Photocatalytic Water Splitting Reactor with Segmented Flow Channels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for photocatalytic water splitting to produce hydrogen are limited by the maximum partial pressure of water vapor in a carrier gas, which restricts the rate of reaction.
Innovation Solution
Introducing water in the liquid state separately from a carrier gas into a reaction volume, where the water is heated above its boiling point and supersaturates the carrier gas, forming a condensed liquid water phase on the photocatalyst.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If water is introduced in vapor state with carrier gas, then the reaction can proceed, but the water quantity is limited by maximum partial pressure which slows down the reaction rate
Solution Approach 1:
The patent separates the introduction of water and carrier gas into two distinct channels: a first flow channel for liquid water and a second flow channel for carrier gas. This segmentation allows independent control of water and gas flows, enabling water to be introduced in liquid state without being constrained by vapor pressure limitations, thereby increasing water concentration and reaction rate
Solution Approach 2:
The patent changes the physical state parameter of water from vapor to liquid. By introducing water in liquid state rather than vapor state, the system overcomes the partial pressure limitation that restricts water vapor concentration in the reaction volume, thus enabling higher water concentration and improved hydrogen production rate
2Productivity
If water is introduced in liquid state separately from carrier gas, then water concentration increases and reaction rate improves, but the device complexity increases due to separate flow channels
Solution Approach 1:
The patent implements nesting by positioning the first flow channel (for liquid water) inside the second flow channel (for carrier gas). The first channel is located within the volume defined by the second channel, allowing both channels to be integrated in a compact configuration. This nested arrangement increases water concentration for higher productivity while minimizing the increase in device complexity through spatial 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 increases the water concentration in the reaction volume, enhancing the rate of hydrogen production compared to methods where water is introduced in vapor form.
Implementation Method 1
a semi-conductor photocatalyst capable, when irradiated with a specific excitation light, to absorb photons and generate excited electrons in its conduction band and holes in its valence band
Implementation Method 2
heated at a temperature greater than the boiling point of water
Implementation Method 3
water being introduced in the liquid state in a sufficient quantity to supersaturate the carrier gas with water vapor and form the condensed liquid water phase on the photocatalyst
Data Source
Figure 1
Figure 2~3
AI summary
The invention concerns a method for producing hydrogen by continuous-flow photocatalytic water splitting allowing higher water concentration to be attained in the reaction volume and therefore higher rates of reaction in comparison with the prior art. The invention also concerns an associated apparatus.