Ohmic Heating Biomass Conversion for Subcritical Fuel Production
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Solution Overview
Problem
Current methods for converting organic and biomass materials into combustible fuels are inefficient, costly, and unsustainable, particularly due to high moisture content requirements, unsafe steam injection practices, and challenges with uniform heating and particle size management.
Innovation Solution
A subcritical hydrothermal processing method using ohmic heating to convert organic and biomass feedstocks into a combustible product with high net calorific value, allowing for efficient temperature and pressure control within 280°C to 320°C and 6.6-11.6 MPa, without the need for drying, and producing a product with reduced particle size for easier filtration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If steam is blown into organic waste under high pressure to cause reaction while heating, then the organic waste is converted to a slurried material, but the method leads to unsafe engineering issues, non-uniform heating, and unnecessary dilution of the finished product with water
Solution Approach 1:
The patent removes the steam injection step from the process, using direct heating of the organic waste in the absence of excess water. This extracts the harmful element (steam blowing under pressure) while maintaining the beneficial conversion function through alternative heating methods.
Solution Approach 2:
The patent introduces an indirect heating mechanism where heat is transferred through a reactor wall or heating element rather than direct steam injection. This intermediary approach maintains safety while achieving uniform heating and conversion.
2Productivity
If steam is blown into organic waste under high pressure to cause reaction while heating, then the organic waste is converted to a slurried material, but the method causes non-uniform heating of the reaction mixture
Solution Approach 1:
The patent removes the steam injection mechanism that caused non-uniform heating, replacing it with a direct heating approach that heats the organic waste uniformly throughout the reaction vessel.
Solution Approach 2:
The patent applies heating uniformly across the entire reaction mixture volume through the reactor walls or distributed heating elements, ensuring each region receives consistent thermal energy for uniform conversion.
3Productivity
If steam is blown into organic waste under high pressure to cause reaction while heating, then the organic waste is converted to a slurried material, but the method leads to unnecessary dilution of finished product with water, increasing drying costs
Solution Approach 1:
The patent removes the excess water introduction step by eliminating steam blowing, thereby preventing dilution of the product and avoiding the energy cost of removing unnecessary water in the drying stage.
Solution Approach 2:
The process uses the organic waste's intrinsic moisture content rather than adding external water through steam, allowing the material to self-regulate its moisture level and eliminating the need for costly drying operations.
4Ease of manufacture
If sewage sludge is spread onto farmland as fertiliser and soil improver, then the sludge is disposed of, but the process is expensive due to high water content requiring costly transport
Solution Approach 1:
The patent changes the physical and chemical parameters of the sewage sludge through thermal processing, converting it from a high-moisture waste material into a low-moisture, high-calorific-value fuel product that is economically viable to transport and utilize.
Solution Approach 2:
The process utilizes phase transitions during thermal treatment to remove water from the sewage sludge, transforming it from a liquid-dominated sludge into a solid or semi-solid fuel product with significantly reduced moisture content and improved transportability.
5Ease of manufacture
If wood fines are disposed of as waste material, then the disposal problem is addressed, but the completely random and changing composition makes reuse especially difficult under waste legislation
Solution Approach 1:
The patent transforms the variable composition of wood fines into a consistent, standardized fuel product through thermal processing. The heterogeneous input materials are converted into a uniform output with stable calorific value and properties, making it suitable for various fuel applications despite the random composition of raw materials.
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 process achieves a high calorific value combustible product in under 30 minutes, reducing particle size and enhancing fuel efficiency, while minimizing costs and environmental impact, and is suitable for converting waste wood and sewage sludge into viable fuels.
Implementation Method 1
A subcritical hydrothermal processing method using ohmic heating to convert organic and biomass feedstocks into a combustible product
Implementation Method 2
A subcritical hydrothermal processing method using ohmic heating to convert organic and biomass feedstocks into a combustible product with high net calorific value, allowing for efficient temperature and pressure control within 280°C to 320°C and 6.6-11.6 MPa
Data Source
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AI summary
A process for producing combustible product from an organic or biomass feedstock, the process comprising: mixing the feedstock with an alkaline material to give an alkaline aqueous mixture; heating the mixture by ohmic heating to a temperature in the range of about 280°C to about 320°C and reacting the mixture under subcritical conditions at the said temperature range and a pressure of about 6.6 to about 11.6 MPa (65 bar gauge to about 115 bar gauge); and removing at least some of the water to leave a combustible product, which may be used to form an aqueous slurry, suspension or emulsion and combusted in a suitable engine.