REPORT ON SDC EC INDIA WEBINAR'

 

A REPORT ON SDC EC INDIA WEBINAR

END TO END: PROCESSING AND WASTE MANAGEMENT 

Day: Friday, 14th MAY 2021	Time: 5:30 PM to 7:30 pm
Online Platform Virtual Panel Discussions MS Teams	Participants: 227

Event Sponsors: AMA Herbal Group Companies, Britacel Silicones Ltd., Archroma Ltd., Ion Exchange (I) Ltd and DR. JD

The attendees were welcomed by Dr. Vishaka Karnad, Hon. Trustee, SDC EC who briefed the audience on SDC and introduced the Moderators of the two Panel Discussions.

PANEL DISCUSSION 1.  Wet Processing Technologies and Methods

Moderator : Mr. Anjani Prasad

Managing Director & Member of Global Leadership Team, Archroma Pvt. Ltd.

Panellists:

Mr. Arindam Choudhuri (Business Head – Global, Britacel Silicones Ltd.)

Mr. Yawar Ali Shah (Co-Founder & CEO, AMA Herbal Group Companies)

Mr. Klaus Bergmann (MD of Erbatech India PVT. LTD., Director Sales & Director Textile Technology of Erbatech GmbH Germany)

Mr. Anjani Prasad introduced all the panellists and the theme of wet processing technologies and methods. Safety he said was of prime importance - safe purchase, safe process and safe disposal. It is important to take care of chemical management. Check for RSL, MRSL at the starting point, if inputs are right only then, the output will be right. It is important to make the right choices for purchasing dyes and chemicals and we make the right processes. Inappropriate choices can have hazardous impact of life and environment. He suggested that the discussion would be around the solutions to processing both improving efficiency and process enhancement. It is important to consider if the Plant is being used for more enhanced features and efficiency to get the right values on the ecological and social aspects of sustainability. There are a lot of areas to improve on namely to improve productivity and efficiency ratios, to have reduced lead times for value generation of products, of company with sustainability along with enhanced functionality features. All this considering enhanced social economics as the goal. With this, he posted some questions to the panellists.

Mr. Arindam Choudhuri stressed the importance of adopting efficient machinery and new technologies saving water and energy voluntarily by Companies. He suggested the move towards continuous process rather than discontinuous process, ZLD or water harvesting or re-cycling, installation of solar system across the free space inside dye house to save natural energy, design dye house premises efficiently to save day light, process optimization to reduce the machine run time, reduce the inorganic chemical use in the process, reduce the sludge after ETP, or concentrated chemical use to reduce petrochemical base packing material and air pollution while transporting the chemicals.

Non PVA/Non-Synthetic (Acrylic /Resin/Binder) base Sizing agent, use of hot water to de-size natural starch which can easily be removed from fabric in PTR washing range (without enzymatic de-sizing) saving on one process / hold time 8 – 12 hours, electrical rotation cost & labour man hour etc. He suggested Pad–Steam de-size over Pad–batch de-size for regular/conventional sizing process. In Pad batch you need rotation that leads to increase in lead time, electrical energy consumption and wastage of water. Caledon Vat pigment dyeing system for light and pastel shades over CPB/PDPS System with no washing required, in Caledon dyeing, Hydrose and Soda Ash replacement by chemicals, Low temperature, Soaping, Bleaching, RT de-size/bio-polish, Resin. Avoid Sanforize/Calendar which ever possible so that extra mechanical process can be avoided and energy cost reduced. Purchase and concentrated chemicals to avoid unnecessary packing material wastage, limit transport of chemicals, saving in utility/energy/raw material.

Knits Continuous bleaching and CPB dyeing to avoid salt/time/energy consumption. He touched on the Green chemistry concept for textile finishes and the usage of Sustainable Certified chemicals. He mentioned the advantages of Chemical Fission that found to yield uniform particle size, better finish batch to batch, equal surface preparation, reduction in silicone consumption and ease of crosslinking with organic molecules. Textile finishes need to be sourced from renewable, natural raw materials, that achieves high levels of textile performance while radically lowering carbon emissions. On the activation of silicone open chain polymer emulsion yields component that is readily reactive with easy penetration, giving durable finish, low consumption and uniform softness.

Mr. Yawar Ali Shah said that there are millions of dollars spent on sustainability. We are responsible enough to make textile processing sustainable. We need to plan Exhaust method in garment dyeing, planning that is necessary, as prevention is better than cure. To illustrate, he compared the process of Natural Dyeing as compared to reactive dyeing. He proved from R&D studies that the saving of auxiliaries, dyeing time and dyeing at room temperature, clearly directed to zero consumption of energy, saving the time of dyeing and remarkable reduction of BOD, COD, TDS and pH values with no serious modifications.

