Incineration

it describe the methods of incineration and pyrolysis in details

1. BY LECTURER AKASH BAJAJ VISHWESHWARAYYA POLYTECNIC, ALMALA (DIST. LATUR ) INCINERATION AND PYROLYSIS

2. INCINERATION

3. Introduction of incineration process Incineration  is a  waste treatment process  that involves the  combustion  of  organic  substances contained in waste materials. Incineration of waste materials converts the waste into  ash ,  flue gas  and heat . The ash is mostly formed by the  inorganic  constituents of the waste, and may take the form of solid lumps or  particulates  carried by the flue gas. The flue gases must be cleaned of gaseous and particulate pollutants before they are dispersed into the  atmosphere .  heat generated by incineration can be used to generate  electric power .

4. Types of incinerators Multiple chamber incinerators Municipal incinerators

5. Types of incinerators Multiple chamber incinerators: “ it is an incinerator with two or more refractory lined combustion chambers in series separated physically by refractory walls , interconnected by gas passage .

6. WORKING OF MUNICIPAL INCINERATOR It involves the combustion of solid waste at 1000ᵒc Waste converted into ash, gas, and heat.

7. Use and by product of incineration (S15) After the incineration process the left out product can be used as aggregate for low grade concrete Also used as road metal. Ash is used for making bricks or block manufacturing. Steam used for electricity generation by running turbine. Also used as filler material.

8. Products of incineration process with their use

9. HEAT Heat is used for generating Steam which is used for electricity generation by running turbine.

10. Furans and Dioxins It is the most biggest concern for environmentalists. These are injurious to health.

11. CARBON DIOXIDE CO2 plays a vital role in global warming , as this is green house gases. Generally it is seen that every thing which has carbon in its composition is when processed by incineration evoles out as co2.

12. PYROLISIS OF WASTE Pyrolysis can be defined as the thermal decomposition of organic material through the application of heat without the addition of extra air or oxygen . In this process thermal decomposition of organic matter at high temperature take place. Pyrolysis is an endothermic process which requires heat for an external source. In this method solid waste material is heated in specially designed chamber which is called as pyrolysis reactor. In pyrolysis reactor, heating is carried out in closed environment which is almost oxygen free at an average temperature above 650o c which may rise to 1000o c. The end products are Hydrogen, methane, carbon mono-oxide, tar or oil, char, inert material.

13. Methods of Pyrolysis: Dry pyrolysis Oxidizing pyrolysis

14. Dry pyrolysis Process of thermal decomposition without access of oxygen (O₂ ) Products of dry pyrolysis are gas with high heat of combustion, liquid and solid carbon residue . Type of dry pyrolysis depend on the temperature of the process i.e. Low Temperature Analysis, Medium Temperature Analysis, High Temperature Analysis.

15. Oxidizing pyrolysis It’s impossible to achieve a completely oxygen-free atmosphere. Thus, a small amount of oxidation occurs. If volatile or semi-volatile materials are present in the waste, thermal desorption will also occur. Thermal decomposition of industrial waste by its partial burning or direct contact with end product of fuel combustion This method is used for neutralization of most wastes including “inconvenient” ones for burning are present in the waste, thermal desorption will also occur. Thermal decomposition of industrial waste by its partial burning or direct contact with end product of fuel combustion This method is used for neutralization of most wastes including “inconvenient” ones for burning

16. MERITS OF PYROLISIS REDUCE GREENHOUSE GAS EMISSION WASTE GOING TO LANDFILL PRODUCE MARKETABLE PRODUCT LIKE GASES, BIO OIL , BIO CHEMICAL, CHARCOAL. LOW RISK OF WATER POLLUTION LOW RISK OF ODOURS HIGH ROCOVERY RATE OF RESOURCES MINIMUM HEALTH CONSEQUENCE

17. DEMERITS OF PYROLISIS LESS CAPACITY LESS EFFICIENCY MORE EXPENSIVE TECHNOLOGY IS STILL EVOLVING

18. ADVANTAGES i) This is most hygienic method, since it ensures the complete destructions of pathogens ii ) There is no odour trouble or dust nuisance iii ) The heat generated can be used for raising the steam power iv) Clinkers produce can be used for the road purpose

19. DISADVANTAGE i) Large initial expenditure ii ) Improper operation results air pollution problems and incomplete reduction of waste materials iii ) Disposal of remaining residue is required iv) High stacks are needed for the natural draft chimneys present safety problems