The present study challenges the traditional view that the *respiration of
organic carbon to CO2* is an exclusively intracellular process, revealing that
*organic compound respiration can occur spontaneously in an extracellular
context in soils*.
On the surface, it looks like they rediscovered that oxidation of organic / carbonaceous compounds occurs at low temperatures independently of presence of living organisms. The real contribution of the paper would be in elucidation of the specific mechanisms of oxidation of these organic compounds (e.g. via abiotic catalysis).
Coal oxidation at low temperatures is the major heat source responsible for
the self-heating and spontaneous combustion of coal and is an important source
of greenhouse gas emissions. This review focuses on the chemical reactions
occurring during low-temperature oxidation of coal. Current understanding
indicates that this process involves consumption of O2, formation of solid
oxygenated complexes, thermal decomposition of solid oxygenated complexes and
generation of gaseous oxidation products. Parameters, such as mass change,
heat release, oxygen consumption, and formation of oxidation products in the
gas or solid phase, have been used to qualitatively and quantitatively
describe the oxidation process. Reaction mechanisms have been proposed to
explain the characteristics of consumption of O2, and formation of oxidation
products in the gas and solid phases. Various kinetic models have also been
developed to describe the rate of oxygen consumption and the rates of
formation of gaseous oxidation products in terms of the rate parameters of the
relevant reactions, oxidation time, temperature, and initial concentration of
oxygen in the oxidising medium.
The translations of the title (Finnish, Greek, others?) referencing Rita Hayworth make more sense if you know the title of Stephen King's novella the movie was based on (Rita Hayworth and Shawshank Redemption).
The movie casts a spell far beyond its merits. Warner Brothers would have made it thirty-five years ago as a hundred-minute feature, lively, brilliantly paced, and economical. Now, in the reverent hands of Francis Ford Coppola, it has swelled into an overblown, pretentious, slow, and ultimately tedious three-hour quasi-epic. Gangsters at last have their Greatest Story Ever Told, but minus George Stevens. Inflation does not always assure survival. My guess is that three years from now we will still remember scenes from Raoul Walsh’s The Roaring Twenties (1939) while The Godfather will have become a vague memory.
PSA: If you are logged in to LinkedIn, then clicking on a LinkedIn profile registers your visit with the owner -- it's a great way for someone to harvest new people to target.
On another note, what's unreal about the pseudonym? It's a Ukrainian transliteration of Николай Янчий (Nikolay Yanchiy). Here's a real person with this name: https://life.ru/p/1490942
Never trust anything written by lawyers/economics/MBAs on climate change - only analysis by chemical or mechanical engineers is worth reading.
Just so we know if we should keep reading, which one are you?
Methane pyrolysis is an old technology from early days of oil refining for production of hydrogen & Ammonia/fertilizer/Methanol. it yields half as much H2 than SMR/ATR so it can't compete on cost, unless there is carbon tax/CO2 penalty.
It's not appropriate to call it "technology," in the same way it's not appropriate to call "combustion" a "technology." There's a very wide variety of technological solutions to realize this family of chemical processes, and some are going to be better than other, depending on the use case or scenario. The report actually covers those pathways reasonably well.
Also, coke produced by pyrolysis is lower quality than that produced by Delayed Coking of crude oil refining.
Ideally, you would not be producing coke at all, but a higher value material. However, even coke will be of much higher purity than petcoke (before calcining) -- i.e. it would be intrinsically zero-sulfur carbon material, - but I'm not sure what applications it would have that don't involve production of CO2.
But obviously the carbon co-product should have value, which would provide a cost offset to the hydrogen. With a high-quality co-product (> $1/kgC), this offset would be significant enough to provide that hydrogen essentially free of charge.
SMR and ATR generate significant amounts of CO2 (~10 kgCO2/kgH2), which does not provide a cost offset, and in a fair world would instead incur a significant added cost.
Electrolysis requires 4x more energy (also electric, not thermal) and does not have a marketable/valuable co-product. Just on the energy cost alone (50 kWh/kgH2 * 0.12 USD/kWh = 6 USD/kgH2 > 40 USD/MMBTU) electrolyzer hydrogen is not competitive with any of the above.
Commonsense should tell you e- generated by H2 can't compete with CH4, because Ch4 is the feedstock & H2 is the product!
Didn't parse this statement, sorry. Can you rephrase?
You would want to use solar power for electrolysis. In the US, regions with abundant solar power are also the ones that:
- have true water scarcity - Nevada and Arizona
- have low population and industrial density, so any generated hydrogen would need transported to the point of use.
The bigger problem is the energy disparity. Electrolysis of water requires 50 kWh/kgH2 or more. Even a 70% efficient fuel cell would get ~25 kWh/kgH2 -- horrible roundtrip efficiency. With pyrolysis, that equation is exactly inverted: at 9-12 kWh/kgH2, you can generate excess electricity with no CO2 emissions.
