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Composting is revenue.

ZWE offers a number of approaches to turn SMARTFERM® digestate into salable compost.  Our fully enclosed  In-Vessel Composting System is a proven industrial approach to complete maturation of compost for sale.  The ZWE Lane Turner is the newest technology to use traditional turning technologies with IVC to mature and process digestate into high quality compost.

ZWE offers a post-digester treatment technology to mature the compost and remove ammonia from the digestate with its In-Vessel Composting (IVC) and Lane Turner (LT) technologies.  IVC is a fully enclosed system that accelerates and accurately controls the natural aerobic break down of biodegradable waste to create a high-quality compost product.  With the ZWE patented IVC and LT Systems, the active compost process and maturation period can be accomplished in less than 28 days.  At the end of this period, compost is ready to bag for retail sales or sold in bulk to end users.

ZWE can also provide a partial treatment version of its IVC System that offers a more limited process.  This is a shorter process that treats digestate for three to four days in the IVC tunnel, removing most of the odor-causing ammonia to make it acceptable for truck transport, if necessary.  The combination of the ZWE AD process for green energy production and IVC for composting of the digestate yields a complete organics strategy that can be deployed in an urban location.

Highlights of the full IVC process include:

  • The 28-day batch average cycle time is more than 50% less than traditional aerobic compost processes.  It includes the active composting process as well as the aeration and circulation system to expedite pathogen kill and control odors.
  • The finished product meets all Process to Further Reduce Pathogens (PFRP) requirements and is technically classified as finished compost.
  • Plants require a smaller footprint than traditional systems because there is no requirement for product maturation in windrows.  This creates opportunities for comprehensive urban applications as well as lower infrastructure and operating costs.
  • All odor issues are addressed during the 28-day process.
  •  The material produced at the end of the process contains the lowest moisture content of any available system and produces premium grade, mature compost.

These features allow for a high proportion of the waste stream to be diverted from the landfill and add value by improving material throughput time.  This creates advantages for the customer in the form of reduced storage space requirements and lower operating costs per ton processed. It also effectively addresses pathogen kill requirements, eliminates odor concerns, and produces mature compost.

Lane Turner technologies are an alternative to our In-Vessel Composting. Our closed lane composting provides dynamic material processing for homogeneous moisture distribution, good access for fresh air supply, thorough disintegration of larger aggregates, and faster processing and better process control.  The closed lane design of lane turners also assists in emission control. The optional irrigation system enables adjustment of moisture content.

The turning device is a rotor that is installed horizontally and guarantees intensive aeration and homogenization of the rotting material.  The material is transported in longitudinal direction by the turning process. The machine drives on rubber-lined running gears, which are fully automatically controlled on the lane walls.  The wheel hub motors are controlled via hydraulic system.

Starting with automatic operation at the discharge side, the rotor is lowered into the material and moves with working speed towards the input. Lateral guiding assemblies guarantee directional stability on the lane walls. At the end of the lane the rotor is brought into transport position automatically by means of a special excavation kinematics.

The main components of this aerobic, closed lane composting treatment include lane structure, lane roof, lane turner, transfer wagon, irrigation system and aeration floor.

Compared with existing composting systems:

  • Lower construction costs
  • Smaller facility footprint
  • Highest turning capacity on the market
  • Shorter processing/residence time
  • Reduced air handling requirements/costs
  • Reduced maintenance costs as process equipment operates outside the material enclosure
  • Flexibility to process multiple waste streams, either batch or continuous, all in the same facility

Process applications:

  • Mechanical Biological Treatment (MBT)
  • Composting
  • Bioremediation
  • Sludge treatment