The present invention relates to a new process for the synthesis of 2,3,4,5,6,7-substituted indenes, which are useful precursors for the formation of certain ansa-metallocene catalysts.

The present invention relates to a catalyst for the conversion of oxygenates to olefins, wherein the catalyst comprises one or more zeolites of the MFI, MEL and/or MWW structure type and particles of one or more metal oxides, the one or more zeolites of the MFI, MEL and/or MWW structure type comprising one or more alkaline earth metals, and the particles of the one or more metal oxides comprising phosphorus, the phosphorus being present at least partly in oxidic form, and the one or more alkaline earth metals being selected from the group consisting of Mg, Ca, Sr, Ba and combinations of two or more thereof, to the preparation and use thereof, and to a process for converting oxygenates to olefins using the catalyst.

A continuous mixing reactor has an outer shell having a cylindrical portion with a central section and two opposite conical end sections; a circulation tube within the shell so that an annular passage forms between the shell and the circulation tube; an impeller within and positioned adjacent to one end of the circulation tube; and heat exchange means penetrating the outer shell and extending into the end of the circulation tube opposite the impeller. The outer shell has a hydraulic head forming one end of the shell, a heat exchange medium header at the opposite end of the shell. The circulation tube nearer the heat exchange medium header terminates at or downstream from a tangential plane extending through the shell at the intersection of the central section and the conical end section of the cylindrical portion of shell. The reactor is useful in an alkylation process.

The invention provides non-naturally occurring microbial organisms having a butadiene pathway. The invention additionally provides methods of using such organisms to produce butadiene.

A process provides oligomerization feed stream comprising C.sub.5 hydrocarbons and olefins along with C.sub.4 olefins to an oligomerization zone. The oligomerization feed stream may be obtained from cracked FCC products. Unreacted C.sub.5 hydrocarbons can be recycled to the oligomerization zone to maintain the liquid phase therein.