Distillery waste processing becomes cleaner and leaner

Diageo is the world's leading premium drinks business and their distillery in Cameronbridge makes much of the grain alcohol used in their world-renowned whisky, gin and vodka brands. It is also their flagship manufacturing site for innovation, renewable energy and environmental sustainability. Veolia is responsible for taking the distillery’s spent wash (a mixture of wheat, malted barley and yeast) and transforming it into solid fuel and biogas for the biomass boiler, purifying the waste water extracted and exporting the steam and electricity, using Veolia’s turbine, back into the distilling process. 
 
Atana was asked by Veolia to develop a solution that could increase the amount of renewable energy harvested whilst improving on the performance and the environmental footprint that the originally-installed belt presses could achieve.
 
Solution:
The distillery’s spent wash is a mixture of wheat, malted barley and yeast and is generated from the extraction of sugars and starch during the grain alcohol’s distillation process. The mixture is processed through 11 Atana volute dewatering screw presses which offer both sludge thickening and dewatering processes in each machine. It is the largest operation of its kind worldwide. 
The volute dewatering process converts the spent wash into dry cake that is used in the biomass boilers. The liquid extracted is then processed through anaerobic digesters. The biogas generated is used to burn the cake producing steam and also electricity through the turbine, both are supplied to Diageo to be used in the distillation process.
 
The process was proven before installation using Atana’s portable trial units, which increased in size and throughput, and were used for one week, one month and three months respectively. Veolia and Atana managed the two floor plant installation and commissioning (which involved the building’s roof being removed to allow the removal of the old belt presses and easy access for the new volute screw presses).
 
Benefits:
  • Larger through-put in the dewatering and water treatment plant
  • 10% more solids - “cake”  - harvested
  • Drier cake results in more efficient burning and less ash for disposal going from averages of 25-28% dry cake up to 28-31% dry cake
  • Improved filtrate quality ~2-3000 mg/l Suspended Solids down to 1 – 1500 mg/L
  • This cleaner filtrate allowed the anaerobic reactor to significantly increase its gas yield allowing the boiler to be run routinely
  • Reduced energy and water needed in the dewatering and distillation process
  • Less humidity in the plant reduced fungal growth, resulting in a cleaner environment
  • Cleaner, quiet plant as both noise and vibrations are minimised as the Volutes have a low speed screw at running at 2-4 rpm
  • Neater, more compact installation that has freed up space.
  • Less maintenance required (previously 60+ bearings were being replaced each week) as the Volute’s low energy screw, and negates high volume water waste during spray washing
  • Reduced chemical usage across the waste processing treatments
  • Disposal & transportation of non-reusable waste is hugely reduced which in turn has saved significant costs, substantially cut traffic on local roads and vehicle emissions pollution

Atana youtube video
    See the solution in action here. If you want to know more please contact: enquiries@atana.co.uk

 

 

April 25 2018