Preparation and Characterization of High Performance Zeolite T Membranes from Clear Solutions

doi:10.15541/jim20150631

Abstract

Abstract:

T-type zeolite membrances with high permeation performance were successfully synthesized on the low cost macroporous α-Al₂O₃ tubular support by secondary growth from clear solutions. The effects of the concentration of seeds and the membrane crystallization time on the morphology and pervaporation properties of zeolite T membrances. When the molar ration of the synthesis solution was 1SiO₂:0.05Al₂O₃:0.26Na₂O:0.09K₂O: 30H₂O, a high quality T zeolite membrane was obtained at crystallization temperature of 120 ℃ for 16 h, with water flux of 2.96 kg/(m²·h) and separation factor of 6400 for dehydration of IPA aqueous solution by pervaporation at 75℃. XRD pattern and SEM observation suggested that the shortened membrane crystallization time resulted from the secondary nucleation induced by the seeds and the seeds epitaxial growth.

Key words: T-type zeolite membrance, varying temperature hot dip-coating method, secondary growth, pervaporation

CLC Number:

TQ174

LV You-Jia, LI Hua-Zheng, YANG Jian-Hua, WANG Jin-Qu, YIN De-Hong, LU Jin-Ming. Preparation and Characterization of High Performance Zeolite T Membranes from Clear Solutions[J]. Journal of Inorganic Materials, 2016, 31(7): 705-710.

Figures/Tables 8

Fig. 1 SEM images of the α-Al2O3 support (a,b), the support modified by seeds (c,d) and seed layers of S1 (e,f), S2 (g,h) and S3 (i,j)

Fig. 2 XRD patterns of membranes T1-T3

Fig. 3 SEM images of zeolite T membranes of T1 (a,b), T2 (c,d), and T3 (e,f)

Table 1 Seeding conditions and PV performances of zeolite T membranes at 75℃

Sample	Seed layer	First step coating (2 μm) seed concentration/wt%	Second step coating (400 nm) seed concentration/wt%	Flux/ (kg·m^-2·h^-1)	Separation factor
T1	S1	2.00	0.10	2.31	716
T2	S2	2.00	0.30	2.64	>5700
T3	S3	2.00	0.50	1.17	>10000

Fig. 4 XRD patterns of seed layer (a); as-synthesized membrane crystallized at 120℃for 4 h (b);8 h (c);12 h (d);16 h (e) and 20 h (f)

Fig. 5 SEM images of zeolite T membranes crystallized for 4 h (a,b); 8 h (c,d); 12 h (e,f); 16 h (g,h) and 20 h (i,j)

Table 2 Pervaporation performances of zeolite T membranes crystallized for different time

Sample	Crystallization time/h	Flux/ (kg·m^-2·h^-1)	Separation factor
T4	12	1.95	1500
T5	16	2.96	6400
T6	20	2.32	2500
T7	24	1.90	1300
T8	28	1.61	1100

Table 3 PV performance of zeolite T membranes towards water/isopropanol(10:90,w/w) mixture at 75℃

Support	Seed size/μm	Temperature/℃	Time/h	Flux/(kg·m^-2·h^-1)	Separation factor	Ref.
α-Al₂O₃	0.4-2.0	120	16	2.96	6400	This work
α-Al₂O₃	0.4-2.0	100	30	2.52	10000	[11]
α-Al₂O₃	8.0	100+140	8+1	2.15	10000	[12]
Mullite	0.1	150	20	3.10	3400	[9]
Mullite	4.0	150	35	2.50	13000	[9]
Mullite	﹤1.0	100	30	2.20	8900	[6]

References 15

[1]	LIPNIZKI F, FIELD R W, TEN P K.Pervaporation-based hybrid process: a review of process design. J. Membr.Sci., 1999, 153(2): 138-210.
[2]	FENG X, HUANG R Y M. Liquid separation by membrane pervaporation: a review.Ind. Eng. Chem. Res., 1997, 36(4): 1048-1066.
[3]	MORIGAMI Y, KONDO M, OKAMOTO K, et al.The first largescale pervaporation plant using tubular-type module with zeolite NaA membrane. Sep. Purif. Technol., 2001, 25(1): 251-260.
[4]	LI Y S, ZHOU H, YANG W S, et al.Hydrothermal stability of LTA zeolite membranes in pervaporation. J. Membr.Sci., 2007, 297(1): 10-15.
[5]	HASEGAWA Y, NAGASE Y, KIYOZUMI Y, et al.Influence of acid on the permeation properties of NaA-type zeolite membranes. J. Membr.Sci., 2010, 349(1): 189-194.
[6]	CUI Y, KITA H, OKAMOTO K I.Zeolite T membrane: preparation, characterization, pervaporation of water/organic liquid mixtures and acid stability. J. Membr.Sci., 2004, 236(1): 17-27.
[7]	CUI Y, KITA H, OKAMOTO K I.Preparation and gas separation performance of zeolite T membrane.J. Mater. Chem., 2004, 14(5): 924-932.
[8]	CUI Y, KITA H, OKAMOTO K I.Preparation and gas separation properties of zeolite T membrane.Chem. Commun., 2003, 9(17): 2154-2155.
[9]	ZHOU R F, HU L, ZHANG Y, et al.Synthesis of oriented zeolite T membranes from clear solutions and their pervaporation properties.Microporous. Mesoporous. Mater., 2013, 174(3): 81-89.
[10]	WANG X, YANG Z, YU C, et al.Preparation of T-type zeolite membranes using a dip-coating seeding suspension containing colloidal SiO2. Micropor. Mesopor. Mater., 2014, 197(10): 17-25.
[11]	CHEN X X, WANG J Q, YIN D H, et al.High-performance zeolite T membrane for dehydration of organics by a new varying temperature hot-dip coating method.AICHE. J., 2013, 59(3): 936-947.
[12]	ZHOU H, LI Y, YANG W S, et al.Microwave-assisted hydrothermal synthesis of a&b-oriented zeolite T membranes and their pervaporation properties. Sep. Purif. Technol., 2009, 65(2): 164-172.
[13]	KAMIMURA Y, TANAHASHI S,ITABASHI K, et al.Crystallization behavior of zeolite Beta in OSDA-Free, seed-assisted synthesis.J. Phys. Chem., 2011, 115(3): 744-750.
[14]	IYOKI K, ITABASHI K, OKUBO T. Seed-Assisted, One-pot synthesis of hollow Zeolite Beta without using organic structure- directing agents. Chem-Asian J., 2013, 8(7): 1419-1427.
[15]	ZHENG B, WAN Y F, GUO H C.et al.Mechanism of seeding in hydrothermal synthesis of zeolite Beta with organic structure-directing agent-free gel.Chinese J. Catal., 2014, 35(11): 1800-1810.