Food Waste Depackaging System Review

The Veolia Ecrusor™ is a twin-auger food waste depackaging system designed to separate packaged biodegradable material before anaerobic digestion or sewage-sludge co-digestion.

The machine uses two shaftless screw augers to agitate and compress packaged waste against a toothed end plate. The teeth puncture or cut the packaging while pressure generated by the augers forces food and liquid through perforated screens into a collection hopper below.

This article reviews how the Ecrusor works, the feedstocks for which Veolia promotes it, the available operating evidence and the questions buyers should resolve before selecting the system.

Disclosure: This is an independent equipment review based on publicly available information. Performance statements attributed to Veolia should be confirmed through representative feedstock testing and contractually defined acceptance criteria.

Key Takeaways

The Ecrusor uses two shaftless screw augers, a toothed end plate and perforated screens to open packages and recover their organic contents.
Veolia calls the augers “spiral grinding screws,” although its public description does not identify a separate grinding mechanism within the screws.
The principal package-opening action appears to occur when the augers press containers against protruding cutting or puncturing teeth.
At Hermitage Municipal Authority, the Ecrusor was installed in parallel with an existing hammermill, providing a separate depackaging route.
Veolia does not state whether that hammermill was later removed, retained as standby capacity or continued to process particular waste streams.
Additional screening was used at Hermitage to prevent residual contaminants from entering downstream processes.
Veolia publishes a maximum volumetric capacity of 52 cubic yards per hour, but buyers should obtain a guaranteed mass throughput for their own feedstock.
The cleanliness, moisture content and recyclability of the discharged packaging should be demonstrated rather than assumed.

Image showing the Veolia Ecrusor unit for depackaging. — Copyright VEOLIA and downloaded with no changes.

What Is the Veolia Ecrusor?

The Veolia Ecrusor food depackaging and organics recovery system is designed to extract food and other biodegradable material from its packaging before biological treatment.

The recovered organic material passes through perforated plates and is collected as a pumpable slurry. Plastic, metal, cardboard and mixed-material packaging retained by the screens is discharged separately.

Veolia promotes the Ecrusor particularly for wastewater treatment facilities that wish to co-digest imported food waste with sewage sludge. Imported organic material can potentially:

increase the organic loading available to anaerobic digesters;
increase biogas production;
generate waste-reception income;
divert biodegradable waste from landfill; and
support combined heat and power or biomethane production.

How Does the Ecrusor Work?

Veolia describes the machine as using “spiral grinding screws” that move forwards and backwards while agitating, squeezing and breaking apart packaged waste.

The Renewable Energy Association provides a more readily understandable mechanical description. It describes the Ecrusor as using two shaftless screw augers to force packaged food against a plate fitted with protruding teeth. Those teeth puncture the packaging, allowing food and liquids to be forced through a screen into a hopper beneath.

The operating sequence appears to be:

Packaged or unpackaged waste is discharged into the receiving hopper.
Two shaftless screw augers move, agitate and compress the material.
The augers force packages towards a toothed end plate.
The protruding teeth puncture, cut or tear open the packaging.
Continued auger pressure squeezes food and liquid from the opened containers.
The recovered organic fraction passes through perforated screens into a hopper below.
Packaging retained above the screens is conveyed towards a separate discharge point.

What Does Veolia Mean by “Grinding Screws”?

Veolia refers to the augers as “spiral grinding screws.” However, its published explanation does not identify separate knives, grinding discs or a conventional grinding chamber incorporated within the screws themselves.

Any auger handling mixed food waste will churn, compress and abrade the material to some extent. This may produce a grinding effect, but that does not necessarily make the screw a grinder in the usual engineering sense.

Based on the available description, a clearer engineering summary would be:

A twin shaftless-auger compression and screening system in which packaged waste is opened against a toothed plate.

The package-opening and separation action appears to result from the combination of:

agitation and pressure generated by the augers;
protruding puncturing or cutting teeth;
compression of the opened packages; and
perforated screens through which the organic fraction is expressed.

