[Scott]

There are many benefits from digestate, as a source of nutrients and organic matter that contribute to improve soil health. By generating value-added by-products, digestate can contribute positively to a RNG facility’s economic profitability.

[Peter]

Digestate has few advantages as a fertilizer over manure.

First anaerobic digesters kill a lot of the human and animal pathogens that might be in the manure. Next while weed seeds can survive in cattle manure, they are typically killed after digestion. Finally, the nitrogen in digestate has largely been converted to ammonia which is will be available to plants faster than the organic nitrogen in manure or compost.

[Ryan]

In addition to the benefits mentioned, the use of digestate offsets the use of synthetic fertilizers, and the emissions associated with their production

[Peter]

A great point Ryan!

[Scott]

Regarding benefits of the use of digestate, I would like to suggest a presentation I put together that compiles digestate solids/liquids separation performance data from facilities in Canada and in Scandinavian countries: https://5799596.fs1.hubspotusercontent-na1.net/hubfs/5799596/WEF%20Biosolids%202022-Technology%20Spotlight.pdf

[Burak]

I have to say this again. Fournier solution to separation is one of the most creative solutions I ever seen. I am eagerly waiting for a project where we need to utilize it.

[Ryan]

As noted, beneficial reuse of digestate as a fertilizer / soil amendment provides a source of N that is more available to plants, reduced pathogen content, reduced ordour, among others. Some additional benefits are tied to the source of the organic material going through the digester and the typical method those materials were managed. For example, a SSO facility or a comingled system can divert organic from disposal in landfills, converting them into a form more suitable for land application as a fertilizer. When used by an industrial operation, like a food processor, processed organic waste from a digester could provide additional opportunities for disposal and cost reduction for the management of the organic wastes generated.

There are some things that need to be considered, include the total nutrient content of the digestate, especially when utilizing ag source materials such as manure with non ag source organics on farms. The controlling nutrient when applying manure to ag lands it typically P, for comingled systems that often changes to N being the controlling nutrient. That change can impact the acres needed to sustainably manage the digestate.

[Scott]

I was amazed by the creativity of Norwegians in producing added-value products, such as the Bio-tak green roofing!