Imperial College London

ProfessorKangLi

Faculty of EngineeringDepartment of Chemical Engineering

Professor in Chemical Engineering
 
 
 
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Contact

 

+44 (0)20 7594 5676kang.li

 
 
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Location

 

419ACE ExtensionSouth Kensington Campus

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Summary

 

Overview

Research Interests

My current research focuses on the development of various hollow fibre membranes and membrane systems for fluid separations/reactions. I am particularly interested in developing fundamental understanding of the relationship between the membrane structure and its characteristic separation properties.

Preparation of PVDF Membranes for Waste Treatment Membrane separation technology has emerged as an interesting alternative to the conventional techniques for waste treatment, primarily attributed to its relative simplicity, cost-effectiveness and its multidisciplinary character. In this research, some important aspects for the development of asymmetric PVFD membranes via immersion precipitation method have been extensively investigated. The resulting PVDF membranes are then being tested for its application performance in waste treatment, i.e. (1) waste gas removal (odour control) and (2) wastewater treatment.

The development and application of novel inorganic hollow fibre membranes for catalytic membrane processing This research describes a highly innovative design for a catalytic membrane reactor. It involves the combination of several advanced, but individually proven, catalyst and membrane technologies with the novel inorganic asymmetric hollow fibre membranes recently developed. The membranes are specifically fabricated with an asymmetric pore structure and are being coated with either (i) a thin, dense, electroless-plated palladium-silver hydrogen separation layer and a washcoated support plus Pt-Sn alkane dehydrogenation catalyst or (ii) a thin, dense, sol-gel coated, perovskite layer, providing a bifunctional hydrogen separation & catalytic layer. The Pd/Ag type composite hollow fibre membrane reactors will be tested for the conversion of propane to propene, and will be suitable for other moderate temperature dehydrogenations. For higher temperature dehydrogenations perovskite type composite hollow fibre reactors are necessary and will be tested for methane coupling. Use of a membrane reactor allows the continuous removal of hydrogen from the reaction zone during dehydrogenation, thus substantially increasing the conversion obtained from these equilibrium-limited reactions. The use of a bundle of ceramic hollow fibres in place of the single ceramic tube (diameter of the order of 10mm) or flat disc used in conventional inorganic membrane reactors confers major process engineering advantages.

Formation of annular hollow fibre membranes and membrane bioreactors This research concerns the development of annular hollow fibre membranes and its application to biochemical reactions. The annular hollow fibre membranes having two distinct separation layers have been prepared and are being tested for alcoholic fermentation. The variables examined include the types of polymers, solvent and additives used in preparing the spinning solution and the spinning conditions. The membrane structure has been characterized by its permeation coefficient and its morphology, while the fermentation of glucose to ethanol has been selected as an example to analyze a membrane bioreactor fabricated by immobilizing an yeast in annulus of the annular hollow fibre membranes developed. The annular hollow fibre developed may also be employed in the development of artificial organs such as artificial liver if the liver cells can be successfully immobilized the annular passage.

Carbon dioxide recovery from combustion processes using structured ceramic membranes Innovative solutions are required to reduce carbon dioxide emissions from energy production processes. In this research, mixed ionic and electronic conducting membranes with novel dual structures consisting of a thin dense layer with porous layers on both sides of the membrane will be prepared using a innovative fabricating method. Such membranes will consist of one single phase capable of conducting both oxygen-ions and electrons. Under reaction conditions methane will be fed to one side of the membrane and air to the other. Ionic oxygen transport across the thin dense layer will result in methane combustion (the porous surfaces on either side of the membrane may be modified catalytically to improve overall membrane performance). The advantage of such a membrane is that the fuel exhaust stream is kept separate from the combustion air exhaust stream allowing for carbon dioxide recovery followed by possible recycle or sequestration.

Membrane-UV Reactor: a novel technique for dissolved oxygen removal in ultrapure water production This research concerns a study on the development of a novel membrane-UV reactor, which is capable of reducing the dissolved oxygen in water to a few parts per billion (ppb) for semiconductor industries. The reactor contains an UV light either well surrounded or randomly surrounded by hollow fibre membranes functioning as hydrogen gas distributors. The dissolved oxygen removal is achieved by the chemical reaction between the dissolved oxygen and the dissolved hydrogen in the presence of the ultraviolet rays. This method is attractive, as it produces no by-product to further contaminate the product water. An additional merit of the novel membrane-UV reactor is that UV radiation is an effective means of carrying out sterilization of the water and hence eliminates bacteria. Also, oxidation of organic materials (TOC) can be accomplished by using UV radiation. Hence the method carries out simultaneous removal of bacteria and organic matter as well. The study will be focused on both the theoretical and experimental aspects of the reactor design and final optimization of the process for the purpose of the ultrapure water production.

Selected Research Projects

  1. "Carbon dioxide recovery from combustion processes using structured ceramic membranes" in collaboration with Prof. Ian S Metcalfe at UMIST funded by EPSRC. download PDF
  2. "Membrane Aromatic Recovery System (MARS) – A Novel process for recovery of aromatic molecules from waste streams" in collaboration with Prof. Andrew Livingston at Imperial College, funded by EPSRC. download PDF
  3. "Development of inorganic hollow fibre membranes for methane coupling reactions" in collaboration with Prof. R. Hughes at Salford, funded by EPSRC. download PDF