This differs from machines in which hopper augers merely meter waste at a controlled rate into a separate depackaging chamber. In the Ecrusor, the augers and toothed plate together form the principal depackaging mechanism.

Does the Ecrusor Incorporate a Hammermill?

No hammermill is identified as part of the Ecrusor machine itself.

Veolia’s case study for Hermitage Municipal Authority states that the Ecrusor was installed in parallel with an existing hammermill. The two machines, therefore, provided separate depackaging routes rather than consecutive stages in which the Ecrusor fed a hammermill.

Veolia does not state whether the hammermill was subsequently removed, retained as standby capacity or continued to process particular waste streams.

Possible reasons for retaining two parallel lines could include:

maintaining operational resilience during commissioning;
providing standby depackaging capacity;
accommodating peak loads;
processing different packaging or feedstock types; or
avoiding dependence on a single machine.

However, these are possible explanations only. Veolia does not provide sufficient information to establish the later operating strategy at Hermitage.

Downstream Screening at Hermitage

Veolia reports that further screening of the recovered organic material was used at Hermitage to prevent contaminants from entering downstream processes.

This downstream screen should not be confused with the existing hammermill. It appears to have been included as an additional contaminant-control stage after depackaging.

This is an important design consideration. A depackaging machine should normally be assessed as one component within a complete reception, separation and digester-feed system.

Depending on the feedstock and the performance required, additional treatment may include:

fine screening;
grit and glass removal;
magnetic metal separation;
dense contaminant removal;
buffer storage and mixing;
pasteurisation; and
protection for pumps, heat exchangers and digesters.

Feedstocks Identified by Veolia

Veolia identifies potential Ecrusor feedstocks including:

expired dairy products;
meat products;
confectionery manufacturing residues;
bakery waste, including cooked and uncooked dough;
expired soft drinks;
expired packaged foods;
waste from grocery chains;
food waste from cafeterias, restaurants and commercial kitchens;
household and kitchen waste;
landfill-diverted organics;
dairy-processing waste;
sewage liquids containing between 1% and 30% dry solids;
septic-tank sewage; and
dewatered sludge cake from other facilities.

This is a very broad range. Suitability should be demonstrated through representative trials because rigid containers, flexible film, cans, composite cartons, cardboard packs and loose slurries will behave differently within the machine.

Published Capacity

Veolia states that the Ecrusor is capable of processing up to 52 cubic yards of waste per hour.

This is a volumetric figure rather than a mass-throughput guarantee. The weight represented by 52 cubic yards will vary considerably according to:

feedstock bulk density;
packaging type;
liquid content;
the proportion of loose and packaged material; and
the consistency of the flow with which the hopper is supplied.

Prospective buyers should obtain a guaranteed tonnes-per-hour throughput based on representative feedstock, together with the bulk-density assumptions used in the calculation.

Evidence from the Hermitage Installation

Veolia has published a case study describing the Ecrusor installation at Hermitage Municipal Authority in Pennsylvania, USA.

The wastewater treatment facility imported high-strength organic wastes to increase biogas production from its anaerobic digesters. An Ecrusor was installed in parallel with an existing hammermill that Veolia describes as labour-intensive and requiring frequent operator intervention.

According to Veolia:

the Ecrusor increased food-waste processing capacity tenfold compared with the previous arrangement;
labour and operator intervention were reduced;
packaged material could be received without extensive manual preparation;
the unit was capable of processing approximately 15 tons of imported organics per day; and
additional screening prevented contaminants from entering downstream processes.

Veolia reports that the facility received approximately 12 to 20 tons of imported organic waste for every 20 tons of municipal sludge processed.

The reported tenfold capacity increase is a site-specific comparison with the earlier arrangement. It should not be interpreted as proof that every Ecrusor installation will achieve the same improvement.

Potential Advantages of the Ecrusor

A mechanically straightforward concept

Shaftless screw augers are well-established components in wastewater and waste-handling applications. Their use is not, by itself, an unusual innovation.

Nevertheless, a mechanically straightforward system may offer operational advantages. Shaftless augers can handle irregular and sticky materials without material winding around a central shaft.

