Hollow fiber nanofiltration

Patent filing no.: 742/KOL/2014

Technology title: Novel hollow fiber nanofiltration membrane using ZnCl₂ incorporated polysulfone Polysulfone (PSF)/Polyethyleneglycol (PEG) blend

1. Brief description

            In this work, organic (polyethylene glycol, PEG-200)  as  well  as inorganic  (ZnCl₂)  are simultaneously used as additives  (both  are  well  known  pore  constrictors) to polysulfone (PSF)/ dimethyl formamide (DMF) system  in order  to get hollow fiber NF membrane. Synergistic effects of pore constriction by zinc chloride and polyethylene glycol (PEG) are exploited to get nanofiltration grade fibers. The composition of the membrane was 16 to 18 wt% PSF, 2 wt% PEG-200, ZnCl₂ 1 to 2 wt% and rest dimethyl formamide (DMF). The molecular weight cut off of this membrane was 250 to 900 Da. This membrane is used for rejection of multivalent salts and organic dye. 30 to 45 % NaCl salt are rejected through this membrane at pH 2 to 11 range. 55 to 60% Na₂SO₄ salt are rejected at pH 11 through this membrane.   

2. Commercial aspects of the technology & Industries benefiting from it

            Commercial NF hollow fiber membrane is prepared using a spinneret which is costly. Therefore, the commercial hollow fiber cartridges are expensive. In this invention, nanofiltration hollow fibers were spun using an indigenously designed low cost process. Synergistic effects of pore constriction by zinc chloride i.e. inorganic additive and polyethylene glycol (PEG) i.e. organic additive are exploited to get nanofiltration grade fibers.

Some applications of hollow fiber NF are listed below. 

 (i) Removal of dyes (or colored component) from water by physical separation without any chemical treatment.

(ii) Concentration of fruit juices without any thermal treatment.

(iii) Removal of humic acid, bacteria and other pathogenic organisms from waste water.

 (iv) Textile industry effluent water treatment (reduction in COD content) without any chemical treatment.

(v) Desalination of salt water.

(vi) Removal of heavy metals from industrial pollutant.

3. Advantages of this technology

·         Unique formulation of membrane to obtain NF hollow fiber in one step.

·         No additional step for surface modification.

·         Solutes with molecular weight 250 to 900 are completely removed from solution.

4. Summary of the technical details

            Polymer (PSF) was heated to 70 to 80^oC for 2-3 h so that the moisture in the polymer was evaporated. Fixed amount (2%) of PEG (molecular weight 200 Da) and ZnCl₂ 1.0 to 2.0 % was added to a premixed 16 to 18% PSF in DMF dissolved at 60 to 80°C. The polymer was dissolved in DMF and the mixture was kept for 6 to 8 hours at 60 to 80^oC temperature under mild stirring. This solution was used for spinning the hollow fibers.

5.    Future prospects of the technology:

Uses as waste water treatment in textile and pharmaceutical industries, desalination. The technology is off the shelf and can easily be scaled up for industrial purposes.

Technology for removal of humic acid

Patent filing no.: 1058/KOL/2014

Technology title: Chitosan coated iron-oxide- polyacrylonitrile mixed matrix membrane for removal of humic acid

1. Brief description of the technology

            The proposed invention relates to the fabrication of mixed matrix membrane (MMM) using iron oxide nanoparticles and polyacrylonitrile (PAN) coated with chitosan which is used for removal of humic acid from surface water. Typical humic acid concentration in surface water is up to 50 mg/l whereas in drinking water EPA imposed limit is 2 mg/l. The composition of the membrane was 15 wt% PAN, 0.4 wt% iron oxide and rest was solvent dimethylformamide (DMF). The molecular weight cut off of this membrane was 44 kDa. The membrane was tested at different concentration of synthetic humic acid as well as pond water. The range of operating conditions for was 276 kPa to 550 kPa and 40 to 80 l/h cross flow rate. The filtered water produced was in the range of 15 to 25 l/m²h and total humic acid concentration in filtrate reached below permissible limit i.e., 2 mg/l. The process does not need addition of external additives or catalysts and process throughput is high.

2. Commercial aspects of the technology & industries benefiting from it:

1.     Waste water treatment plant, as an annexure to the main operating section of various plants.

2.     Scaled-up filter for domestic and industrial use.

      3.   Advantages

·         Unique formulation of membrane removes humic acid.

