Silane Production via Electrolytic Halide Recycling
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Solution Overview
Problem
Current methods for producing silane are economically inefficient due to high starting material and equipment costs, and lack closed-loop systems for halogen and alkali or alkaline earth metal usage.
Innovation Solution
A process involving electrolysis of alkali or alkaline earth metal halide salts to produce metallic alkali or alkaline earth metal and halogen gas, which is then reacted with hydrogen to form a halogenated silicon feed gas, ultimately producing silane and a closed-loop system for recycling halide salts and metals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the Union Carbide Process is used to produce silane, then silane can be produced through disproportionation and distillation steps, but the process requires large recycle streams which increases initial equipment costs and operating costs
Solution Approach 1:
The patent extracts and eliminates the complex recycle streams from the Union Carbide Process by using a direct synthesis method where silane is produced in a single reaction step from silicon and hydrogen, avoiding the need for multiple disproportionation and distillation steps with large recycle loops
Solution Approach 2:
The process segments the silane production into simpler, more manageable steps: direct synthesis of silane from silicon and hydrogen, followed by simple condensation and storage, replacing the complex integrated process with discrete, independent operations that reduce equipment requirements
2Productivity
If metallurgical-grade silicon is reacted with hydrogen and silicon tetrachloride to produce trichlorosilane, then silane can be produced through subsequent disproportionation steps, but the process requires a number of large recycle streams increasing operating costs
Solution Approach 1:
The patent implements continuous silane production through a direct synthesis process where silicon and hydrogen continuously react to form silane, which is then continuously condensed and stored, eliminating the intermittent operations and energy-intensive recycle streams required in traditional batch-wise disproportionation processes
Solution Approach 2:
The process changes the reaction parameters by using direct synthesis at controlled temperatures and pressures rather than the high-temperature disproportionation reactions, thereby reducing energy consumption and operating costs while maintaining productivity
3Use of energy by moving object
If silicon tetrafluoride is reacted with aluminum hydride to produce silane, then high energy efficiency is achieved, but starting material costs negatively influence the economics of the system
Solution Approach 1:
The patent changes the chemical parameters by using silicon and hydrogen as starting materials instead of expensive silicon tetrafluoride and aluminum hydride, achieving a balance between energy efficiency and economic viability through more cost-effective reactants
Solution Approach 2:
The process uses inexpensive, readily available starting materials (silicon and hydrogen) rather than expensive, specialized reagents, making the process economically viable while maintaining reasonable energy 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
This process reduces costs by recycling materials and maintaining a closed-loop system, enhancing the economic viability of silane production while minimizing material losses and equipment requirements.
Implementation Method 1
electrolyzing an alkali or alkaline earth metal halide salt to produce metallic alkali or alkaline earth metal and halogen gas
Implementation Method 2
The metallic alkali or alkaline earth-metal is contacted with hydrogen to produce an alkali or alkaline earth metal hydride
Implementation Method 3
contacting the halogen gas with at least one of (1) silicon to produce silicon tetrahalide
Implementation Method 4
contacting the halogen gas with at least one of (1) silicon to produce silicon tetrahalide and (2) hydrogen to produce a hydrogen halide
Implementation Method 5
The halogenated feed gas is contacted with the alkali or alkaline earth metal hydride to produce silane and an alkali or alkaline earth-metal hydride salt
Data Source
AI summary
Methods and systems for producing silane that use electrolysis to regenerate reactive components therein are disclosed. The methods and systems may be substantially closed-loop with respect to halogen, an alkali or alkaline earth metal and/or hydrogen.