Tire Pyrolysis Base Oil Hydroprocessing for Low-Sulfur Quality

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Solution Overview

Problem

Existing methods for preparing base oil from tire pyrolysis oil (TPO) fail to meet commercial criteria for sulfur content, appearance, and aniline point, and often contain high acidity and oxygen, which affect the oil's performance and stability.

Innovation Solution

A method involving a hydroprocessing step with hydrotreatment and distillation, optionally followed by catalytic dewaxing and hydrofinishing, is used to produce a base oil with sulfur content below 1%, aniline point above 50°C, and minimal aromaticity, using base metal catalysts without noble metals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If tire pyrolysis oil is used as base oil after simple distillation, then the process is simple and fast, but the sulfur content is high (1.58 wt %) and the appearance is dark-brown with strong acrid smell

Engineering Contradiction:

Improvebase oil production speedVSAvoidsulfur content and appearance quality

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent extracts harmful components (sulfur, aromatics, acidity) from tire pyrolysis oil through sequential hydroprocessing steps including hydrotreatment and hydrodesulfurization, achieving sulfur content below 1.0 wt% while maintaining production efficiency

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes process parameters by conducting hydroprocessing at controlled temperatures (290-370°C) and pressures (50-170 bar) with specific liquid hourly space velocities (0.4-2.0 h−1) to transform the chemical composition of base oil fractions, improving appearance and reducing harmful components

Inventive Principle:

Principle #35Parameter changes

2Quantity of substance

If tire pyrolysis oil is used as base oil with minimal processing, then the biogenic carbon content is high, but the aniline point is low (18° C.) indicating high aromaticity which is not commercially acceptable

Engineering Contradiction:

Improvebiogenic carbon contentVSAvoidaniline point and aromaticity control

Core Design Contradiction:

Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent replaces simple mechanical distillation with chemical hydroprocessing methods that selectively modify aromatic compounds through hydrogenation reactions, raising the aniline point above 50°C while preserving biogenic carbon content of at least 1%

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses composite catalyst systems comprising base metal catalysts (nickel, cobalt, iron, or manganese) supported on alumina or silica-alumina, combining multiple functional properties to achieve simultaneous aromatic saturation and sulfur removal

Inventive Principle:

Principle #40Composite materials

3Object-generated harmful factors

If tire pyrolysis oil undergoes extensive hydroprocessing to reduce sulfur and improve appearance, then the sulfur content decreases below 1.0 wt %, but the process complexity increases with multiple hydroprocessing steps

Engineering Contradiction:

Improvesulfur content reductionVSAvoidhydroprocessing process complexity

Core Design Contradiction:

Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent merges multiple hydroprocessing functions (hydrotreatment, hydrodesulfurization, aromatic saturation) into a single integrated reactor system operating under unified conditions, simplifying the process while achieving sulfur content below 1.0 wt% and aniline point above 50°C

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent employs a universal base metal catalyst system that performs multiple functions simultaneously including sulfur removal, aromatic hydrogenation, and acidity reduction, eliminating the need for separate treatment stages

Inventive Principle:

Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method produces a stable, naphthenic base oil with biogenic carbon content, low viscosity, and improved low-temperature properties, avoiding hydrodeoxygenation and maintaining biogenic carbon content while meeting commercial standards.

Implementation Method 1

subjecting a tire pyrolysis oil to a hydroprocessing step comprising a hydrotreatment step, so as to obtain a hydroprocessed tire pyrolysis oil, wherein the hydrotreatment step is carried out at a pressure within the range of 50-170 bar, a temperature within the range of 290-370° C., and a liquid hourly space velocity within the range of 0.4-2.0 h−1 in the presence of a base metal catalyst

Methodology Applied

Scientific EffectCatalysis: Catalysis

Implementation Method 2

distillation of the hydroprocessed tire pyrolysis oil obtained from the hydroprocessing step so as to obtain at least two fractions, thereby obtaining a base oil as at least one of the fractions

Methodology Applied

Scientific EffectDistillation: Distillation

Data Source

PatentUS20250354066A1Method of preparing a base oil from tire pyrolysis oil and a base oil obtainable using the method

Publication Date: 2025.11.20 NYNAS

AI summary

A method of preparing a base oil from tire pyrolysis oil (TPO), and a base oil obtainable by means of the method exhibiting a biogenic carbon content as measured by ASTM D6866 of at least 1% by weight, a viscosity index (VI) of no more than 110 and containing no oxygen are described.