2. 0 Plastic Waste Management Disposal of plastic waste is a serious concern in India. New technologies have been developed to minimize there adverse effect on the environment. Currently world wide accepted technology used for the plastic disposal is incineration. However, the incinerators designed poorly, releases extremely toxic compounds (chlorinated dioxins and furans) therefore, facing strong opposition from various non-government organizations. In India to introduce a safer disposal technology various new technologies were experienced enclosed in Fig. 1.
Plastic Waste Management Conventional Technology New Technology Recycling Plasma Pyrolysis Technology Polymer Blended Bitumen Roads Co-processing in Cement Kiln Incineration Liquid Fuel Land filling Fig.
1 Plastic Waste Management 3. 0 New Technology for Plastic Waste Management 3. 1 Polymer Blended Bitumen Roads The process of road laying using waste plastics is designed and the technique is being implemented successfully for the construction of flexible roads at various places in India. A brief description is given below followed by a detailed description. Brief description
Plastic waste collection, segregation & storage. Cleaning & drying of Plastic waste .
Shredding plastic waste into required size (2 to 4 mm). The coated aggregate is mixed Shredded polymer waste (5-10% w/w) is Stone aggregate (granite, with hot bitumen at temperature added to heated stone aggregate for 30- ceramic) heated to around 40 sec and mixed for uniform coating at 160°C-170°C. ranges from 155°C-163°C. surface of aggregate The mix (composite) known as waste plastic- aggregatebitumen mix (130°C-140°C). This composite used for road laying at temperature between 110°C-130°C. . 1. 1 Merits of Polymer Blended Bitumen Roads • Stripping and pothole formation: Bitumen film is often stripped off the aggregates because of the penetration of water, which results in pothole formation. This is accelerated during the movement of vehicle. When polymer is coated over aggregate, the coating reduces its affinity for water due to non-wetting nature of the polymer and this resists the penetration of water. Hence the penetration of water is reduced which resists stripping and hence no pothole formation takes place on these roads. Leaching: Polymer will not leach out of the bitumen layer, even after laying the road using waste plastics-bitumen-aggregate mix. • Effect of Bleeding: Waste polymer-bitumen blend shows higher softening temperature. This increase will reduce the bleeding of bitumen during the summers. • Effect of fly ash: It is also observed that the fly ash does not leach from this mixture. 3. 1. 2 Demerits of Polymer Blended Bitumen Roads There is no observable demerit either in this process or in the road characteristics.
For the past 2 years various roads laid using waste plastics are functioning well. 3. 2 Co-processing of Plastic waste in Cement Kiln 3. 2. 1 Operating Manual for Co-processing of Plastic Waste in Cement Kilns 3. 2. 2 Introduction Plastic waste generated from different cities and towns is a part of municipal solid waste (MSW). It is a matter of concern that disposal of plastic waste is causing many problems such as leaching impact on land and ground water, choking of drains, making land infertile, indiscriminate burning causing environmental hazards etc.
Plastics waste being non-biodegradable is littered in most of the cities/towns and their-by giving an ugly appearance. It is estimated approximately 15,342 tons/day (TPD) of plastic waste (on per capita basis) is generated in the country. To get rid of plastic waste disposal problems, Central Pollution Control Board (CPCB) in association with MP Pollution Control Board has taken initiative to use the plastic waste in cement plant at ACC Kymore (Katni, MP). The stack monitoring result revealed that emission values are found below the standard set for Common Hazardous Waste Incinerators.
After getting encouraging results CPCB has granted permission to many cement plants to co-process the hazardous and non-hazardous (including plastic) waste in their kilns after trial burns. 3. 2. 3 Co-processing of plastic waste as Alternative Fuel and Raw Material (AFR): Co-processing refers to the use of waste materials in industry process such as cement, lime or steel production and power stations or any other large combustion plants. Co-processing indicate substitution of primary fuel and raw material by waste, recovering industry and material from waste.
Waste material such as plastic waste used for co-processing are referred to as alternative fuels and raw material (AFR). Co-processing of plastic waste offers advantages for cement industry as well as for the Municipal Authorities responsible for waste management. In other hand, cement producers can save fossil fuel and raw material consumption, contributing the more eco-efficient production. In addition, one of the advantage recovery method used in existing facility, eliminating the need to invest on other plastic waste practices and to secure land filling. 3. . 4 Types of AFR including plastic waste for co-processing: This refers to waste material used for co-processing such waste typically include plastics, paper, cardboard, tetra-pack, packaging waste, waste tyres, waste oil, bio-mass waste cloths, auto-motive, shredder residues, hazardous industrial waste, obsolete pesticide, outdated drugs, chemical etc. Whereas plastic waste include carry bags, broken PET bottles, broken trays, pens, discarded plastic gift items, multi-layer and metalized pouches such as gutka, biscuits, namkeen, wafer pouches and packagings.
However, as per Holcim Policy, some wastes are banned for co-processing, it include; (i) (ii) (iii) (iv) (v) (vi) (vii) (viii) (ix) (x) Anatomical Hospital Waste; Asbestos containing wastes; Bio-medical waste; Electronic Scrap; Entire batteries; Explosives; High concentration Cyanide waste; Mineral Acids; Radioactive wastes and Unsorted Municipal Solid Waste (MSW) 3. 2. 5 Pre-processing of plastic waste : The plastic waste should be received in segregated and bundled form in HDPE/Jute bags. Then the plastic waste will be sun dried and subjected to shredding before feeding into cement kilns.
