu Q N, Li X S, Xu C G, et al. Progress of purification technology for low concentration coal-bed methane[J]. Chemical Industry and Engineering Progress, 2013, 32(6): 1267-1272.
8	聂李红, 徐绍平, 苏艳敏, 等. 低浓度煤层气提纯的研究现状[J]. 化工进展, 2008, (10): 1505-1511+1521.
	Nie L H, Xu S P, Su Y M, et al. Progress of recovery of low concentration coal bed methane[J]. Chemical Industry and Engineering Progress, 2008, (10): 1505-1511+1521.
9	Kuo J C, Wang K H, Chen C. Pros and cons of different nitrogen removal unit(NRU) technology[J]. Journal of Natural Gas Science and Engineering, 2012, 7: 52-59.
10	Liu C M, Zhou Y P, Sun Y, et al. Enrichment of coal-bed methane by PSA complemented with CO₂ displacement[J]. AIChE J., 2011, 57(3): 645-654.
11	杨江峰, 赵强, 于秋红, 等. 煤层气回收及CH₄/N₂分离PSA材料的研究进展[J]. 化工进展, 2011, 30(4): 793-801.
	Yang J F, Zhao Q, Yu Q H, et al. Progress of recovery of coal bed methane and adsorption materials for separation of CH₄/N₂ by pressure swing adsorption[J]. Chemical Industry and Engineering Progress, 2011, 30(4): 793-801.
12	Ruthven D M. Past progress and future challenges in adsorption research[J]. Industrial & Engineering Chemistry Research, 2000, 39(7): 2127-2131.
13	Kaerger J, Ruthven D M. Diffusion in nanoporous materials: fundamental principles, insights and challenges[J]. New Journal of Chemistry, 2016, 40(5): 4027-4048.
14	Sethia G, Somani R S, Bajaj H C. Sorption of methane and nitrogen on cesium exchanged zeolite-X: structure, cation position and adsorption relationship[J]. Industrial & Engineering Chemistry Research, 2014, 53(16): 6807-6814.
15	刘海庆, 吴一江, 杨颖, 等. 沸石ZSM-5吸附回收低浓度煤层气中CH₄[J]. 化工学报, 2016, 67(5): 1931-1941.
	Liu H Q, Wu Y J, Yang Y, et al. Adsorption and recovery of low concentration coal-bed methane by zeolite ZSM-5[J]. CIESC Journal, 2016, 67(5): 1931-1941.
16	Mello M R, Phanon D, Silveira G Q, et al. Amine-modified MCM-41 mesoporous silica for carbon dioxide capture[J]. Microporous and Mesoporous Materials, 2011, 143(1): 174-179.
17	Pan H Y, Zhao J Y, Lin Q, et al. Preparation and characterization of activated carbons from bamboo sawdust and its application for CH₄ selectivity adsorption from a CH₄/N₂ system[J]. Energy & Fuels, 2016, 30(12): 10730-10738.
18	Zhang J H, Qu S J, Li L T, et al. Preparation of carbon molecular sieves used for CH₄/N₂ separation[J]. Journal of Chemical & Engineering Data, 2018, 63(5): 1737-1744.
19	Yang Y, Ribeiro A M, Li P, et al. Adsorption equilibrium and kinetics of methane and nitrogen on carbon molecular sieve[J]. Industrial & Engineering Chemistry Research, 2014, 53(43): 16840-16850.
20	Majumdar B, Bhadra S, Marathe R, et al. Adsorption and diffusion of methane and nitrogen in barium exchanged ETS-4[J]. Industrial & Engineering Chemistry Research, 2011, 50(5): 3021-3034.
21	Yang J F, Yu Q H, Zhao Q, et al. Adsorption CO₂, CH₄ and N₂ on two different spacing flexible layer MOFs[J]. Microporous and Mesoporous Materials, 2012, 161: 154-159.
22	Saha D, Bao Z B, Jia F, et al. Adsorption of CO₂, CH₄, N₂O, and N₂ on MOF-5, MOF-177, and zeolite 5A[J]. Environmental Science & Technology, 2010, 44(5): 1820-1826.
23	贾晓霞, 王丽, 元宁, 等. 二价铬/钼/镍空配位MOFs的CH₄/N₂吸附分离研究[J]. 化工学报, 2018, 69(9): 3896-3904.
	Jia X X, Wang L, Yuan N, et al. CH₄/N₂ adsorption separation research of MOFs with divalent Cr/Mo/Ni unsaturated metal sites [J]. CIESC Journal, 2018, 69(9): 3896-3904.
24	Ho M T, Allinson G W, Wiley D E. Reducing the cost of CO₂ capture from flue gases using pressure swing adsorption[J]. Industrial & Engineering Chemistry Research, 2008, 47(14): 4883-4890.
