Differences Between Pyrolysis and Incineration As Well As Advantages

Differences between pyrolysis and incineration provide people with distinct choices for waste disposal solutions. Despite incineration being the most widely employed method to convert waste into energy, pyrolysis has been more and more popular in pursuit of sustainability development in recent years. Through a comparison of pyrolysis and incineration, an effort is made to help you contemplate which one is better suited for your waste recycling project.

Pyrolysis vs Incineration

What Is Pyrolysis?

Pyrolysis is a thermal decomposition process in which organic substances (tyre, plastic, biomass, etc.) break down due to high-temperature heating under anaerobic conditions. Lack of oxygen prevents combustion and allows these complex materials to decompose thermally into simpler products like pyrolysis oil or biochar. Pyrolysis is typically carried out using specialized pyrolysis plant. It transforms low-energy-density materials into high-energy-density fuels and high-value chemicals.

Pyrolysis Machine

What is Incineration?

Incineration is the combustion process of burning waste into ashes and gases in an aerobic environment. Incineration is conducted in an “incinerator,” which is a type of furnace designed for burning hazardous materials in a combustion chamber. Incineration proves effective in reducing waste volume, but it requires careful environmental measures for handling waste gases and ash residues.

Waste Incineration Plant

Differences Between Pyrolysis and Incineration

Pyrolysis and incineration have similarities and differences. The similarity is that both of them are thermochemical conversion processes and take the use of heat that the organic matter itself contains as the target. The difference is that the two are completely different processes, which are mainly reflected in the following aspects:

Difference in technical principle

Pyrolysis process (with little O2, 300 – 600°C)

  1. Pretreatment: Dry and shred plastic to meet the feed standards.
  2. Feeding: Input small chunks of plastic into pyrolysis reactor through a feeder.
  3. Pyrolysis: Start combustion chamber. At 180-280℃, oil gas is generated. Light oil gas rises and enters the condenser.
  4. Condensation: Oil gas is liquefied into pyrolysis oil. Non-liquefiable syngas are recycled.
  5. Dedusting: Exhaust gas undergoes multiple dedusting treatments to meet the emission standards. (The above takes plastic pyrolysis plant as example.)

Incineration process (with sufficient O2; 850 – 1300°C) 

  1. Pretreatment: Pick up recyclable materials like metal. Shred residual waste.
  2. Combustion: Waste is burned into ash and gas in an oxygenated combustion chamber at high temperatures of 800-2000 ℃.
  3. Energy recovery: Through heat recovery, The gases released during combustion generate steam. The steam is used to power electrical generators.
  4. Environmental control: The cooled gas is treated by scrubbers, precipitators, and filters to remove pollutants. Waste residues are disposed of in a landfill. (The above takes a mass burn incinerator as example.)
Difference in application fields
  • Pyrolysis: It is usually used for organic waste disposal and recycling (waste tire/plastic/rubber/oil sludge/biomass, etc.),  and energy production.
  • Incineration: It is commonly used in household waste disposal, medical waste disposal, and hazardous waste elimination.
Difference in end products
  • Pyrolysis:  For waste tires/plastics/rubber/oil sludge, end products of the pyrolysis are mainly pyrolysis oil, carbon black, syngas, etc. For biomass and sewage sludge, the main end products of pyrolysis are biochar, wood vinegar, tar, and syngas.
  • Incineration: The end products of incineration are mainly ash, CO2, and water.

Why Incineration Is Not a Good Waste Treatment Solution?

Incineration does reduce the volume of waste, but it is not waste recycling. The waste it produces poses a huge threat to the environment and human health.

Environmental pollution

The process of waste incineration produces large amounts of CO2, exacerbating global warming. Additionally, it may produce particulate matter (PM2.5 and PM10), acid gases, nitrogen oxides and cancer-causing dioxins.

