Biogas Reactor With Movable Partitions For Substrate Adaptation

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Solution Overview

Problem

Existing biogas production systems face instability due to changes in substrate composition and supply, leading to pH shifts and microbial colonization imbalances, especially in transportable systems with small fermenter volumes, where methane-producing bacteria are sensitive and have slow multiplication rates, and acetogenesis bacteria are hindered by high hydrogen content, resulting in susceptibility to failure and low efficiency.

Innovation Solution

A reactor design with movable partitions that adjust chamber volumes based on dry matter content, allowing separate gas spaces for each compartment, enabling controlled biogas production with countercurrent gas flow and introduction of oxygen to enhance hydrolysis, thereby stabilizing the process and increasing biogas yield.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If small fermenter volumes are used in transportable systems, then the system becomes mobile and space-efficient, but the susceptibility to failure increases due to sensitive methane bacteria and slow multiplication rates

Engineering Contradiction:
Improvefermenter volumeVSAvoidsusceptibility to failure
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The fermenter is divided into multiple compartments (first compartment for hydrolysis/acidogenesis, second compartment for acetogenesis, third compartment for methanogenesis) separated by partition walls. This segmentation allows each microbial community to occupy its own space with optimized conditions, preventing failure propagation across the entire system while maintaining small overall volume.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each compartment is equipped with separate gas spaces and gas outlets tailored to local requirements: the first compartment has a gas space for CO2/H2 removal to prevent pH drop, the second compartment has a gas space for H2 removal to support acetogenesis, and the third compartment collects biogas. This local optimization enhances reliability in small volumes.

Inventive Principle:
Principle #3Local quality

2Stability of the object's composition

If degradation stages are spatially separated to meet different bacterial habitat requirements, then process optimization is improved, but acetogenesis bacteria are hindered by high hydrogen content from mixed gas spaces

Engineering Contradiction:
Improvemicrobial habitat optimizationVSAvoidhydrogen content affecting acetogenesis
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

Gas spaces are completely separated between compartments with individual gas outlets. The gas space above the second compartment (acetogenesis) is extracted and vented separately, removing harmful hydrogen before it can inhibit acetogenesis bacteria. This extraction principle eliminates the harmful factor while maintaining spatial separation benefits.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Partition walls with adjustable positions act as intermediaries between compartments. They physically isolate gas spaces while allowing controlled interaction through adjustable openings, enabling hydrogen removal in the second compartment without completely isolating the microbial communities needed for process continuity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If rigid packaging is used in biogas plants, then structural stability is maintained, but the system cannot adapt to substrate composition changes and shows high susceptibility to failure

Engineering Contradiction:
Improvestructural stabilityVSAvoidadaptability to substrate changes
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

Partition walls are made adjustable rather than fixed. The position of partition walls can be changed to modify compartment volumes and gas space configurations in response to substrate composition changes. This dynamic adjustment capability allows the rigid structure to adapt flexibly to varying operational conditions while maintaining structural stability.

Inventive Principle:
Principle #15Dynamics

4Reliability

If continuously stirred tank reactors (CSTR) with large volumes are used, then process stability is improved, but space-time yield decreases and the system becomes non-transportable

Engineering Contradiction:
Improveprocess stabilityVSAvoidspace-time yield
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The fermenter is segmented into multiple compartments, each optimized for specific degradation stages. This allows intensive operation with short residence times (2-10 days) while maintaining stability through compartmentalized microbial communities. The segmented design achieves high space-time yield in small volumes that would be transportable.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system transitions from temporal separation (sequential batch processing) to spatial separation (parallel compartmentalized processing). Multiple degradation stages occur simultaneously in different compartments rather than sequentially in one large reactor, enabling intensive operation with high space-time yield while maintaining stability through spatial distribution of microbial functions.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 system achieves stable biogas production with high calorific value and increased biogas formation rates, even in small volumes, by decoupling hydraulic and solids residence times and optimizing microbial activity, making it robust against substrate fluctuations and maintaining high methane content.

