Plasma pyrolysisand hydroclave-1.pptx

Microbiology

1. Plasma pyrolysis, hydroclave Dr.D.Gayathri Devi II year postgraduate Dept of Microbiology

2. CONTENTS presentation title 2 Introduction METHODS OF BMW DISPOSAL Overview of incinerator Plasma PYROLYSIS HYDROCLAVE REFERENCES

3. Introduction presentation title 3 BMWM Rules,2016- Only segregation and pretreatment is required at the healthcare facility level. Final disposal & recycling must be performed at the common BMW treatment facility

4. Methods of BMW disposal Incineration Autoclave Hydroclaving Chemical disinfection Microwaving Mechanical processes: Shredder, 4 presentation title Deep burial, Sharp pit Encapsulation Inertization Plasma pyrolysis Modern methods of disposal- Alkaline hydrolysis,Promession,Ozone

5. OVERVIEW INCINERATION: Method of choice of BMW disposal, Principle:high temperature (800-1450℃ ) oxidation process Reduces organic combustible matter into inorganic noncombustible matter Indications: Human anatomical waste, Microbiological waste and solid non plastic infectious waste Disadvantage: Release of combustion by products into the atmosphere such as steam,CO2,NO ,volatile substances & residual ash 5 presentation title

6. PLASMA PYROLYSIS 6 presentation title Plasma pyrolysis technology is a non-incineration thermal process Uses extremely high temperature in an oxygen starved environment Disintegrates the organic compounds into gases and non leachable solid residues Utilizes large fraction of electrons, ions and excited molecules together with the high energy radiation for decomposing chemicals. Both the physical and chemical reactions occur rapidly in the plasma zone.

7. Plasma, the fourth state of matter and the most active state of matter which is formed by removing the bound electrons from atoms, is an electrically conducting fluid consisting of charged and neutral particles. The charged particles have high kinetic energies. When the ionized species in the plasma recombine with the stripped electrons, significant amounts of energy in the form of ultraviolet radiation are released. The particle kinetic energy takes the form of heat and can be used for decomposing chemicals Plasma pyrolysis integrates the thermo-chemical properties of plasma with the pyrolysis process High temperatures combined with high UV radiation flux destroys the pathogens completely 7 presentation title

8. Hot plasma which is generated using plasma torch and power supply is used for the disposal of waste. There are two types of plasma arcs: transferred arc and non-transferred arc. In this case non-transferred arc has been selected because organic waste has been used. Graphite plasma torch is used for the disposal of plastic waste. In plasma pyrolysis the most likely compounds which are produced include carbonaceous matter, methane, carbon monoxide, hydrogen, carbon dioxide and water molecules 8 presentation title

9. 9 presentation title

10. components 1.Plasma torch 2.Power supply, 3.Gas injection system 4.Primary reaction chamber, 5.Secondary reaction chamber, 6.Quenchingsystem-cum-scrubber, 7. Induced draft fan and chimney 10 presentation title

11. 1.Plasma torch & power supply Plasma torch comprises of three graphite electrodes (one anode and two cathodes). DC power supply is used to produce plasma arc among these electrodes. Plasma torch converts electrical energy into heat energy in an efficient manner. It is used to heat the primary chamber where pyrolysis takes place The graphite plasma torch produces non-transfer arc. Entire torch operation is auto controlled to sustain continuous pyrolysis reaction. The electrodes are powered by 200 Ampere and 125 Volt power supply. The advantage of graphite plasma torch is that it does not require electrode cooling, which eliminates heat losses. In addition, one can strike and maintain the plasma in the absence of gas flow. 11 presentation title

12. 2.FEEDER: Feeder has two door arrangements and used for feeding the waste material in primary chamber & the feeder doors are opened and closed hydraulically. Steam is purged in the feeder to remove air. 3.PRIMARY CHAMBER: It is a rectangular chamber made-up of mild steel and it has refractory lining to reduce heat losses In primary chamber, waste is pyrolysed at high temperature (>1000ºC near pyrolysis zone and >650ºC close to chamber wall) is generated by plasma torch. After the pre-heating, organic waste is fed into the primary chamber where it is decomposed in oxygen starved environment. In primary (pyrolysis) chamber, gases such as methane, carbon monoxide, hydrogen, are produced. 12 presentation title

