Biogen invests in fleet of seven UNTHA food waste shredders for AD

Boroughbridge, Jul 27, 2015

What UNTHA shredding technology have you invested in to date?

We currently have five four-shaft RS40 shredders from UNTHA UK and have placed an order for a further two.

What are these shredders tasked with?

Biogen is the UK’s largest operator of food waste anaerobic digestion (AD) plants. We take organic materials from food manufacturers, retailers, pubs, restaurants, hotels, offices and homes (via local authorities) and process them to create:

  • Biogas, which is fed into a Combined Heat and Power unit to produce renewable electricity for the national grid
  • A pasteurised PAS110-certified digestate, which is returned to the agricultural industry as a biofertiliser to grow crops.


We have carefully designed and built a number of plants to cost-effectively transform food waste into these valuable resources. UNTHA’s shredding technology forms a key part of this system.

The shredders very much act as our ‘front line’ processing machines. They liberate unpackaged organic matter and materials stored in corn starch bags, achieving a core shred that our other sophisticated equipment can then handle. The robust RS40s also provide us with a much-needed defence mechanism – they have no problem dealing with contaminants such as metals, which protects the rest of our plant and ensures we do not have any unwanted foreign objects in our AD feedstock.

What throughputs do you achieve?

Throughputs depend on the feedstock but typically we process 8 tonnes/per hour, on average.



How do you tackle maintenance?

Our plants are incredibly valuable assets to us, so we take great care in ensuring the appropriate maintenance of all of our technologies. For the shredder, we have a defined maintenance regime. We carry out daily machine inspections and cleans, and grease the gearboxes weekly to ensure optimal operational performance. The RS40s are very easy to look after, and indeed run.

Every 12-18 months UNTHA’s specialist engineers carry out an overhaul of the machinery, very much like an MOT. This is a proactive measure we take to safeguard the uptime and productivity of our plants.

How do you rate UNTHA’s RS40 shredders in terms of cost?

Whilst the RS40 is not necessarily the cheapest machine on the market, it does this difficult job very well. What’s more, it is an incredibly cost-effective machine in terms of ongoing running costs and spare parts, and its productivity and uptime means it is a value-adding tool for our business.

Anything else?

When we work with technology providers, we often find that they are learning ‘on the job’ from our experienced food waste experts. However, UNTHA has been operating in this specialist field for some time, therefore they have a solid understanding of our industry and our complex shredding requirements.

A message from UNTHA’s food waste shredding expert Gary Moore:

“The UNTHA RS40 is a specially-configured machine with an innovative cutter and sealing system, perfect for shredding organic waste and packaging. This slow running technology has been specifically designed to produce a reliable particle size. Key benefits include foreign object protection, impressive uptime and productivity, machine durability, low running costs, ease of maintenance and the support of a knowledgeable aftersales team.”

To find out more about UNTHA’s approach to shredding food waste for anaerobic digestion, please visit our dedicated organic waste shredding page. Alternatively, if you would like to speak to one of our food waste shredding experts please contact us via email or call +44 845 450 5388.