Processes of ethylene production from nonrenewable and renewable resources : bachelor thesis

Etilen je jedan od najvažnijih proizvoda kemijske industrije. Zbog njegove velike primjene u industriji polimera, proizvodnja etilena raste iz godine u godinu. Najznačajniji način dobivanja etilena je parno krekiranje ugljikovodika. To je proces koji koristi sirovine iz fosilnih izvora. Sirovina se izlaže visokim temperaturama i vodenoj pari pri čemu dolazi do cijepanja ugljikovodičnih lanaca i nastajanja molekula ugljikovodika manjih molekulskih masa. Nakon procesa krekiranja slijedi složeni postupak odvajanja različitih ugljikovodika kako bi se dobili čisti proizvodi za upotrebu u drugim industrijama. Uz etilen, kao značajni proizvodi dobivaju se propilen i pirolitički benzin (bogat aromatima). Parno krekiranje je usavršen proces te mu ostali procesi dobivanja etilen ne mogu parirati. Zbog povećane ekološke osviještenosti i smanjenja zaliha fosilnih goriva, počinju se razvijati nove metode dobivanja etilena koje imaju manju emisiju CO₂ i koriste sirovine iz obnovljivih izvora. Većina procesa je još u fazi razvoja, ali pokazuju obećavajuće rezultate. Procesi koji se najviše istražuju za proizvodnju etilena su dobivanje iz metanola (metanol se dobiva iz otpadnog CO₂), oksidacijom metana, elektrolitičkom redukcijom CO₂ i dobivanje pomoću biljaka. Ovi procesi će biti neophodni u daljoj budućnosti, no za sada parno krekiranje ostaje primaran način proizvodnje etilena.Ethylene is one of the most important products of chemical industry. Production of ethylene increases by year due to its extensive usage in polymer industry. The most important way of producing ethylene is steam cracking of hydrocarbons. It uses raw materials such as fossil fuels and exposes it to high temperatures and steam which leads to cracking of hydrocarbon chains and formation of hydrocarbons with lower molecular mass. The cracking process is followed by complex process of separation of all hydrocarbons in order to get clean products for subsequent usage in other industries. Beside ethylene, propylene and pyrolysis gasoline (rich with aromatics) are significant products from stean cracking. Steam cracking is a very developed process and other processes of ethylene production can't even come close to it. New ethylene production methods that have lowered emission of CO₂ and use renewable resources are being developed because of increased enviromental awareness and lower stock of fossil fuels. Most of processes are still in the phase of development but they show promising results. Some of the processes that are being developed include production from methanol (which is produced from waste CO₂), oxidative coupling of methane, electrochemical reduction of CO₂ and production through plants. These processes will be necessary in the further future but for now steam cracking remains the main way of ethylene production