AA42
Industrial
- Oct 23, 2024
- 1
Hi guys, I blend gasoline and these days with weak naphtha gasoline spread, blending is difficult without cheap and unused blendstocks.
I've dealt with high olefin content components before and easily stabilized them with antioxidants, specifically N,N'-Di-2-butyl-1,4-phenylenediamine, and TBC.
Today I'm dealing with a cheap C6 olefins stream. It comes from a 1-butene unit that's producing via ethylene dimerization. GC results show:
29% 3-methyl-1-pentene
54% 3-methylene-pentane (aka 2-ethyl-1-butene)
7% 1-hexene
However, I haven't been able to stabilize it yet, and it behaves very weird. On day 1 (about 36 hours after sampling from plant, transport on ice to our office), when I blended it with other components, it instantly turned from clear, barely-light-yellow colour to a dark but clear yellow-orange. As in my other components were also light yellow but some reaction would take place making it much darker. Pretty identical to very dehydrated urine in terms of colour, not cloudy at all.
However since then, on day two any beyond in my blends. It no longer changes colour, instead it coagulates/polymerizes into floaters after about 30 minutes, that eventually settle at the bottom. Even with an extremely high dose of the phenylenediamine (1000ppm) this happens. If I add TBC, it instantly turns into a Fanta-like orange and gives extreme gum, like 1/3 of the bottle turns into those floaters except a lot more dense.
I've done everything imaginable to recreate day 1 behaviour of changing colour instead of giving floaters with no colour change, but have been unable to recreate the initial colour change.
Any ideas on fixes? Have you seen anything like this before? Or even any ideas on what even is going on? I suspect it has to do with some equilibrium shifting between radicals to peroxides and polymers but not at all sure and completely stumped on how to proceed.
I've dealt with high olefin content components before and easily stabilized them with antioxidants, specifically N,N'-Di-2-butyl-1,4-phenylenediamine, and TBC.
Today I'm dealing with a cheap C6 olefins stream. It comes from a 1-butene unit that's producing via ethylene dimerization. GC results show:
29% 3-methyl-1-pentene
54% 3-methylene-pentane (aka 2-ethyl-1-butene)
7% 1-hexene
However, I haven't been able to stabilize it yet, and it behaves very weird. On day 1 (about 36 hours after sampling from plant, transport on ice to our office), when I blended it with other components, it instantly turned from clear, barely-light-yellow colour to a dark but clear yellow-orange. As in my other components were also light yellow but some reaction would take place making it much darker. Pretty identical to very dehydrated urine in terms of colour, not cloudy at all.
However since then, on day two any beyond in my blends. It no longer changes colour, instead it coagulates/polymerizes into floaters after about 30 minutes, that eventually settle at the bottom. Even with an extremely high dose of the phenylenediamine (1000ppm) this happens. If I add TBC, it instantly turns into a Fanta-like orange and gives extreme gum, like 1/3 of the bottle turns into those floaters except a lot more dense.
I've done everything imaginable to recreate day 1 behaviour of changing colour instead of giving floaters with no colour change, but have been unable to recreate the initial colour change.
Any ideas on fixes? Have you seen anything like this before? Or even any ideas on what even is going on? I suspect it has to do with some equilibrium shifting between radicals to peroxides and polymers but not at all sure and completely stumped on how to proceed.
