Separation of p‐xylene from ternary xylene mixture using silicalite‐1 membrane: process optimization studies

Abstract

BACKGROUND: The design of experiments (DoE) is applied to the process optimization of p-xylene (pX) separation from its isomers m-xylene (mX) and o-xylene (oX) mixture using silicalite-1 membrane supported on α-alumina. A central composite design (CCD) coupled with response surface methodology (RSM) was used to correlate the effect of two separation process variables, temperature (150-250• C) and pX feed partial pressure (0.10-0.26 kPa) to three responses: (i) pX flux; (ii) pX/oX separation factor; and (iii) pX/mX separation factor. The significant factors affecting each response were elucidated from the analysis of variance (ANOVA). The interaction between two variables was investigated systematically based on threedimensional response surface plots.

Influence of the acidity of solid catalyst HSO3-ZSM-5 on the hydrolysis of pretreated corncob

“…This can be done by introducing functional groups to the structure of zeolite including surfaces and pores. [11][12][13] The modied zeolites then show better catalytic activity, acidity, and selectivity in a series of importantly industrial reactions and processes. Yeong et al 11 successfully introduced 3-mercaptopropyltrimethoxysilane into the silicalite-1 pore-structure by using in situ deposition method and subsequently oxidized to sulfonic acid silicalite-1 membrane.…”

“…[11][12][13] The modied zeolites then show better catalytic activity, acidity, and selectivity in a series of importantly industrial reactions and processes. Yeong et al 11 successfully introduced 3-mercaptopropyltrimethoxysilane into the silicalite-1 pore-structure by using in situ deposition method and subsequently oxidized to sulfonic acid silicalite-1 membrane. The sulfonated silicalite-1 membrane was acting as a membrane with high selectivity and applicable to combined separation and reaction processes.…”

Synthesis of highly b-oriented zeolite MFI films by suppressing twin crystal growth during the secondary growth

“…Zeolite films and membranes have been widely studied during the past two decades. They could be applied to separation membranes for their uniform molecular pore size, [1][2][3][4] membrane reactors for their catalytic activity, 5 microprocessor insulator materials for their low dielectric constant, [6][7][8] and corrosion resistant coatings for their excellent chemical and thermal stability. 9,10 In a MFI crystal, the 0.53 Â 0.56 nm straight channels (b-axis) are interconnected with 0.51 Â 0.55 nm sinusoidal channels (a-axis).…”

“…Therefore, b-oriented MFI films are of great interest from the viewpoint of both fundamental study and practical applications, though most of the zeolite films reported are randomly oriented. [3][4][5]11 In situ crystallization and secondary growth are two major methods to synthesize b-oriented MFI films. The advantage of the former is its simplicity, but some a-oriented MFI crystals always exist.…”