Ammonia synthesis method
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Solution Overview
Problem
Conventional ammonia synthesis processes incur high costs and operational inefficiencies due to the large power requirements for compressing and cooling the product ammonia used as a chiller refrigerant, necessitating the development of a method to reduce refrigerant manufacturing costs and improve operating efficiency without relying on product ammonia as a chiller refrigerant.
Innovation Solution
An ammonia synthesis method utilizing a ruthenium catalyst, water-cooled or air-cooled cooling, and ammonia separation to achieve an ammonia concentration of 5 mol% or more in the return raw material gas, which is then compressed and recycled, eliminating the need for product ammonia as a chiller refrigerant and optimizing cooling temperatures between 30 to 50°C.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If product ammonia is used as a chiller refrigerant, then cooling function is achieved, but power consumption and equipment cost increase significantly
Solution Approach 1:
The invention extracts the cooling function from the product ammonia circulation system by introducing a separate water-cooling system. The synthetic gas is cooled by water cooling instead of using product ammonia as refrigerant, thereby eliminating the need for large-scale refrigeration equipment and reducing power consumption while maintaining effective cooling.
2Temperature
If product ammonia is used as a chiller refrigerant, then cooling function is achieved, but large-scale equipment is required
Solution Approach 1:
The cooling function is extracted from the ammonia product system and implemented through a separate water-cooling system. This eliminates the need for large-scale ammonia refrigeration equipment, reducing device complexity and equipment investment while achieving the same cooling effect.
Solution Approach 2:
Water is introduced as an intermediary cooling medium between the synthetic gas and the environment. Instead of directly using product ammonia as refrigerant, water serves as a mediator to absorb heat from the synthetic gas, simplifying the equipment requirements and reducing the scale of cooling systems needed.
3Productivity
If ammonia concentration in return raw material gas is increased, then synthesis efficiency improves, but catalyst performance may deteriorate
Solution Approach 1:
The invention optimizes the ammonia concentration parameter in the return raw material gas to be 5 mol% or more, which improves synthesis efficiency while maintaining catalyst performance. Additionally, the synthetic gas temperature after cooling is controlled at 30 to 50°C, creating optimal conditions for the ruthenium catalyst to function effectively even with higher ammonia concentrations in the recycle stream.
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 enhances the operating efficiency of ammonia synthesis, reduces refrigerant manufacturing costs, and maintains high reaction activity with a ruthenium catalyst, thereby minimizing the need for large catalyst amounts and equipment, while maintaining a high ammonia synthesis rate.
Implementation Method 1
an ammonia synthesis catalyst that synthesizes the ammonia gas is a ruthenium catalyst
Implementation Method 2
a water-cooled or air-cooled cooling step of water-cooling or air-cooling a synthetic gas containing the obtained ammonia gas
Implementation Method 3
a compression step of compressing a return raw material gas when the raw material gas containing the separated ammonia gas is returned to the ammonia synthesis step side
Data Source
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AI summary
The present invention comprises: an ammonia converter 13 that synthesizes ammonia; a discharge line L11 that discharges a synthesis gas 14 which includes an obtained ammonia gas 12A and an unreacted source gas 11A; a water cooled condenser 16 that is interdisposed in the discharge line L11 and cools the synthesis gas 14 with a coolant 15; an ammonia separator 17 into which the cooled synthesis gas 14A is introduced, said separator 17 separating the ammonia gas 12A and liquid ammonia 12B; a source return line L12 that returns the source gas including the separated ammonia gas 12A to the ammonia converter 13 side as a return source gas 11B; and a compressor 18 that is interdisposed in the source return line L12 and compresses the return source gas 11B. The ammonia concentration in the return source gas 11B intro - duced into the ammonia converter 13 is 5 mol% or more and an ammonia synthesis catalyst that synthesizes the ammonia gas 12A in the ammonia converter 13 is a ruthenium catalyst.