Hydrothermal Liquefaction System Staged Pressurization

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Solution Overview

Problem

Existing hydrothermal liquefaction (HTL) systems face challenges in efficiently pressurizing and heating biomass slurries due to high viscosity, requiring robust and expensive equipment that suffers from poor thermal efficiency and high pressure drops.

Innovation Solution

The system pressurizes and heats biomass slurry in multiple discrete steps, adjusting for viscosity changes, using multiple pumps and heat exchangers configured for specific temperature, pressure, and viscosity ranges, reducing the capital cost and improving efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If robust equipment is used to pressurize and heat high viscosity biomass slurry, then the system can handle the viscous feedstock, but the capital cost increases and thermal efficiency decreases

Engineering Contradiction:
Improveability to handle high viscosity slurryVSAvoidcapital cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent divides the single-step pressurization and heating process into multiple discrete steps. The slurry is pressurized in stages (e.g., first to an intermediate pressure, then to final pressure) and heated in stages (e.g., first to an intermediate temperature, then to final temperature). This segmentation allows each pump and heat exchanger to be sized for lower, more efficient operating conditions rather than requiring oversized equipment capable of handling the full viscosity range in one step.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the physical parameters (pressure and temperature) in discrete steps rather than in a single operation. By incrementally increasing pressure and temperature, the slurry viscosity is progressively reduced, allowing subsequent equipment to operate more efficiently. This staged parameter change enables the use of smaller, less expensive equipment while maintaining the ability to process high-viscosity biomass slurry.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If robust equipment is used to pressurize and heat high viscosity biomass slurry, then the system can handle the viscous feedstock, but thermal efficiency decreases due to high pressure drops

Engineering Contradiction:
Improveability to handle high viscosity slurryVSAvoidthermal efficiency
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent segments the pressurization and heating into multiple steps, with each step using equipment sized for the specific viscosity conditions at that stage. This prevents the excessive pressure drops that would occur in a single-step process using oversized equipment, as each heat exchanger operates at more optimal pressure and temperature conditions for heat transfer efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

By changing pressure and temperature parameters in staged increments, the patent maintains the biomass slurry in a state where viscosity is progressively reduced. This allows each subsequent heat exchanger to operate with lower pressure drops and better thermal efficiency, as the slurry becomes easier to pump and heat with each stage.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If single-step pressurization and heating is used, then the system is simpler, but it cannot efficiently handle viscosity changes during the process

Engineering Contradiction:
Improvesystem simplicityVSAvoidpumping and heat transfer efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent uses multiple pumps and heat exchangers arranged in series, with each unit optimized for specific operating conditions. This segmentation allows the system to adapt to changing slurry viscosity as pressure and temperature increase, maintaining efficient pumping and heat transfer throughout the process rather than using a single oversized unit that operates inefficiently across all conditions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

While the system has multiple components, each pump and heat exchanger is designed for a specific operating range, allowing the overall system to handle the full range of viscosity conditions through coordinated operation of specialized units rather than requiring one universal piece of equipment.

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

This approach reduces capital costs by 75% and improves thermal efficiency, allowing for the use of less material in pumps and heat exchangers, and enhances pumping and heat transfer efficiency.

Implementation Method 1

a first heat exchanger in fluid communication with the first pump and configured to heat a biomass slurry stream received from the first pump at the first pressure to a first temperature

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 2

a second heat exchanger in fluid communication with the second pump and configured to heat a biomass slurry stream received from the second pump at the second pressure to a second temperature that is higher than the first temperature

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 3

a third heat exchanger configured to receive the product mixture stream from the HTL reactor to heat a heat transfer liquid

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Data Source

PatentEP4081620B1Hydrothermal liquefaction system
Publication Date: 2025.11.26 BATTELLE MEMORIAL INST
  • EP4081620B1 patent drawingFigure 1
  • EP4081620B1 patent drawingFigure 2~3
  • EP4081620B1 patent drawingFigure 4~5

AI summary

A hydrothermal liquefaction (HTL) system can include a biomass slurry source, a first pump in fluid communication with the slurry source and configured to pressurize a biomass slurry stream from the slurry source to a first pressure, a first heat exchanger in fluid communication with the first pump and configured to heat a slurry stream received from the first pump to a first temperature, a second pump in fluid communication with the first heat exchanger and configured to pressurize a slurry stream received from the first heat exchanger to a second pressure higher than the first pressure, a second heat exchanger in fluid communication with the second pump and configured to heat a slurry stream received from the second pump to a second temperature higher than the first temperature, and a HTL reactor configured to produce biocrude from a slurry stream received from the second heat exchanger.