Tire-derived Oil Shows Potential As An Advanced Fuel Pool Component

This article gives an overview of recent development trends regarding options for upgrading the tire-derived oil (TDO) with chemical and physical techniques.

Pyrolysis processes are an efficient, viable and sustainable approach for converting end-of-life tires (ELT) into oil, value-added gas and recovered carbon black (rCB).  Advances in industrial scale production, including product quality, production efficiency, operational costs, capital investment, and tipping fees, have allowed ELT pyrolysis to prove itself as technically mature and economically viable.

Besides being a valuable feedstock, TDO is an attractive source of renewable energy. Waste tires contain a fraction of biogenic carbon that mainly comes from their natural rubber content, allowing the tire-derived pyrolysis liquids (TDO) to be specified as advanced fuel pool components.

Raw waste tire-derived pyrolysis liquids are limited by a number of properties including their distillation characteristics, proportion of compounds having boiling point over 360°C, flash point, cetane number, density, PAH content, sulfur and chlorine content, storage stability, combustion properties and more. The presence of micro-carbon particles in the pyrolysis oil can also cause erosion or corrosion problems in engines.

Thus, the pre-treatment of pyrolysis feed and upgrading of raw tire-derived-oils (TDO) with chemical and physical techniques are being explored to further enhance the TDO properties.

Current options for upgrading TDO  found that distillation/fractionation can enhance general properties of raw TDO, namely: density, viscosity, heating value and flash point. Desulfurization, hydrotreating has been found to reduce sulphur, chlorine and water content, while hydro-denitrification removes nitrogen compounds.

However,  commercializing these upgrading processes is still in its infancy. There is a distinct lack of clarity on TDO quality gate limits for refineries. Also, there is no exact input data for TDO fractionation. Without these clear targets, financiers and investors become hesitant to invest without knowing how the products will comply with refinery criteria.

The article recommends a “round table”  with stakeholders in the ELT pyrolysis industry and potential buyers of TDO fractions to develop uniform standards and gate limits. The ASTM D36 committee on recovered Carbon Black could serve as a good example, the article concludes.

Weibold Academy article series www.weibold.com periodically discusses practical developments and scientific research findings in the ELT recycling and pyrolysis industry.

© Scrap Tire News, October 2021