Collect and suspend residues
Distillers' stillage, filter dust, cleaning media, fusel oils and suitable sludge are combined with dry-matter-rich co-substrates to form a pumpable biosuspension.
Process solution for bioethanol plants
Biogas from distillers’ stillage and bioethanol residues
Distillers’ stillage and other bioethanol residues are converted through anaerobic digestion into biogas, biomethane, process heat and organic NPKS fertilisers. This reduces fossil-energy demand and supports energy self-sufficient bioethanol production.
Technology basis: German patent application DE 10 2014 001 912 A1
Starting challenge
Distillers’ stillage and bioethanol residues create high energy, logistics and disposal costs
Distillers' stillage has limited storability and makes the operator dependent on buyers and reliable transport logistics. Other residues such as filter dust, contaminated cleaning media, fusel oils and sludge contain additional energy and nutrient potential. At the same time, fossil process energy and high nitrogen and sulphur loads affect economics and process stability.
Process principle
From stillage and distillery residues to biogas, process energy and fertiliser products
Aerobic hydrolysis
The biosuspension is hydrolytically pretreated with air. This improves the accessibility of lignocellulosic components for subsequent methane production.
Multi-stage anaerobic digestion
The hydrolysate is treated in main and secondary digesters using adapted microbial cultures operated to preserve their activity. This allows varying residue qualities to be processed reliably.
Remove inhibitors
Ammonium and sulphur compounds are selectively reduced in recycled biofiltrates. The recovered nutrients are utilised as a liquid fertiliser concentrate.
Produce biogas and NPKS fertiliser
The biogas is desulphurised, dried and prepared for combined heat and power generation. The solid digestate fraction becomes an organic NPKS fertiliser.
Suitable feedstocks
Distillers’ stillage and other bioethanol residue streams
Distillers' stillage
Thin or concentrated stillage and solid fractions from mechanical separation.
Production residues
Filter and grain-cleaning dust, fusel oils, contaminated cleaning media and pressed sour-mash cake.
Wastewater-related residues
Sludge from on-site wastewater treatment and suitable flotation sludge.
Client benefits
Commercial, energy and environmental benefits for bioethanol producers.
Lower process-energy costs
Biogas can cover a significant share of the bioethanol plant's heat and power demand and reduce dependence on fossil fuels.
Lower disposal and logistics costs
Direct on-site utilisation reduces dependence on feed buyers, transport and external disposal routes.
Additional products and revenues
Organic NPKS fertilisers, surplus energy and potentially CO₂ certificates can create additional value.
More reliable residue management
Treating several on-site residue streams in one coordinated process chain improves disposal security and planning certainty.
Lower environmental impact
Fewer transports, lower odour and wastewater loads, and renewable process energy support the decarbonisation of production.
Potential for production expansion
Relieving on-site wastewater and residue systems can reduce existing bottlenecks and facilitate expansion.
Your bioethanol project