The invention relates to a process for the dehydrogenation of a feedstock comprising ethanol, using at least one multitubular reactor advantageously comprising a plurality of tubes comprising at least one dehydrogenation catalyst, and a calender, said feedstock being introduced into the tubes in gas form, at an inlet temperature of greater than or equal to 240° C., a pressure between 0.1 and 1.0 MPa, and a WWH between 2 and 15 h.sup.−1, wherein a heat-transfer fluid circulates in said calender at a flow rate such that the weight ratio of said heat-transfer fluid relative to said feedstock is greater than or equal to 1.0, and such that said heat-transfer fluid is introduced into said calender in gas form at an inlet temperature of greater than or equal to 260° C. and at an inlet pressure of greater than or equal to 0.10 MPa, and less than or equal to 1.10 MPa, and leaves the calender at least partly in liquid form.

The present invention relates to a process for producing butadiene from ethanol, in two reaction steps, comprising a step a) of converting ethanol into acetaldehyde and a step b) of conversion into butadiene, said step b) simultaneously implementing a reaction step and a regeneration step in (n+n/2) fixed-bed reactors, n being equal to 2 or a multiple thereof, comprising a catalyst, said regeneration step comprising four successive regeneration phases, said step b) also implementing a regeneration loop for the inert gas and at least one regeneration loop for the gas streams comprising oxygen.

Disclosed are a spiro-bisphosphorous compound, and a preparation and application thereof. The spiro-bisphosphorous compound is expressed in formula (I), (II) or (III).

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Disclosed are a spiro-bisphosphorous compound, and a preparation and application thereof. The spiro-bisphosphorous compound is expressed in formula (I), (II) or (III).

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A composition can photocatalytically reduce carbon dioxide.

A composition can photocatalytically reduce carbon dioxide.

A composition can photocatalytically reduce carbon dioxide.

A composition can photocatalytically reduce carbon dioxide.

A composition can photocatalytically reduce carbon dioxide.

A composition can photocatalytically reduce carbon dioxide.