A reducing agent for use in production of a product gas containing carbon monoxide, the reducing agent being brought into contact with a raw material gas containing carbon dioxide to reduce the carbon dioxide to produce the product gas; the reducing agent containing a composite metal oxide represented by Ce.sub.1-x(M).sub.xO.sub.y, where M is a metal element with an ionic radius smaller than an ionic radius of Ce with an identical valence number and an identical coordination number, x represents a positive real number, and y represents a real number from 1 to 4. The reducing agent that has a high conversion efficiency of carbon dioxide to carbon monoxide, and can be used, for example, in a chemical looping method, and a method for producing a gas using such a reducing agent.

A process for recovering and regenerating a tungsten compound suitable as co-catalyst in converting carbohydrates with hydrogen into alkylene glycols and polyols, from ash comprising one or more tungsten-oxygen components (e.g. comprising a tungstate and/or tungstic acid). Such ash is obtainable from burning a liquid mixture comprising alkylene glycols and/or polyols and sodium tungstate and/or tungstic acid.

A process for recovering and regenerating a tungsten compound suitable as co-catalyst in converting carbohydrates with hydrogen into alkylene glycols and polyols, from ash comprising one or more tungsten-oxygen components (e.g. comprising a tungstate and/or tungstic acid). Such ash is obtainable from burning a liquid mixture comprising alkylene glycols and/or polyols and sodium tungstate and/or tungstic acid.

The present disclosure relates to a process for stabilizing an antimony ammoxidation catalyst in an ammoxidation process. The process may comprise providing an antimony ammoxidation catalyst to a reactor; reacting propylene with ammonia and oxygen in the fluidized bed reactor in the presence of the antimony ammoxidation catalyst to form a crude acrylonitrile product; and adding an effective amount of an antimony-containing compound to the antimony ammoxidation catalyst to maintain catalyst conversion and selectivity; wherein the antimony-containing compound has a melting point less than 375° C. The present disclosure also relates to catalyst compositions and additional processes using the antimony ammoxidation catalyst stabilized by an antimony-containing compound.

The present disclosure relates to a process for stabilizing an antimony ammoxidation catalyst in an ammoxidation process. The process may comprise providing an antimony ammoxidation catalyst to a reactor; reacting propylene with ammonia and oxygen in the fluidized bed reactor in the presence of the antimony ammoxidation catalyst to form a crude acrylonitrile product; and adding an effective amount of an antimony-containing compound to the antimony ammoxidation catalyst to maintain catalyst conversion and selectivity; wherein the antimony-containing compound has a melting point less than 375° C. The present disclosure also relates to catalyst compositions and additional processes using the antimony ammoxidation catalyst stabilized by an antimony-containing compound.

A process and reactor for contacting a feed stream with a catalyst stream comprises a reaction chamber comprising two spent catalyst inlets for delivering two spent catalyst streams to the reaction chamber and at least one regenerated catalyst inlet for delivering a regenerated catalyst stream to the reaction chamber. The reaction chamber may also include a second regenerated catalyst inlet for delivering a second regenerated catalyst stream to the reaction chamber. The second spent catalyst inlet enables thorough mixing of catalyst streams.

A process and reactor for contacting a feed stream with a catalyst stream comprises a reaction chamber comprising two spent catalyst inlets for delivering two spent catalyst streams to the reaction chamber and at least one regenerated catalyst inlet for delivering a regenerated catalyst stream to the reaction chamber. The reaction chamber may also include a second regenerated catalyst inlet for delivering a second regenerated catalyst stream to the reaction chamber. The second spent catalyst inlet enables thorough mixing of catalyst streams.

A composition of fuel gas that when mixed with spent catalyst and oxygen has an induction time that allows bubbles to break up while combusting in the regenerator. Bubble breakage in a dense bed avoids generation of a flame that can generate hot spots in the regenerator which can damage equipment and catalyst. The fuel gas can be obtained from paraffin dehydrogenation products, so it can sustain operation of the unit even in remote locations. Heavier streams can be mixed with lighter streams to obtain a fuel gas composition with a desirable induction time to avoid such hot spots. Mixing of a depropanizer bottom stream and/or deethanizer overhead stream with lighter gas streams such as cold box light gas or PSA tail gas can provide the desired fuel gas composition.

A mesoporous ozonation catalyst including a cerium-titanium-zirconium composite oxide. The catalyst is in the form of a solid spherical particle having a diameter of between 0.7 and 1.2 mm. The solid spherical particle exhibits lattice fringes under transmission electron microscope, and the lattice fringes have a spacing between 0.332 and 0.339 nm.

A mesoporous ozonation catalyst including a cerium-titanium-zirconium composite oxide. The catalyst is in the form of a solid spherical particle having a diameter of between 0.7 and 1.2 mm. The solid spherical particle exhibits lattice fringes under transmission electron microscope, and the lattice fringes have a spacing between 0.332 and 0.339 nm.