Making
Ethylene From Ethane
Assalamu'alaikum Netizens, Peace be with you all. This post is about making Ethylene from Ethane using dehydrogenation and cracking reactions. Please see the information below :
Baca Juga : Alat Industri Scrubber (Alat Penyerap Partikel Tersuspensi)
Ethylene is made primarily by steam cracking of ethane and higher alkanes. These alkanes undergo dehydrogenation and cracking reactions. A higher-molecular-weight fraction of alkanes, C4 to C7, is called naphtha, which in steam cracking reacts as
When ethane is used as a feedstock, the major reaction is simple dehydrogenation,
Baca Juga : Alat Industri Boiler dan Jenis - Jenisnya
In modern steam cracking processes using ethane as a feedstock approximately 80% ethylene selectivity is attained at approximately 40% ethane conversion. This reaction is highly endothermic, and more than 25 kcal/mole of ethane converted must be supplied in the reactor.
Equilibrium in the reactions shown is unfavorable except at high temperatures, and modem plants operate at temperatures of 850 - 900°C. At these temperatures reaction takes place homogeneously, but it is far from elementary and proceeds by a chain reaction involving many free-radical intermediates. Reaction is roughly first order in ethane,
In-free radical reactions many products are formed in small quantities such as propylene, methane, butadiene, acetylene, and benzene. A major cost of an olefin plant is the separation of these byproducts from ethylene and also separation of unreacted ethane, which is recycled and fed back to the reactor.
Another major cost in producing ethylene results from the formation of carbon on the walls of the reactor. This occurs through reactions such as
although ethane and all hydrocarbons can also decompose to carbon. Carbon formation from pure alkane feed would plug the reactor very quickly, and in olefin plants a large excess of water is added to suppress the cracking of large hydrocarbons into smaller ones.
Baca Juga : Buku - Buku Teknik Kimia Part 1
The process is called steam cracking because water is added to suppress coke formation. Water does not react directly with the hydrocarbon, but it reacts with carbon in the reaction
a process called steam gasification. The addition of steam reduces the rate of coke formation such that the tubes of the reactor only slowly develop significant pressure drops because of carbon buildup. In an olefin plant the process must be shut down approximately once a month for a day or so while air is blown through the tubes to oxidize the carbon,
a very exothermic gas-solid reaction.
Baca Juga : Buku - Buku Teknik Kimia Part 2
Steam-cracking reactors typically consist of several steel tubes, perhaps 100 m long and 4 in. in diameter in a tube furnace with reactants and steam fed through the several tubes in parallel. The ceramic lined furnace is heated by burning natural gas at the walls to heat the tubes to 900°C by radiation. The reactor is fed by ethane and steam in a ratio of 1:l to I:3 at just above atmospheric pressure. The residence time in a typical reactor is approximately 1 set, and each tube produces approximately 100 tons/day of ethylene.
Source : The Engineering Of Chemical Reactions L. D. Schmidt Oxford University Press
Baca Juga : Emulator Android Ringan Terbaik Dari High Spec Sampai Spec Low End
That's information about the manufacture of ethylene from ethane. Look forward to more information from this blog.
That's all hopefully useful. Wassalamualaikum wr. wb.
0 Komentar