Low-Temperature Biogas Digestate Nutrient Separation
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Solution Overview
Problem
Current methods for treating digestate from biogas plants are inefficient in reducing nutrient content, particularly nitrogen, phosphorus, and potassium, leading to environmental pollution and increased costs, and are not suitable for high dry matter content substrates like manure.
Innovation Solution
A method that reduces organic dry matter content through biogas plant degradation followed by partial nutrient separation at low temperatures, using nitrification, denitrification, or deammonification processes to convert nitrogen into N2 for climate-neutral release, without requiring additional carbon sources or energy-intensive heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional nutrient separation methods are used on digestate, then nutrient content is reduced, but the process requires energy-intensive heating and is not suitable for high dry matter content substrates
Solution Approach 1:
The patent changes the temperature parameter from conventional high-temperature heating to low-temperature operation (below 35°C), utilizing psychrophilic bacteria that are active at low temperatures. This eliminates the need for energy-intensive heating while maintaining effective nutrient separation capability
Solution Approach 2:
The patent adapts wastewater treatment principles to digestate treatment by using similar biological processes (nitrification, denitrification, deammonification) but modifies them for low-temperature operation and high dry matter content conditions, effectively copying and adapting proven methods to a new context
2Manufacturing precision
If artificial colonization surfaces are added to biogas plants, then nutrient separation efficiency improves, but the surfaces clog quickly due to high fiber content
Solution Approach 1:
The patent extracts and removes the problematic artificial colonization surfaces from the system, instead relying on the natural substrate surfaces provided by the high-fiber digestate material itself. This eliminates the clogging issue while maintaining separation functionality
Solution Approach 2:
The patent enables the system to use its own natural components (substrate surfaces, psychrophilic bacteria present in the digestate) to perform the nutrient separation function, eliminating the need for external artificial colonization surfaces and reducing system complexity
3Ease of manufacture
If digestate is applied to agricultural land without nutrient reduction, then application costs are reduced, but environmental pollution from excessive nutrients increases
Solution Approach 1:
The patent applies partial nutrient removal rather than complete elimination, reducing nutrient content to levels suitable for agricultural application while maintaining the cost-effectiveness of direct land application. This partial action achieves the optimal balance between cost and environmental protection
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 method effectively reduces nutrient content in manure and poultry manure, allowing for safe application on agricultural land without environmental contamination, while being simple, cost-effective, and compatible with biogas plant operations at low temperatures.
Implementation Method 1
carbon degradation in a biogas plant... the substrate of a biogas plant... contains sufficient surface area for the necessary bacterial cultures... fermented in a biogas plant, typically at mesophilic or psychrophilic temperatures, under anaerobic conditions to break down organic components
Implementation Method 2
nitrification and denitrification... The nitrogen is converted to N2 nitrogen... nitrifying bacteria
Implementation Method 3
nitrification and denitrification... The nitrogen is converted to N2 nitrogen... denitrification processes
Implementation Method 4
deammonification processes to convert nitrogen into N2
Data Source
AI summary
The invention relates to a process for reducing the nutrient content of liquid manure and poultry droppings, wherein a reduction in the organic dry matter content by carbon degradation in a biogas plant is followed by at least partial nutrient separation from the liquid digestate of the biogas plant. According to the invention, the carbon degradation in the biogas plant and the nutrient separation from the digestate take place at a process temperature below 35°C. The at least partial nutrient separation includes the at least partial removal of nitrogen compounds as well as phosphorus and potassium compounds, wherein the at least partial removal of nitrogen is provided for by means of nitrification and denitrification or by means of deammonification, whereby the nitrogen is converted to N₂ nitrogen.