CAN PLASTIC WASTE BECOME THE NEW UPSTREAM?

The short answer is yes, we are getting closer to this reality and the ambitions are now more achievable and sustainable in terms of technology developments, industry collaborations and scaling up to commercial operations.

According to public domain statistics, more than 8 billion tons of plastic has been produced globally sine the 1950’s. More than half of this went straight to landfills, while only about 9% of it has been recycled properly, and by properly we mean either, the mechanical, or chemical method and not direct incineration and utilization because burning solid carbon-based polymers is the least environmentally friendly option available.

Plastics are an important part of modern life - we couldn’t exist the way we do without these polymer advancements however, global plastics pollution is an undeniable fact, and we cannot live in a 100% plastic-free environment. The global pandemic fuelled the necessary production of single-use medical grade polymers, but how will we manage this waste? The answer can be summarized using the three fundamental R’s of waste management practices: Reduce, Reuse, Recycle.

Reducing and Reusing plastic products must be ingrained in the minds of future generations - from kindergarten to school and university, we must instill the fundamentals to build a responsible global community.

Refineries and their associated facilities can play an important role in the third and final R - Recycling, but once again, we need society to play its part by sorting the plastic waste properly to ensure the correct recycling technology is applied to the correct batch of waste. For example, food-grade PET bottles can be recycled mechanically, many times in just a few steps - collecting, washing, smelting, peletising and then that feedstock is re-usable for injection molding of new drinking bottles. PP products can also be mechanically recycled, however as with PET, the plastic waste must come from homogeneous sources to ensure consistent grade quality of the secondary raw material.

In reality, most of the plastic waste ends up as a pile of mixed and varied grade polymers, which are not suitable for mechanical recycling and incineration is not an option due to the various chemical elements found in them. For example, the PVC compound has a Chlorine molecule in its structure which is highly toxic if burned and released into the atmosphere, together with the rest of the flue gases.

In reality, most of the plastic waste ends up as a pile of mixed and varied grade polymers, which are not suitable for mechanical recycling and incineration

The solution for mixed plastic waste is to chemically convert them, back into a synthetic, reverse-engineered/depolymerised, crude-like feedstock which can be further processed within an integrated refinery. This sounds simple, but depending on the technology, there are always challenges that need to be solved, before and during processing of the feedstock.

One example of a solution to such a challenge is Austrian energy company OMV’s proprietary technology, ReOil. You need around 400 °C in a typical refinery to smelt mixed polymers however, this smelted feedstock is highly viscous and cools down quickly, which can cause critical issues to the typical refinery flow systems. The solution for high-viscous flows is to inject and mix them with an organic solvent, in proportions that will result in achieving an overall, lower viscosity of the feed. Once the feed is pre-treated that way, it is suitable for rectification and further purification, while the solvent can also be recovered during the process and reused for processing of the next batch of plastic waste.

Another example is the recent collaboration between PLASTIC ENERGY and AXENS. PLASTIC ENERGY provides the processing technology, Thermal Anaerobic Conversion (TAC) which produces TACOIL, a recycled oil that, when purified by AXENS proprietary technologies, can be used in petrochemical plants to produce clean ethylene and propylene.

Written by: Miro Cavkov , Technical Director - Downstream & Energy, Euro Petroleum Consultants

Like what you read??Subscribe to?Shaping Downstream ?to receive first-hand insights, reports and interviews at the pulse of the global oil and gas downstream industry!??