|R&D Achievements in 10th Five Year Plan period
- TDS Reduction through in-plant measures
In-plant TDS reduction measures were developed. Two tanning clusters were directed by the TNPCB to reduce the TDS of the treated wastewater. The TDS level of the treated wastewater of Dindigul and Pernambut clusters was about 15-22,000 mg/l. After having studied the process schemes and the emission pattern in the tanneries of these two clusters, suitable in-plant TDS reduction measures were identified. These measures were implemented and standardised. On account of these implemented measures, TDS was reduced to 7,000 mg/l in the treated waste waters in both the clusters.
- Low salt and salt-less preservation
Since the salt based curing methods contribute highest to the TDS loads in effluent, it is necessary to develop and adopt salt-free and less-salt preservation methods. A low salt preservation method based on a combination of NaCl-carbonate has been developed and field tested on semi-commercial scale by working with a reputed tanner at Ambur. The method has been found to be suitable for both wet blue and E.I. leather production.
A salt-free short term preservation by chilling has been developed. Basic works related to preservation of skins and hides by chilling technique have been carried out. The fundamental microbiological and engineering aspects of the chilling system have been studied in detail. The process conditions have been standardised. A mobile chiller have been designed and procured. Trails at semi commercial / commercial scale have been conducted and cost benefit analysis carried out for the system and the technology package finalized.
- Containing hexavalent chromium in finished leathers
Compliance to eco bans on some compounds/substances imposed by importing countries is a major issue confronting the leather industry world over. Though there are direct sources of hexavalent chromium in leather such as unreduced chromium in BCS, metal complex dyes, lead chromate based pigments etc, the most worrying factor is the possibility of conversion of Cr(III) to Cr(VI) by the reaction with contaminants present in auxiliaries used in wet finishing and finishing. A simple screening method for identifying such auxiliaries has been developed and applied to determine the oxidizing potentials of many of auxiliaries. Simple scavenging methods for the elimination of hexavalent chromium from leathers have been developed
- Achieving Zero liquid discharge in raw to wet blue stage
A process technology package has been developed for Zero liquid discharge for raw to tanning process scheme. Engineering package for zero discharge has also been designed. A pilot plant for zero discharge has been established. This plant has been established for carrying out further research on Zero liquid discharge and for conducting trials for the tanners to practice zero discharge at pilot scale.
- Chicken feed / Dog biscuits from lime fleshing
A technology for manufacturing animal feed products such as chicken feed, dog biscuits and fish feed has been developed and patented. Depending upon the requirement for these intended products this technology can be propagated to various leather clusters under technology mission mode.
- Pickle liquor recycling in E.I. Tanning
A pickle liquor recycling procedure suitable for E.I.leather processing has been developed and field implemented in a tannery at Dindigul. This method has been shown to reduce TDS loads in leather process considerably and at the same time there is a possibility to reducing the burden on solar pans for disposal of this saline waste stream.
- Direct chrome liquor recycling
A system of direct chrome liquor recycling has been developed and standardised. This system provides a comfortable means of reuse of chromium. Moreover this system also provides solution for pickle liquor management. This system shall be propagated under technology mission mode in chrome tanning clusters.
- Enzyme only unhairing process
Package of sulphide free unhairing has been standardised for various raw materials.