(147b) Hydro-PRT - the Differentiated Plastic Waste Recycling Technology from KBR | AIChE

(147b) Hydro-PRT - the Differentiated Plastic Waste Recycling Technology from KBR


Increasing global production and consumption of plastics is leading to accumulation of waste plastic in landfills and the environment, leading to societal, ecological and economic imbalances.

Advanced recycling technologies such as KBR’s Hydro-PRTSM process end-of-life and contaminated plastic waste, that can be further refined to produce virgin polymers and chemicals. KBR's Hydro-PRT is a differentiated, stable and scalable technology, based on a unique patented process using supercritical water to convert plastic waste into commercial products that can be used to produce new polymers delivering a truly circular economy.

The uniqueness of Hydro-PRT process offers following advantages:

High-product yields: no char or unwanted by-products, combined with the ability to control reaction conditions contribute to high liquid products yields.

Feedstock versatility: ability to process mixed composite polymers, flexible and rigid plastics and insensitivity to organic contaminants such as paper, card and biomass means the Hydro-PRT process can process a wider range of waste plastic feedstock than other competing technologies.

Scalability: direct heat transfer between the plastic and the heating medium (supercritical water) leads to an efficient heat transfer mechanism. Scale up is a simple process, not affected by heat transfer considerations.

Product stability: the water surrounding the plastic in the hydrothermal reactors acts as a suppressant to unwanted free radical reactions giving a higher yield of a far more consistent, stable product.

Product quality: the distillation of products allows for ready separation of fine solids and particulates into the heavy wax residue and water from the naphtha fraction. This provides high quality product oils (naphtha, distillate gas oil and heavy gas oil) with low solids and water content. Low chloride content, with most chlorides partitioning to the water phase rather than product oils.

Thermal efficiency: the process operates at lower temperatures requiring lower thermal energy input and the product gas can be reused in the process boiler to generate the supercritical steam providing a highly energy efficient process.

Operational flexibility: Hydro-PRT has a high degree of process control allowing products with different distillation ranges to be produced. Operators can bias products by operating parameters and blend of plastics in the feedstock.

Modular Offering: a modular offering of the technology brings cost and schedule benefits to any project.

Well-studied and demonstrated technology: the technology has been successfully demonstrated on pilot scale since 2014. A 20 thousand ton per year commercial scale plant utilizing Hydro-PRT is under design and construction by ReNew ELP in Wilton, UK. Using end-of-life plastic as feedstock, this plant will produce liquid hydrocarbon cracker feedstock alongside intermediate products. This plant will eventually process over 80 thousand tons of plastic waste feedstock per year and is scheduled to start-up in 2022.

Hydro-PRT provides clear environmental benefits:

- independent studies have demonstrated that advanced recycling technologies such as Hydro-PRT can reduce CO2 emissions by 1.5 tons for every ton of plastic waste processed when compared to incineration.

- utilizing Hydro-PRT process to recycle plastics into new polymers leads to reduction in the use of fossil-sourced feedstocks.

- when recycling plastics waste via the Hydro-PRT process, minimal waste is produced -- impurities (colorants, additives, fillers etc.) in the plastic feedstock fall out into the heavier hydrocarbon feedstocks, which can be used in construction.

Benefits for business include reaching sustainability goals, developing sustainable infrastructure and reducing emissions and environmental footprint.

Hydro-PRT products resemble natural gas and oil with key applications ranging from making sustainable fuels to being refined into truly circular monomers, like ethylene.

The products, separated into fractions of choice based on their boiling points, are suitable for further processing in different types of crackers.