Ethylene is a "colorless and combustible gas used to fumigate some agricultural products, sterilize medical equipment and in the production of other industrial chemicals. The gas is a carcinogen that has been linked to breast, lymphoid, leukemia and other types of cancers."
Ethylene is transported as a cryogenic liquid, which means when it leaks it immediately boils to gas form. Once released it takes 2 to 4 days to break down in the atmosphere. Chlorine takes years.
Maybe some people are assuming the old remark:
"The solution to pollution is dilution."
Chlorine is also a molecule and it was clearly this meaning that the author intended.
Cl2 --> 2Cl
Naw. That reaction requires energy.
Yes. In this case, it's called 'sunlight'.
The results of reaction
Cl2 --> 2Cl
from energy from "sunlight" is reactive and will reverse the reaction and get back to Cl2 or maybe
2H2O + 2Cl --> 2HCl + O2
hydrochloric acid, also very reactive.
It's still Chlorine, reactive and dangerous, destructive and has not broken down.
Yes, the Chlorine may react.
Again, once again, over again, yet again, one more time, the Chlorine will NOT
===>>>"break down"<<<===
Simple. High school science simple.
This whole exchange seems to have nothing, nichts, nil, nada to do with Chlorine or chemistry but just, for whatever reason, arguing just to be arguing.
I'm not interested in the arguing, and I have no more to say about the chemistry.
Like Table salt for example: sodium chloride. Sodium spontaneously ignites in AIR and is explosive in water. Chlorine is highly toxic and poisonous. But you bond the two chemically and you get a stable, safe, delicious flavor enhancer.
Edit: Perhaps I misunderstood your comment. Are you saying that transporting the raw chemicals required to make it on site wouldn’t be any safer to transport?
The precursors are more accurately acetylene and hydrogen chloride. But acetylene can be stored and transported as the solid calcium acetylide (aka calcium carbide), which releases acetylene by reaction with water. So this is potentially easier than you made it sound.
I agree that it addresses the utility of PVC. I wrote: "It addresses the industrial applications of the chemical." But the article never makes the claim that rail is an efficient means of transporting it. It also never answers why the chemical cannot be made on-site.
Unless you're talking about in situ chlorine production, which has its own list of issues.
Either trucks or trains, and trains are more cost effective.
If so, it remotivates an analogue of TCP's MTU: if the size of shipments were small, but the number of shipments high, would a single "packet loss"/derailment be less catastrophic?
A better alternative is to keep using trains, but have sufficient protection built in to survive a derailment and fires.
https://channelnz.com/what-we-do/terminal-pipeline-services
Not sure how dangerous it would be though to have one transport wildly different chemicals...
Who wants a pipeline behind their home that transports chlorine gas one hour and ethylene gas the next?
I'm not throwing that out there as a justification for deliberately releasing industrial quantities of chemicals into the environment (including residential areas), but rather examining the decision process. An alternative approach would have been bringing in mobile chillers and replacement tank cars to cool and recover the vinyl chloride. But of course that would have cost more than simply discarding the product. Everyone is talking about railroad safety, and that needs addressing for sure. But the situation with the vinyl chloride specifically was a direct result of a deliberate decision, and not accidental. If we want this decision process to be different in the future, then we need to focus on that.
Dioxins are a result of low temperature burning of chlorinated hydrocarbons.
I can totally see the scenario where the people signing off on the burn look at the ideal combustion products (only CO2, H2O, and a little HCl), while a much more imperfect burn creates a bunch of other crap, that becomes significant due to the quantities involved.
FWIW do you know which dioxins are possible? The only specifics I've seen seemed to be people fearmongering about things like 2,3,7,8-TCDD, which seemed implausible to form from vinyl chloride, at least as far as my rudimentary knowledge of ochem would suggest.
As of today/yesterday: "The EPA has not yet tested for dioxin contamination" https://www.statnews.com/2023/02/21/east-palestine-train-che...
From a brief look at Pubmed it looks like the top articles investigating dioxin formation look at total dioxins formed, not the specific molecules. This one states that PCDFs form in greater amounts than PCDDs: https://pubmed.ncbi.nlm.nih.gov/17432330/
I agree that there should be more testing, and the fact that testing for expected combustion products wasn't start immediately to inform decisions about evacuation is criminal.
Chlorine is a precursor to Vinyl Chloride and is far more dangerous than Vinyl Chloride.
The issue is that the companies have been playing fast and loose with safety. If you don't choose to reverse that, it doesn't matter whether you transport the chemical or manufacture it on site.