Production of ether and olefin from an hydrocarbon feed containing a tertiary olefin

摘要

The production of ether and olefin from an hydrocarbon feed containing a tertiary olefin is claimed. It consists of several steps: (a) synthesis of the tertiary alkyl ether by contacting a hydrocarbon feed containing a tertiary olefin with an alcohol in a contact zone, in the presence of a catalyst; (b) separation step of the product resulted from step (a) in an organic fraction O1 deficient in tertiary alkyl ether and an organic fraction E1 rich in tertiary alkyl ether; (c) decomposition of the tertiary alkyl ether of the organic fraction E1 of step (b) in a reaction zone R1 in the presence of catalyst into a product P1 containing an alcohol and a tertiary olefin; (d) purification step of the product P1 resulting from step (c) in an extraction zone (L1) by washing with water where A1 containing most of the alcohol and B1 ther tertiary olefin are obtained; (e) recovery of the aqueous liquid fraction La1 from the separation zone (Co1) where B1 is fed and the organic liquid fraction Lb1 containing the tertiary olefin, ether and low and high molecular weight compounds; and (f) feeding of the fraction A1 from step (d) to a fractionating zone (D3) from which G1 fraction containing most of the alcohol and an aqueous fraction (H1) almost alcohol free are recovered. Preferably part of the aqueous fraction La1 and the aqueous fraction (H1) are recycled towards the water extraction zone (L1) of step (d). Part of the fraction G1 is sent to the ether synthesis zone (R100) of step (a). The water extraction zone L1 and L2 contain means of introducing water. Part of the organic fraction Lb1 of step (e) is sent in a fractionating zone D1 from which a fraction E10 containing most of the un-decomposed ether from step (c) and a fraction F1 containing most of the tertiary olefin are recovered. The E10 fraction is recycled in the step (c) zone. Part of the F1 fraction is sent to a fractionating zone D2 from which Lg1 fraction containing most of the low molecular weight compounds and Ohp3 fraction containing most of the tertiary olefin are recovered. It is also sent to the water extraction zone L2 from which an aqueous fraction A2 containing most of the alcohol and B2 containing most of the olefin are obtained.