The solution

Eco-Clarity Ltd has developed a “Hub” solution for GTW separation that is efficient, fully automatic and has a small footprint in physical and energy consumption terms. Eco Clarity and Argent Energy have a shared belief that the GTW collection and processing industry-wide can improve significantly. Although they are not a fat collector, Argent Energy has enabled Eco Clarity to run trials of its new technology solution at their site in Amsterdam to help demonstrate the reliability and decarbonisation value of this route to biodiesel for processed fats.

During the trial, GTW collected from the Amsterdam region is discharged and separated at the Argent facility, producing a fraction of fats, oils and grease (FOG) for biodiesel production. Suspended solids are fed to biogas production, and the wastewater has a significantly reduced chemical oxygen demand (COD).

Eco Clarity’s hubs have a small footprint of 10m², made up of an automated Huber solids screen, two 20-foot treatment containers, and a 20-foot FOG post-processing and storage container.

A standard Eco Clarity GTW hub is capable of accepting 10 tonnes of GTW in 10 minutes, with a further 10-tonne truck every 15–20 minutes thereafter. Being automated, the system can receive waste 24/7. With a quick setup, the Eco Clarity GTW Conversion Hub was ready to process waste within three days of delivery.

Results and benefits

From the first 320 tonnes of waste accepted at the hub, Eco Clarity was able to harvest 30 tonnes of concentrated FOG and FOG-containing solids as a feedstock for biodiesel production. Analysis shows that there is a 99.99% reduction of FOG within the discharge effluent and an average 30% reduction in COD, with a pH of between 4 to 5.

Average effluent results
pH	4.8
COD	9158.3	mg/l
Sulphate	158.8	mg/l
Phosphate	91.3	mg/l

The above table shows the average effluent results after treatment.

The ratio of GTW to de-watered FOG depends on the volume of FOG within the GTW load and where the trucks have collected that day. Some loads may have low volume of less than 2–3%, whilst others have as much as 20%.

Within two weeks of operating, Eco Clarity were accepting all the daily loads from the 5 trucks and, during slow periods, had started processing materials stored in the local storage tank.

The plant accepts 20 tonnes of GTW per hour and has processed GTW 24/7 when in automated mode. Maximum power consumption when accepting waste is 40 kWh, and when in maintenance and harvesting mode it is approximately 5 kWh.