Global Fertilizer Contributions from Specific Biogas Coproduct

Abstract

The impact of Haber-Bosch process on modern agriculture is prodigious. Haber-Bosch process led to invention of chemical fertilizers that powered green revolution, minimized food scarcity, and improved human and animal nutrition. Haber–Bosch process facilitated agricultural productivity in many parts of the world, with up to 60% of crop yield increase attributed solely to nitrogen fertilizer. However, Haber-Bosch fertilizers are expensive, and their poor use efficiency exerts adverse external consequences. In European Union for example, the annual damage of up to € 320 (US$ 372.495) billion associated with chemical fertilizers outweighs their direct benefit to farmers, in terms of crops grown, of up to € 80 (US$ 93.124) billion. A substitute for chemical fertilizers is therefore needed. In this chapter, external costs of chemical fertilizers are highlighted. The capability of liquid fraction of cassava peeling residue digestate to supplant and mitigate pecuniary costs of chemical fertilizers required for production of cassava root is also analyzed and presented. Results indicate that about 25% of fund used to purchase chemical fertilizers required for cassava root production could be saved with the use of liquid fraction of cassava peeling residue digestate. The pecuniary value is estimated at US$ 0.141 (≈ € 0.121) billion for the 2019 global cassava root output. This saving excludes external costs associated with Haber-Bosch fertilizers such as ammonia air pollution, eutrophication, greenhouse gasses emissions, and contamination of potable water supply reserves. Consequently, liquid fraction digestate could reduce the cost of cassava root production, as well as minimize adverse health and environmental consequences attributed to chemical fertilizers.

Dialing Back the Doomsday Clock with Circular Bioeconomy

“…Approaches of IRA and AD were discussed. AD is a wise way to recycle resources of land, nutrients (e.g., N, P, K), carbon, water, and sunlight [83,101,102,108,109,115,153,158,167,182,183]. AD converts organic matter into valuable energy carriers (e.g., biogas, biomethane, electricity, and biofertilizer) for beneficial domestic and industrial applications.…”

“…Digestate is rich in plant growth macronutrients; with their quantities and micronutrients contents related to the quality of the feedstock [98,99]. Digestate attributes, AD's technical feasibilities, types of feedstocks utilized (virtually all organic matter), limitations, advantages, benefits, applications, and much more have been presented in the literature [83,96,98,[100][101][102]. AD may be now considered a mature technology that could help humanity decarbonize industries, supplant inorganic fertilizers, and address waste management shortcomings.…”

“…Profit margins and pecuniary savings might incentivize entrepreneurs/businesses to adopt circular bioeconomic tools. Studies monetized the benefits of climate mitigation via gains associated with O 3 management [52,168,171]; and cost savings inherent in the application of digestate biofertilizer [102]. Monetized benefits of O 3 reduction through NOx mitigation were estimated at $1875 per metric ton of NO 2 , and that for NMVOCs at $1100 per metric ton NMVOC [171].…”

“…The monetized benefits were valued at $0.141 billion for the year 2019 global cassava root output. However, this valuation was conservative as the monetization did not include external costs of inorganic fertilizers such as air pollution, eutrophication, GHGs, and the contamination of potable water supply reserves [102]. Related to profit motive is the ethical and philosophical inclinations of humans to do good albeit for self-preservation.…”