As we all know, plastic is a waste that has threatened human health and the environment. Currently, many countries have pushed out the “plastic ban” in the world. But, there is still a huge amount of plastic production every year. A statistic shows that the worldwide production of plastics reached a staggering 390.7 million metric tons in 2021. Plastic recycling is a problem that needs to attract people’s attention.
What Plastics Are Made Of?
The raw materials used to make plastic are derived primarily from petrochemicals. Here, we will list the ingredients for making traditional petrochemical-based plastics:
- Crude oil: It is the primary source of petrochemicals used in plastic production. Through refining, various hydrocarbons -ethylene and propylene are exacted from the crude oil. They are key raw materials to form many types of plastics.
- Natural gas: Ethane and propane are extracted from natural gas. They are also important feedstocks for the production of plastics.
- Coal: Coal can be used as a raw material to produce certain chemicals that serve as intermediates in the plastic manufacturing process.
What Are the Kinds Of Plastics?
Acrylic or Polymethyl Methacrylate (PMMA)
Acrylic is a general term that refers to a group of synthetic resins or plastics derived from acrylic acid. PMMA is a specific type of acrylic. Acrylic is a transparent thermoplastic used as a lightweight, shatter-resistant alternative to glass. Also, it has applications in products like optical lenses, signage, aquariums, and various household items.
Because of tough, stable, and transparent, Polycarbonate is an excellent plastic. Its clearness is the same as glass and its strength is two hundred and fifty times stronger than glass. Polycarbonate plastic sheets can be cut or cold-formed on-site without pre-forming and fabrication. Polycarbonate plastic is in a wide variety of products including greenhouses, DVDs, sunglasses, police riot gear, and more.
Polyethylene is the most common plastic that has varying densities. Different densities of polyethylene are suitable for making different final plastic products. Here, we list them for your reference:
- Low-density polyethylene: It has good ductility that is suitable for making products: shopping bags, plastic bags, clear food containers, disposable packaging, etc.
- Medium-density polyethylene: It is typically fit for making gas pipes, shrink film, carrier bags, screw closures, and more.
- High-density polyethylene: It is used in products such as plastic bottles, piping for water and sewer, snowboards, boats, and folding chairs.
Polypropylene (PP) is a thermoplastic polymer that is widely used in various applications due to its versatile properties. It has many features: lightweight, high melting point, resistance to moisture, high tensile strength, flexibility, chemical resistance, transparent or translucent, and recyclability. Here, we list the common usages of PP for you.
- Packaging: PP is widely used in the packaging industry for the production of containers, bottles, caps, and films.
- Textiles: It is used in the textile industry for applications such as carpets, ropes, and fabrics.
- Automotive Parts: PP is used in the manufacturing of automotive components like bumpers, interior trims, and battery cases.
- Medical Applications: PP is used in medical devices and packaging due to its chemical resistance and sterilizability.
- Household Goods: Many household items, including containers, utensils, and furniture, are made from PP.
- Stationery and Office Supplies: PP is used in the production of folders, binders, and other stationery items.
- Fibers: PP fibers are used in non-woven fabrics for applications such as diapers, filters, and geotextiles.
Polyethylene Terephthalate (PET)
Polyethylene Terephthalate (PET) is also a type of thermoplastic polymer. Here, we list some characteristics and applications for your reference:
- Higher transparency: PET is transparent and commonly used for clear containers and bottles.
- Mechanical Properties: PET bottles have good impact resistance but may be more prone to cracking than PP.
- Temperature Resistance: PET can soften at a lower temperature than PP, limiting its use in high-temperature applications.
- Chemical Resistance: PET has good chemical resistance but may be affected by certain solvents.
- Applications: Predominantly used in the production of clear plastic bottles for beverages and food packaging; Used in the textile industry for polyester fibers.
Polyvinyl Chloride (PVC)
Polyvinyl Chloride, commonly known as PVC, is a versatile and widely used thermoplastic polymer. It has high density, high durability, transparent or opaque, rigid or flexible, good tensile strength, dimensional stability, impact resistance, chemical resistance, flame resistance, electrical insulation, and so on. Here are the key and uses of PVC:
- Construction and Building Materials: PVC is widely used in pipes, fittings, and conduits for plumbing and electrical applications; It is used in window frames, doors, siding, and roofing materials.
- Electrical Applications: PVC is used for insulation and sheathing in electrical cables and wires.
- Automotive Applications: PVC is used in automotive interiors, such as dashboard covers and door panels.
- Medical Devices: PVC is used in medical tubing, bags, and containers due to its chemical resistance.
- Packaging: PVC is used for blister packaging and clamshell containers.
