Waste to Energy │Bio Gas │Bio CNG

 

Generation of waste from industries and urbanization leads to threat to environment. This article is related to types of organic waste and energy generated from the waste. There are following types of waste : organic waste, e waster, hazardous waste.

Types of organic waste

• Waste which degrades or broken down by microorganism over the time
• Organic wastes are carbon-based compounds
• Significant portion of overall waste generation in industries / agricultural section is orgnatic waste
• The organic waste is further classified as Biodegradable waste and Non – biodegradable waste.

Biodegradable waste	Non – biodegradable waste
It consists of organics that can be utilized for food by naturally occurring microorganisms within a reasonable length of time. It is basically Solid waste like food waster, leaves from trees, paper, clothes etc Waste from poultry farms AGRO residue Food processing rejections Waste from dairy , sugar, paper, oil extraction plant, leather industries etc.	It has very low degradation rate. It includes wooden furniture, agricultural dry waster, baggage, discarded clothes, cartons, cardboard, pouches

 

Waste to Energy

• The process of energy produced by waste is explained in different steps including Bio-methanation, Gasification and Pyrolysis. 
• The energy recover from waster in the form of  

1. Electricity
2. Biogas / Synthetic gas
3. Bio-methanation

Bio-methanation

• It is anaerobic digestion of organic materials which is converted into gas.
•  The Anaerobic digestion is a bacterial fermentation process that operates without oxygen, which produces biogas contains methane ( 60% ), carbon dioxide ( 40% )  and other gases. 
• It gives biogas as well as manure as the end product. 
• The organic waste produced by kitchens, canteens, hotels, vegetable markets etc are used in the Bio- methanation process.
• The bio gas generated from this process can be used directly in to gas burner to produce heat for cooking purpose / industrial applications. The gas engine is used to produce electricity.

                                                 OR

• The biogas can be cleaned to remove carbon dioxide and other gases to produce BIOCNG. 
• This BIOCNG is used in the vehicle as fuel. 

Gasification

• It is a process that uses high temperature in the presence of limited amount of oxygen to decompose material to produce synthetic gas ( mixture of carbon monoxide and hydrogen ) . 
• The Bio gas, AGRO residues are used in the gasifier to produce synthetic gas. This gas can be used for thermal and power generation purposes.

Pyrolysis

• It uses heat to break down combustible materials in the absence of oxygen, which produces a mixture of combustible gases ( methane, complex hydro carbon, hydrogen and carbon monoxide ) , liquid. 
• The output or product of pyrolysis process is

1. Gas mixture
2. Liquid
3. Carbon black

• The gas generated in this process can be used in the boilers to provide heat. The main purpose of pyrolysis is to minimize emissions.

Electricity from Organic Waste

Organic waste	Output
20 – 25 kg of organic waste	1 meter cube biogas                      OR 2 units of electricity                     OR 0.4 KGs of Bio CNG

Energy Potential from Waste

Sectors	Types of waste	Energy Potential (MW )
Urban liquid waste	Liquid waste	375
Paper	Liquid waste	254
Processing and preserving of meat	Liquid waste	182
Processing and preserving of fish	Liquid waste	17
Milk processing	Liquid waste	24
Maize starch	Liquid waste	47
Tapioca starch	Liquid waste	36
Sugar	Liquid waste	49
Distillery	Liquid waste	781
Slaughter house	Liquid waste	263
Tanneries	Liquid waste	9
Total		2037

Sectors	Types of waste	Energy Potential ( MW )
Urban solid waste	Solid waste	1247
Processing and preserving of meat	Solid waste	13
Vegetable processing	Solid waste	3
Vegetable raw	Solid waste	579
Fruit processing	Solid waste	8
Fruit raw	Solid waste	203
Palm oil	Solid waste	2
Sugar press mud	Solid waste	200
Slaughter house	Solid waste	48
Cattle farm	Solid waste	862
Poultry	Solid waste	462
Chicory	Solid waste	1
Tanneries	Solid waste	10
Total		3638

 

Waste to Energy Plant in India as on 31.3.2021 

State	Capacity
Punjab	10.75 MW
Delhi	52 MW
Madhya Pradesh	15.4 MW
Maharashtra	12.59 MW
Karnataka	1
Tamil Nadu	6.4
Andhra Pradesh	23.16
Telangana	45.8

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