Hydrodesulfurizer Temperature Control to Prevent Carbon Deposition

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Solution Overview

Problem

Conventional methods for operating hydrogen generators do not effectively suppress carbon deposition onto hydrodesulfurization catalysts in hydrodesulfurizers, leading to potential passage blockages and instability in hydrogen generator operations.

Innovation Solution

A method that involves generating hydrogen-containing gas, removing sulfur compounds using a hydrodesulfurizer heated by the hydrogen generation unit, and only supplying the raw material to the hydrodesulfurizer when its temperature is below a predetermined level to prevent carbon deposition, ensuring the hydrodesulfurizer is cooled or heated appropriately to maintain optimal operating conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the raw material is supplied to the hydrogen generator at a suitable timing in a predetermined temperature range, then thermal decomposition of the raw material is suppressed and carbon deposition onto the reforming catalyst is reduced, but this does not address carbon deposition onto the hydrodesulfurization catalyst in the hydrodesulfurizer

Engineering Contradiction:
Improvecatalyst functionVSAvoidcarbon deposition onto hydrodesulfurization catalyst
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies preliminary action by cooling the hydrodesulfurizer before supplying raw material to it. The control unit cools the hydrodesulfurizer to a predetermined temperature or lower before raw material supply, preventing carbon deposition on the hydrodesulfurization catalyst in advance. This resolves the contradiction by taking preventive action before the harmful effect occurs.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses feedback control by monitoring the temperature of the hydrodesulfurizer with a temperature sensor and adjusting the cooling operation accordingly. The control unit determines whether to perform cooling based on the detected temperature, creating a closed-loop control system that prevents carbon deposition while optimizing energy consumption.

Inventive Principle:
Principle #23Feedback

2Adaptability or versatility

If the hydrogen generator is stopped and restarted frequently to meet energy demand, then distributed energy source flexibility is improved, but carbon deposition occurs on the hydrodesulfurization catalyst during re-starting operations

Engineering Contradiction:
Improvestart-stop capabilityVSAvoidcarbon deposition during re-starting
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

Before re-starting the hydrogen generator, the control unit performs preliminary cooling of the hydrodesulfurizer to a predetermined temperature or lower. This preliminary action prevents carbon deposition that would otherwise occur during re-starting operations, enabling frequent start-stop cycles without catalyst damage.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements dynamic temperature control of the hydrodesulfurizer based on operational status. The cooling operation is dynamically adjusted according to whether the system is starting, stopping, or running, allowing the system to adapt to frequent start-stop requirements while preventing carbon deposition at critical transition moments.

Inventive Principle:
Principle #15Dynamics

3Use of energy by moving object

If the hydrodesulfurizer is heated by heat transferred from the hydrogen generation unit, then energy efficiency is improved, but the temperature may exceed the level that causes carbon deposition when hydrogen generation stops

Engineering Contradiction:
Improveheat utilization efficiencyVSAvoidexcessive temperature causing carbon deposition
Core Design Contradiction:
Use of energy by moving objectVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a cooling unit as an intermediary between the heat transfer from the hydrogen generation unit and the hydrodesulfurizer. When hydrogen generation stops, the cooling unit activates to remove excess heat from the hydrodesulfurizer, preventing temperature from rising to levels that cause carbon deposition while maintaining efficient heat utilization during operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system uses temperature feedback control where the control unit monitors the hydrodesulfurizer temperature and activates cooling when the temperature approaches levels that cause carbon deposition. This feedback mechanism balances heat utilization efficiency with temperature control, preventing harmful effects while maximizing energy efficiency.

Inventive Principle:
Principle #23Feedback

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 effectively suppresses carbon deposition onto hydrodesulfurization catalysts, reducing the risk of pressure loss and ensuring stable hydrogen generator operation by controlling the temperature of the hydrodesulfurizer.

Implementation Method 1

a hydrodesulfurizer configured to remove a sulfur compound from the raw material; a reformer configured to generate a hydrogen-containing gas by causing a reforming reaction of the raw material

Methodology Applied
Scientific EffectHydrodesulfurization: Hydrogenation

Implementation Method 2

The hydrogen generator is configured to cause a steam reforming reaction of a raw material such as city gas or LPG obtained from an existing fossil fuel infrastructure, thereby generating a hydrogen-containing gas

Methodology Applied
Scientific EffectSteam reforming reaction: Chemical Transport Reactions

Implementation Method 3

a hydrodesulfurizer which is heated by heat transferred from the hydrogen generation unit

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP2837594B1Method for operating hydrogen generation device and method for operating fuel cell system
Publication Date: 2024.05.01 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP2837594B1 patent drawingFigure 1
  • EP2837594B1 patent drawingFigure 2
  • EP2837594B1 patent drawingFigure 3

AI summary

A method of operating a hydrogen generator includes: a step (a) of generating a hydrogen-containing gas by a hydrogen generation unit by using a raw material in the hydrogen generation unit; a step (b) of removing a sulfur compound from the raw material by a hydrodesulfurizer which is heated by heat transferred from the hydrogen generation unit; and a step (c) of performing an operation of supplying the raw material to the hydrogen generation unit after stopping the generating of the hydrogen-containing gas by the hydrogen generation unit. The step (c) is not performed unless, at least, a temperature of the hydrodesulfurizer is such a temperature at which carbon deposition from the raw material is suppressed.