Did I Come Across A HiiRoc-Style Process In the 1960s?
The home page of the HiiROC web site has a title of Thermal Plasma Electrolysis with this sub-heading.
A Transformational New Process For Affordable Clean Hydrogen.
This is the first paragraph.
Leading with our proprietary plasma technology, HiiROC has developed a new process for producing affordable clean hydrogen: Thermal Plasma Electrolysis
The further I read it starts to appear familiar.
It was a long time ago in 1968, but I shared an office at ICI Mond Division with a guy called Peter, who was helping to try to get a similar process working.
ICI were using a bought-in process to try to make acetylene.
I seem to remember that ethylene was burnt in a aerosphere with little oxygen.
Was it then quenched with naphtha?
Acetylene was then supposed to be released, but all the plant did was produce lots of soot, which it spread all over Runcorn.
Peter’s job was to measure the acetylene in the burner off gas. The section I worked in had developed, a very clever instrument that could measure levels of one chemical in another by infra-red comparison to very low levels.
In this plant, it was measuring acetylene in burner off-gas.
They did it successfully, but it was a disaster, as the gas on the output of the burner was straying into explosive limits.
The plant was was immediately shut down and dismantled.
The Versatile Substance That Is Carbon Black
I suspect very few of us think much about carbon black.
In an over fifty-year working life, I have only come across carbon black indirectly and no-one has actually shown me any carbon black.
This is the first sentence of the Wikipedia entry for carbon black.
Carbon black (with subtypes acetylene black, channel black, furnace black, lamp black and thermal black) is a material produced by the incomplete combustion of coal tar, vegetable matter, or petroleum products, including fuel oil, fluid catalytic cracking tar, and ethylene cracking in a limited supply of air.
It doesn’t sound the most appetising of substances and the next sentence reinforces that view.
Carbon black is a form of paracrystalline carbon that has a high surface-area-to-volume ratio, albeit lower than that of activated carbon. It is dissimilar to soot in its much higher surface-area-to-volume ratio and significantly lower (negligible and non-bioavailable) polycyclic aromatic hydrocarbon (PAH) content.
The text is illustrated with what looks like a small pile of soot.
I first came across carbon black, in my first job after leaving Liverpool University at ICI Mond Division at Runcorn.
For a time, I shared an office with Peter, who was part of a number of engineers, who were trying to get a new plant, that had been purchased from BASF to make commercial quantities of acetylene. All the plant seemed to make was large quantities of soot, which it then proceeded to spread all over the town of Runcorn.
If I remember correctly, the process worked by burning ethylene in a limited supply of air and then quenching it with naphtha. The similarities between the BASF process and the method for producing carbon black lead me to believe, that ICI’s process was probably producing a lot of carbon black.
Peter was working on an instrument that measured the quantity of acetylene in the off-gas from the burners and he succeeded, but unfortunately proved that the plant was going into explosive limits. For this reason, ICI shut their process, although BASF persevered.
Ethylene is a hydrocarbon which has the formula C2H4 or two carbon and four hydrogen atoms. So if you can get them to stop tightly holding hands with no oxygen around, the hydrogen will pair off as H2 and the carbon will exist as a lot of single C atoms or carbon black.
BASF and ICI were trying to produce acetylene or C2H2, where there is a powerful triple bond between the two carbon atoms. All that energy in the acetylene makes it useful for activities like welding.
Common Uses Of Carbon Black
The Wikipedia entry for carbon black, has this summary of its uses.
The most common use (70%) of carbon black is as a pigment and reinforcing phase in automobile tires. Carbon black also helps conduct heat away from the tread and belt area of the tire, reducing thermal damage and increasing tire life. Its low cost makes it a common addition to cathodes and anodes and is considered a safe replacement to lithium metal in lithium-ion batteries. About 20% of world production goes into belts, hoses, and other non-tire rubber goods. The remaining 10% use of carbon black comes from pigment in inks, coatings, and plastics, as well as being used as a conductive additive in lithium-ion batteries.
The entry then gives a list of other uses, some of which are still being developed.
Global Production Of Carbon Black
This paragraph is from the Wikipedia entry for carbon black.
Total production was around 8,100,000 metric tons (8,900,000 short tons) in 2006. Global consumption of carbon black, estimated at 13.2 million metric tons, valued at US$13.7 billion, in 2015, is expected to reach 13.9 million metric tons, valued at US$14.4 billion in 2016.
So we have the useful paradox, that we don’t want to emit more carbon dioxide, but extra carbon black could probably be usefully used.
Conclusion
Using the HiiROC process to extract hydrogen could even give us a biproduct ; carbon black, that has uses.