#video showing a polyethylene plant operated by BP, starting from #ethylene (usually derived from cracking naphtha #materials) at 1500 atmospheres and 160° with about 20% yield of polyethylene on each go-around, so the unreacted ethylene gets compressed again.
on 02025-09-26#video of stock footage and animations explaining how #ethylene is industrially produced by thermal cracking of ethane #materials distilled from natural gas at 850° (catalysts unspecified), and the ethylene is reacted with butylene (using other unspecified catalysts) to polymerize it. Free-radical peroxide initiation is not mentioned.
on 02025-09-26another #video on #manufacturing #ethylene #materials automatically by #Hyperspace-Pirate. He wants to use it as a second-stage refrigerant for his vapor-compression cryocooler for #cryogenics. He wants to separate ethanol into ethylene and water over a propane-heated sapphire catalyst (Wisesorb activated alumina from wisesorbent.com in 3.5mm balls) at 450°, which is fucking awesome. Around 300° to 350° you would instead get ether, and above 550° you mostly get carbon and hydrogen, the production of which starts at around 500°. Between 400° and 500° you mostly get ethylene (and water). Aluminum pipe contains the catalyst (and a thermocouple for temperature control), and copper line and flare nuts move the ethanol and ethylene vapor around. The pieces are supported on cinder blocks and bricks on what looks like a concrete floor. Bubbling the output through water produces a lot of flammable gas, which is probably ethylene. He adds a plastic juice bottle full of water as a bubbler to remove particles and a second plastic juice bottle full of silica-gel desiccant to separate the ethylene from the water, and then a dust filter to remove particles of the silica gel. He bolts together some aluminum L-profiles to hold things in place and 3-D prints a fixture for the bottles. A “25-foot” condenser coil of copper line with a fan blowing on it serves as a heat exchanger to cool the hot ethylene to near ambient. A second bubbler collects the liquids, which include a significant amount of ether. He collects the ethylene output in a beach ball. He uses a fridge compressor to pump it from the beach ball into a pressure tank previously purged with propane. His 500cc of 151-proof Everclear turned into 69.7g of ethylene, only a 39% yield, probably because he made about 50 grams of ether. On a second run he used a higher catalyst temperature and got a 70% yield. Chemical engineer in the comments: “It absolutely blew my mind to see someone casually building a packed-bed plug-flow reactor from plumbing parts and unspecified alumina beads in his garage, and the damn thing actually working! Seriously, well done! (Deep down I’m almost insulted by the fact you managed to get a decent yield without doing any equations to work out the reaction rate, and therefore flow rate and reactor length required 😂)” but he also suggests that the output ethylene product is probably contaminated with a lot of ether.
on 02024-09-03#video #toread on #manufacturing #ethylene #materials automatically by #Hyperspace-Pirate
on 02024-09-03