Digester and reactor engineering
Four concepts improve material flow, minimum treatment time, retention of specialised microbial cultures, hydrolysis and the use of existing stirred digesters.
4 innovationsTechnology portfolio
Technology innovations for biogas, biomethane and process plants
Six technical concepts combine digester and reactor engineering, decentralised plant modules and industrial process control. They address common bottlenecks such as high auxiliary energy demand, undefined minimum treatment times, difficult residues and fluctuating product quality.
This overview classifies each innovation by the initial problem, operating principle, application and technical benefit. The linked technical pages explain process flow, construction features and the published technical basis in detail.
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Technology fields
From digester engineering to industrial process control
The six solutions are grouped into three application fields, helping operators, investors and planners identify which technical direction may fit their project challenge.
Decentralised plant concepts
A mobile modular biogas plant supports the treatment of biogenic residues at sites with limited infrastructure.
1 innovationIndustrial process and control engineering
Independent temperature and pressure control stabilises the head of vacuum distillation columns, particularly in bioethanol production.
1 innovationTechnical solutions
Six innovations at a glance
Each card summarises the technical problem, operating principle, typical applications and key benefits. The detail page provides further process and construction information.
01
Decentralised plant concepts
Mobile biogas plant for decentralised sites
Transportable process modules treat faecal sludge, kitchen and food waste and similar biogenic residues at sites with limited infrastructure.
Technical basis: WO 2022/096048 A1- Initial problem
- Missing sewerage, unreliable energy supply, high mechanical auxiliary demand and changing waste volumes make small decentralised plants difficult to operate.
- Operating principle
- Multi-stage wet digestion in containerised modules; gravity, hydrostatic pressure and biogas pressure support material transfer and circulation.
- Typical applications
- Decentralised waste treatment, municipal residues, faecal sludge, kitchen and food waste, temporary sites and modularly expandable plants.
- Technical benefits
- Transportability, reduced pumping, mixing and compression demand, enclosed hygienising treatment and potential for largely energy-autonomous operation.
02
Digester and reactor engineering
Culture-retaining hydraulically circulated methane digester
Concentric inner and outer digesters combine hydraulic circulation with spatially separated microbial environments.
Technical basis: DE 10 2020 004 136 A1- Initial problem
- Mechanical mixers consume energy and require maintenance; complete mixing can displace specialised cultures and promote floating or settled layers.
- Operating principle
- Gas lift and controlled gas routing create natural hydraulic circulation between the outer and inner digester while different microbial cultures are retained in separate reaction zones.
- Typical applications
- Wet digestion of highly viscous, fibrous or nitrogen-rich residues and large digester volumes with demanding reliability requirements.
- Technical benefits
- Lower mechanical mixing energy and wear, retention of adapted microbial cultures, treatment at higher dry-matter contents and a more uniform raw-gas flow.
03
Digester and reactor engineering
Plug-flow methane fermentation
Defined hydraulic routing through connected digester zones limits short-circuit flows and provides a traceable treatment path.
Technical basis: DE 10 2016 009 223 A1- Initial problem
- In fully mixed continuous digesters, some feed may leave much earlier than indicated by the calculated average hydraulic retention time.
- Operating principle
- The biosuspension passes through outer and inner digester zones in a defined sequence; gas-pressure differences and hydraulic routing support plug flow without permanent complete mixing.
- Typical applications
- Fibrous and heterogeneous biomass, processes requiring defined minimum treatment time, hygienisation and high substrate utilisation.
- Technical benefits
- Assured minimum treatment time, improved conversion of slowly degradable components, retention of adapted cultures and lower mixing-energy and wear demand.
04
Digester and reactor engineering
Combined hydrolysis and fermentation apparatus
A central hydrolysis vessel and surrounding digestion zone integrate two biological process stages within one vessel geometry.
Technical basis: EP 2 982 739 A1- Initial problem
- Separate hydrolysis and digestion vessels require additional footprint, pipework, heat transfer surfaces and construction interfaces.
- Operating principle
- The heated wall of the central hydrolysis zone also tempers the surrounding digester, while hydrolysis gases are transferred in a controlled manner to the anaerobic stage.
- Typical applications
- New multi-stage biogas plants, retrofits of existing digesters or digestate stores and plants with alternating batch hydrolysis and digestion.
- Technical benefits
- Compact construction, direct heat integration, separated biological environments, reduced additional vessel and heating-surface demand and flexible reuse of existing structures.
05
Digester and reactor engineering
Batch operation of fully mixed stirred digesters
Existing or new stirred digesters operate alternately as temporarily closed batch reactors with partial emptying.
Technical basis: DE 10 2018 002 883 A1- Initial problem
- Continuous flow can wash out slow-growing cultures, allow short-circuiting and make defined minimum treatment or hygienisation difficult to demonstrate.
- Operating principle
- At least two vessels per process stage operate alternately; after treatment, part of the substrate remains as adapted inoculum for the next batch.
- Typical applications
- Repowering existing CSTR plants, multi-stage mesophilic and thermophilic digestion, fibrous or changing feedstocks and processes requiring hygienisation.
- Technical benefits
- Reuse of proven vessels, defined minimum times, retention of adapted cultures, improved substrate conversion and demand-based mixing operation.
06
Industrial process and control engineering
Temperature and pressure control in vacuum distillation
Independent control loops stabilise vacuum, head temperature and head pressure in a distillation column.
Technical basis: DE 10 2017 010 783 A1- Initial problem
- Variable pressure losses in the column and heat exchangers can change actual head pressure and distillate composition even when temperature appears stable.
- Operating principle
- The vacuum station maintains the base vacuum; recycled condensate controls head temperature and metered CO₂ or nitrogen stabilises absolute head pressure.
- Typical applications
- Vacuum distillation columns, particularly bioethanol production, processes with changing loads and plants with an available CO₂ source and heat-integration potential.
- Technical benefits
- More consistent product quality, lower process temperatures, transparent automated control loops, use of existing condensate and CO₂ streams and improved heat integration.
Project-specific engineering
From a technical concept to a robust plant solution
A published technical solution must always be adapted to the feedstocks, throughput, operating mode, safety requirements and existing plant configuration.
Check technical suitability
Feedstock analyses, dry matter, viscosity, biodegradability, temperature regime and required retention times determine whether a concept is suitable.
Engineer integration and safety
Vessels, pressure ratings, materials, gas routing, heat integration, instrumentation, control and permitting requirements are defined for the project.
Assess economics and rights
Capital expenditure, operating costs, savings potential and possible intellectual-property or usage rights are reviewed separately before implementation.
Notice on patents and intellectual-property rights
Some of the technical solutions shown are based on published patent applications or patent publications. Publication does not automatically mean that a patent was granted or that an intellectual-property right remains in force. Engineering design and any protection or usage rights must be checked for the specific project before implementation.
Your innovation project
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