N. Sazali

Effect of intermediate layer on gas separation performance of disk supported carbon membrane

ABSTRACT Porous alumina disk ceramic was decorated with various types of intermediate layers via one-step spray coating-carbonization technique. P-84 (BTDA-TDI/MDI) polymeric solution was sprayed on the alumina disk with an incorporation of intermediate layer. The membrane was carbonized at 700°C under nitrogen (N2) atmosphere with a heating rate of 3°C/min. The resultant carbon membrane was characterized in terms of its thermal stability, structural morphology, and gas permeation properties. A high-performance carbon membrane was obtained with the intermediate layer of the alumina powder, which exhibited the best selectivity of O2/N2, CO2/N2 and CO2/CH4 of 4.39, 19.89 and 58.43, respectively.

The effect of polymer composition on CO2/CH4 separation of supported carbon membrane

Recently, membrane technology has attracted vast attention from many scientists and engineers, particularly from the industrial area. The membrane for gas separation is favoured due to its economically feasibility and high separation performance with respect to gas permeability and selectivity. In this study, the effect of different polymer concentrations (5, 10, 13, 15 and 18 wt%) on the gas permeation properties of CO2/CH4 separation was investigated. Matrimid 5218 was chosen as the based polymer for tubular carbon membrane preparation owing to its excellent membrane properties (i.e. high mechanical and thermal stability) in order to fulfil the membrane requirement for high gas separation performance. The commercialised tubular membrane was dip-coated into Matrimid/NMP solution and then proceed with carbonisation process at the optimum condition with a heating rate of 2 K/min and under Argon gas flow rate at 200 mL/min at temperature of 1,123.15 K by using argon gas. The pure gas permeation tested for both CO2 and CH4 was carried out under room temperature at pressure controlled at 800 kPa. From the experimental results, the tubular membrane made of 15 wt % Matrimid performed the highest CO2/CH4 selectivity (87.34 %) as compared to the other membranes. The excellent performance obtained from the membrane could be attributed by the micropores formation, where the chain of the polymer had increased its packing density. Thus, membrane porosity can be increased by increasing the polymer concentration in the solution.

P84 Co-Polyimide Based-Tubular Carbon Membrane: Effect of Heating Rates on Helium Separations

Helium is one of the most valuable gases with unique features and properties as well as widely used in various applications. Generally, most of the helium sources was extracted from natural gas and it is very crucial to develop efficient technology for helium recovery from natural gas sources, in order to overcome the deficit of the helium supply. Up to now, there are various available traditional separation methods for helium recovery, however these methods possessed several disadvantages such as expensive in cost and energy intensive. Recently, gas separation by using membranes have been utilized and showed potential in recovering and purifying helium from natural gas. This method directly separating the helium from the methane through natural gas liquefaction process where in this process the helium is recovered from the nitrogen rejection unit (NRU) exit gas. Due to the potential benefits that can be obtained from this membrane-based separation method, this current study is aiming to provide more comprehensive scientific reports on the effects of preparation parameters on the performance of tubular carbon membranes (TCMs) for helium separation. In this study, the carbonization heating rate was varied from 1 to 7°C/min by controlling the final temperature at 800°C under Argon environment for all polymeric tubular membranes. The permeation performance of the resultant TCMs have been determined by using a single permeation apparatus. It is necessary to fine-tuning the carbonization conditions in order to obtain the desired permeation properties. From the results, it can be concluded that the most optimum heating rate was found to be at 3°C/min with 463.86±3.12 selectivity of He/N2 separation.

Pengaruh suhu karbonisasi kepada pembangunan membran karbon dengan kesan pemisahan gas CO2/CH4 yang cemerlang

In this study, P84 - based carbon tubular membranes were fabricated and characterized in terms of their structural morphology and gas permeation properties, by using Scanning Electron Microscopy (SEM) and pure gas permeation system, respectively. The polymer tubular membranes were then carbonized under nitrogen atmosphere at different carbonization temperatures of 600, 700, 800 and 900 °C, with heating rate of 3°C/min and thermal soak time of 30 minutes. The manipulation of carbonization temperatures was requ ired to see if it could enhance the permeation properties as desired. Pure gas permeation tests were performed using CO 2 and CH 4 gases. The CO 2 /CH 4 selectivity was found increasing as the carbonization temperature was increased from 600 to 800 °C. The carb on membrane carbonized at 800°C showed the most promising result for CO 2 /CH 4 selectivity, rendering 69.48 and CO 2 permeance of 206.1 GPU.

Influence of carbonisation temperature on gas permeation properties of matrimid-based carbon membrane

The utilisation of tubular support for carbon membrane preparation is beneficial for gas separation by providing high membrane area per unit volume and mechanically stronger than conventional flat substrate. In this study, tubular carbon membrane derived from Matrimid was fabricated via dip-coating method and three different carbonisation temperatures were used in order to produce high performance carbon membrane (600 °C, 750 °C and 850 °C). The physicochemical property of the carbon membrane is highly dependent on the final carbonisation temperature. By increasing carbonisation temperature, it will result in higher micropores and increasing gas pair selectivity. Whereas, low carbonisation temperature constricts pore formation and resulting in lower gas separation properties. The carbon membrane carbonised at 850 °C showed the highest gas separation properties of CO2/CH4 selectivity of 87.30 with CO2 permeance of 287.36 GPU. The resulted membrane is compared with literatures and has highlighted the potential of carbon tubular membrane for future membrane development.

Separation of CO2/CH4 through Carbon Tubular Membranes: Effect of Carbonization Temperature

Carbon membranes have received much attention as advance materials in the gas separation technology due to their superior gas permeation performance and thermal and chemical stability. In order to increase the mechanical strength of the membrane, supported carbon membrane were produced using ceramic tube as support layer. Carbon tubular membranes were produced by carbonizing polymeric tubular membrane under different process parameter. In this study, carbon tubular membranes originating from Matrimid were prepared and characterized in term of its gas permeation properties. The preparation method involved dip-coating of the ceramic tubes with a Matrimid-based solution. The carbon tubular membranes were obtained by carbonization of the resultant polymeric tubular membrane under Argon gas flow in the horizontal tube furnace. The effects of the carbonization temperature on the gas permeation performance were investigated. Pure gas permeation tests were performed using CO 2 and CH 4 at room temperature with pressure 8 bars. The permeance and selectivity data indicate that the highest CO 2 /CH 4 selectivity of 87.30 was obtained for carbon tubular membrane prepared at carbonization temperature of 850oC.