Why Is Plastic Hard to Recycle?

Plastics are not pure. In meeting the unique requirements for an array of applications, different types of plastic and additives are often combined in precise recipes to provide the characteristics desired. Separating these different mixes is impossible. When melted together as it is in mechanical recycling to produce pellets, the plastic produced no longer has those unique characteristics and cannot used for certain applications. When you add in colour and waste contamination (such as food) the problem becomes much worse. Mechanical recycling, however, is an ideal solution for relatively pure and easily segregated wastes such as PET drinks bottles or rigid HDPE.

 

What Is Pyrolysis?

Pyrolysis is the heating of a substance without the presence of oxygen to create conditions for cracking. Cracking is the subdivision of a long chain molecule into smaller pieces. When applied to plastic the process will produce gas, oil and carbon with ash. Pyrolysis oil has long been considered a potential substitute for crude oil or even diesel but has failed thus far to meet acceptance in industry.

 

Why Can't a Refinery Use Pyrolysis Oil?

They can, but only in very small quantities. The problem a refinery faces is that pyrolysis oil can cause severe damage to equipment. Pyrolysis oil itself is highly reactive and re-polymerises to form gums during heating or storage which fouls equipment and causes blockages. Often, pyrolysis oil also contains solids which can be damaging to equipment, especially engines. Of real concern are heteroatoms such as chlorine or metals. These can cause severe corrosion in chemical plant and poison catalysts.

 

What Is Different Between Pyrolysis Oil and Crude Oil?

While on first glance they look similar, there are in fact some significant chemical differences. Crude oil has stabilised over millennia to form a stable and consistent composition. Pyrolysis oil is different in that is contains still chemically reactive species such as olefin and di-olefin. In addition, there are elements that do not exist in crude oil such as chlorine, which present specific challenges when processing. Also, depending on the plastic type put into the reactor, the oil can have a different chemical make-up from one day to the next, making it hard for a large refinery to depend on.

 

Why Is Refiniti Unique?

Refiniti utilises proprietary and patented processes to refine pyrolysis oil from any reactor technology to create recycled hydrocarbons of unparalleled quality. We produce oil with stability for atmospheric fractional distillation, long term storage and catalyst processes. Nobody else can do this. 

 

 

What Is the Circular Economy?

Finite resources mean that our current economic system is unsustainable in the long term. A circular economic model would replace the current ‘take-make-consume-waste' extractive industrial model found in all developed economies. Supported by a transition to renewable energy sources, the circular model is based on minimising waste and pollution, keeping products in use and regenerating natural systems. Mere adjustments won't make a circular model possible. Rather, a systemic transformation would be required to build long term resilience that would bring environmental, societal and business benefits. The world's population continues to grow, as does the demand for raw materials. Moving to a circular economy may not only reduce carbon emissions, it could stimulate innovation, boost growth and increase competitiveness.

 

How Are Plastics Made?

Plastics consist of synthetic polymers that are constructed from carbon and other elements. A process called cracking converts crude oil and natural gases into hydrocarbon monomers such as ethylene, propylene, styrene, vinyl chloride and ethylene glycol. These substances are then mixed with other chemicals. These could be plasticisers like phthalates to make PVC soft, or butadiene to make plastic strong. Additional additives will also be added to improve light, colour and friction. The material is then cast, spun and fabricated to produce the final shape and form of the plastic.

 

Chemical Recycling, Advanced Recycling, Feedstock Recycling – What's the Difference?

Feedstock recycling is also known as chemical recycling, or advanced recycling, and refers to the process at which plastics are broken down into monomers and other basic chemical elements (depolymerisation). Low-quality, composite and low economic plastics are typically difficult to recycle, and so feedstock recycling is an excellent solution. The resulting monomers can be used as new material alternatives in manufacturing new polymers. The process for feedstock recycling will include pyrolysis which involves the creation of syngas and liquid fuels through the chemical and thermal decomposition of materials at high temperatures without any oxygen. Gasification is another part of the feedstock recycling and refers to the creation of syngas from the leftover char from pyrolysis, using very high temperatures and minimal oxygen. Hydrogenation also occurs, and is the creation of syncrude (liquid and gaseous) from the use of hydrogen in high temperatures and high pressures.

 

What Are Additives in Plastic?

Additives are used to improve or enhance a polymer, by making it more durable, sustainable or functional. For example, flame retardant additives can be added to plastics to make them safer, which is especially useful in the electric or automotive industries. Additives can also be used to increase the protection that plastic mask and disposable medical masks provide. Although additives have a variety of applications and are cost-effective, research suggests that microplastics are negatively impacting ecosystems. These very small microplastics are being found in food chains, water sources and sewage systems.

 

What Are Contaminants in Waste Plastic?

Different types of plastics (polymer types), biomass (food residual), moisture and additives make plastic recycling an extremely challenging task. Our technology has solved different contamination by making chemical works.

 

What Are Composite Materials?

These are plastics made from more than one type of polymer e.g. crisp packets (aluminium and plastic) or coffee cups (paper and film).

 

What Are Liquid Hydrocarbons?

Liquid hydrocarbons are the unprocessed oily liquids that are extracted from natural gas. Liquid hydrocarbons exist as a gas when held at an atmospheric pressure of 14.7 pounds per square inch. At higher pressures, they will appear as liquids. Most liquid hydrocarbons are formed from natural gas plant processing, however some will occur naturally from drilling operations. Liquid hydrocarbons are also formed in the refining of crude oils or from natural gas separation. Liquid hydrocarbons are typically used in fuels for heating and cooking, as well as transportation fuels and as additives in gasoline.

 

What Are the Uses of Crude Oil?

If you look around you may be surprised by just how many things are made in part from crude oil. It's not just the plastic objects, lubricant and fuels you use everyday, crude oil can be found in paints, varnishes, synthetic carpets as well as clothing and make-up.