Porous Solid Support Bioreactor for Hydrogen Fermentation
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Solution Overview
Problem
Conventional solid-state bioreactors face challenges in achieving uniform microbial growth and efficient gas transfer due to varying environmental conditions, particularly when dealing with gaseous starting materials and end products, leading to uneven nutrient availability and limited aeration, which complicates low-cost and low-maintenance hydrogen production.
Innovation Solution
A bioreactor design featuring a porous solid support with specific pore volume characteristics, allowing for a gaseous phase volume of 20-80% and inoculation with micro-organisms capable of catalyzing the water-gas shift reaction, which maintains unsaturated conditions to enhance gas and liquid transfer without the need for agitation, using materials like particles, spongy structures, or filamentous materials with appropriate pore sizes and cation-exchange properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If solid-state fermentation is used to avoid high temperature and agitation costs, then operating cost and safety are improved, but gas transfer efficiency and aeration may be limited
Solution Approach 1:
The patent employs a porous solid support material with specifically controlled pore size distribution (at least 10% of pore volume with pore diameter 0.01-10 μm) to enable efficient gas-liquid mass transfer. The porous structure provides capillary action for liquid distribution and sufficient surface area for microbial attachment, resolving the contradiction by maintaining gas transfer efficiency without requiring mechanical agitation.
Solution Approach 2:
The solid support acts as an intermediary between the liquid phase and gaseous phase, facilitating mass transfer through its porous structure. It provides a large surface area for microbial growth while enabling diffusion of gaseous substrates and products, thus mediating the interaction between phases without requiring direct contact or mechanical mixing.
2Quantity of substance
If solid support with small pore size is used to increase microbial attachment surface area, then microbial growth density is improved, but gas and liquid transfer may be restricted
Solution Approach 1:
The patent applies local quality by having different pore sizes serve different functions: smaller pores (0.01-10 μm) provide attachment surfaces for high microbial density, while larger pores (0.1-10 mm) maintain inter-particle void space for gas circulation and liquid distribution. This localized differentiation of pore functions resolves the contradiction between microbial attachment and mass transfer.
Solution Approach 2:
The patent changes the pore size parameter from uniform small pores to a bimodal distribution with both small pores (for microbial attachment) and large pores (for mass transfer). This parameter modification enables simultaneous achievement of high microbial density and efficient gas-liquid transfer.
3Stability of the object's composition
If liquid fermentation with agitation is used to ensure homogeneous nutrient distribution, then microbial growth uniformity is improved, but equipment complexity and energy consumption increase
Solution Approach 1:
The patent replaces the mechanical agitation system with a passive porous solid support structure that achieves homogeneous nutrient distribution through capillary action and large surface area. The mechanical complexity of agitation instruments is eliminated while maintaining composition uniformity through the physical properties of the porous material.
Solution Approach 2:
The solid support material provides self-service by using its inherent porous structure to distribute liquid and support microbial growth uniformly without requiring external agitation mechanisms. The system serves itself through the natural capillary properties of the porous material.
4Speed
If trickle bed reactor is used for solid-state fermentation, then gas flow is improved, but liquid saturation level becomes too high preventing effective water suction
Solution Approach 1:
The patent uses a porous solid support with controlled pore size distribution that maintains unsaturated conditions. The porous structure allows the material to function both as a water reservoir and as a water suction mechanism, preventing the liquid saturation problems of trickle bed reactors while maintaining gas flow.
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 enables efficient, low-cost, and low-maintenance hydrogen production by ensuring even microbial growth and gas transfer, achieving high fermentation efficiency and reducing the need for additional pH control and agitation, with the bioreactor capable of producing hydrogen and carbon dioxide efficiently over extended periods.
Implementation Method 1
at least 10% of which has a pore volume size which results in a water suction of about 0.01 to about 1.0 bar as compared to free water
Implementation Method 2
inoculated with micro-organisms catalysing water-gas shift reaction
Implementation Method 3
carbon monoxide (CO) to carbon dioxide (CO2) and hydrogen (H2) through a reaction with water (H2O) in a water-gas shift reaction: CO+H2O→CO2+H2
Implementation Method 4
using materials like particles, spongy structures, or filamentous materials with appropriate pore sizes and cation-exchange properties
Data Source
AI summary
The present invention relates to a solid state fermentation process for producing hydrogen, and to a bioreactor and solid support for use in the fermentation process.