Industrial Consultancy & Sponsored Research (IC&SR) , IIT Madras
Cellulose Derived Graphenic Fibers for Capacitive Desalination of Brackish Water and Preparation Method of the Electrode thereof
Technology Category/Market
Category-Micro & Nano Technologies
Industry Classification:
- NIC (2008)- 3600- Water collection, treatment and supply; 28195- Manufacture of filtering and purifying machinery or apparatus for liquids and gases
Applications:
Drinking water and sanitation, Desalination of brackish water and sea water.
Market report:
The global desalination systems market was valued at USD 1.54 trillion in 2024, and is projected to reach USD 2.35 trillion by 2029, growing at a CAGR of 8.91% during the forecast period.
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Problem Statement
- The need for clean water for domestic, agricultural, and industrial processes has resulted in intense search for alternate sources of water supply, such as brackish groundwater and seawater.
- Conventional methods such as Reverse Osmosis (RO), Ultra Filtration (UF) etc. are energy intensive and result in rising proportion of concentrates. Capacitive deionization (CDI) is increasingly being considered as a viable solution for water desalination that is more energy efficient..
- However, the existing mainstream CDI materials with their inherent limitations in stability and resistance to biofouling limit the application of such electrodes for larger scale operations. Carbon-based electrodes such as mesoporous carbon have larger pore size and can address the problem of slow diffusion. However, mesoporous carbon has high inner resistance.
- There is a need for a cost-effective mesoporous carbon based CDI electrode with enhanced conductivity using incorporated graphene and higher resistance to biofouling.
Technology
- The invention describes a graphite reinforced-cellulose (GrC) derived 3D mesoporous fibrous carbon electrode for capacitive deionization and a capacitive deionization apparatus with improved desalination efficiency.
- The Graphite reinforced-cellulose (GrC) derived carbon electrode was synthesized on a tissue paper using a layer-by-layer method followed by carbonization under nitrogen atmosphere at 700 °C for 3 h. After carbonization, silica was etched out from the stacked GrC electrode by aqueous NaOH (I mM) for 3h to generate pores then washed and dried.
- The laboratory-scale CDl batch reactor consisted of a single pair of GrC electrodes and a pair of current collectors. The conductivity was measured at the cell exit stream by using a conductivity meter while the regeneration of the electrodes was carried out by reversing the terminal of the electrodes.
- The electrode was tested for biofouling using monoculture biofilms of pseudomonas putida grown on the surface of the electrodes and imaged using a Scanning Electron Microscope (SEM)
- The GrC electrodes are collectively intertwined in a unique fiber-like morphology with a thickness of 4-5 μm and a length of ten to several hundred micrometers. Further, the layer by layer staking enhances graphite reinforcement leading to enhanced conductivity and mechanical strength.
Key Features/Value Proposition
- The GrC electrode maintains its adsorption and desorption capacity even after ten consecutive cycles. These results exhibit high electro-adsorption capacity and a fast and reversible electro adsorption/desorption.
- The developed electrode was effective in the presence of multiple anions (〖SO〗_4^(2-),〖Cl〗_^-,〖NO〗_3^- and〖 F〗_^-) and the electrode successfully reduced the concentration of all the anions over time. While the fractions of 〖Cl〗_^-and 〖NO〗_3^- are removed more than the other two anions, the recyclability of the GrC electrodes was excellent resulting in regeneration of the electrode even after 10 cycles.
- The SEM results show that in comparison to a commercially available electrode, the invented graphite reinforced-carbon fiber electrode has an enhanced resistance to biofouling.
Questions about this Technology?
Contact for Licensing
Research Lab
Prof. Pradeep T
Department of Chemistry
Intellectual Property
- IITM IDF Ref 1308
- IN 335882 Patent Granted
Technology Readiness Level
TRL 5
Technology Validated in Relevant environment