Directly Cooled Ammonia Reactor for Lower-Temperature Conversion
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Solution Overview
Problem
Conventional ammonia production processes face challenges in flexibility and efficiency due to thermodynamic limitations and the use of fluctuating renewable energy sources, leading to incomplete reactions and high operating temperatures, which affect the conversion rate and require costly adaptations.
Innovation Solution
Employing a directly cooled reactor with catalysts based on ruthenium, nickel, cobalt, and/or iron, using coolants like water, thermal oil, or molten salt to dissipate heat directly, allowing operation at lower temperatures and increased conversion rates, and incorporating adjustable catalysts and multiple reaction beds to enhance flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional ammonia synthesis reactors operate at high temperatures (400-450°C) to maintain catalyst activity, then the reaction rate is sufficient, but the conversion rate is limited due to thermodynamic equilibrium constraints
Solution Approach 1:
The patent implements dynamic temperature control by dividing the reactor into multiple adiabatic beds with inter-bed cooling sections. This allows the reaction temperature to be dynamically adjusted along the reactor length, maintaining high conversion rates by removing heat at strategic points without requiring uniformly high temperatures throughout the reactor.
Solution Approach 2:
The reactor is segmented into multiple catalyst beds separated by cooling sections. This segmentation allows independent temperature management in each bed, enabling the system to overcome thermodynamic equilibrium limitations by continuously removing reaction heat and maintaining favorable temperature gradients for higher overall conversion.
2Adaptability or versatility
If green hydrogen from renewable energy sources is used, then environmental sustainability is improved, but the fluctuating power output leads to variable hydrogen supply that conventional reactors cannot adapt to
Solution Approach 1:
The multi-bed adiabatic reactor design provides inherent dynamic flexibility by allowing independent adjustment of conversion rates in each bed. When green hydrogen supply fluctuates, the system can dynamically redistribute the reaction load across different beds and adjust cooling section operations to maintain stable ammonia production despite variable feed conditions.
Solution Approach 2:
The system can change operating parameters such as space velocity, temperature distribution across beds, and cooling rates to adapt to varying hydrogen supply conditions from renewable sources, enabling reliable operation across a wide range of feed rates without compromising stability.
3Temperature
If intermediate cooling sections are used to remove reaction heat, then thermal management is improved, but the device complexity increases with additional cooling units between catalyst beds
Solution Approach 1:
The cooling sections are merged with the reactor structure itself, forming an integrated multi-bed adiabatic reactor where cooling channels are built into the reactor walls between catalyst beds. This integration eliminates the need for separate external cooling units while maintaining effective heat removal, thus reducing overall device complexity.
Solution Approach 2:
The reactor structure serves multiple functions simultaneously: it contains the catalyst beds, provides thermal insulation, incorporates cooling channels for heat removal, and maintains structural integrity under high pressure. This multi-functionality reduces the number of separate components needed, simplifying the overall reactor design.
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 enables flexible operation, increased conversion rates, reduced investment costs, and efficient energy utilization through steam generation, while maintaining catalyst activity at lower temperatures, thereby improving the overall process efficiency and adaptability.
Implementation Method 1
conversion of a hydrogen-containing reactant mixture in a reactor to an ammonia-containing product mixture in an exothermic reaction
Implementation Method 2
directly cooled reactor with a catalyst... using coolants like water, thermal oil, or molten salt to dissipate heat directly
Implementation Method 3
catalytic assistance after the supply of activation energy
Data Source
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AI summary
The invention relates to a process for producing a process product in which a reactant mixture (1) is fed into a reactor (10) comprising a catalyst and is catalytically at least partially reacted in the reactor (10) in an exothermic reaction with activation energy, wherein at least part of the activation energy is provided in the process using thermal energy generated during the exothermic reaction, wherein the reactor (10) is a directly cooled reactor and is equipped with a catalyst based on ruthenium, nickel, cobalt and/or iron with promoters. The invention further relates to a plant (100) designed for carrying out the process.