Anaerobic Digestion of Distillery Spent Solids
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Solution Overview
Problem
Current anaerobic digestion processes for energy crops are not effectively utilized for waste products from distillery and other industrial sources, requiring specific conditions for each substrate and lacking a simple, wide-range applicable method for biogas and methane production.
Innovation Solution
A process involving a slurry with high bicarbonate alkalinity, subjected to anaerobic digestion at pH 6.6-7.6, using spent solid products from malt and grain distilling, and potentially recycling liquid digestate to maintain alkalinity, allowing for continuous or semi-continuous operation with various substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional anaerobic digestion processes are used for energy crops, then biogas production is achieved, but the process requires specific conditions for each substrate and cannot effectively process distillery waste products
Solution Approach 1:
The patent changes the pH parameter to a neutral range (6.6-7.6) and maintains high bicarbonate alkalinity (≥2000 mg/L as CaCO3) to create optimal conditions for mesophilic methanogenic bacteria. This parameter adjustment enables the system to process diverse substrates including distillery spent solids that cannot be effectively digested by conventional acidophilic processes
Solution Approach 2:
The patent creates a universal anaerobic digestion system that can process multiple substrate types (energy crops, distillery spent solids, brewery waste, food waste) using the same neutral pH conditions and mesophilic methanogenic bacteria, eliminating the need for separate process configurations for different substrates
2Reliability
If pH control is maintained in conventional anaerobic digestion, then process stability is achieved, but constant monitoring and adjustment is required for each substrate
Solution Approach 1:
The patent employs high bicarbonate alkalinity (≥2000 mg/L as CaCO3) which provides natural buffering capacity that maintains pH stability without requiring constant external control. The system self-regulates pH through the bicarbonate buffer system, reducing operational complexity while maintaining process reliability
Solution Approach 2:
The bicarbonate alkalinity acts as an intermediary buffer that mediates pH fluctuations during digestion. The high bicarbonate concentration absorbs acid production from substrate degradation, maintaining stable pH conditions without requiring active control mechanisms
3Productivity
If spent solids from distilling are not processed, then they remain as waste material, but no biogas or methane is produced from these substrates
Solution Approach 1:
The patent converts distillery spent solids, which are typically discarded as waste or used only for low-value animal feed, into valuable biogas and methane energy sources. The neutral pH anaerobic digestion process extracts energy from these waste materials, transforming them from environmental burdens into renewable energy resources
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
Enables efficient biogas and methane production from diverse spent solid materials, reducing the need for constant pH control and enabling the use of a wide range of substrates, including those with high protein content, with significant biogas production achievable in shorter retention times.
Implementation Method 1
subjecting the slurry to an anaerobic digestion comprising methanogenisis at a pH of pH 6.6 - 7.6, in order to obtain a biogas and liquid digestate
Implementation Method 2
subjecting the slurry to an anaerobic digestion comprising methanogenisis at a pH of pH 6.6 - 7.6
Implementation Method 3
providing a slurry comprising one or more solid spent product(s) and a liquid which possesses a high bicarbonate alkalinity
Data Source
AI summary
The present invention provides a process for producing biogas and/or methane from solid spent products derived from, for example, the mashing process of malt whisk(e)y and/or beer production, processing of sugar or other industrial processes. There is also provided a system for producing biogas and/or methane from solid spent products derived from, for example, the mashing process of malt whisk(e)y and/or beer production, processing of sugar or other industrial processes.