·         Concentration of humic acid in the treated water was reduced below 2 mg/l (EPA limit).

·         Iron oxide nanoparticles are inexpensive thereby, reducing the operating cost.

·         Any post processing step is not required.

·         Selective adsorption of humic acid, microorganisms and filtration of larger particles are attained in a single step.

       4.  A summary of the technical details involved

1.     Composition of base mixed matrix membrane:

a)     15 wt% coated polyacrylonitrile (PAN);

b)    iron oxide in an amount ranging from 0.4 wt%; and

c)     solvent dimethyl formamide (DMF) in an amount ranging from 84.6  wt%.

2.     Composition of chitosan coating:

a)     1 to 5 wt% chitosan in 1 to 6 vol% acetic acid;

b)    Glutaraldehyde in an amount of 0.1%;

c)     NaOH in an amount ranging from 0.5 to 1 N.

        5. Future prospects of the technology

 1.     Possible use in waste water treatment plant.

 2.     Development of scaled-up filter for domestic and industrial use.

Inventors: Prof. Sirshendu De, Ms. Swapna Rekha Panda, Ms. Munmun Mukherjee

High performance electrodes for Li-ion battery

Patent filing number: 613/KOL/2014

Technology title: Porous nanostructured tin-animony-copper intermetallic electrodes as anode material for lithium ion batteries

1.    A brief description of the technology

The technology is capable of fabricating Tin-Antimony- Copper based open-pore three dimensional nanostructure anodes for lithium ion batteries, which display high discharge capacity as well as good cyclability. The fabrication was carried out through electrodeposition route and devoid of any post-plating treatment except vacuum drying. The developed anode did not contain any binder or additive which take up lithium and add to capacity.

2.    Commercial aspects of the technology & Industries benefiting from it

Electronics industries are heavily dependent on high capacity batteries.Various automobile companies are looking forward to launch electric vehicles to conserve fossil fuels. However they are stuck with performance of the battery especially the specific capacity. This technology has come up with a cheap fabrication process to increase battery capacity and will definitely be in the eye of those companies.This methodology can also be implemented to design and fabricate power sources for MEMS devices which are currently finding its use in diverse fields like biomedical instrumentation.

3.    Advantages of this technology over the already existing methods

Currently, most commercial lithium - ion batteries use graphite as the anodic material and lithium mixed oxide (e.g. LiCoO₂) as the cathodic material. Graphite, though readily available at an economical price, has a low theoretical gravimetric capacity (372mAh/g). This, in turn, reduces the overall discharge capacity of the battery. Recently, tin has emerged as one of the novel materials which have the potential to replace carbonaceous anode materials as it has a very high theoretical capacity (993 mAh/g). It however suffers from the drawback of a very high volume change during the lithiation/delithiation process (about 300%). This high volumetric expansion can lead to the gradual detachment of the anodic material from the current collector as well as its pulverization which ultimately results in a poor cyclability performance of the battery.

Various efforts have been made in this direction to overcome this particular shortcoming of tin based anodes. Alloying or forming mixtures with other active metals, notably antimony, is one of the most tried methods. While antimony is an active element, it reacts with lithium at a potential different from tin and hence buffers the expansion of the latter when it reacts with lithium.

Various efforts have been made in this direction to overcome this particular shortcoming of tin based anodes. Alloying or forming mixtures with other active metals, notably antimony, is one of the most tried methods. While antimony is an active element, it reacts with lithium at a potential different from tin and hence buffers the expansion of the latter when it reacts with lithium.

4.    A summary of the technical details involved.

This method uses an aqueous solution of inorganic salts of tin, antimony and copper and does not consist of any kind of surfactant or detergent. Deposition was done at very high overvoltage to facilitate hydrogen evolution in order to obtain a porous structure. The anode material shows a consistent capacity over 1100mAh. This is possible because of the presence of intermetallics in the material and open-pore morphology.

          5.    Future prospects of the technology.

To further increase the electronic conductivity of the anode and hence improve the rate capability, we plan to incorporate carbon nanotubes or graphene into our alloy system. This methodology is expected to show a drastic increase in the power density of the anode. We further plan to use this system as the anode for a battery along with the cathode which has been developed by our collaborators and improve on the results which we will obtain.

