We’ll start this off by saying I am openly admitting I claim no additional comprehension beyond those who have contributed various theories and concepts regarding the subject matter. In fact I would qualify myself as falling very short of others pertaining to their span of their understanding of this stuff.
I also thought this would be better off in its own independent discussion thread so as not to steer any other conversations in different directions that could ultimately yield the corrective actions and highlight the underlying cause of this issue.
Let’s start out by saying what I think it is and why, and then I will provide the homework/references towards the bottom of the post. The idea of this is to discuss, openly, what the potential cause is…
The theory; Isobutane PPM within the n-butane and the isobutane itself are “tainted” from production. The idea is that during COVID, when the world was shutting down, demand for energy plummeted. Plants shut down and capacity was reduced. There are several press releases highlighting this and I’ve included a release by Divergent regarding how they stated
“While revenues decreased 47% from 2019, the Company maintained gross margins of 25% (2020) vs 23% in 2019 by implementing cost control and cost reduction measures to adjust to the lower levels of activity”
(what exactly did Divergent do in regards to “cost reduction measures”). Then I did some digging, and found a paper from the EPA that talks about catalyst by product build up in NA and describes the business these refineries are in, how they operate, and even how many plants there are! The paper is from 1996, and at the time, only 15 butane isomerization plants existed! Check out this little tid-bit excerpt from the paper defining the TWO MAIN different catalysts used to isomerize butane;
As discussed in Section 3.4.1, the most prevalent catalyst used for both butane and
naphtha isomerization is platinum or platinum chloride on alumina or zeolite. When the catalyst
loses activity, it is removed from the reactor and replaced with fresh catalyst. Prior to removal,
the reactor may be swept to remove hydrocarbons from the catalyst. These preparation steps can
include one or more of the following:• Nitrogen sweep (to remove hydrocarbon)
• Oxygen sweep (to burn hydrocarbon)
• Steam stripping (to remove hydrocarbon).This procedure of catalyst preparation, removal, and replacement is relatively lengthy (typically
one week or more) and requires the unit, or at least the reactor, to be shut down such that no
hydrocarbon is processed during the time of catalyst replacement.There are a handful of isomerization processes used at domestic refineries that do not use
platinum or platinum chloride catalyst. At these facilities, spent catalyst is generated in one of
the following two methods:• A method similar to the generation of spent platinum/platinum chloride catalyst described above. Fixed-bed processes are used in both palladium and nonprecious metal catalyst applications and spent solid catalyst is infrequently removed.
• A method where catalyst is removed from the fixed-bed reactor frequently (up to
once a day) in liquid/semi-solid form, presumably with little to no disruption of
the process. This method is used only for one process which uses aluminum
chloride/hydrochloric acid catalyst.
Anyway, if you read the EPA paper entirely you can see it says when they use the alternative catalyst there is a large amount of “residual” oils from manufacturing as well… i.e. sludge?!? I will also include a little engineering case study about how “de/isobutanizer” systems can run inefficiently and foul up the process but who would notice such deviation from product output if there are no analytics for something like that? The EPA article talks about classifications of hazardous materials by the refineries themselves and obviously they want to not say its hazardous so why would they be analyzing for it… Oh, and don’t forget; they have to replace the catalyst once it loses activity. All of this leads me to believe there is a rush in the refinement process and not everything is getting refined, as well as they are using cheaper methods to manufacture to maintain profitability quota during unprecedented(?) supply/demand cycles and labor shortages?
Then it says
“A method where a catalyst is removed from the fixed-bed reactor frequently (up to once a day) in liquid/semi solid form, presumably with little to no disruption of the process… uses Aluminum chloride/hydrochloric acid”
… maybe due to labor shortage, it gets changed out less?
Check out the paper “New Metal Halide Catalysts for Hydrocarbon Reactions” … it mentions how;
hydrocarbons react among themselves when aluminum chloride is present. It goes on to say “These halides all have similar chemical nature and show similar behavior towards water and in the formation of double salts or addition compounds; they form the transition between the purely heteropolar salt-type halides and the typically homopolar covalent halides”
When you talk about a polymorphing affect, could it be related to the aluminum chloride? I also realized that there is no other thing you can make from crude or natural gas regarding solvents that we use that requires a catalyst to isomerize. Only isobutane, and I would bet that the process changed due to supply problems as @Dr.stanky mentioned in the Hydrogen peroxide thread.
Is it possible trace PPM of isobutane within the n-butane cylinders is leaching the catalyst or result of the catalyst into the process? This makes sense why you would use activated alumna and sieve beads to mitigate the issue, just read the EPA paper as it does mention that. Very cool stuff.
In business, you want to provide a quality product, but if you’re trading in a commodity, sometimes you will cut corners to keep the price steady and sacrifice that quality, very straightforward and makes a lot of sense.
Prior to COVID, the isobutane was perfect, now it is not?, this is because they had to make measures to still output the stuff they care about, I don’t think they care much at all about butane or isobutane, they would much rather use the butane to make propane?
EPA Archived Study 1996
New Metal Halide Catalysts for Hydrocarbon Reactions - 1937
The Action of the Catalyst Aluminum Chloride-Hydrogen Chloride on Toluene at LT
How Deisobutanizer systems can run inefficiently without operator knowing
Butane Isomerization
Artcle of timeline depicting production changes and cost control measures due to COVID;
Check out this video that explains more about the refineries and the pricing markets
So what the hell am I talking about? Honestly, I have no clue and was hoping someone would call me a moron…
Also shoutout to @anon64373531 for the inspiration and @TheLostBiologist for saying it was/might be Hydrogen Peroxide which made my fingers use google and also @TRIPPIE lol its definitely not the isobutane 
Is it the Aluminum Chloride in the Isobutane, leaching into the n-Butane, causing a polymorphing effect/affect?