Implementation Method 1

passing the substrate through the reactor, the reactor having a plurality of partitions (6) which divide at least the internal volume of the reactor intended for the substrate into a plurality of compartments (7 (i) - 7 (iv)) and divide each individual compartment (7 (i) - 7 (iv)) into at least two chambers (8 (i) - 8 (iv); 9 (i) - 9 (iv)) through which the substrate flows in opposite directions

Methodology Applied
Scientific EffectHydraulic flow:

Implementation Method 2

In the first step, the 'hydrolysis ', the complex compounds of the substrate material (e.g. carbohydrates, proteins, fats) are broken down into simpler organic compounds (e.g. amino acids, sugars, fatty acids). The bacteria involved release enzymes that decompose the material biologically.

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Implementation Method 3

In principle, this can The first step, hydrolysis, takes place both anaerobically and aerobically.

Methodology Applied
Scientific EffectAerobic decomposition: Aerobic Digestion

Implementation Method 4

In the second step, the intermediate products formed are then processed within the so-called 'acidification phase' (Acidogenesis) further broken down by acid-producing bacteria to lower fatty acids (e.g. acetic, propionic and butyric acid) as well as carbon dioxide (CO2) and hydrogen.

Methodology Applied
Scientific EffectAcidogenesis: Fermentation

Implementation Method 5

In the third step, the preliminary products are then processed within the 'acetic acid formation' (Acetogenesis), converted by bacteria into precursor substances of biogas (acetic acid, hydrogen and carbon dioxide).

Methodology Applied
Scientific EffectAcetogenesis: Fermentation

Implementation Method 6

In the last step of biogas production, the 'Methanogenesis' Methane is also formed by bacteria from the products of acetogenesis.

Methodology Applied
Scientific EffectMethanogenesis: Anaerobic Digestion

Implementation Method 7

at least one gas space from at least one compartment, selected from all gas spaces (5 (i) - 5 (iv)) of all compartments (7 (i) - 7 (iv)), is designed separately from the remaining gas space or the remaining gas spaces (5 (i) - 5 (iv)) of the remaining compartments (7 (i) - 7 (iv))

Methodology Applied
Scientific EffectGas separation:

Implementation Method 8

divide each individual compartment (7 (i) - 7 (iv)) into at least two chambers (8 (i) - 8 (iv); 9 (i) - 9 (iv)) through which the substrate flows in opposite directions

Methodology Applied
Scientific EffectCountercurrent flow:

Data Source

PatentEP2565259B1Method and device for biogas production
Publication Date: 2014.04.23 CONVIOTEC
  • EP2565259B1 patent drawingFigure 1
  • EP2565259B1 patent drawingFigure 2a~2e

AI summary

A process for the production of biogas is proposed, wherein the process comprises at least the following process steps: □ supplying the substrate through at least one inlet (1) of the reactor, □ passing the substrate through the reactor, wherein the reactor has a plurality of partitions (6) that divide at least the internal volume of the reactor intended for the substrate into a plurality of compartments (7 (i) - 7 (iv)) and each individual compartment (7 (i) - 7 (iv)) into at least two chambers (8 (i) - 8 (iv); 9 (i) - 9 (iv)) through which the substrate flows in opposite directions, □ discharge of the fermented substrate from at least one outlet (3) of the reactor, wherein the process proposed here is characterized by,that ■ to increase or reduce the ratio of the volume of the chambers (8 (i) - 8 (iv)) through which the substrate flows in one direction to the volume of the chambers (9 (i) - 9 (iv)) through which the substrate flows in the other direction, at least a part of the partitions (6) are moved in their spatial position and/or extent, wherein the movement and/or extent of the partitions (6) is controlled depending on the dry matter content of the flowable substrate, and wherein the method proposed here characteristically comprises at least the following further process steps: ■ removal of process gas from the at least one gas space, which is formed separately from the remaining gas space or gas spaces (5 (i) - 5 (iv)) of the remaining compartments (7 (i) - 7 (iv)),■ Supplying previously discharged process gas and/or foreign gas into the internal volume of at least one of the formed compartments (7 (i) - 7 (iv)) intended for the substrate. A reactor such as that used in the process according to the invention is also proposed.