Differences Between Pyrolysis and Incineration
With the growing threat of solid waste management, it is vital to explore efficient and environmentally friendly waste conversion technologies. Although incineration has been the main method of solid waste treatment, pyrolysis has been attracting a lot of attention in recent years. By comparing pyrolysis and incineration, we hope to provide you with a reference for finding a more sustainable waste treatment solution.
Pyrolysis is the process of breaking down solid waste (e.g. plastics, rubber, biomass, etc.) into smaller molecular compounds at high temperatures in an anaerobic environment, a process that takes place mainly in specialized pyrolysis equipment. Anaerobicity is one of the core elements of pyrolysis, as it limits combustion and encourages the breakdown of this waste into products such as biochar, pyrolysis oil, and syngas. In recent years, pyrolysis has gained much attention due to its potential for resource recovery and energy conversion.
Incineration is the process of completely or partially burning solid waste into gas and ash in an oxygen-rich environment. Currently, incineration is widely used in the treatment of municipal wastes, medical wastes and certain industrial wastes. However, emissions such as carbon dioxide, nitrogen oxides and sulphur oxides produced during incineration need to be handled with care, otherwise they can cause irreversible harm to the environment.
Application
Pyrolysis: It’s mainly used for organic waste treatment and recycling (waste rubber/plastics, agricultural and forestry waste, animal manure, industrial sludge, etc.) and energy production.
Incineration: It’s mainly used for solid waste that is large in volume and difficult to recycle, especially municipal solid waste, medical waste, hazardous waste, to achieve harmless waste and resourcefulness by reducing the volume of waste, eliminating pathogens and recovering heat energy.
End Products
Pyrolysis: The end products of pyrolysis are mainly divided into three types: gas (e.g., syngas), liquid (e.g., pyrolysis oil, wood vinegar liquid, wood tar), and solid (e.g., carbon black, biochar), which can be further processed and utilized.
Incineration: The end products of incineration are mainly ash and flue gas, of which the flue gas needs to undergo rigorous purification to reduce pollutant emissions, while some waste residue can be used for paving bedding, making no-burn bricks, etc., and the part that cannot be comprehensively utilized is sent to a special landfill plant.
Diverse Energy Products: Pyrolysis is more efficient in converting waste into high-value-added energy and chemicals such as bio-oil, renewable gas, bio-char, etc. These end products can be stored and utilized as well as processed and sold.
Low Environmental Pollution: Since pyrolysis takes place under anaerobic or low-oxygen conditions, it reduces the emission of greenhouse gases such as carbon dioxide, produces relatively few pollutants, and reduces exhaust emissions.
High Energy Conversion Efficiency: The energy released during the pyrolysis process can be collected and utilized more efficiently, e.g., converted into electrical or thermal energy through heat recovery systems, which can be used for external power generation or heating and drying, as well as for driving the operation of the pyrolysis equipment.
Wide Adaptability: Pyrolysis is suitable for many types of solid waste treatment, including plastics, rubber, sludge, and biomass (rice husk, straw, nut shells, palm waste, wood waste, bamboo, animal manure, etc.) that are difficult to recycle.
What is Pyrolysis?
Pyrolysis is the process of breaking down solid waste (e.g. plastics, rubber, biomass, etc.) into smaller molecular compounds at high temperatures in an anaerobic environment, a process that takes place mainly in specialized pyrolysis equipment. Anaerobicity is one of the core elements of pyrolysis, as it limits combustion and encourages the breakdown of this waste into products such as biochar, pyrolysis oil, and syngas. In recent years, pyrolysis has gained much attention due to its potential for resource recovery and energy conversion.
What is Incineration?
Incineration is the process of completely or partially burning solid waste into gas and ash in an oxygen-rich environment. Currently, incineration is widely used in the treatment of municipal wastes, medical wastes and certain industrial wastes. However, emissions such as carbon dioxide, nitrogen oxides and sulphur oxides produced during incineration need to be handled with care, otherwise they can cause irreversible harm to the environment.
Differences between Pyrolysis and Incineration
Working Process| Pyrolysis | Incineration | |
| Raw material preparation | Raw materials (waste rubber, plastics, biomass, etc.) are crushed, dried and then fed into the pyrolysis furnace | Domestic waste is sorted, crushed and then fed into the incinerator. |
| Pyrolysis/Combustion | Raw materials enter the pyrolysis furnace and are cracked into light products at the temperature of 450℃~550℃ in an anaerobic environment | Refuse is burned into ashes and gas at a high temperature of 800-2000℃ in the oxygen-containing combustion chamber |
| Product Treatment | During the pyrolysis process, cracked products such as syngas, cracked oil, biochar, etc. are purified and recovered through a series of separation and treatment devices | The gases released in the combustion process produce ashes and gases |
| Energy Recovery | The thermal energy generated during the pyrolysis can be recovered through boilers and other devices for use in power generation, drying or heating, etc. | The gases released during the combustion process release steam, which can be used to power generators |
| Exhaust gas treatment | The exhaust gas generated is filtered and dusted and then discharged in accordance with the EU 2019 emission standards. | Hazardous gases produced are treated with precipitators and filters to remove pollutants. |
Application
Pyrolysis: It’s mainly used for organic waste treatment and recycling (waste rubber/plastics, agricultural and forestry waste, animal manure, industrial sludge, etc.) and energy production.
Incineration: It’s mainly used for solid waste that is large in volume and difficult to recycle, especially municipal solid waste, medical waste, hazardous waste, to achieve harmless waste and resourcefulness by reducing the volume of waste, eliminating pathogens and recovering heat energy.
End Products
Pyrolysis: The end products of pyrolysis are mainly divided into three types: gas (e.g., syngas), liquid (e.g., pyrolysis oil, wood vinegar liquid, wood tar), and solid (e.g., carbon black, biochar), which can be further processed and utilized.
Incineration: The end products of incineration are mainly ash and flue gas, of which the flue gas needs to undergo rigorous purification to reduce pollutant emissions, while some waste residue can be used for paving bedding, making no-burn bricks, etc., and the part that cannot be comprehensively utilized is sent to a special landfill plant.
Advantages of Pyrolysis over Incineration
Diverse Energy Products: Pyrolysis is more efficient in converting waste into high-value-added energy and chemicals such as bio-oil, renewable gas, bio-char, etc. These end products can be stored and utilized as well as processed and sold.
Low Environmental Pollution: Since pyrolysis takes place under anaerobic or low-oxygen conditions, it reduces the emission of greenhouse gases such as carbon dioxide, produces relatively few pollutants, and reduces exhaust emissions.
High Energy Conversion Efficiency: The energy released during the pyrolysis process can be collected and utilized more efficiently, e.g., converted into electrical or thermal energy through heat recovery systems, which can be used for external power generation or heating and drying, as well as for driving the operation of the pyrolysis equipment.
Wide Adaptability: Pyrolysis is suitable for many types of solid waste treatment, including plastics, rubber, sludge, and biomass (rice husk, straw, nut shells, palm waste, wood waste, bamboo, animal manure, etc.) that are difficult to recycle.
