The Lively Lab's research focuses on bridging the gap between nanoporous materials synthesis and scalable advanced separation devices.
Modern chemical manufacturing (e.g., pharmaceuticals, specialty chemicals, fuels) depends upon purification via chemical separations. Today, most separations are achieved with energy-intensive, thermally-driven processes (e.g., distillation) that account for 10-15% of global energy usage. For instance, one separation – the initial distillation of crude oil – consumes approximately 1100 TWh/yr (global energy consumption is approximately 157,000 TWh/yr), and the various fractions leaving this initial separation are then refined and purified further and further.
These separation processes are driven by heat, and the heat is typically derived from fossil fuel combustion. This reliance on heat in separation technology results in a tremendous carbon footprint associated with such systems. Beyond carbon, thermally-driven separation processes require enormous quantities of water (and are thus part of the famous ‘energy-water nexus’) for process cooling and heat integration.
chunyi li (Graduate student) examines adsorbents
Materials-driven separation, purification, and concentration technologies have the potential to dramatically drive down the energy, carbon, and water intensity of heat-based separation processes. This is done by applying lower-grade heat, utilizing easily-recoverable mechanical energy, or avoiding the necessity for heat altogether in the separation system. These alternative strategies are enabled by adsorption- and membrane-based approaches. For instance, a membrane system was deployed in ExxonMobil’s Beaumont refinery and helped reduce the energy load associated with a lubrication dewaxing process. The installation of the membrane ultimately reduces 20% process energy intensity, 20,000 tons/year GHG emissions, 4 million gal/day water usage, and 125 tons/year VOC emissions.
Our research group focuses on the creation of novel adsorbent and membrane materials that can provide low-energy solutions to some of the world’s most challenging and important separations. Beyond making materials, we focus on developing these materials into scalable, modular devices that can be challenged with realistic feeds in our facilities or at collaborator’s facilities. Our ultimate objective is to translate enabling materials from the lab into devices that can then be sent out into the field. Separating molecules is and always will be a hallmark of modern society – whether applied to conventional refining, biorefining, or futuristic “e-refining”, all of these systems (and many more) will rely upon advanced low energy, low carbon separation technologies that are waiting to be discovered.
Image from Treatment 4 Water
Useful definitions
Reverse Osmosis – a process by which a solvent passes through a porous membrane in the direction opposite to that for natural osmosis when subjected to a hydrostatic pressure greater than the osmotic pressure.
Hollow fiber spinning – A technique for creating polymeric hollow fiber structures. The polymer and another fluid are extruded through a co-annular die into a quench bath to form the hollow fibers.
Hollow fiber sorbents – A hollow fiber architecture with the walls of the fiber loaded with porous particles. These fibers are typically co-spun with a barrier layer.
Asymmetric hollow fiber membranes – Typically a pure polymer hollow fiber membrane with a radial gradient in pore size that terminates in a dense polymer skin layer (the membrane).
Mixed matrix membranes – A membrane comprised of two solid phases, typically a polymer phase and a nanoporous particle phase. Combines the processability of polymers and the separation efficiency of nanoporous materials.
Metal-organic framework – Nanoporous materials comprised of metal ions or clusters coordinated to organic molecules to form one-, two-, or three-dimensional structures.
Fiber Properties
Asymmetric Hollow Fiber Membranes –
OD: 200 microns
ID: 100 microns
Skin layer thickness: 200-400 nm
Typical polymers: Cellulose acetate, polysulfones, polyimides.
Dual-layer Hollow Fiber Membranes –
OD: 200-300 microns
ID: 100-150 microns
Sheath layer thickness: 1-5 microns
Skin layer thickness: 300-600 nm
Typical core polymers: Cellulose acetate
Typical sheath polymers: advanced polyimides, mixed matrix membranes
Hollow Fiber Sorbents –
OD: 200-2000 microns
ID: 100-1000 microns
Typical sorbents: zeolites, carbons, MOFs/ZIFs, solid-supported amines
Typical core polymers: Cellulose acetate, polyamide-imides
Typical barrier polymers: polyvinylidene chloride, polychloroprene
