5)AromatizationreactionsRT-2H2
(5) Aromatization reactions R -2H2 R
3.Cracking reaction of cycloalkanes2H4+1V4H8Chain scission and ringCH2--C2H4 + C4H + H2openingreactionCH2CH2Ring-opening*2C.H6DehydrogenationCH2CH2-CH6 + C2H6reactionCH233HzSide chain cleavage4Ho22reactionDehydrogenationRing-opening-H2H-HdehydrogenationreactionCHCHCH2H-CH2侧链断裂CH2CH2CH2CHz+ CHH2H2
➢ Chain scission and ringopening reaction ➢ Dehydrogenation reaction ➢ Side chain cleavage reaction ➢ Ring-opening dehydrogenation reaction 3. Cracking reaction of cycloalkanes Dehydrogenation Ring-opening
Crackingrulesof cycloalkanesThe chain scission reaction of side chain alkyl group is easier thanring-openingThe aromatics formedby dehydrogenationreactions ofcycloalkanes is superior to the alkenes formed by ring-openingreactions of cycloalkanes.It is more difficultfor the cracking reaction ofthecycloalkaneswith five-carbon ring than that with six-carbon ring.The cycloalkanes are easier to formtar,and produce coke thanchainalkanes
⚫ The chain scission reaction of side chain alkyl group is easier than ring-opening ⚫ The aromatics formed by dehydrogenation reactions of cycloalkanes is superior to the alkenes formed by ring-opening reactions of cycloalkanes. ⚫ It is more difficult for the cracking reaction of the cycloalkanes with five-carbon ring than that with six-carbon ring. ⚫ The cycloalkanes are easier to form tar, and produce coke than chain alkanes. Cracking rules of cycloalkanes
4.Cracking reactions of aromatics)Crackingreactions ofalkylaromaticsArH+C,H2nAr-C,H2n+1Ar-C,H2k++CmH2mAr-C,H2n-1+H2Ar-C,H2n+1ArAryl; n=k+mDealkylation or scission of side chain
4. Cracking reactions of aromatics (1) Cracking reactions of alkyl aromatics Ar—Aryl；n=k+m Ar-CkH2k+1+CmH2m ArH+CnH2n Ar-CnH2n+1 Ar-CnH2n+1 Ar-CnH2n-1+H2 Dealkylation or scission of side chain
(2)CrackingreactionsofcycloalkylaromaticsDehydrogenation andisomerization-dehydrogenation reactions+R;HCondensation-dehydrogenation reactionsHH+R.H
(2) Cracking reactions of cycloalkyl aromatics Dehydrogenation and isomerization-dehydrogenation reactions Condensation-dehydrogenation reactions