The composition of biomass changes as it moves through a biogas plant. Whether it is livestock manure, organic waste from households or industrial waste, most of the nutrients in the mix is left in the digestate after the biogas is produced. A biogas plant even improves the availability of nutrients to plants, particularly nitrogen.
Most of the nitrogen in biomass is locked up in organic molecules when it enters a biogas plant, making it unavailable to plants. The impact of treatment in a biogas plant is significant, particularly for manure, where it is still common practice to disperse it on agricultural lands in raw form. The biogas plant not only reduces agricultural GHG emissions but also increases fertilizer value. This results in reduced nutrient runoff into recipient waterways and less reliance on commercial fertilizers, which also have a financial and environmental cost. Especially these days as the price of commercial fertilizers is closely tied to the energy price.
A circular economy that works
One of the downsides of the circular economic principle is the staggering number of stakeholders in the system elevating the complexity compared to the more linear consumption pattern we have proven to master. The collaborative and circular model with agricultural production, food processing industries, and society surrounding biogas plants as the central platform for the recirculation of nutrients is an excellent example of a circular economy at work.
The current situation
A nutrient crisis has developed as a result of the unpredictability of the current geopolitical scenario and the unusual energy prices. Most commercial nutrients are extremely energy intensive, thus costs are skyrocketing, and availability is tight, and buyers must pay astronomically inflated rates. This condition, combined with the fact that biogas is a tradeable, transportable, and usable energy form, makes the biogas industry more essential than ever, and farmers that work with biogas plants are in a much better position than those going to the current fertilizer market.