Trial of catering waste composters.

Biolan 550 and 220 closed vessel compost bins.

550 litre capacity (120cm x 88cm x 74cm).

Integrated thermometer.

2 year manufacture guarantee

Cost - £737 plus vat

220 litre capacity (120cm x 75cm x 75cm).

Integrated thermometer.

2 year manufacture guarantee.

Cost - £615 plus vat

Erddig Hall(2no.), Chirk Castle(2no.), Powis Castle(1no.), Llanerchaeron(1no.).

Medium price range closed vessel composters.

Treats all catering wastes (including cooked meat products). Fully compliant with Animal bye-law exemptions.

Insulated composting vessel allows all year round operations.

Mixture 50/50 - catering waste/woodchip

Ideally purchase 2no. – Allows one to mature whilst filling the other.

Compost transferred via lower access point to site composting pile where aerobic composting process is completed.

Feedback.

“These stopped working over the winter as the temperature dropped. I did consolidate some, to completely fill one, to try to mix it a bit and aerate the compost but things have only just started to pick up temperature wise.I need to find time to sort through the oldest bin full and move stuff to the garden compost heaps to continue aerobic digestion.There is quite a lot of poor material goes in them. Thick potato skins, (peeled with a knife not a peeler) Onion skins, lemons. Teaspoons.” – Glyn Smith (Head Gardener, Erddig)

- Although sold as all-year round systems, extreme temperatures obviously affect the composting process. In order to ensure compliance with Animal bye-law regulations the contents must reach temperature in excess of 65 degrees celsius to ensure pathogens are destroyed. Colder temperatures mean that this process takes longer.

Another reason to have 2 bins = one can be left closed in order to retain heat from the composting process.

-Initial “teething troubles” with the locking hinge mechanism.

Plastic hinge mechanism locks the lid open for ease of access. Unless staff are aware of the need to press the release mechanism on the hinge the act of forcing the lid breaks the hinge mechanism.

Bioclere technologies - http://www.bioclere.co.uk/composting-composters.php

Were extremely quick and efficient in sending out replacement mechanisms at no cost.

“Only issue at the moment is the odour coming off the Biolan composter.  It is working fantastically and hitting 55-60 degrees C but producing the smell you would expect from the composter.  Several staff members that pass by the recycling compound have expressed a dislike of the smell.  Otherwise it is no problem to the public.” – Adrian Lovatt (Head Gardener, Powis Castle)

- As with any “new” system, the cultural and training elements affect success or failure. The need to take “ownership” of the composter means that lapses in ensuring the 50/50 mixture of catering waste and woodchip leads to odour problems. Obvious issues if liquids are added (soups and sauces).

Jura JK270 composterThe JK125/270 is divided into two compartments. One is being filled while the compost in the other matures. Once the compartment being filled can take no more, the mature compost is emptied from the other compartment, and the cycle begins again.

It will take somewhere in the region of 6 to 8 weeks for each chamber from starting to fill to production of compost - so once both chambers are in operation you should be emptying one chamber every 3-4 weeks or so.

Woodchip must be added to provide a source of carbon for micro-organisms (as with the Biolan composter).

JK 270 costs £349 plus £40 delivery - total £389

Dimensions -950 x 836 x 836 mm (38 " x 33" x 33") overall with standCapacity -30 litres or 15 kg per week

Website - http://www.smartsoil.co.uk/composter270.htm

At Llanerchaeron, the JK270 is being used solely to provide high quality compost for the walled garden.

No catering waste is being composted, instead Paul Boland, Property manager confirms that the composters “tombola” action ensures high quality

The insulated closed vessel composter ensures that the production of quality compost does not slow too much even during the recent Winter months – taking 8 weeks for full composting action to take place.

Aerobin 400 Hot composting vessel.

Dimensions –740mm x 740 mm x 1200 mmCapacity 400 litres/400 kg3 years manufacturers guaranteeCost - £239 plus vat

www.Aerobin400.com

Has a static aeration lung which allows passive ventilation throughout the whole composting mass.

Leachate collects at the bottom. This can be used as liquid fertiliser.

Currently being trialled at Plas Newydd and Powis Castle catering outlets.

Feedback –

Does need a combined approach with catering staff and gardens team working together to ensure the composting material is not too moist (Again, bulked up with equal amounts”Brown material”).

Not as robust as the Biolan composters, and obviously cannot take meat products. This is reflected in the overall price of the composter.

There have been odour problems due to the extreme cold periods and too much liquid entering the composter. This is now sorted out.

Gardens team liked the liquid fertiliser collection at the bottom of the composter. This is being used in the glasshouses at Plas Newydd.

A500 – A1200 “Rocket Closed Vessel Composter.

Cost – Up to £15,000

The largest and most complex of the closed vessel composters. Incorporates an electrically heated jacket to ensure temperatures rise above 60 degrees celsius.

Integrated timed auger system which moves the composting material along the composter. Can provide data logging of the temperatures reached at the various stages of the composting process

Suitable for larger scale composting activities, and is suitable for all catering wastes including cooked meat products.

Feedback –

Must be sited undercover.

Requires a 240 volt power supply. Associated running costs which rise depending on the size of the composter from £.50 per week to £1.20 per week.

Quite an involved composting process as large stores of woodchip required. “Fiddle factor” in order to get the correct consistency of compost.

Currently in operation at Craflwyn Hall –

Some issues with “Too wet” compost coming out of the machine due to internal filters becoming blocked. These are not easily accessible for ongoing preventative maintenance.

During extreme cold period the fuses on the control panel have consistently blown. Also several panels fail over time.

Summary• All of the above composter vessels suffer from extremes in cold. The composting process invariably slows over Winter periods.

• The type of composter you choose is dependant on the scale of operation, space restrictions, financial constraints.

• Jura – Produces high quality compost, but not in large quantities. Ease of operation, with the two access doors allowing one to be left to mature whilt the other compartment is filled.

• Rocket – Expensive to purchase. Requires appropriate infrastructure and is quite labour intensive. Associated ongoing electrical running costs.

• Aerobin – Cost effective solution for hot box composting at small to medium sized properties. Not suitable for Cooked meats.

• Biolan – This has been the most successful composter. Suitable for cooked meat products (meeting Animal bye-law regulations). Well priced, offering a robust and well insulated closed vessel composter.

NB: All of the composter vessels require “buy in” from staff in order to ensure quality compost production.