13. 4. SECONDARY CHAMBER: It is cylindrical chamber having refractory lining. In this chamber there is provision to mix air. One electrically operated igniter is mounted to ignite combustible gases that come out from primary chamber. The pyrolysis gases are combusted in secondary chamber which increases its temperature between 800-1000°C. The product gases formed after the combustion reactions are primarily CO2 and water vapour 13 presentation title

14. 5. SCRUBBERS: Venturi and secondary scrubbers are used for quenching as well as for scrubbing the gases. In scrubbing chamber pH-12 NaOH solution is sprinkled using a pump. The hot gases comes out from the secondary chamber are quenched in venturi scrubber and finally scrubbed in the secondary scrubber. 6. INDUCED DRAFT FAN AND CHIMNEY: The gases such as CO2, H2O are released in the environment using induced draft fan 14 presentation title

15. advantages Unlike incinerators, segregation of chlorinated waste is not essential. The reduction in volume of organic matter, which is more than 99% In plasma pyrolysis the quantity of toxic residuals (dioxins and furans) is much below the accepted emission standards and it does not require segregation of hazardous waste. The pathogens are completely killed and there is a possibility to recover energy. 15 presentation title

16. Demerits of PPT The product stream is complex The product gases cannot be directly vented in the cabin without further treatment because of high CO conc. Wastes gasification and combustion ultimately releases carbon dioxide to the Atmosphere instead of sequestrating a large fraction of the carbon in a landfill. Requires large electrical energy input, if the waste stream does not contains a large fraction of hydrocarbon. The highly corrosive plasma may lead to frequent maintenance and component replacement with associated down time of facility. 16 presentation title

17. PROPERTIES PYROLYSIS INCINERATION Temperature 800-1000℃ 800-1450℃ Pressure(Bar) 1 1 Atmosphere Inert/nitrogen Air Stoichiometric ratio >1 Gas products released H2,CO,H20,N2,Hydrocarbons CO2,H2O,O2 Solid products released Ash, Coke Slag, Ash Liquid products released Pyrolysis oil,Water NO2 17 presentation title

18. HYDROCLAVE Is a low temperature steam sterilizer involving steam treatment with fragmentation and drying of waste Has a double-walled (jacketed) cylindrical, pressurized vessel, horizontally mounted, with one or more side or top loading doors, and a smaller unloading door at the bottom Very small Hydroclave units have a single side door for both loading and unloading. 18 presentation title

19. The vessel is fitted with a motor driven shaft, to which are attached powerful fragmenting/mixing arms that slowly rotate inside the vessel. When steam is introduced in the vessel jacket, it transmits heat rapidly to the fragmented waste, which, in turn, produces steam of its own. A temperature sensor is located in the bottom inside part of the vessel, which measures the temperature of the waste as it is agitated and mixed, and this sensor reports back to the main computerized controller, which automatically sets treatment parameters ensuring complete waste sterility – even liquid infectious waste. After sterilization, the liquid but sterile components of the waste, are steamed out of the vessel, re-condensed and drained to sewer. The remaining waste is dehydrated, fragmented, and self-unloaded via a reverse rotation of the mixer/agitator 19 presentation title

20. Sterilizes the waste utilizing steam, similar to an autoclave, but with much faster and much more even heat penetration. Hydrolyzes the organic components of the waste such as pathological material. Removes the water content (dehydrates) the waste. Breaks up the waste into small pieces of fragmented material. Reduces the waste substantially in weight and volume. Accomplishes the above within the totally sealed vessel, which is not opened until all waste it totally sterile. 20 presentation title ADVANTAGES

21. No correlation between waste characteristics and treatment efficacy. All the waste is consistently sterilized. Liquid and heavy loads, however, will take longer time so to reach the temperature and pressure required to initiate the sterilization cycle, but sterilization automatically occurs. There is no need for “pre-and post-vacuum”, that is, pull infectious air and liquids of the vessel, as is the case with autoclaves. Pulling air and liquids out of an infectious environment increases the risk of live pathogen emission. The Hydroclave eliminates this risk due to the vigorous dynamic activity within , which mixes and heats any entrained air with the steam and waste material. 21 presentation title