25	Epiepang F E, Yang X, Li J, et al. Air separation sorbents: mixed-cation zeolites with minimum lithium and silver[J]. Chemical Engineering Science, 2019, 198: 43-51.
26	Fan M, Panezai H, Sun J, et al. Thermal and kinetic performance of water desorption for N₂ adsorption in Li-LSX zeolite[J]. The Journal of Physical Chemistry C, 2014, 118(41): 23761-23767.
27	Bao Z B, Yu L, Dou T, et al. Adsorption equilibria of CO₂, CH₄, N₂, O₂, and Ar on high silica zeolites[J]. Journal of Chemical & Engineering Data, 2011, 56(11): 4017-4023.
28	Yang J F, Li J M, Wang W, et al. Adsorption of CO₂, CH₄, and N₂ on 8-, 10-, and 12-membered ring hydrophobic microporous high-silica zeolites: DDR, silicalite-1, and beta[J]. Industrial & Engineering Chemistry Research, 2013, 52(50): 17856-7864.
29	宋汉成, 焦文玲, 李娟娟, 等. 煤层气利用与输送的安全性[J]. 燃气与热力, 2006, 26(11): 8-11.
	Song H C, Jiao W L, Li J J, et al. Safety of utilization and transmission of coalbed methane[J]. Gas & Heat, 2006, 26(11): 8-11.
30	Myers A L, Prausnitz J M. Thermodynamics of mixed-gas adsorption[J]. AIChE J., 1965, 11(1): 121-127.
31	Rudzinski W, Everett D H. Adsorption of Gases on Heterogeneous Surfaces[M]. Cornwall: Academic Press, 2012: 59-64.
32	Yang J F, Yuan N, Xu M, et al. Enhanced mass transfer on hierarchical porous pure silica zeolite used for gas separation[J]. Microporous and Mesoporous Materials, 2018, 266: 56-63.
33	Yang J F, Shang H, Krishna R, et al. Adjusting the proportions of extra-framework K⁺ and Cs⁺ cations to construct a “molecular gate” on ZK-5 for CO₂ removal[J]. Microporous and Mesoporous Materials, 2018, 268: 50-57.
34	Shang H, Li Y P, Liu J Q, et al. CH₄/N₂ separation on methane molecules grade diameter channel molecular sieves with a CHA-type structure[J]. Chinese Journal of Chemical Engineering, 2019, 27(5): 1044-1049.
35	Sing K S. Reporting physisorption data for gas/solid systems with special reference to the determination of surface area and porosity(Recommendations 1984)[J]. Pure and Applied Chemistry, 1985, 57(4): 603-619.
36	Lestinsky P, Vecer M, Navratil P, et al. The removal of CO₂ from biogas using a laboratory PSA unit: design using breakthrough curves[J]. Clean Technologies and Environmental Policy, 2015, 17(5): 1281-1289.
37	Liu W J, Jiang H, Tian K, et al. Mesoporous carbon stabilized MgO nanoparticles synthesized by pyrolysis of MgCl₂ preloaded waste biomass for highly efficient CO₂ capture[J]. Environmental Science & Technology, 2013, 47(16): 9397-9403.
38	Bakhtyari A, Mofarahi M. Pure and binary adsorption equilibria of methane and nitrogen on zeolite 5A[J]. Journal of Chemical & Engineering Data, 2014, 59(3): 626-639.
39	Mofarahi M, Bakhtyari A. Experimental investigation and thermodynamic modeling of CH₄/N₂ adsorption on zeolite 13X[J]. Journal of Chemical & Engineering Data, 2015, 60(3): 683-696.
40	Kumar K V, Gadipelli S, Wood B, et al. Characterization of the adsorption site energies and heterogeneous surfaces of porous materials[J]. Journal of Materials Chemistry A, 2019, 7(17): 10104-10137.
41	Birkmann F, Pasel C, Luckas M, et al. Adsorption thermodynamics and kinetics of light hydrocarbons on microporous activated carbon at low temperatures[J]. Industrial & Engineering Chemistry Research, 2018, 57(23): 8023-8035.

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PSA simulation and adsorption separation of CH₄-N₂ by self-supporting pellets Silicalite-1

CH₄-N₂在自支撑颗粒型Silicalite-1上的吸附分离及PSA模拟

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