Opening packaging without high-speed impact milling

The Ecrusor appears to open packages through relatively slow agitation, compression and puncturing rather than high-speed hammermill impact.

This may retain packaging in larger pieces than a conventional hammermill. Retaining relatively large packaging fragments can reduce the number of small pieces capable of passing into biological treatment and may improve the potential for subsequent identification or sorting.

Integrated receiving and depackaging

The augers do more than convey material at a consistent rate. They also apply the pressure required to force packages against the toothed plate and express their organic contents through the screens.

Reduced operator intervention

At Hermitage, Veolia reports that the Ecrusor accepted packaged material with less operator intervention than the existing hammermill arrangement.

Integration with wastewater treatment facilities

The Ecrusor appears particularly suited to wastewater treatment works that already possess:

anaerobic digesters;
sludge tanks and pumping systems;
biogas storage and utilisation equipment;
liquid waste reception facilities; and
trained process operators.

An established process supplier

Veolia Water Technologies has extensive experience in wastewater treatment, sludge processing, anaerobic digestion and resource recovery. This may be attractive to buyers seeking an integrated co-digestion system rather than a standalone machine.

Technical Limitations and Unanswered Questions

The meaning of “grinding” remains unclear

Veolia’s term “grinding screws” may suggest more deliberate particle-size reduction than is evident from its published description.

Until more detailed drawings or test data are available, buyers should not assume either that the screws perform substantial grinding or that the packaging remains almost intact.

A representative reject sample and particle-size analysis should be requested.

Organic slurry dry-solids concentration

Veolia describes the recovered output as pureed or macerated organic material but does not publish a universally applicable output dry-solids concentration.

Excessive dilution can:

consume digester hydraulic capacity;
increase pumping and heating requirements;
reduce the organic loading that can be accepted by an existing digester; and
increase the quantity of digestate requiring storage and management.

The slurry concentration cannot be assessed reliably from promotional video footage. It should be measured during representative feedstock trials.

Reject cleanliness and moisture content

Veolia describes the separated packaging as inert material sent towards a collection or recycling bin. This should not be interpreted as proof that the reject will automatically be clean, dry or commercially recyclable.

Publicly available product information does not provide sufficient data to establish:

the residual organic content of the reject;
the reject moisture content;
the amount of food trapped within folded or crushed packaging;
whether separate reject washing is included at a particular installation;
whether the material requires further dewatering or drying; or
whether it meets the acceptance criteria of a recycler or fuel producer.

“Inert packaging” does not necessarily mean a recyclable product

The word “inert” appears to be used to distinguish packaging from biodegradable organic material.

It does not necessarily mean that the reject is:

free from adhering food;
dry;
sorted into individual materials or polymers;
accepted by a recycling facility;
suitable for solid recovered fuel production; or
capable of generating revenue.

If the reject remains wet, mixed and contaminated, it may continue to represent a disposal or energy-recovery cost.

Reject recyclability

The practical destination for the separated packaging will depend on:

remaining organic contamination;
moisture content;
particle size;
the mixture of films, rigid plastics, metals, paper and composite materials;
local recycling infrastructure;
the availability of RDF or SRF outlets; and
the acceptance criteria imposed by the receiving facility.

A confirmed outlet and written material specification should be obtained before recycling revenue or avoided disposal costs are included in the project business case.

Organic recovery and slurry purity

No universally applicable independently verified recovery or slurry-purity guarantee has been identified in the public product information reviewed for this article.

Buyers should measure three separate performance indicators:

Organic recovery: the proportion of available food recovered from the incoming packaged waste.
Reject organic loss: the amount of food remaining attached to or mixed with the discharged packaging.
Recovered slurry purity: the concentration of plastic, metal, glass and other physical contaminants in the organic output.

A machine may achieve high organic recovery while producing contaminated slurry, or clean slurry while losing an excessive quantity of food with the rejects. Both recovery and purity must therefore be assessed.