Plus for pyrolysis, you have to deal with the carbon which makes up 75% of the methane by weight. A non-trivial issue.
Exactly. 20 kg of methane costs $3 today, but contains 15 kg of carbon that could be worth $20-$30. It's a non-trivial issue if you hate generating value.
In 2015, the Department of Energy estimated that the CO2 footprint for production, processing, and pipeline transportation of natural gas averaged between 8 and 14 kgCO2-e per MMBTU of natural gas [1].
The average natural gas CO2 emissions (kgCO2/MMBTU) has been going down over time [2], and will be reduced even further in the next few years thanks to increasing fines [3] on one hand and financial incentives to reduce flaring and venting [4] on the other hand. A large percentage of these emissions are not due to accidental leaks, but are essentially intentional -- due to flaring, venting, and high-bleed controllers and actuators [2].
For an idea of how much emissions can be reduced, consider that the so-called certified gas has 90% lower CO2 footprint than the average today [5]. For example, the methane emissions for a natural gas utility in Oregon are 90% lower than EPA nationwide assumptions [6].
Carbon black has the average CO2 intensity of almost 4 kgCO2/kgC [1] and its conventional production is so dirty and low-margin, that companies have been walking away from their plants rather than implement EPA-mandated upgrades. [2]
On the subject of methane pyrolysis, it turns out if you look at the Gibbs free energy calculation, about half of the energy of methane combustion is released from the formation of water, and the other half from the formation of carbon dioxide.
About 70% of the energy is in hydrogen, 30% is in carbon.
1 GJ of methane weighs about 20 kg, 5 kg of which comprise hydrogen.
At 142 MJ/kgH2 (higher heating value, which implies condensation of the produced water), 710 MJ out of that 1 GJ is due to hydrogen.
With a 60%-70% efficient hydrogen fuel cell, about 50% of the electricity generated from hydrogen from pyrolysis of methane would drive the process, and 50% could go into the grid.
Pyrolysis is a less energy intensive way to produce hydrogen, and does deserve more attention. But it still requires methane as a feedstock.
So why is methane as feedstock a problem?
Isn't it better to spend less energy convert a ubiquitous, but environmentally harmful gas into hydrogen along with useful materials, than spend 4x more energy to convert a critical resource -- fresh water -- into hydrogen without any valuable by-products?
As bonus trivia, depiction of Bilbo was based on the "short, round stature, expressive eyes, broad and open face" of the famous Soviet actor Yevgeniy Leonov (https://en.m.wikipedia.org/wiki/Yevgeny_Leonov).
For whatever reason, evolution decided those wavelengths should be overlapping. For example, M cones are most sensitive to 535 nm light, while L cones are most sensitive to 560 nm light. But M cones are still stimulated quite a lot by 560 nm light—around 80% of maximum.
The reason is simple: genes coding the long wave opsins (light-sensitive proteins) in these cones have diverged from copies of the same original gene. The evolution of this is very interesting.
Mammals in general have only two types of cones: presumably they lost full color vision in the age of dinosaurs since they were primarily small nocturnal animals or lived in habitats with very limited light (subterranean, piles of leaves, etc.) Primates are the notable exception, and have evolved the third type of cone, enabling trichromatic color vision, as a result of their fruitarian specialization and co-evolution with the tropical fruit trees (same as birds, actually).
So, what's interesting is that New World and Old World primates evolved this cone independently. In Old World primates the third cone resulted from a gene duplication event on the X chromosome, giving rise to two distinct (but pretty similar) opsin genes, with sensitivity peaks at very close wavelengths. As a note, because these genes sit on the X chromosome, colorblindness (defects in one or both of these genes) is much more likely to happen in males.
New World primates have a single polymorphic opsin gene on the X chromosome, with different alleles coding for different sensitivities. So, only some (heterozygous) females in these species typically have full trichromatic vision, while males and the unlucky homozygous females remain dichromatic.
> One particular take away for me was his finding that when the body enters a ketogenic state due to fasting the body produces defences that eat up cancer cells
“We did indeed see that the ketogenic diet suppressed tumor growth — but we also saw, surprisingly, that it promoted tumor metastasis,” says Gu. “That was really a shock to us.”
On the surface, it looks like they rediscovered that oxidation of organic / carbonaceous compounds occurs at low temperatures independently of presence of living organisms. The real contribution of the paper would be in elucidation of the specific mechanisms of oxidation of these organic compounds (e.g. via abiotic catalysis).
Compare to this paper from 2003:
https://sci-hub.kvnp.top/10.1016/s0360-1285(03)00042-x