Zeolite Membrane Composition for High-Temperature Ammonia Separation
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Solution Overview
Problem
Existing methods for separating ammonia from a mixture of hydrogen, nitrogen, and ammonia gas are inefficient, require multiple stages, consume excessive energy, and are not practical under high temperature conditions, leading to increased production costs and complexity.
Innovation Solution
A zeolite membrane with a specific molar ratio of nitrogen atoms to Al atoms, Si atoms to Al atoms, or alkali metal atoms to Al atoms, as determined by X-ray photoelectron spectroscopy, is used to enhance ammonia gas separation performance and stability under high temperatures, preventing pore clogging and improving selectivity and permeability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a polymer membrane is used for ammonia separation, then processability into flat or hollow fiber membranes is excellent, but the membrane is easily swelled and has low heat resistance, making it impractical under high temperature conditions
Solution Approach 1:
The patent changes the fundamental material parameter from organic polymer to inorganic zeolite, which fundamentally alters the thermal stability parameter. Zeolite membranes can operate at temperatures up to 500°C while maintaining structural integrity and separation performance, completely resolving the heat resistance limitation of polymer membranes.
Solution Approach 2:
The patent employs composite material design by forming zeolite crystalline layers on porous support substrates. This composite structure combines the mechanical strength and structural stability of the inorganic support with the selective separation properties of the zeolite active layer, achieving both manufacturability and high-temperature stability.
2Ease of manufacture
If a polymer membrane is used for ammonia separation, then it can be processed into various membrane forms, but the membrane easily deteriorates due to adsorptive components such as sulfides and has low resistance to reactive chemicals
Solution Approach 1:
The patent changes the chemical composition parameter from organic polymer to inorganic zeolite material. This fundamental parameter change confers exceptional chemical inertness to the membrane, making it resistant to sulfides, oxidants, and other reactive chemicals that would deteriorate polymer membranes, thereby dramatically improving reliability in harsh chemical environments.
3Ease of manufacture
If a polymer membrane is used for ammonia separation, then it can be formed into practical membrane structures, but the membrane is easily deformed by pressure and the separation performance is thereby lowered
Solution Approach 1:
The patent changes the material phase parameter from flexible polymer to rigid inorganic zeolite structure. This parameter change confers high mechanical strength and dimensional stability to the membrane, enabling it to withstand high operating pressures without deformation while maintaining consistent separation performance, thus resolving the pressure resistance problem.
4Quantity of substance
If conventional cooling methods are used to separate ammonia from mixed gas, then ammonia can be condensed and separated, but the concentration of ammonia gas is low and cooling efficiency is poor, consuming a great amount of energy
Solution Approach 1:
The patent replaces the thermal-based separation mechanism (cooling and condensation) with a membrane-based selective permeation mechanism. The zeolite membrane selectively transports ammonia molecules through its pores based on molecular size and shape, enabling separation at ambient or elevated temperatures without the energy-intensive cooling process, thereby dramatically reducing energy consumption.
Solution Approach 2:
The patent exploits the phase transition capability of ammonia by controlling the permeation process to produce ammonia in a concentrated form that can be directly utilized or condensed only when needed, rather than requiring continuous cooling for separation. This on-demand phase control optimizes energy efficiency.
5Quantity of substance
If conventional ammonia separation processes are used, then ammonia can be recovered from mixed gas, but it is necessary to separate and recycle large amounts of hydrogen and nitrogen gas, increasing production complexity and energy consumption
Solution Approach 1:
The patent extracts only the ammonia component from the mixed gas stream through selective membrane permeation, while the bulk hydrogen and nitrogen gases pass through or are left in the retentate stream. This extraction approach simplifies the process by eliminating the need for complex multi-stage separation and recycling systems, reducing both device complexity and energy consumption while maintaining high ammonia recovery efficiency.
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 effectively addresses the technical problem by enhancing ammonia gas separation performance, and the efficacy of the technical solution is the zeolite membrane achieves high selectivity and permeability of the ammonia gas separation and stability of the ammonia gas separation.
Implementation Method 1
a zeolite membrane has ordered sub-nanometer pores and functions as a molecular sieve
Implementation Method 2
selectively allows specific molecules to permeate
Implementation Method 3
a zeolite membrane has ordered sub-nanometer pores and functions as a molecular sieve
Data Source
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AI summary
Provided is a method for separating ammonia gas using zeolite membrane having excellent separation stability at a high temperature capable of separating ammonia gas from a mixed gas composed of multiple components including ammonia gas, hydrogen gas, and nitrogen gas to the permeation side with high selectivity and high permeability. Also provided is a method for separating ammonia by selectively permeating ammonia gas from a mixed gas containing at least ammonia gas, hydrogen gas, and nitrogen gas using a zeolite membrane, wherein the ammonia gas concentration in the mixed gas is 1.0% by volume or more.