22. STAGES OF STERILISATION 1.LOADING 2.HEATUP & FRAGMENTATION 3.STERILISATION 4.DE PRESSURIZATION & DEHYDRATION 5.UNLOADING 22 presentation title

23. 1.Loading The waste can be loaded into the Hydroclave treatment vessel depending on the requirement Smaller units dropping the waste bags manually into a side or end door. Medium-sized units by tipping waste containers into top or angled loading doors. Electric or hydraulic tipping devices are an available option with the Hydroclave . 23 presentation title

24. Medium to large sized units, for large scale commercial operation, a combination of conveyors, hoppers and tippers are available to load the waste into large top loading doors No special operator skill is required, since over-loading or loading too tightly is not an issue with this type of process. 24 presentation title

25. 2.Heat-up and fragmentation After loading, the vessel doors are closed, and the outer jacket of the vessel is filled with high temperature steam, which acts as an indirect heating medium for heating the waste The jacket steam condenses into clean, hot condensate, which is returned back to the steam boiler. 25 presentation title

26. Unique feature of the Hydroclave :So efficient in operation since no steam or hot condensate is lost. During heat-up, the shaft and mixing arms rotate, causing the waste to be fragmented and continuously tumbled against the hot vessel walls. The waste is broken up into small fragments, and all material heats up rapidly, being evenly and thoroughly exposed to the hot inner surfaces. The moisture content of the waste will turn to steam, and the vessel will start to pressurize. 26 presentation title

27. Initially, no steam will be injected into the waste. If there is not enough moisture in the waste to pressurize the vessel, a small amount of boiler steam is added until the desired pressure is reached. The uniform jacket heat, and the location of the temperature sensor ensures that even liquid waste will be heated up uniformly. At the end of this period, the correct sterilization temperature and pressure are reached, and the sterilization period is initiated automatically. 27 presentation title

28. 3.Sterilization period By computer , the temperature and pressure are maintained for the desired time to achieve sterilization. If for any reason the sterilization parameters drop below desired levels, the sterilization cycle is stopped, and re-initiated. This ensures sterilization prior to commencement of the next stage. The mixing/fragmenting arms continue to rotate during the entire sterilization period, to ensure thorough heat penetration into each waste particle. 28 presentation title

29. Sterilization time of 15 minutes at 132 C., or 30 minutes at 121 C. achieves 6log10 inactivation of the spores of bacillus stearothermophilus. The intense subjugation of the waste to such temperature and pressure moisture in a dynamic environment will also cause the waste to hydrolyze, that is a rapid decomposition of organic waste material. 29 presentation title

30. 4.De-pressurization and De-hydration After the sterilization period ends, the vessel is de-pressurized via a steam condenser, which causes initial waste dehydration due to depressurization. The steam to the jacket will remain on, agitation continues, and the waste loses its remaining water content through a combination of heat input from the jacket and continued agitation. All waste, no matter how wet initially, even liquid waste, will be dehydrated by this process. 30 presentation title

31. 5. Unloading At the end of the depressurization/dehydration period, jacket steam is shut off, the discharge door is opened, and the powerful mixing arms are reversed to a clockwise rotation. Due to the unique construction of the mixing arms, the opposite rotation causes the fragmented waste to be pushed out of the vessel discharge door, into a waste container, or onto a conveyor. 31 presentation title

32. If desired, the waste can be further fine-shredded prior to final disposal, by a separate shredding system. The dry, sterile, fragmented waste is well suited for further fine shredding. The vessel is now ready for another treatment cycle, having retained most of its heat for the treatment of the next batch. Safety:Consistent waste sterilization is the automation and safety features provided by the Hydroclave control system . As a safety feature, should any of the automatic features of operation fail, the operator is still able to go through a complete cycle in the manual mode 32 presentation title

33. REFERENCES Essentials of hospital infection control by Apurba sastry Study on Plastic Waste Disposal through “Plasma Pyrolysis Technology“, Central Pollution Control Board , (October, 2016) Plasma pyrolysis of medical waste , Current Science   83(3) August 2002 Sudhir Kumar Rema,K.S.Ganeshprasad Guidelines for Management of Healthcare Waste as per Biomedical Waste Management Rules, 2016 Hydroclave Systems Corporation,Canada technical sheet 33 Plasma pyrolysis

34. Thank you