Research

The Yip Research Lab at Columbia University focuses on advancing technologies and innovations to address challenges at the nexus of water, energy, and the environment. Below are our active research projects:

 

Low-grade Heat Utilization

Low-temperature heat is widely abundant from natural and anthropogenic sources (e.g., low-grade geothermal and waste heat from industrial processes, respectively). However, converting the low-temperature energy to useful work is challenging and, at present, there are no established techniques to harness the thermal energy <80 ºC. We are exploring a novel membrane-based technology, co-pioneered by the Yip Lab, that is driven by the vapor pressure of water to access low-temperature heat for sustainable power generation (schematic on the right).

Vapor-pressure driven energy production schematic  
  Permeability-selectivity tradeoff

Permeability-Selectivity Tradeoff

Seawater desalination allows us to tap into a practically infinite reservoir to meet our water needs. However, desalting seawater with reverse osmosis – the most efficient desalination technique – is still energy intensive. To enable a more fundamental understanding of the reverse osmosis process that can then guide energy-efficiency enhancements, we are studying the intrinsic transport mechanism of reverse osmosis, specifically the water permeability-salt selectivity tradeoff that governs all salt-rejecting polymeric membranes.

 
 

Salinity Gradient Energy

The Gibbs free energy, ΔGmix, from mixing two solutions of different concentration is an overlooked energy source that can be harnessed for useful work production. Salinity gradient energy can be derived from natural origins, such as the mixing of fresh river water with salty seawater, or from anthropogenic and engineered sources (illustration on the right). We are at the forefront of developing leading salinity gradient technologies, such as pressure retarded osmosis and reverse electrodialysis, to utilize Gmix for sustainable energy production.

Salinity gradient energy  
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