Continuous Sterilization of Lignocellulose Substrates for Mushroom Cultivation

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Solution Overview

Problem

Current batch processes for sterilizing and inoculating mushroom substrates are inefficient, leading to high labor, energy, and material costs, and are not suitable for large-scale production of lignocellulose-containing sterile substrates for noble mushroom cultivation.

Innovation Solution

A continuous process involving crushing, screening, conditioning, suspending, sterilizing, filtering, cooling, and inoculating lignocellulose-containing substrates, utilizing a system with double-pipe heat exchangers and vacuum drying to achieve efficient sterilization and preparation of substrates for fungal growth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If batch processes are used for sterilization and inoculation, then manual operation and batch-wise processing are maintained, but labor costs and production time increase significantly

Engineering Contradiction:
Improvemanual operationVSAvoidproduction time
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent implements continuous sterilization and inoculation processes where substrate material flows continuously through sterilization chambers and inoculation stations, eliminating batch-wise interruptions. The system maintains continuous operation with multiple processing zones working in sequence, allowing uninterrupted production flow and significantly reducing overall production time compared to batch processes.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent replaces manual mechanical operations with automated systems including conveyor belts for substrate transport, automated inoculation mechanisms that deposit spawn without human intervention, and mechanical sorting systems. This substitution eliminates manual labor requirements while maintaining operational control, directly addressing both the ease of operation and productivity parameters.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If batch sterilization in stationary autoclaves is performed, then sterilization effectiveness is achieved, but energy consumption and processing time increase

Engineering Contradiction:
Improvesterilization effectivenessVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The continuous sterilization system processes substrate material continuously through heated zones, eliminating the repeated heating and cooling cycles inherent in batch autoclaving. The substrate moves through a temperature gradient that maintains sterilization effectiveness while continuously processing material, reducing total energy consumption by avoiding repeated thermal cycles.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent employs a temperature gradient approach where substrate passes through zones of progressively increasing temperature, achieving sterilization through controlled exposure to elevated temperatures over an extended period. This parameter change from constant high-temperature batch sterilization to progressive temperature increase allows energy optimization while maintaining sterilization effectiveness.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If batch processes with sequential steps are used, then process control is simplified, but production capacity and efficiency are limited

Engineering Contradiction:
Improveprocess control simplicityVSAvoidproduction capacity
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent divides the continuous production process into distinct functional segments including separate sterilization zones, cooling zones, inoculation stations, and drying areas. Each segment performs a specific function independently while contributing to the overall continuous process, allowing simplified control of individual zones while achieving high production capacity through their integrated operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from temporal sequencing of batch operations to spatial arrangement of continuous processing zones. Instead of completing all steps for one batch before starting the next, the system arranges processing steps in parallel spatial zones that handle material simultaneously at different stages, dramatically increasing production capacity while maintaining control simplicity through zoned management.

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

This process significantly reduces labor and energy costs, achieves high efficiency in substrate production, and allows for the economical production of over 100 tons per year of sterile substrates, with estimated cost savings of 20% or more compared to conventional methods.

Implementation Method 1

heating the suspension to the sterilization temperature in a double-pipe apparatus with hot water

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

sterilization in a pressure vessel at 1.43 bar for 20 minutes

Methodology Applied
Scientific EffectPressurization: Pressurisation

Implementation Method 3

water is separated from the substrate in a filter press

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Implementation Method 4

water is evaporated from the substrate in a vacuum

Methodology Applied
Scientific EffectVacuum evaporation: Evaporation

Implementation Method 5

The suspension is then cooled countercurrently with water to below 100 °C

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP3824742B1Process and system for continuous production of sterile substrate for solid-state fermentation with mushrooms
Publication Date: 2023.11.08 VOGEL ULLRICH FELIX
  • EP3824742B1 patent drawingFigure 1

AI summary

Revealbart is a continuous process for the production of sterile substrates for the cultivation of fungal mycelium and fruiting bodies ("mushroom cultivation"). The process comprises providing a plant-based raw material consisting of at least 40% by weight (based on its dry weight) lignocellulose and hemicellulose, the raw material being formed from particles with an average size of less than 10 mm; mixing the plant-based raw material with water to form a mass with a solids content of 40 to 75% by weight; heating the aqueous mass to activate the microbiome present on the substrate; mixing the substrate with water to form a suspension with a solids content of 5 to 15% by weight; and heating the suspension. The suspension is pumped through two double-pipe apparatuses and a pressure vessel. There, it is heated continuously to 100 to 121 °C at a pressure of up to 2 bar.After separating the water from the recooled suspension, a sterile substrate with a solids content of 30 to 50 wt% is obtained. The water contained therein is evaporated at reduced pressure until the substrate has a water content of 45 to 55 wt%. The substrate is then inoculated with pure fungal cultures. A system for carrying out the process is also disclosed.