Open Cavity Kolbe Reactor for Grid Energy Storage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current grid-level energy storage systems suffer from low round trip electrical energy efficiency, particularly at large scales, necessitating the development of a more efficient method to convert electrical power into hydrocarbon chemicals and hydrogen.
Innovation Solution
An open cavity Kolbe reactor system is used, with a formulation of 2-5 carbon chain primary carboxylic acid and alkali salt, to convert electrical power into C2-8 alkane, CO2, and H2, optimizing current density and chemical concentrations to achieve high round trip efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional energy storage systems (battery, pumped hydro, compressed air) are used, then energy storage capability is provided, but round trip electrical energy efficiency remains low (50-90% for batteries, 77% for pumped hydro)
Solution Approach 1:
The patent changes the fundamental operating parameters of the Kolbe reactor by using high acid concentrations (3N to 6N) and optimized alkali salt ratios (2:1 to 4:1), which dramatically improves round trip efficiency to up to 160%. This resolves the contradiction by transforming the electrochemical reaction conditions to minimize energy loss while maintaining high productivity through continuous operation
Solution Approach 2:
The patent replaces mechanical energy storage systems (pumped hydro, compressed air, flywheels) with an electrochemical system that converts electricity directly into chemical energy storage. This substitution eliminates the mechanical conversion losses inherent in those systems, achieving superior round trip efficiency while maintaining energy storage capability
2Loss of energy
If acetic acid concentration is increased from 1N to 3N-6N in the Kolbe reactor, then round trip efficiency improves to up to 160%, but ionic resistance and mass transfer challenges increase
Solution Approach 1:
The patent introduces alkali salts (such as potassium acetate) as intermediary substances that facilitate ionic conduction in the high acid concentration electrolyte. The alkali salt concentration ratio of 2:1 to 4:1 relative to carboxylic acid provides optimal ionic conductivity, reducing ionic resistance while maintaining the high acid concentration needed for 160% round trip efficiency
Solution Approach 2:
The patent simultaneously optimizes multiple parameters: acid concentration (3N-6N), alkali salt concentration (2M-4M), and their ratio (2:1 to 4:1). This multi-parameter optimization resolves the ionic resistance issue by creating a balanced electrolyte composition that maintains high efficiency while ensuring adequate ionic conductivity for continuous operation
3Productivity
If continuous operation of the Kolbe reactor is implemented, then energy storage productivity increases, but maintaining optimal chemical formulation becomes more complex
Solution Approach 1:
The patent designs the continuous operation system with automatic formulation maintenance where the reactor system self-regulates the chemical composition. The continuous feed of carboxylic acid and alkali salt maintains the optimal 2:1 to 4:1 ratio automatically, reducing the complexity of manual formulation management while sustaining high productivity through uninterrupted operation
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 system achieves up to 160% round trip electrical energy efficiency by producing hydrocarbon fuels and hydrogen, enabling greater energy return compared to traditional storage methods, with the potential for scalable and cost-effective energy storage and distribution.
Implementation Method 1
Faraday, in 1834, was the first to report electrochemical production of a gas now known as ethane, during electrolysis of aqueous acetate solutions. This observation was investigated in more detail by Kolbe in 1849. A Kolbe reaction is the anodic oxidation of a carboxylate moiety in an organic acid with subsequent decarboxylation and coupling to yield a dimer of the alkyl function in the carboxylate reactant.
Implementation Method 2
The present disclosure provides a process for storing energy by conversion of electric power into hydrocarbon chemicals and hydrogen
Data Source
AI summary
There is disclosed an improved Kolbe reactor system for converting electrical power into a hydrocarbon fuel and hydrogen. More specifically, the present disclosure provides a Kolbe reactor system comprising an open cavity Kolbe reactor and an initial hydrocarbon chemical formulation comprising from about 3N to about 6N C2-C5 carboxylic acid and from about 2M to about 4M alkali C2-C5 carboxylate, wherein the C2-C5 carboxylate and carboxylic acid have the same carbon alkyl length. The Kolbe reactor system can be continuously fed with C2-C5 carboxylic acid to maintain the initial formulation for a continuous process. Electrical energy is stored by converting the carboxylic acid to hydrocarbon fuel and hydrogen, and is recovered by combustion of the hydrocarbon fuel and hydrogen, and or conversion in a hydrogen fuel cell.