CO2 Hydrogenation Reactor with Syngas Recirculation

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Solution Overview

Problem

Current technologies for producing methanol and synthetic methane face challenges in managing intermittency of renewable energy, achieving stable production, and efficiently storing excess reagents, with existing systems requiring multi-stage operations, high pressure, and risking catalyst degradation due to temperature peaks.

Innovation Solution

A device and process for cogenerating methanol and synthetic methane using a CO2 hydrogenation reactor with recirculation systems to control flow rates and maintain isothermality, allowing flexible operation and efficient conversion of excess electrical energy into chemical products, with recirculation pipes and sensors to regulate temperature and flow rates, enabling constant production rates and storage of excess syngas as synthetic methane.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multi-stage reactor operations with intermediate cooling are used to achieve high conversion rates, then conversion efficiency is improved, but device complexity and operating cost increase

Engineering Contradiction:
Improveconversion rateVSAvoidreactor configuration
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent divides the catalytic bed into multiple zones with different catalyst types or activities arranged in sequence. This segmentation allows each zone to perform a specific function (e.g., primary conversion, secondary conversion, temperature control) within a single reactor, achieving high overall conversion without requiring multiple separate reactor stages and intermediate cooling systems.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs dynamic control mechanisms such as adjustable syngas flow rates, variable heating zones, or movable catalyst beds that can adapt to changing operating conditions. This dynamic capability allows the single reactor to maintain optimal conversion efficiency across different production rates without requiring complex multi-stage configurations.

Inventive Principle:
Principle #15Dynamics

2Productivity

If high pressure operation is used to favor methanol production, then conversion efficiency is improved, but operating cost and safety requirements increase

Engineering Contradiction:
Improvemethanol production efficiencyVSAvoidoperating cost
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent optimizes the pressure parameter by operating at moderate pressures (e.g., 5-50 bar) rather than traditional high pressures. This is achieved by compensating for the reduced pressure effect through other means such as optimized catalyst selection, adjusted temperature profiles, or modified reactor configuration, thereby maintaining good conversion efficiency while significantly reducing operating costs and safety requirements.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite catalyst materials or reactor structures that enhance reaction efficiency at lower pressures. For example, novel catalyst compositions with higher activity or reactor designs with improved heat and mass transfer characteristics allow the system to achieve high methanol production rates without requiring high pressure operation.

Inventive Principle:
Principle #40Composite materials

3Reliability

If temperature control measures are implemented to prevent catalyst degradation, then catalyst lifetime is improved, but device complexity and energy consumption increase

Engineering Contradiction:
Improvecatalyst stabilityVSAvoidtemperature control system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent designs the reactor to utilize the reaction heat itself for temperature control. The exothermic methanol synthesis reaction generates heat that is automatically distributed throughout the catalytic bed through the reactor design (e.g., specific bed geometry, heat conduction pathways), preventing localized hot spots and catalyst degradation without requiring external cooling systems or complex temperature control mechanisms.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent maintains continuous optimal temperature conditions for catalyst performance by designing the reactor to sustain steady-state operation with uniform heat distribution. This continuous thermal management approach, achieved through optimized reactor geometry or catalyst bed configuration, prevents temperature fluctuations that could degrade catalysts while avoiding the need for intermittent cooling or complex control systems.

Inventive Principle:
Principle #20Continuity of useful action

4Stability of the object's composition

If recirculation systems are used to manage excess syngas and maintain stable production, then production stability is improved, but device complexity increases

Engineering Contradiction:
Improveproduction stabilityVSAvoidrecirculation system
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent combines the recirculation function with the main reactor system by integrating the unreacted syngas loop back into the reactor inlet or by merging multiple reactor outlets into a common recirculation line. This integration allows stable production to be maintained while minimizing the number of separate recirculation devices and reducing overall system complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent designs components to serve multiple functions: the reactor vessel simultaneously performs conversion, temperature control, and recirculation; the catalyst bed provides both primary and secondary conversion zones; heat exchangers serve both cooling and preheating functions. This multi-functionality reduces the number of dedicated recirculation components needed while maintaining production stability.

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 solution provides flexible operation to match renewable energy availability, ensures stable methanol production, and stores excess energy as synthetic methane, enhancing the value of methanol production and reducing greenhouse gas emissions, while avoiding costly separations and maintaining reactor stability.

Implementation Method 1

CO2 hydrogenation reactor to produce methanol

Methodology Applied
Scientific EffectHydrogenation: Hydrogenation

Implementation Method 2

hydrogenation reaction... catalysts whose existing formulations are very diverse and widely available on the market

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 3

a condenser, hydrogenation reaction products leaving the reactor, to separate at least the methanol and the water from the syngas in excess

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 4

recirculation pipes and sensors to regulate temperature and flow rates... a heat exchanger whose outlet temperature is determined as a function of the sensed reaction temperature

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 5

a methanation reactor comprising: an entry for part of the hydrogenation products comprising at least excess syngas following the hydrogenation reaction and an outlet for methanation reaction products comprising at least synthetic methane

Methodology Applied
Scientific EffectMethanation: Chemical Bonding

Data Source

PatentEP3443051A1Device and method for the cogeneration of methanol and synthesis methane
Publication Date: 2019.02.20 GDF SUEZ SA

AI summary

The invention relates to a device (200) for the cogeneration of methanol and synthesis methane, comprising a CO2 hydrogenation device (100) for producing methanol from a syngas containing dihydrogen, H2 and carbon dioxide CO2, and a methanation reactor (205) for producing synthesis methane. The hydrogenation device comprises: a CO 2 hydrogenation reactor (105) for producing at least methanol CH 3OH; a condenser (145) for the hydrogenation reaction products leaving the reactor (105), intended to separate at least methanol and water form the excess syngas following the hydrogenation reaction; a first line (150) for the recirculation of the excess cold syngas leaving the condenser (145), connecting the outlet (155) of the condenser and the inlet (110) of the hydrogenation reactor (105), comprising a recirculator (160) for said syngas; a means (165) for measuring the flow rate of the methanol condensed by the condenser; and a means (170) for controlling the second recirculator, configured to control the recirculation of a quantity of excess hydrogen reaction products, determined according to the measured condensed methanol flow rate and a second given set value (175). The methanation reactor (205) comprises: an inlet (210) for part of the hydrogen products comprising at least the excess syngas following the hydrogenation reaction, and an outlet (215) for the methanation reaction products comprising at least the synthesis methane.