As the global plastic pollution problem becomes increasingly serious, plastic recycling has become an important issue around the world. Among the many recycling methods, the technology of converting waste plastic into naphtha can not only effectively reduce plastic pollution. In addition, this solution can provide high-value chemical raw materials and energy. Thus, it provides new possibilities for the circular economy. Read on to discover how to extract naphtha from waste plastic.
What is Naphtha?
Naphtha is a mixture of light hydrocarbons (boiling point 30-220℃). It is a key raw material for the petrochemical industry. Traditional naphtha extraction methods usually rely on fossil fuels.
However, with the increasing demand for sustainable development, more and more research has begun to explore the possibility of producing naphtha from non-fossil resources such as waste plastics. Converting plastics into naphtha through pyrolysis & distillation technology provides a greener solution for naphtha production.
Plastic to Naphtha Processing: Pyrolysis to Distillation
Catalytic Pyrolysis of Plastic
Plastic catalytic pyrolysis is a process that heats waste plastics to high temperatures and decomposes them into smaller hydrocarbon molecules under the action of a catalyst. This process is mainly achieved by pyrolysis equipment, and the following are the key steps.
Polymer Chain Scission
The main components of plastics are long-chain polymers, such as polyethylene, polypropylene, and polystyrene. During the catalytic pyrolysis process, the high-temperature micro-oxygen environment will break the molecular chains of the polymers. The macromolecular polymers are broken into a series of short-chain hydrocarbons, which mainly exist in the form of oil and gas.
Catalyst Action
The catalyst can not only promote the cracking reaction in the reaction, but also inhibit the formation of high-boiling and viscous wax oil. This improves the fluidity and availability of oil and gas. In addition, the catalyst can optimize the plastic to oil process at a lower temperature and in a short time. This reduces incomplete cracking and improves the quality of plastic pyrolysis oil.
Pyrolysis Oil Formation
During the cooling process of pyrolysis oil and gas, the condensable components (mainly C5-C12 hydrocarbons) will condense and convert into liquid oil. This process is actually achieved through a condensation system. After exchanging heat with cooling water, hydrocarbon molecules gradually aggregate into liquid due to intermolecular interactions to form pyrolysis oil.
Pyrolysis Oil Distillation
Distillation is the process of further separating and purifying plastic pyrolysis oil. This process is mainly completed by distillation equipment. The specific steps are as follows:
Heating Process
In the distillation tower, the pyrolysis oil is heated to a gaseous state. Different components (naphtha, diesel, heavy oil, etc.) condense at different heights in the distillation tower according to their boiling points.
Fraction Cutting
Through temperature control, the distillation tower separates the hydrocarbon molecules in the pyrolysis oil into different fractions. Naphtha is the part with a boiling point in the range of 30℃-220℃.
Separation and Cooling
The low-boiling point components are condensed first to obtain light naphtha, which is mainly composed of alkanes, cycloalkanes, and aromatics. Through cooling and separation, naphtha is finally obtained.
Wide Application of Naphtha
Chemical Raw Materials
Naphtha is a key raw material for producing basic chemicals like ethylene and propylene, which are the most common building blocks for various plastics (such as polyethylene and polypropylene), synthetic fibers, and rubber. The hydrocarbon components in naphtha undergo catalytic cracking to produce ethylene and propylene. These chemicals then serve as essential ingredients in manufacturing a wide range of products for industrial applications.
Solvents
Naphtha has excellent dissolving power. It is often used as paint, coating, cleaning agent and industrial solvent. In particular, it has excellent dissolving properties for those chemicals with poor water solubility, such as resins, paints, inks, etc. During manufacturing of coatings and paints, naphtha can help dissolve and dilute viscous substances. In addition, naphtha as an industrial cleaning agent can remove oil stains, dirt, pollutants on metal surfaces, etc.
Gasoline Blending Component
Naphtha has a low octane number and good volatility. Therefore, it can improve the stability, combustion efficiency and low-temperature starting performance of gasoline. By blending naphtha with other gasoline components, such as high-octane components, high-performance gasoline can be produced. In addition, naphtha blending components can enhance the anti-knock properties of gasoline. This reduces engine knocking and improves combustion efficiency. This improves vehicle power output and fuel economy.
Kerosene & Fuel Oil Production
The energy density and stability of naphtha make it an ideal alternative fuel source. The hydrocarbon compounds in naphtha produce kerosene and jet fuel, which are widely used in aviation, shipping, and other industrial fields. Naphtha serves as a raw material for aviation kerosene and jet fuel. Its high-quality components ensures safe and efficient operation of aircraft. Additionally, naphtha can also produce other types of fuel oil, such as fuel for power plants, industrial boilers and large industrial equipment.
Advantages of Using Plastics to Produce Naphtha
Sustainability
- Waste Plastic Recycling: Converting waste plastics into naphtha reduces the pollution of plastic waste to the environment.
- Source of Green Raw Materials: Recycled naphtha can be reused to produce basic chemicals. This reduces dependence on oil resources.
- Reduce Carbon Emissions: The pyrolysis process of waste plastics is relatively low-carbon. This helps the low-carbon transformation of the plastics industry.
- Circular Economy: Achieve a closed loop of “waste plastics → naphtha → new plastics”. This promotes the recycling of plastic production.
High Economic Value
- Increase Market Demand: Green naphtha is environmentally friendly and sustainable, and market demand is gradually increasing.
- Replace Fossil Fuels: Green naphtha reduces dependence on traditional fossil fuels and has cost advantages.
- Environmental Policy Support: With the advancement of environmental policies, the economic value of green naphtha in the market has gradually increased.
- Multiple Uses: It can be used to make plastics, solvents, fuels, etc., which broadens the application field and creates more economic returns.
From Plastic Waste to Naphtha: A Greener Path to Sustainability
Converting waste plastics into naphtha through pyrolysis and distillation is an important step in solving the global plastic pollution crisis. As the world continues to seek sustainable solutions, converting plastic waste into valuable resources will play a key role in shaping the future of global industry and the health of the planet. If you are interested in this project, Beston Group provides the corresponding equipment and solutions. Welcome to contact us.