Questions to Ask Before Buying an Ecrusor

What mechanical action is intended by the term “grinding screws”?
Do the screws contain any cutters, teeth or other grinding elements?
At what rotational and reciprocating speeds do the augers operate?
What packaging particle-size distribution is produced?
What screen apertures are available?
What mass throughput is guaranteed for the proposed feedstock?
What organic recovery and slurry-purity levels are guaranteed?
How much organic material remains with the discharged packaging?
What process water is added per tonne of incoming waste?
What dry-solids concentration is achieved in the recovered slurry?
What moisture and organic content remain in the reject?
Is any reject washing system included, optional or site-specific?
Does the reject require further dewatering, washing or drying?
Has a recycler, RDF producer or SRF outlet agreed to accept the material?
What additional downstream screening and grit removal are required?
What electrical energy is consumed per tonne processed?
What are the expected service lives of the screws, teeth and perforated plates?
How is the equipment cleared following a blockage?
What feedstock trial and acceptance-test procedure will form part of the contract?
What is the footprint needed for the equipment?
Maintenance and spares required?
Power consumption?

Independent Assessment

The Ecrusor appears to be a credible industrial depackaging machine based on a relatively straightforward arrangement of two shaftless augers, perforated screens and a toothed end plate.

The use of shaftless augers is not itself unusual within waste and wastewater equipment. The more significant feature is the way the augers apply pressure against the toothed plate, opening containers and expressing their contents through the screen.

Veolia’s term “spiral grinding screws” arguably makes the mechanism sound more specialised than its published description demonstrates. However, mechanical simplicity may be an operational advantage rather than a weakness.

The Hermitage case study confirms that the Ecrusor was installed as a separate depackaging route operating in parallel with an existing hammermill. It would therefore be incorrect to describe the Ecrusor as merely a twin-auger receiving hopper feeding that hammermill.

Equally, Veolia does not state whether the hammermill was later removed, retained for standby duty or continued to process selected waste streams.

It also appears inappropriate to classify the Ecrusor itself as a hammermill-based, high-impact depackager. Nevertheless, its environmental and commercial performance should be judged from measurable outputs rather than its brand description.

The most important performance considerations are:

packaging fragmentation;
organic recovery;
recovered slurry purity;
added-water demand;
slurry dry-solids content;
reject cleanliness and moisture;
downstream screening requirements;
operating and wear costs; and
the availability of a viable reject outlet.

Where preserving packaging, producing a relatively clean and dry reject, minimising water addition or maximising reject recovery is a priority, buyers should compare the Ecrusor with other food waste depackaging machine technologies using the same representative feedstock and test protocol.

Frequently Asked Questions

Is the Ecrusor a twin-auger system?

Yes. The Renewable Energy Association describes it as using two shaftless screw augers. Veolia calls these components spiral grinding screws.

Do the augers merely feed another depackaging machine?

No. In the Ecrusor, the augers apply pressure that forces packages against a toothed plate and expresses the organic contents through perforated screens. They form part of the depackaging mechanism itself.

Does the Ecrusor contain a hammermill?

No hammermill is identified as part of the Ecrusor. At Hermitage, an existing hammermill operated in parallel as a separate depackaging line.

Did the Ecrusor replace the Hermitage hammermill?

Veolia does not say. Its case study states that the Ecrusor was installed in parallel with the existing hammermill, but it does not state whether the hammermill was later removed, retained as standby capacity or continued to process selected wastes.

What creates the package-opening action?

The augers force packages against protruding teeth on an end plate. The teeth puncture or cut the packaging, after which auger pressure squeezes food and liquid through perforated screens.

Does the Ecrusor produce recyclable packaging?

Not necessarily. The separated material may remain mixed, wet or contaminated. Its recyclability depends on measured reject quality and the acceptance requirements of an identified outlet.

Does the Ecrusor produce a dry reject?

Veolia does not publish a universally applicable reject moisture specification. Buyers should require representative testing to determine moisture content and the quantity of organic material remaining in the discharged packaging.

Does the Ecrusor require additional downstream screening?

This depends on the incoming waste and the downstream process. At Hermitage, Veolia states that further screening was used to prevent contaminants from entering downstream treatment equipment.

Ecrusor™ Food Depackaging and Organics Recovery – Veolia