HDC Pitch Pelletization Using Polymer Additives

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Solution Overview

Problem

Slurry HDC pitch is challenging to handle due to its high metals content and high Conradson carbon residue, leading to storage, shipping, and stability issues, and requires further processing to achieve a suitable softening point for pelletization without altering the slurry HDC process or impacting product slate.

Innovation Solution

A small amount of polymer additive, such as polyethylenes, polypropylenes, or polycarbonates, is mixed with the HDC pitch to increase its softening point, allowing for the production of solid pellets with a softening point of at least 65°C (150°F) to 93°C (200°F), enhancing transportation capabilities without affecting the slurry HDC process or product slate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the softening point of HDC pitch is increased by deep cuts and high initial boiling points, then the softening point is improved, but the slurry HDC process conditions must be altered which adversely impacts the product slate

Engineering Contradiction:
Improvesoftening pointVSAvoidproduct slate
Core Design Contradiction:
TemperatureVSAdaptability or versatility

Solution Approach 1:

A polymer additive is introduced as an intermediary substance that modifies the softening point of HDC pitch without requiring changes to the slurry HDC process conditions. The polymer additive acts as a mediator between the pitch molecules, increasing intermolecular forces and thereby raising the softening point while leaving the original hydroconversion process intact and the product slate unchanged.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The softening point parameter of HDC pitch is modified by adding a polymer additive with specific molecular characteristics. This changes the physical-chemical parameters of the pitch system through compositional modification rather than process parameter changes, allowing the softening point to be increased to at least 65°C (150°F) or 93°C (200°F) without affecting the slurry HDC operation.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If liquid pitch is fluxed to be sold or used as fuel oil, then the pitch can be utilized, but it cannot be fluxed economically with a reasonable amount of flux and may contain solids preventing fluxing

Engineering Contradiction:
Improvefluxing capabilityVSAvoidamount of flux required
Core Design Contradiction:
Ease of manufactureVSQuantity of substance

Solution Approach 1:

The invention transforms the pitch from a difficult-to-handle liquid requiring expensive fluxing into a free-flowing solid pellet that requires no fluxing. The polymer additive enables the pitch to be pelletized directly, eliminating the need for economic fluxing operations and associated costs.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Ease of operation

If pitch is pelletized without sufficient softening point, then transportation is enabled, but agglomeration occurs when pellets are subjected to load stresses

Engineering Contradiction:
Improvetransportation capabilityVSAvoidresistance to agglomeration
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The softening point parameter is increased through polymer additive incorporation, ensuring that the pellets maintain structural integrity at transportation temperatures. The modified thermal properties prevent agglomeration under load stresses while enabling free-flowing characteristics during transport.

Inventive Principle:
Principle #35Parameter changes

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 effectively increases the softening point of HDC pitch pellets, ensuring they remain free-flowing during transport and offering a higher heating value than petcoke or coal, making them a suitable alternative for fuel, while maintaining the integrity of the slurry HDC process and product slate.

Implementation Method 1

a small amount of a polymer additive to increase the softening point of the slurry HDC pitch

Methodology Applied
Scientific EffectSoftening point increase through polymer addition:

Implementation Method 2

mixing the stream of HDC pitch with the stream of polymer additive to produce a mixture of HDC pitch and polymer additive

Methodology Applied
Scientific EffectMixing:

Implementation Method 3

pelletizing the mixture of HDC pitch and polymer additive to produce pellets having a softening point of at least 65°C (150°F)

Methodology Applied
Scientific EffectPelletization:

Data Source

PatentEP3010999B1Methods for slurry hydroconversion pitch disposition as solid pellets
Publication Date: 2019.11.20 EXXONMOBIL TECHNOLOGY & ENGINEERING CO
  • EP3010999B1 patent drawingFigure 1

AI summary

A system and method for producing solid pellets from a slurry HDC pitch is disclosed which utilizes a polymer additive that is mixed with the pitch to increase the softening point of the solid pellets.