Development of Solubility Selective Mixed Matrix Membranes for Gas Separation

Abstract

A new kind of gas permeation membrane is developed to separate higher hydrocarbons (C 3+ ) from permanent gases. State of the art for such gas permeation applications are membranes based on solubility selective, rubbery polymers, which offer high permeances but relatively low selectivities. The new membrane is designed to improve selectivity, and therefore, significantly reduce energy demand and size of a gas separation plant. The membrane is based on the mixed matrix concept and consists of a rubbery polymer matrix with incorporated activated carbon particles. This two phase separation layer forms a solubility selective mixed matrix membrane by combining the advantages of both materials. The separation of n-C 4 H 10 /CH 4 mixtures is investigated. Based on experimental results a new concept for a transport model for mixed matrix membrane is introduced.

Effect of the reactive amino and glycidyl ether terminated polyethylene oxide additives on the gas transport properties of Pebax® bulk and thin film composite membranes

“…The CO 2 permeance of the prepared ethyl cellulose TFC membrane was 4.1 Nm 3 m À2 h À1 bar À1 and CO 2 /N 2 selectivity 16.8 at 30 C. This permeance is three times higher than the CO 2 permeance of the pure Pebax® TFC membrane (1.37 Nm 3 m À2 h À1 bar À1 at 30 C) and thus layers supporting Pebax® based selective layer did not inuence the total membrane selectivity which could occur when inappropriate support is used for TFC membrane formation. 36,37 The permeance of the TFC membrane having pure Pebax® selective layer is not competitive compared to other available CO 2 selective membranes and should be improved for the use in industrial processes. 38 As seen on the 5, the permeance divergence was observed for the threecomponent system (not thermally treated before the gas permeation experiment) Pebax®/ED600/DG 526 20% during the heating and cooling parts of measurements in the temperature range from 20 C to 90 C. Exposure to the elevated temperatures facilitates leaching out of the low molecular weight components from the selective layer and leads to reduced membrane permeance observed during the cooling from 90 to 20 C part of the gas transport experiment.…”

Synthesis and characterisation of MOF/ionic liquid/chitosan mixed matrix membranes for CO2/N2 separation

“…5 Mixed matrix membranes (MMMs), where the combination of organic and inorganic materials has been proved as a promising way of merging and enhancing the properties of both phases, have been attracting interest in the last decades. [6][7][8][9][10] Recently the MMMs devoted as CO 2 selective have been the object of an extended overview of CO 2 selective membranes. 11 New materials based on renewable resources are most recently sought for to avoid dependency on petroleum-based products.…”

Detailed Investigation of Separation Performance of a MMM for Removal of Higher Hydrocarbons under Varying Operating Conditions

“…Further characteristic properties are summarized in Table 2 . The AC was selected due to its high affinity towards C 3+ hydrocarbons with the adsorption isotherm following the equation of Tóth [ 20 ]. AC particles were dried at 150 °C in a vacuum oven for at least 24 h prior to use.…”

“…MMM coating suspensions were prepared by stepwise addition of polymer precursor solution and catalyst to isooctane saturated AC particles and thoroughly mixing with a dissolver for 10–20 min at 8000 rpm (Dispermat ® , VMA Getzmann GmbH) after each step. The AC content was adjusted to 20 wt% with respect to mass of polymer as identified as optimum filler content in previous work [ 20 ]. A final 2 min sonication step was applied prior to casting to ensure homogeneous dispersion and removal of trapped air.…”

“…The promising application of MMMs based on POMS and activated carbon (AC) has been described in our previous work [ 20 , 21 ]. Best performance was found for a filler content of 20 wt% showing an improved selectivity n -C 4 H 10 /CH 4 up to 20% compared to pure POMS.…”