Waste of resources
  • Burning waste might be more convenient and offer a shorter return on investment period compared to recycling. As a result, incineration can compete with material recycling, impeding the recovery of recyclable materials.
  • Incineration with energy recovery only generates a small amount of energy. Creating energy from waste relies on burning mixed garbage and materials with a high energy value: dried organics and plastics. These are materials we can, and should, be composting or recycling. The energy we can conserve by recycling something is far greater than the energy we can get from burning it.
Health risk
  • Due to exposure to air pollutants and harmful emissions, incineration may pose health risks to individuals residing near the incineration facilities. Prolonged exposure to these pollutants can lead to respiratory, cardiovascular, and other health issues.
  • The pollutants generated by incineration can enter the food chain, posing a significant concern for public health. For instance, dioxins have been found in eggs and vegetables grown in areas surrounding incinerators, making the consumption of such produce unsafe.
Challenging to get project approval
  • Due to considerations for sustainable development, environmental policies globally are leaning towards becoming more stringent. Governments of various countries are raising the bar for environmental standards related to incineration, and they are imposing stricter requirements on the approval process by limiting the number and scale of incineration projects.
  • Residents are also increasingly focusing on environmental quality. They do not want waste disposal projects to harm their residential areas. Therefore, incineration projects may face strong resistance from local communities.

Obvious Advantages Of Pyrolysis Technology 

Eco-friendly:
  • The design of pyrolysis equipment typically takes environmental considerations into account. Taking Beston’s plastic pyrolysis plant as an example, its design involves separating the heat exchange water in the condenser from fuel oil and gas, allowing wastewater recycling. Equipped with multiple dedusting designs, its emissions can achieve EU environmental standards. Its cater-cooled slag design can reduce dust pollution.
  • Moreover, pyrolysis is carried out under the condition of hypoxia, so there are fewer CO2, NOX, SOX, HCI, and other public hazard generating.
  • The resulting gas or oil can be burned at a low air ratio with less exhaust gas and pollution.
Energy-saving
  • Pyrolysis usually produces large amounts of syngas. The syngas can be directly returned to combustor to provide heat to the reactor. This reduces the utilization of fossil energy.
  • Pyrolysis generally takes place at relatively lower temperatures, typically between 400°C and 800°C. In comparison, incineration may require heating up to 2000 degrees Celsius to minimize the generation of dioxins. Undoubtedly, pyrolysis consumes less energy in the process.
Circular and Storeable products

Pyrolysis products can be stored, processed, and marketed, making it more sustainable and well-suited for the circular economy. For example, liquid pyrolysis fuel oil is convenient for storage and long-distance transportation to serve as fuel. In contrast, incineration’s substantial heat can be harnessed for power generation, but in smaller amounts, it is limited to heating water or generating steam. Its energy is suitable for nearby use.

Versatile system
  • Pyrolysis can treat various a variety of wastes, including tyres, plastics, oil sludge, sewage sludge, and various biomass (coconut shells, fruit husks, bagasse, empty fruit bunch, palm shells, bamboo, sawdust, wood, straw, rice husks, elephant grass, etc.).
  • Compared to the typical singular purpose of incineration used for electricity generation, pyrolysis oil and biochar, have broad applicability. Pyrolysis oil can be directly used as fuel or be reprocessed into non-standard diesel. Biochar is popular in industrial fuel, soil remediation, carbon sequestration, feed additives, etc.

Pyrolysis Technology at Beston Group

If you’ve developed an interest in pyrolysis technology and are looking for a solution to your waste recycling needs, consider reaching out to Byte Company. We are a leading manufacturer in the pyrolysis field, ranking among the top 3 in the Chinese industry. With over 100 successful collaboration cases worldwide, we specialize in waste recycling. Our range includes intermittent, batch, and continuous pyrolysis plant. We look forward to the possibility of working with you in the future.

BLL-30 Coutinuous Pyrolysis Plant
BLL-30 Coutinuous Pyrolysis Plant – Suitable for Tyre/Plastic/Oil Sludge
BST-50 Continuous Biomass Pyrolysis Plant
BST-50 Continuous Biomass Pyrolysis Plant

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