Testing the Compostability of Commercial Feedstocks & Other Applications on a Bench Scale Composting Reactor

Envar and Gicom Composting Systems b.v. have developed a bench scale composting reactor that replicates the operating conditions of commercial scale Gicom composting tunnels by using sophisticated environmental control software. Using the same software and principles as the commercial scale system allows us to derive accurate test data on a variety of feedstocks prior to potential full scale application. The reactor could also assess the effects of the composting process on a variety of other applications like the degradation of pesticides and pathogen kill.

Operation of the Bench-Scale Reactor

The schematic diagram below shows the design of the reactor. The central part of the composting reactor is a stainless-steel chamber of 30 litre capacity which holds the composting material. The chamber which has a lid which can be screwed down tightly to provide an air-tight seal, sits within a heated control box that supplies the air movement and temperature-control hardware. The composting chamber is linked to the control box by means of a number of ports monitoring:

Inlet air temperature

Return air temperature

Compost temperature

Air flow volumes


Applications to date

The unit was commissioned in early 2010 and used initially to undertake composting trials for the Home Office under CBRN (Chemical, Biological, Radiological & Nuclear) Resilience Programme.

Further work has been completed to:

Compost digestate from wet and dry Anaerobic Digestion (AD) processes with the findings presented at an international conference in Des Moines, in October 2010.

Blend vegetable based digestate with other feedstocks such as wood shavings and finished green waste compost to produce a nutrient rich product with an increased percentage of dry solids.

Study the degradation of biodegradable bags under conditions that simulate the pasteurisation phase required by the ABPR and the composting phase in windrows.

Assess the biodegradability of certain mix of feedstocks and to supply data to support end of waste status of these blends.
What Envar Can Offer

The bench scale composting reactor is situated at the Envar Composting Facility in St. Ives, Cambridgeshire. Envar offer a service to the industry that covers all aspects of compost feedstock testing and trials.

This includes:

Designing trials as required specific to a certain feedstock.

Carrying out tests & trials

Providing trial data & laboratory analysis

Customer contact at every stage