Intermediate-Medium Energy Conversion for Low-Grade Carbon Sources
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Solution Overview
Problem
Existing methods for generating power or producing hydrogen face inefficiencies when using low-grade carbon sources and low-temperature waste heat, particularly in converting carbon sources with high moisture content and utilizing waste heat at temperatures below 350°C.
Innovation Solution
A method involving a chemical conversion step where a mixture of an intermediate medium and carbon source reacts at a temperature where the chemical exergy of the carbon source exceeds that of the intermediate medium's reduced state, followed by an electrochemical conversion step using a battery structure to generate power or hydrogen, without converting the carbon source into thermal energy, and a reuse step to recycle the intermediate medium.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional combustion methods are used to convert carbon sources into thermal energy, then large energy can be extracted, but energy conversion efficiency is low when using low-grade carbon sources with high moisture content
Solution Approach 1:
The patent introduces an intermediate medium (metal oxide such as Fe3O4 or CeO2) that acts as a mediator between the carbon source and the final energy output. The metal oxide undergoes cyclic reduction and oxidation reactions, enabling efficient energy conversion from low-grade carbon sources without direct combustion, thus improving energy conversion efficiency while adapting to high-moisture carbon materials
Solution Approach 2:
The patent changes the reaction parameters by conducting reactions at controlled temperatures (350-650°C for chemical conversion, lower temperatures for electrochemical conversion) rather than high-temperature combustion. This parameter change enables efficient utilization of low-grade carbon sources with high moisture content that would be unsuitable for conventional combustion
2Loss of energy
If waste heat at low temperature is utilized using conventional methods, then energy recovery is achieved, but energy conversion efficiency remains insufficient
Solution Approach 1:
The patent merges two conversion processes: chemical conversion (reacting carbon source with metal oxide at 350-650°C) and electrochemical conversion (reacting the reduced metal with water or oxygen). This combination enables efficient utilization of low-temperature waste heat that would be unusable in conventional single-stage systems
Solution Approach 2:
The patent utilizes phase transitions in the intermediate medium (metal oxide reduction and oxidation) to enable energy conversion at low temperatures. The metal oxide undergoes reversible phase changes between oxidized and reduced states, allowing efficient energy recovery from low-temperature waste heat sources
3Power
If direct combustion of carbon sources is performed, then thermal energy is produced quickly, but energy conversion efficiency to electrical energy or hydrogen is low
Solution Approach 1:
The patent replaces the mechanical/thermal combustion system with a chemical conversion system followed by electrochemical conversion. Instead of directly burning carbon to produce thermal energy, the system uses controlled chemical reactions with metal oxides and subsequent electrochemical reactions to generate electricity or hydrogen, achieving higher overall conversion 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 approach enhances energy conversion efficiency by utilizing low-grade carbon sources and low-temperature waste heat, allowing for efficient power generation or hydrogen production with reduced environmental impact and the ability to recover CO2 with high purity.
Implementation Method 1
a chemical conversion step of making, in a chemical conversion unit, a mixture obtained by mixing a solution containing an intermediate medium with the carbon source to react at a temperature at which chemical exergy of the carbon source exceeds chemical exergy in a reduced state of the intermediate medium to reduce the intermediate medium while oxidizing the carbon source
Implementation Method 2
an electrochemical conversion step of bringing a solution containing the intermediate medium reduced at the chemical conversion step into contact with an anode of a battery structure in an electrochemical conversion unit including the battery structure, or using a base material on which the intermediate medium reduced at the chemical conversion step is precipitated as the anode of the battery structure, and bringing oxygen or air into contact with a cathode of the battery structure to generate power
Implementation Method 3
a hydrogen production method including an electrochemical oxidation reduction step of emitting electrons from an alkali metal and producing a fused body of the alkali metal and carbon or a metal by a battery reaction using the alkali metal for a negative electrode and carbon or a metal having a lower ionization tendency than the alkali metal for a positive electrode, a hydrogen generation step of electrolyzing water utilizing the electrons emitted at the electrochemical oxidation reduction step to generate hydrogen
Data Source
AI summary
A method for generating power or producing hydrogen from a carbon source, the method including a chemical conversion step of making, in a chemical conversion unit, a mixture obtained by mixing a solution containing an intermediate medium with a carbon source to react at a temperature at which chemical exergy of the carbon source exceeds chemical exergy in a reduced state of the intermediate medium to reduce the intermediate medium while oxidizing the carbon source, an electrochemical conversion step of bringing the intermediate medium reduced at the chemical conversion step into contact with an anode of a battery structure in an electrochemical conversion unit including the battery structure, and bringing oxygen or air into contact with a cathode of the battery structure to generate power, or bringing water into contact to produce hydrogen, and a reuse step of returning a solution containing the intermediate medium after the electrochemical conversion step to the mixture, and an energy conversion system.