Inventors: Prof. Siddhartha Das, Prof. Karabi Das, Mr. Abhinav Kumar, Mr. Srijan Sengupta, Mr. Arijit Mitra

Food technology to tackle severe acute malnutrition

Patent Filing No. 748/KOL/2014

Media Coverage: Business Standard Link, NDTV Link

1.    A brief description of the technology.

High energy and nutrient rich food paste as per WHO and UNICEF specifications is a “Medical Nutrition Therapy” based on sound scientific principles with a balanced composition of nutrients for the recovery of SAM children. Apart from anthropometric recovery, energy dense food paste results in physiological and functional (including immunological) recovery to tackle severe acute malnutrition (SAM). Five ready to eat (RTE) energy dense food paste recipes are formulated using the Linear Programming in MATLAB. Protein, fat, energy value, moisture content etc. as specified by the UNICEF/WHO standards are maintained as constraints. The prepared formulations were validated. Vitamin & Mineral premix is designed and formulated meeting the requirements as specified by the UNICEF. The developed high energy nutrient rich food pastes are easy digestible, palatable soft and crushable which require no additional method of preparation and can be consumed directly from the pouch / tube. These food pastes require no refrigeration and can be stored at room temperatures. The food paste has low water activity and is shelf stable.

2.     Commercial aspects of the technology & Industries benefiting from it.

The process technology for development of high energy nutrient rich food paste in ready to eat form is entirely new for the Indian market. The high energy nutrient rich food paste that are developed as a part of the project funded by (i) Department of Biotechnology, Government of India and (ii) M/s Gattappu Chemicals Private Limited, New Delhi. The products developed are to be scaled up to pilot scale production after which will be taken up by the industry for clinical trials and subsequent commercial production. A Pilot-Scale unit with a production capacity of 100kg/day is being set up at IIT Kharagpur. The objective of this product is to tackle cases of Severe Acute Malnutrition. The end users of this product are

·         Severe Acute Malnourished Children

·         Children with AIDS who is suffering from wasting

·         AIDS patients with nutritional deficiency

Accordingly suitable NGO’s, other food nutrition and food safety sectors can play a major partner role in taking the product to the required target group. The technology has been transferred to M/S Gattapu Chemical Pvt. Ltd., New Delhi.

3.     Advantages of this technology over the already existing methods.

The main purpose of this ready to eat food paste is to serve the essential nutrients and energy for the severely acute malnourished and favor growth and development.

·         The developed high energy nutrient rich food pastes are easy digestible, palatable soft and crushable which require no additional method of preparation and can be consumed directly from the pouch/tube.

·         This food paste requires no refrigeration and can be stored at room temperatures.

·         The food paste has a low water activity and is shelf stable.

·         The high energy nutrient rich food paste is mainly targeted to eradicate severe acute malnutrition at community level.

·         By shortening the duration of inpatient treatment from an average of 30 days to only 5-10 days, the move towards using food paste in the recovery phase of treatment reduces the resources needed to treat SAM, which improves cost-effectiveness.

4.     A summary of the technical details involved.

High energy and nutrient rich food pastes are made using local ingredients and indigenously developed process technology. Three recipes are made out of peanut and one from potato and one from Bengal gram. The formulations contain other energy rich ingredients like sugar, glucose, skimmed milk powder, soy protein isolate, mineral vitamin mix etc. These ingredients increases the nutritive and sensory value of the final product which are be liked by children community fulfilling the demand of suitable food for SAM children.

 The processing comprises of steps like roasting, grinding, mixing and colloidal milling. The vitamin and mineral premix designed uniquely for these formulations with proper deliverability and stability. The production of the RTE food paste includes various processes like roasting, grinding, mixing, and milling. The process parameter like mixing time and mixing speed are optimized for the mixing of the ingredients in a planetary mixer. Additives like stabilizer and emulsifier required to maintain the stability of the product are also optimized. After mixing the product is passed through colloidal mill to get a fine paste of smooth consistency. The product is then packed in flexible pouches/tubes and stored.

5.     Future prospects of the technology.

Formulations with the alteration of ingredients can be made possible and changes could be made to the technology developed. Further the technology can be used to develop products to deal with various stages of malnutrition. This technology will be an efficient tool to deal with food security aspects in the future.