Four Decades On Four Continents: Reuse of Industrial Fermentation Biomass At Novozymes.

Novozymes globally produces bulk industrial enzymes using large-scale microbial fermentation that generates large quantities of spent microbial biomass as a byproduct.  Since the 1970s spent fermentation biomass has been reused primarily as a multi-nutrient agricultural fertilizer and liming material in Brazil, China, Denmark, and the United States.  Since the 2000s the biomass is also provided for non-agricultural reuse including compost and soon for waste-to-energy.  Novozymes relies on local university expertise to adapt spent biomass to crop systems and soil-climate conditions to ensure optimal use and good environmental stewardship.  Spent biomass is relatively homogenous, very low in regulated metals, stabilized with lime, and provides N, P, K, and micronutrients for crops.  Lime value is highest in regions with acidic soils.  Application rates were initially N-based and have become P-based over the past 20 years with better practices to minimize nutrient losses.  Novozymes began shifting from wet to dry waste biomass in late 1990s due to Danish regulatory restrictions of winter-time spreading to minimize potential N losses to groundwater.  Due to reduced weather risks, dry waste biomass is now the standard practice at new facilities and implemented where feasible at older sites.  Composting was developed as a partial solution in the United States in response to rapid urbanization and loss of farmland in the 2000s.  In addition to the local regulatory frameworks, Novozymes maintains a strong global oversight and vision for management of spent biomass reuse in terms of sensitive environmental concerns such as eutrophication and greenhouse gas impacts.