Mr. Klaus Bergmann emphasized the need for salt-free dyeing or strongly reduced salt dyeing. As the textile industry faces the problem water. He spoke on the key advantages of the continuous dyeing process with low production costs, easy reproducibility, no enzymatic treatment for hairiness and no salt in effluent. It is important to go ahead in adopting safe technologies. He compared the consumption values of continuous dyeing and discontinuous dyeing with 60% reduction in water 52% steam and 45% electricity consumption. There is a potential demand for new technologies, strongly reduced or salt free dyeing of knitted as compared to the Jet/Soft Flow dyeing of Standard Reactive dyeing which requires (where 100g/lt salt was too much) five times the amount of salt.

Mr. Arindam recommended for bio-elimination. He suggested that people from the fashion and processing houses must shorten material to liquor ratio and improve chemical efficiency for old machines by using modern technologies. Mr. Anjani Prasad added that safe selection of products and check on MSDS. OECD can be checked for biodegradability. OECD can be checked whether it will biodegrade on its own. In reality jet technology leads to 2-5%/kg fibre loss which is not sustainable. Solvent-based or acid-based processes are not beneficial. Biopolishing process can be avoided. Mr. Yawar Ali Shah added that brands are recycling 20-30% recycled with fresh. This sustainable concept not only saves energy cost and reduces landfill space. Upcycling of garments has a lot of scope. Mr. Anjani Prasad gave an example of stripping or shredding waste for regeneration for Viscose, paper, nonwovens, nitrocellulose for construction etc. Yawar Ali Shah said that what is waste for one is considered as resource by another e.g., pomegranate rind considered as waste is a source of dye. He gave an example of the extraction of Ethyl alcohol from Sugarcane for sanitizer. Waste from any source has utility and has to be renewed as a resource.

PANEL DISCUSSION 2 : End of pipeline solutions and waste management solutions

Moderator : Mr. Ajay Popat, President, Ion Exchange (I) Ltd.

Panelists:

Dr. K. Ramesh, Tamilnadu Water Investment Company Limited, Tirupur, Tamil Nadu.

Mr. Soren Robenhagen, Sales Director, Industrial Water, Aquaporin, Denmark.

Dr. Jaideep Dudhbhate, Textile Consultant, Pune, India.

Mr Ajay Popat, introduced each of the topic and speakers and the topic of waste management. Textile Waste Water- Current Limitations of conventional effluent treatment processes. The discussion therefore focused on the New technologies / Drivers listed here: Recovery of salts, dyes, energy and water, Automation & Digitalization, Remote Sensing, Monitoring Control, Optimize OPEX, Sustainable Treatment Technologies, Biological processes with lower, Energy Footprint, Sludge generation, Advanced Oxidation, Electro coagulation, Non vortex cavitation, PCO, Affordable ZLD- AMBC and OARO / FO.

• Pollution and increased demand have made good quality water scarce and expensive due to stringent discharge norms.
• ZLD is mandated in  textile units  having effluent discharge more than 25 m3/day & also for all textile units in clusters irrespective of their wastewater discharge
• Textile units face following limitations for ZLD implementation :
• Capital expenditure of  INR 8-9 crore /MLD excluding land cost
• Operating cost  of approximately  INR 225/m3
• Cost of Electricity from 3000-15000 kW/day
• ZLD Increases cost of production by 25-30 %
• Generation of quantum of hazardous solid waste & increase in disposal costs
• High Carbon foot print with power consumption from 8-10 kW/m3, Thermal evaporators require 20-40 kW/m3
• Inefficient functioning of Primary & Secondary involving Biological treatment units leading to choking & scaling of membrane & evaporators which increases expenditure due to repair/replacement.

Mr. Ajay shared the TERI Analysis Report and indicated the technologies and drivers to resolve the limitations and problems of the industry.

Dr. K. Ramesh presented a Case study on Waste Mixed Salt minimization Technique in ZLD Process. The Waste salt generation from RO brine Management system comprised of   Mechanical Vapor Recompression (MVR) type Evaporator, Multiple Effect Evaporator (MEE) and Agitated Thin Film Dryer (ATFD). He spoke on the high waste mixed salt generation due to crystallization of salt from RO brine, generation and disposal issues of considerable amounts of fly ash from boiler due to salt crystallization. 80% salt recovered from the wastewater can be reused in the dyeing process. No fresh salt required. The remaining salt (20%) is waste mixed salt with contaminants and is being stored. He suggested the Treated brine Reuse Technology to reduce waste mixed salt generation.

In another Case study, on Salt Separation and Purification in ZLD Process using Membrane Technology. The improved brine reuse technology with NF, Membrane Distillation (MD) is based on Solar thermal energy for Zero Liquid Discharge (ZLD) with Zero Waste Salt (ZWS) generation.

