Specialty Chemistry Forums > Other Sciences Question Forum
Produce More Food?
Enthalpy:
Up to last year, natural gas made fertilizers over hydrogen, ammonia, then urea. In short, 1/4 of our food is natural gas.
Good news, Nigeria will sell the C3-C4 fraction obtained from wells instead of torching it
aljazeera.com
These gases too can provide hydrogen for fertilizers. This depends competing uses.
Also: the conversion of formerly cheap methane to hydrogen burned the rests, but proven reactions convert the rest to valuable liquid fuels.
chemicalforums
This applies to the C3-C4 fraction too.
Research papers propose biological means to fertilize the fields, mostly to inject nitrogen compounds. I can't assess how cheap and efficiently, but this would free agriculture from fossil fuels. I instinctively disbelieve that hydrogen from electricity is cheap enough for fertilizers. But two decades ago, I believed natural gas would stay cheaper than solar electricity: wrong.
Enthalpy:
Chemists, your ideas, suggestions, remarks, comments are needed!
Before the war in Ukraine, farmers produced 1/4 more food by using fertilizers, essentially ammonia and its derivates urea and ammonium nitrate, where natural gas provided the hydrogen, but now gas is rarer, and we must abandon fossil fuels anyway.
The politicians promote hydrogen from renewables in sunny windy countries, then ammonia etc as before. I disbelieve agriculture can afford that process.
Nitrogen fertilizers outperform phosphates and others. Mines don't cover the needs neither.
So could you propose ways or directions to provide usable nitrogen to the plants? N2 is too inert, but compounds as diverse as ammonia and nitrates are accepted. Nitrogen oxides aren't the energy maelström of hydrogen production. Introduction and more:
Noura Ziadi, Utilisation des engrais minéraux azotés en grandes cultures
Nitrous and nitric acids are acid, nitrogen oxides are gases, but maybe we can combine nitrogen compounds with the straw that farmers bury in the fields. It comprises cellulose and many compounds, with alcohol functions and more, that could catch the nitrogen compounds as nitro- or others.
A mixture of straw and cattle dejections is often buried. Nitrogen compounds could react after or before mixing. Urea seems a target for a nitrate.
Straw could produce biomethane before the rests fertilize the fields
chemicalforums
so a supplementation by nitrogen compounds would usefully be compatible with that step.
Marc Schaefer, aka Enthalpy
marquis:
Re: maple syrup
The problem with maple syrup is the amount of energy required to concentrate the maple sap to maple syrup. The best maple sap is 4% sugar, but many run of the mill trees run much lower. Say 2% or even lower. You must consider the energy required to evaporate off the water. There is another option- to concentrate the sap with the equivalent of an HPLC column. You should be able to find some refs online. It would t get you all the way to the final 66% sugar, but it will save a lot of energy. Good luck.
marquis:
The maple sap is not collectively by buckets around here, anymore. They are using plastic bags. Going down some of the backroads, you will see all these maple trees with white plastic bags attached to them. If you didn't know better, you'd guess they were of bags. The season is usually from about Feb to maybe April, depending on temp. After that, the sap tastes bad. Whether it could be used, I don't know. The better places use tubing instead of bags.
marquis:
This info is pulled from Dow Tech Fact form no 609-00513-1204. The title is Elements used in maple sap concentration.
It gives a run down on different reverse osmosis type elements usable for sap concentration. At one time, they had a product called filmed maple sap Mark I. As far as is known, that's been discontinued. They lost other reverse to elements that can be used in place. 8 inch elements biotech nf279-499, biotech nf90-400,Gingrich xle-440. 4 inch elements, nf270-4040, nf90-4040, Gingrich xle-4040. Sorry, my memory was bad. Thought it was hplc, not RO. This data sheet is rather old. Hopefully, something similar is still available.
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