Case Study: ecoDRYER, the digestate dryer

A well established Suffolk farm growing a wide variety of soft fruits installed a Anaerobic Digester (AD) to produce biogas from their spoiled fruits. It feeds the combined heat and power (CHP) plant which generates 1.25MW/hr of electricity. As a result, the site produces approximately 12,000 tonnes of excess digestate per annum. Continuous emptying of the digestate storage tank is necessary to achieve a uninterrupted supply of electricity.

ecoDRYER installation
The digestate has about 6% dry matter (DM) content. Typical digestate is a good source of natural nutrients and is usually spread on the land. Unfortunately, spreading can only take place, at most, three times a year so large digestate storage tanks or lagoons are necessary to store the excess.

However, the problem is solved by the ecoDRYER which converts the liquid digestate into a high quality dry granular fertiliser which is easy to handle, store and spread thus eliminating the need for large storage tanks and lagoons.

The granular fertiliser has a slow release quality and unlike the majority of chemical fertilisers does not wash away with the rain. It also has the same advantage over liquid digestate which has been spread on the land. It can be utilised at any time of the year, as and when required, and each application helps to improve the quality of the land and soil.

The fertiliser from this Suffolk farm has organic certification from the Soil Association which means that the fertiliser produced by the ecoDRYER is usable for certified organic farming. A great success story.

Advasol Management Ltd. designed, manufactured, installed and commissioned the ecoDRYER. It has a preheating tank, rotary dryer and a wet scrubber for odour control. It includes a remote monitoring system and webcam enabling problems to be dealt with off site if necessary. In addition, the preheating tank can pasteurise the digestate reducing any harmful pathogen counts to an acceptable level. It has a modular design so provides great flexibility in the drying capacity whilst its compact footprint offers different options for installation.

Modular ecoDRYER design

The modular design of the ecoDRYER provides greater flexibility on drying capacity. It has a much compact footprint, again offer many flexible options for installations.