Solid waste reduction techniques and disposal methods. Sludge reduction techniques in ZLD Process/Water recycling Plants. Elimination of primary chemical treatment and treating of combined wastewater (TDS < 10g/L) directly through Aerobic biological treatment (Extended Aeration).For Hardness reduction WAC resin can be implemented instead of Lime-Soda Softening(LSS) treatment. Quantity of Chemicals required to treat the WAC’s side stream waste is very minimal than the LSS.

Disposal and utilization methods were discussed where, the Bio-sludge was stored, mixed with biomass briquettes for burning in boilers. The Chemical sludge for new plants, manufacturing of fly ash brick (from the Captive Power Plant/Boiler) with the lime sludge was proposed. Currently, Chemical sludge basically lime is being sent to nearby cement industries for Co-processing.

Integration of Solar Energy for brine management to eliminate ash generation and disposal issues. Brine Management using solar energy to eliminate ash generation from boiler. Application of Membrane Distillation (MD) system instead of MEE and use of solar thermal system to generate hot water (at 90^oC) which can be used as a heating medium instead of steam.

Advanced Oxidation Process (AOP) is a Sludge-less Technology, to reduce COD and Colour removal. In current treatment methods, Biological treatment is capable of removing COD and BOD but not colour. Generally chemical treatment and Polymeric resin (WBA) are extensively used to remove colour from the secondary treated effluent. High sludge generation from chemical treatment and liquid waste stream from WBA resin are difficult to handle and high Opex.

Electrooxidation (EO) to replace WBA and Chemical treatment methods. Electrooxidation offers a good reduction in COD and Colour, if implemented as a down-stream treatment unit to the secondary treatment system. EO process can also be used as a standalone treatment unit to recycle the brine solution (Post hardness removal). Zero-Sludge from EO Process and hence no sludge handling and disposal issues.

Mr. Soren Robenhagen spoke on Aquaporin’s sustainable re-use of water in industrial applications. He introduced Forward Osmosis and explained how it works. Forward osmosis uses natural energy in the form of osmotic pressure to transport water through a membrane. This process enables efficient extraction of water, leaving challenging contaminants behind and reducing effluent volume. The benefits of applying forward osmosis in textile wet-processing. Reduce water consumption for washing and rinsing operations. Recycle rinsing waters within the wet-processing or reuse the water for utilities. Reduce the effluent volume sent to the effluent treatment plant and evaporator to save costs. Recover chemicals (dyes/salts/metals) for reuse. The concentrated “draw solution” drives the FO process. Regeneration of the draw solution is often needed to maintain the driving force and to extract clean water as a product. Water is recovered from both upstream wet processing and downstream in ETP/ZLD. Cut energy consumption - reduce carbon footprint and operating costs.

Presenting a Case Study on Wool & cotton dye house wastewater, Mr. Soren Robenhagen explained that water saving and reuse allows for 6.7 EUR/m³ saving in bleaching and dying operations. 95 % clean water recovered (20x concentration). Stable water flux at 8-10 LMH, >5 LMH from 90-95 %. Good membrane chemical and physical tolerance. Another Case Study on FO post RO in ZLD scheme with FO brine concentration. LD scheme with FO, which pre-concentrates the brine concentration up to 150,000 ppm and reduces the volume by up to 90 % before it is sent for evaporation.

Dr. Jaideep Dudhbhate contributed to the topic on end of the pipeline solutions for reduction of wastes / sludges generated in the wastewater treatment plants. He presented several case studies and pilot treatments for the reduction in colour and chemical sludge quantity to 0.5-1 ton/d. Although, lime-ferrous treatment is eliminated, the tertiary treatment was needed. However biological sludge generation still takes place (excess bio sludge generation 0.25-0.35 Kg / Kg COD reduced).

He explained the sludge less biological process with a reduction of 90-95%. Some solutions in textile waste water effluents were suggested tertiary decolourization after biological treatment. Low energy requirements–almost 50% power saving in COD reduction. When there is excess bio sludge along with less chemical sludge, less requirement for down-stream sludge handling.

The Panel Discussions ended with a Vote of Thanks by Mr. Sandeep Singh, Hon. Trustee, SDC EC. The chat box had several questions that were answered in the Chat and few queries would be answered through mail. A feedback form was administered and certificates were issued to participants and to all the sponsors for their generous support extended through their sponsorship. Heartfelt thanks to the Sponsors of this Event and SDC EC Team for making the program successful. Looking forward to further interactions and collaborations in our endeavours for learning and enrichment.

-DR. VISHAKA ASHISH KARNAD (CTEXT.FTI)

Associate Professor, College of Home Science, Nirmala Niketan

Honorary Secretary, SDC EC & Hon. Secretary “Textiles” SIG TI