It took several months of work to chip away at the 130 ton ‘fatberg’ that blocked a London sewer last year. Fat, Oil and Grease can be hard to deal with, but it can be made more digestible.
In the world of Anaerobic Digestion (AD), micro-organisms eat away at organic material and produce gas. The gas output can vary greatly depending on the material used as ‘food’. Using crops as the food for the micro-organisms creates a relatively consistent and controllable AD process. It could be argued however that land should be used to grow crops for human consumption rather than energy production. Perhaps waste products could be used for AD, so what about Fat, Oil and Grease?
Fat, Oil and Grease (FOG) doesn’t sound particularly appetising but it can be digested by the AD micro-organisms. It’s a problematic food source however as FOG can generate ammonia in the process and inhibit the AD bacteria.
At the Anaerobic Digestion and Bioresources Association Conference at the end of 2017, Stephen Roe, CEO of AMT, a leading microwave technology company, spoke to delegates about the use of microwaves in pre-treating feedstocks for AD. The benefits of this well-established technology were shown to be impressive, with accelerated AD processing of Fat, Oil and Grease with reduced ammonia. The biogas was produced faster and in greater volume.
Microwave pre-treatment benefits a range of previously difficult AD feedstocks from other waste processes such as materials from the Whisky industry. Other tough organic materials with high cellulose or lignin content can be broken down as the microwaves burst the cell walls and make the starches and sugars available to the hungry AD micro-organisms. The increase in output from microwave pre-treatment is impressive.
Stephen Roe told delegates, “The key to tackling tougher feedstocks is technology and that requires investment. Only by demonstrating a truly viable return on that investment, through faster, more reliable and better biogas production, can we see a step change in the AD industry. I believe that microwave pre-treatment is the future.”
In 2018, no doubt Fat, Oil and Grease will continue to block up the sewers and arteries of the nation. It could be the year however when microwaves unblock the AD process and make Fat, Oil and Grease more palatable for our microscopic energy-producing friends.
For more information contact Stephen Roe at firstname.lastname@example.org.