The concept of MBT originated in Germany where it is an established waste treatment method.

Regulatory restrictions on landfill space, subsequent landfill bans, the search for alternatives to incineration and increased costs of alternative disposal have been the major drivers for the development of these Technologies.

Growth will be mainly driven by the implementation of European-wide energy and waste legislation, such as the Landfill Directive and the Waste Framework Directive

Renesco, serves primarily international operating and integrated waste treatment companies


Anaerobic digestion (AD) is an economically and politically preferred treatment method for organic waste streams. WTT-RENESCO can supply two different AD systems to be able to find the optimal solution for each specific situation: the Dry AD batch process and Wet AD systems.

Composting and biodrying WTT-RENESCO’s biological tunnel process is individually controlled in order to provide each batch with a tailor-made treatment

Odour reduction systemsWTT has developed a wide range of odour-reduction systems, including bio filtration and air humidification technology

Mechanical Treatment

WTT-RENESCO specializes in designing and constructing the most efficient and sustainable integrated mechanical solutions. Without adequate mechanical treatment, aerobic and anaerobic biological processes will not function

By cooperating with our suppliers throughout the world, we are able to provide solutions at any time and place. No matter what mechanical technology is required. WTT-RENESCO will always select the most suitable equipment for the benefit of our clients.

Mechanical Biological Treatment (MBT)

WTT believes that integrating mechanical and biological technology in waste treatment facilities is the way forward. WTT is one of the biggest European players in building integrated mechanical biological treatment installations (MBT)


The turnkey approach ensures WTT-RENESCO as owner of the complete process technology. Hereby WTT-RENESCO can avoid duplicating expensive processes and suboptional interfaces between different suppliers and technology.


WTT can offer several service packages including plant audits, training and the complete management of spare and wear parts. The customer is assured of in time delivery of required original spare and wear parts that support a plant performing at its best, without spending a lot of time to procure necessary parts itself. WTT can offer its customers attractive prices due to bulk purchase.

Types of Digestion Plants:



Biomass is turned into soup, soup is digested in stirred tank reactor.
Dry solids in reactor 5-12%
Continuous system



Biomass is more like sludge, digested in plug-flow reactor.
Dry solids in reactor 10-20%
Continuous system



Biomass is solid, digested in a tunnel without diluting.
Dry solids in reactor 20-40%
Discontinuous system (batch process)

Natural process which takes place in swamps. Recognized by the fermenter tank (“big balloon”)
Different words for the same process:
Anaerobic digestion plant(AD plant)
Fermentation plant
Digestion plant
Biogas plant

Anaerobic (Oxygen < 1%)

  • Biomass + heat => inerts+ CH4 + CO2
  • Endotherm (heat demand)
  • Biogas in the system (Explosive)
  • 3 –4 weeks duration
  • End product = digestate(no compost!)
  • Lignin not decomposed



Optimal DRY AD process parameters:

  • Filling the tunnel / Optimal filling by loader
  • Temperature37 / -42 ºC
  • Oxygen concentration / < 1%
  • Humidity / 60-70 %
  • pH / 7-8
  • Waste composition / 0,65 T/m3


Conversion of organic material towards a stable, inactive product

The following features characterize composting:

  • Aerobic (Oxygen > 8%)
  • Biomass + Oxygen
  • Exotherm (heat production)
  • Air in the system
  • 2-8 Weeks process duration
  • End product = Compost
  • Lignin (woody material) is decomposed



Tunnel system (in-vessel composting) because:

  • 1.Control of all parameters
  • 2.Shortest processing time
  • 3.Control of all emissions
  • 4.Lowest possible footprint using a spigot aeration system
  • 5.Internal recycling of air for maximum process control while maintaining the building in negative pressure
  • 6.Automated water spraying for moisture control
  • 7.Low staff exposure to contaminated air

Composting Phase: “Hygienisation”

  • To kill pathogens and weed seeds
  • Necessary to make quality compost from food waste
  • Different legislation per country
  • Australian standard: 3 days above 60oC

Composting Process Parameters:

  • 1- Composting temperature / 52 ºC
  • 2-Oxygen control / 12 -21%
  • 3-Humidity(water) control / 40 -60%
  • Optimal setpoints= Responsibility operators

    Software = Responsible for maintaining these setpoints

  • 4-Density (filling/mixing tunnel) 0,6 –0,65 T/m3
  • Human operation = Responsibility operators