Why is Oxygen Not Needed in Pyrolysis?

Pyrolysis involves thermal breakdown of substances in an environment lacking oxygen or other reactive gases. The key factor for avoiding oxygen in pyrolysis is to stop combustion or oxidation from happening.

Pyrolysis condition

Below is an explanation:

Stops Burning

If oxygen exists, items like waste tires, plastics, rubber, or organic substances might burn, releasing energy as heat and light. This burning creates main byproducts such as carbon dioxide (CO₂) and water (H₂O), which does not align with pyrolysis objectives. Instead, pyrolysis focuses on splitting materials into smaller components, including gases, liquids (like pyrolysis oil or heavy fuel oil), and carbon black, all without ignition. For example, during waste tire pyrolysis, oxygen would cause quick burning of the tires, resulting in a sudden temperature rise. Such an event might harm the pyrolysis equipment and release toxic gases including sulfur dioxide and nitrogen oxides, leading to serious environmental pollution. Oxygen-free pyrolysis, however, permits a slow decomposition of waste tires at a more stable and manageable temperature, yielding valuable items like carbon black, steel wire, and fuel oil.

Managed Breakdown

In pyrolysis, heat severs chemical bonds without oxygen, causing organic substances to split into basic compounds. This managed process produces helpful byproducts such as syngas (containing hydrogen, carbon monoxide, and additional gases), pyrolysis oil, and carbon black, suitable for energy production, chemical uses, or soil improvement. Different from combustion's fast and unmanaged reaction, pyrolysis takes place in a monitored setting. By adjusting factors like temperature, heating speed, and time of exposure, operators can fine-tune the breakdown to boost the amount and quality of target products.

Prevents Oxidation

Oxygen may interact with organic substances, causing oxidation that changes the makeup of the results. Without oxygen, pyrolysis follows non-oxidative routes, maintaining the needed traits of the outputs. Oxidation typically forms oxygen-based compounds like carboxylic acids, ketones, and aldehydes, which might not fit the planned uses for pyrolysis results. In anaerobic pyrolysis, keeping oxygen out blocks these undesired oxidation effects.

Comparison of pyrolysis and combustion

Better Energy Use

Pyrolysis works to be an efficient energy process that increases the output of practical products. Adding oxygen would cause partial burning, which cuts down on efficiency and the amount of wanted products. Burning uses some of the organic material to generate heat, potentially decreasing the process's overall energy effectiveness. Anaerobic pyrolysis, by comparison, reduces energy waste by directing thermal energy toward bond breaking instead of supporting burning. This leads to greater production of useful items. For instance, in breaking down waste plastics, an oxygen-lacking setup supports a more effective change of plastic into syngas and pyrolysis oil, which can be processed into vehicle fuels or chemical raw materials.

DOING pyrolysis equipment environment protection devices

Applications of pyrolysis oil

Comparison to Other Waste Handling Approaches

When set against common waste handling like combustion, anaerobic pyrolysis provides multiple benefits. Combustion can process high volumes of waste and produce power, but it generates fly ash and dioxins that are hard and expensive to manage. Emissions from combustion might also include dangerous pollutants needing strict controls. Anaerobic pyrolysis, conversely, creates purer gases and liquids, with solid leftovers that can be reused, offering a more eco-friendly way to convert waste. As an example, carbon black from pyrolysis serves in making tires and other rubber goods, while pyrolysis oil can be turned into diesel or gasoline, serving as a reliable option to typical fossil fuels.

Pyrolysis carbon black usages

To wrap up, pyrolysis skips oxygen because it seeks to thermally break down substances in a regulated setup to generate targeted chemical outputs, not to burn them. Excluding oxygen keeps the process from combusting and improves the production of helpful byproducts.

DOING pyrolysis equipment manufacturer

For further details on pyrolysis, or to explore pyrolysis equipment, feel free to reach out. DOING Company, a reliable pyrolysis equipment producer, provides full support such as design, setup, and post-sale care. We focus on tailored options for waste management, aiding clients in effective recycling. Our knowledge and focus on reliability help customers make the most of anaerobic pyrolysis methods.