Roles and Responsibilities in Providing Safe and Sufficient Sufficient Nitrogen Fertilizer Supply.
This is an editorial in the current issue in ACS Sustainable Chemistry and Engineering: Role and Responsibility of Sustainable Chemistry and Engineering in Providing Safe and Sufficient Nitrogen Fertilizer Supply at Turbulent Times, Mohamed Eisa, Dovilė Ragauskaitė, Sushil Adhikari, Federico Bella, and Jonas Baltrusaitis ACS Sustainable Chemistry & Engineering 2022 10 (28), 8997-9001
As I noted in another context, most of the world's hydrogen is made using dangerous fossil fuels, and of that is synthesized, most is used to make ammonia, a key fertilizer without which much of humanity would starve. The Ukraine war has disrupted supplies of dangerous fossil fuels from the pariah nation Russia, which is holding the world hostage.
Here's the graphic I have posted before:
Source: Progress on Catalyst Development for the Steam Reforming of Biomass and Waste Plastics Pyrolysis Volatiles: A Review Laura Santamaria, Gartzen Lopez, Enara Fernandez, Maria Cortazar, Aitor Arregi, Martin Olazar, and Javier Bilbao Energy & Fuels 2021 35 (21), 17051-17084
From the editorial:
One of the United Nations’ Sustainable Development Goals is to achieve food security while transitioning into sustainable agriculture. This goal has been of utmost importance for a long time due to the persistent food shortages in certain geographical locations throughout the world. The recent global events, including the global pandemic and Ukraine’s invasion by Russia, led to unprecedented market volatility and food supply chain disruptions. Furthermore, the Russia–Ukraine conflict also sent fertilizer market indices to unprecedented levels because of disruptions in their production and distribution networks. While correlation does not imply causation, (1) it appears that the world has already been here before. Figure 1a illustrates the historical prices of urea, the most popular nitrogen (N) fertilizer with approximately 180–200 million metric tons of global demand in recent years. (2) It can be seen that the global events, such as the first oil crisis, the 2008 market boom and crash, and especially the recent war in Ukraine, led to unprecedented urea price increases, thus threatening the global food and energy supply. Increases in urea production costs can be attributed, among other things, to the energy cost of atmospheric nitrogen fixation, which is estimated to be from 1% to 2% of global energy consumption. (3,4)...
A figure from the editorial:
The caption:
Figure 1. (a) Historical prices of the most popular N fertilizer, urea, and its response to the selected global events. Data obtained from USDA Agricultural Marketing Service from 2011 through 2022 and USDA National Agricultural Statistics Service before 2011. (b) Available N amount in the US that does not originate from natural gas-derived mineral fertilizers for animal manure, (14,15) food waste of MSW, (16,17) agricultural residues, (18−23) forestry residues, (18,24) and municipal sewage sludge. (25) Uncertainties are provided for the upper and lower values found in the literature.
The caption hints at the proposal to address the issue, which follows:
...What sets N apart from the other critical nutrient, phosphorus, is that the latter is mined as solid rock. The source of potentially mineable solid N feedstock for fertilizers exists in Sputnik Planitia on Pluto, but at 37 K. (10) Furthermore, phosphorus is already mined ready to use in its P5+ oxidation state as a polyatomic phosphate (PO43–) ion, which is very important from the sustainable chemistry point of view. Applying an atom economy argument, (11) a simple and very popular metric of a process’ greenness, the exact stoichiometric quantities of starting materials (12) result in the highest sustainability and directs the search for the feedstock that already contains NH4+ and NO3– rather than undergoing tedious, atom, energy, and process-intensive conversion of N2. The recent concept of green urea, (13) which involves biomass gasification into syngas or water splitting via photovoltaics-generated electricity, results in decreased overall atom efficiency because of the unilateral focus on molecular H2 sources (directly via H2O electrolysis or tandem via N–H or C–N electrochemical bond formation) for N2 hydrogenation...
A very serious issue is subtly evoked in this text, the issue of
mined phosphorous on which modern agriculture depends.
A caveat to this proposal that comes to my mind immediately is that "recycling" always sounds good until an attempt is made to place in practice. Fixed nitrogen, though critical, is a low value product, very diffuse and dilute, but massive, properties it shares with carbon dioxide. The key is
still energy. Without sustainable energy it will not work.
