Carbon hollow fibre membrane
AssigneeNorwegian University of Science and Technology (Ntnu)
InventorsLinfeng Lei, Arne Lindbråthen, Xuezhong He
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Abstract
The present invention relates to a process for the production of asymmetric cellulose hollow fibres and the use of such fibres in the production of asymmetric carbon hollow fibre membranes (CHFMs). In particular, the present invention provides a facile and scalable process for the preparation of asymmetric CHFMs by direct pyrolysis of polymeric precursors without the need for complex pre-pyrolysis treatment steps to prevent pore collapse. The present invention also relates to the use of asymmetric CHFMs prepared according to said process in the separation of hydrogen gas from a mixed gas source, especially in the separation of hydrogen from CO2 in the steam-methane reforming reaction.
Claims21
A process for the production of an asymmetric cellulose hollow fibre comprising the steps of:
- a) providing a dope solution comprising cellulose, at least one ionic liquid, and optionally one or more co-solvent(s);
- b) coextruding into a gaseous atmosphere:
- said dope solution and a bore fluid comprising water, at least one ionic liquid, and optionally one or more co-solvent(s);
- c) quenching the coextruded dope solution and bore fluid in at least one coagulation bath containing water to form a water-wetted fibre, wherein the temperature of the coagulation bath is greater than 40° C.;
- d) contacting said water-wetted fibre with at least one organic solvent having a surface tension lower than that of water;
- and optionally
- e) drying the fibre.
An asymmetric carbon hollow fibre membrane (CHFM) having a dense outer layer and a concentric porous inner layer, wherein the asymmetric carbon hollow fibre membrane comprises at least 85 atomic % carbon, 5 to 15 atomic % oxygen and up to 1.0 atomic % nitrogen.
Dependencies are inferred from the claim text.