However, PVC containing plastic waste will not be accepted in cement kilns as it impair the cement quality. 3. 2. 6 Modification in cement kilns: Different feed points can be used to insert AFR into the cement production process. The most common ones are; The main burner at rotary kilns outlet end; The rotary kiln inlet end; The pre-calciner burners; The mid kiln (for long wet and dry kilns). AFR including plastics waste typically fed to the kiln system as the same way as traditional raw material e. g. normal raw material supply. AFR containing components e. g. lastics waste have to feed into high temperature zones and long residence time in kiln system. The 3 Ts; time, temperature, turbulence in cement kilns in complete combustion of waste material while absorbing the energy and material present in it without impacting the quality product. The alkaline environment of cement process acts as a natural scrubber of the acidic process, if generated. Before accepting AFR including plastic waste cement plants shall modify their feeding system and install a conveyor-belt, one hopper, one winch machine, and one double flap damper. A sketch flow diagram for feeding system and plastic waste handling system at ACC Plant Kymore are shown at Figures 1 & 2. Besides, cement plants shall set-up a minimum laboratory facility to characterize plastic waste in respect of moisture content, calorific value, heavy metal contents, ash contents, Carbon (C), Hydrogen (H), Nitrogen (N), Sulphur (S), Chloride (Cl), and Volatile Carbon to carry out these test analytical instruments such as Thermo-Gravimetric Analyser (TGA) , BombCalorimeter and C, H, N & S Analyser. 3. 2. 7 Indicative Operating Manual for Co-processing of plastics waste is indicated below:
Sr. Item Description Action to be No. taken by 1 Collection of plas Concerned Municipal Authority should create a Municipal waste system for collection of plastics waste from Dustb Corporation, Dhallaos through Public Private Partnership (PPP Nagar Palika Mode on any other feasible method. & Cantonment Boards 2 Segregation & Pr Collected plastics can be reprocessed/sorted for Municipal processing of recyclable and non-recyclable. The Non-recyclab Corporation, plastics waste plastics waste will be transported to nearest ceme Nagar Palika kilns for co-processing by concerned Municipal & Cantonment Authority.
Boards 3 Identification of Mapping of cement kilns for accepting co-process State Pollution cement of plastic waste in same State or neighboring Sta Control factory An agreement shall be signed between Municipal Boards & Corporations and Cement kilns. Pollution Control Committees 4 Modification for Cement Industry to set-up storage facility, shredd Concerned feeding conveyor-belt, one hopper, one winch-machine an Cement plastic waste (PW one double-flap damper. Industries in cement kilns A sketch flow diagram is attached. Cement ndustry shall set-up a minimum lab Concerned 5 Setting-up of facility To analyse plastics waste before Cement laboratory for plastics waste sending for co-processing. The instrumentation Industries analysis include Thermo-Gravimetric Analyser, BombCalorimeter and C, H, N & S Analyser. 6 Monitoring of Cement Industry shall monitor the stack emission emission by respect of routine parameters and hazardous air cement industry/ pollutants (HAPS) SPCBs Forwarding progr Forwarding quarterly progress report of Report to CPCB Co-processing of plastic waste to CPCB.
Concerned Cement Industries and SPCBs/PCCs SPCBs/PCCs and Cement Industries 7 3. 3 Plasma Pyrolysis Technology (PPT) 3. 3. 1 Introduction Plasma Pyrolysis is a state of the art technology, which integrates the thermochemical properties of plasma with the pyrolysis process. The intense and versatile heat generation capabilities of Plasma Pyrolysis technology enable it to dispose of all types of plastic waste including polymeric, biomedical and hazardous waste in a safe and reliable manner. Pyrolysis is the thermal disintegration of carbonaceous material in oxygen-starved atmosphere.
When optimized, the most likely compounds formed are methane, carbon monoxide, hydrogen carbon dioxide and water molecules. 3. 3. 2 Process Technology: In Plasma Pyrolysis, firstly the plastics waste is fed into the primary chamber at 8500 C through a feeder. The waste material dissociates into carbon monoxide, hydrogen, methane, higher hydrocarbons etc. Induced draft fan drains the pyrolysis gases as well as plastics waste into the secondary chamber where these gases are combusted in the presence of excess air.
The inflammable gases are ignited with high voltage spark. The secondary chamber temperature is maintained at 10500 C. The hydrocarbon, CO and hydrogen are combusted into safe carbon dioxide and water. The process conditions are maintained such that it eliminates the possibility of formation of toxic dioxins and furans molecules (in case of chlorinated waste). The conversion of organic waste into non toxic gases (CO2, H2O) is more than 99%. The extreme conditions of plasma kill stable bacteria such as bacillus stereo-thermophilus and bacillus subtilis immediately.
Segregation of the waste is not necessary, as the very high temperatures ensure treatment of all types of waste without discrimination. 3. 3. 3 Environment Related Observations Stack emission monitoring of different categories plastic waste such as (i) 100% Polyethylene Waste (ii) 80% Polyethylene + 20% PVC Waste was carried out by VIMTA Lab. It has been observed that the emission of toxic pollutants such as dioxins and furans from the plasma pyrolysis system developed by FCIPT is lower than the norms set for incinerator.
The summary of the results are mentioned in the Table 1: Table 1: Dioxins & Furans Emissions from Plasma Pyrolysis System Sr. No. Specifications CPCB Norms (As per The Gazette of India) Emission from Plasma System (80% Polyethylene + 20% PVC Waste)* Emission from Plasma system (100% Polyethylene Waste)* 1. 2. 3. Dioxins and Furans (Stack) 0. 1 ng/Nm3 TEQ (Norms are not mentioned) (Norms are not mentioned) 0. 00004 ng/Nm3 0. 00001 ng/Nm3 Dioxins and Furans (Scrubber Water) 0. 36 pg/L
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Plastic Waste Management. (2019, May 02). Retrieved from https://graduateway.com/plastic-waste-management-1069/