%0 Journal Article
%T Valorisation de la coupe C4 de vapocraquage via l'hydrog¨¦nation du butadi¨¨ne, l'isom¨¦risation des but¨¨nes et la m¨¦tath¨¨se, en MTBE ou en propyl¨¨ne Upgrading the C4 Cut from Steam Cracking via the Hydrogenation of Butadiene, the Isomerization of Butenes and Metathesis Into Mtbe Or Propylene
%A Chaumette S.
%A Torck B.
%J Oil & Gas Science and Technology
%D 2006
%I Institut Fran?ais du P¨¦trole
%R 10.2516/ogst:1994040
%X Le surplus de butadi¨¨ne au niveau mondial contraint les p¨¦trochimistes ¨¤ recycler la coupe C4 au vapocraqueur. De plus en plus, le butadi¨¨ne est hydrog¨¦n¨¦ avant de recraquer toute la coupe. Une fois hydrog¨¦n¨¦e, cette coupe peut ¨ºtre beaucoup mieux valoris¨¦e, soit en MTBE avec isom¨¦risation des n-but¨¨nes (proc¨¦d¨¦ ISO-4), soit en propyl¨¨ne et MTBE en utilisant le proc¨¦d¨¦ META-4. L'¨¦tude technico-¨¦conomique montre que cette derni¨¨re voie offre la meilleure rentabilit¨¦ (TRI = 21,5 %). Si le vapocraqueur est int¨¦gr¨¦ ¨¤ une raffinerie, les but¨¨nes peuvent ¨¦galement ¨ºtre transform¨¦s en alkylats ou en MTBE, pour r¨¦pondre ¨¤ une demande en octane ou en oxyg¨¦n¨¦s pour les carburants. Ces diverses voies de valorisation sont plus int¨¦ressantes que la production de MTBE ¨¤ partir des butanes via la d¨¦shydrog¨¦nation de l'isobutane ou que la production du propyl¨¨ne par d¨¦shydrog¨¦nation du propane. Une ¨¦tude de sensibilit¨¦ aux diff¨¦rents prix des produits envisag¨¦s permet d'¨¦tablir des courbes d'isorentabilit¨¦s, d¨¦limitant des zones de prix favorables ¨¤ l'un ou l'autre des produits, pris deux ¨¤ deux. The evolution of the outlets for C4 cuts from steam cracking shows quite contradictory results. On one hand, European and Asian petrochemists are more constrained to recycle this type of effluent, which contains butadiene and isobutene, to the steam cracker. Likewise, the demand for isobutene for MTBE production is such that it has to be produced by the dehydrogenation of isobutane. This situation is effectively caused by the surplus of butadiene, a by-product of ethylene, and for which the demand is not increasing as fast as the demand for ethylene. To improve cracking performances during the recycling of the C4 Cut, butadiene is more and more selectively hydrogenated. Under these conditions, rather than cracking it, the new processes could make it possible to better upgrade it. Indeed, after selective hydrogenation, most of the cut can be transformed into MTBE by implementing the new n-butene isomerization process. Another upgrading scheme consits in transforming isobutene into MTBE and n-butenes into propylene by metathesis with ethylene. These new route may find competition in the transformation of butenes into alkylates, for automotive gasoline, with or without MTBE production. After a brief review of the different markets for the products involved, a technico-economic study serves to classify the different upgrading routes of the C4 cut from steam cracking, by comparing both the minimum profitable selling prices for a discounting rate of 12% and the discounted cash-flow r
%U http://dx.doi.org/10.2516/ogst:1994040