- Clothing and Footwear: Flexible PVC is used in the production of clothing, footwear, and accessories.
- Signage and Banners: PVC sheets are used for signs, banners, and display applications.
Acrylonitrile Butadiene Styrene, commonly known as ABS, is a thermoplastic polymer with a combination of properties that make it suitable for various applications. It has features of rigid and tough thermoplastic, glossy appearance, good tensile, resistance to abrasion, moderate heat resistance, chemical resistance, and ease of processing. Here are the applications of it:
- Automotive Parts: ABS is used for various automotive components, including interior trim, dashboard panels, and exterior body parts.
- Consumer Goods: It is used in the production of appliances, luggage, toys, and electronic housings.
- Electronics: ABS is commonly used for the housing of electronic devices and components.
- Construction Materials: ABS is used in pipes, fittings, and profiles for construction applications.
- Medical Devices: ABS is employed in the production of medical devices and equipment.
- 3D Printing: ABS is a popular material for 3D printing due to its ease of printing and post-processing.
- Prototyping: ABS is commonly used for rapid prototyping in product development.
What Are the Hazardous of Plastics?
Plastics can pose various environmental and health hazards throughout their life cycle, from production to disposal. Some of the key hazards associated with plastics include:
- Marine Pollution: Improper disposal of plastics, especially single-use items like bottles and bags, can lead to marine pollution. Large amounts of plastic waste end up in oceans, harming marine life and ecosystems.
- Microplastics: Plastics can break down into tiny particles called microplastics, which can contaminate soil and water. Microplastics have been found in oceans, rivers, and even in the air, posing risks to wildlife and potentially entering the food chain.
Chemical Additives: Some plastics contain additives, such as plasticizers, flame retardants, and stabilizers, which can leach into the environment. These additives may be harmful to human health and the environment.
- Chemical Exposure: Plastics can release chemicals, especially when exposed to heat or sunlight. For example, some plastic containers may release harmful substances into food or beverages.
- Endocrine Disruption: Certain chemicals in plastics, such as bisphenol A (BPA), have been linked to endocrine disruption, potentially affecting hormonal balance and reproductive health.
Greenhouse Gas Emissions
Production and Incineration: The production of plastics, particularly from fossil fuels, contributes to greenhouse gas emissions. Incineration of plastics can release toxic pollutants into the air.
Fossil Fuel Dependency: The production of many plastics relies on fossil fuels, contributing to resource depletion and dependence on non-renewable resources.
Waste Management Challenges
- Landfill Issues: Plastics contribute significantly to landfill waste, and their slow decomposition can occupy valuable space in landfills.
- Recycling Challenges: Many types of plastics are challenging to recycle due to contamination, lack of infrastructure, and limited markets for recycled materials.
Ingestion and Entanglement: Wildlife, especially marine animals, may ingest or become entangled in plastic debris, leading to injury or death.
Aesthetic and Visual Impact
Litter and Aesthetics: Improperly disposed plastics contribute to litter, affecting the visual appeal of natural landscapes and urban areas.
Efforts are being made globally to address these hazards, including initiatives to reduce single-use plastics, improve recycling systems, and develop alternative materials. Individuals and communities can also contribute by practicing responsible plastic use, recycling, and supporting policies that promote sustainable plastic management.
How To Turn Plastic Into Oil? – Pyrolysis Solution
Pyrolysis is the chemical decomposition. Plastic pyrolysis technology is a thermal degradation process in the absence of oxygen. With the temperature rising, plastic waste begins to decompose into smaller molecules. And, finally, you will get pyrolysis oil from plastic. Here, I will share the detailed processes for you:
- Collection of plastic waste: Gather various types of plastic waste;
- Sorting and shredding: Separate different types of plastic based on their polymer composition; Shred the plastic into smaller pieces to increase the surface area for the pyrolysis process.
- Pyrolysis reactor: Feed the shredded plastic into a pyrolysis reactor; Heat the plastic to high temperatures (usually between 280 to 350 degrees Celsius) in the absence of oxygen.
- Vaporization and condensation: The high-temperature oil gas enters the mainfold that is to separate sludge oil from oil gas. Here, the heavy components are liquefied and stored in the oil tank. Light oil gas will rise into the oil condenser being liquefied and go into the oil tank. That is the pyrolysis oil. The un-condensable gas is purified and stabilized by hydroseal, one part will be recycled to heat the reactor, and another part will be burned out in the waste combustion chamber or reserved in an airbag to use later.
Acceptable Plastics For Pyrolysis and Oil Yields
Not all kinds of plastic can be pyrolyzed to oil. Here, we list acceptable plastics and oil yields for you. You can compare the data to choose your plastic pyrolysis recycling solution.