The present invention relates to a nitro compound hydrogenation reaction process and hydrogenation reaction apparatus, which can achieve the objects of the continuous reaction of the nitro compound and the long-period run of regeneration and activation. The nitro compound hydrogenation reaction process comprises a hydrogenation step, a regeneration step, an optional activation step and a recycling step. There exists at least one step of degassing the spent catalyst between the hydrogenation step and the regeneration step. According to circumstances, there exists at least one step of degassing the regenerated catalyst between the regeneration step and the activation step.

The present invention discloses an efficient mass-transfer separation bulk filler structure, which includes a bulk filler body with closely-fit multilayer structures, wherein an annular wall surface of the bulk, filler body has a corrugated angle group. A lower portion of the bulk filler body is of a bell-mouth shape. Three passages with a same sectional area are formed inside the bulk filler body. The present invention has the characteristics of small pressure drop, large specific surface area, low liquid holdup and large void ratio. The annular wall surface is provided with the corrugated angle group to increase the disturbance and reduce a double-membrane thickness of vapor and liquid phase mass-transfer resistance, thereby improving the mass-transfer coefficient and separation efficiency. Meanwhile, by adopting the bell-mouth shape, the stability and natural stacking regularity of the bulk filler can be improved.

A gas replacement process and a gas replacement apparatus are employed, in the nitro compound hydrogenation reaction process. The gas replacement process at least includes a first step of subjecting a stream to be replaced to the gas replacement in presence of a first replacement gas, and then a second step of subjecting to the gas replacement in presence of the second replacement gas. Assuming the superficial velocity of the first replacement gas is V1, and the superficial velocity of the second replacement gas is V2, then V2/V1≥1.5.

The present invention discloses an efficient mass-transfer separation bulk filler structure, which includes a bulk filler body with closely-fit multilayer structures, wherein an annular wall surface of the bulk, filler body has a corrugated angle group. A lower portion of the bulk filler body is of a bell-mouth shape. Three passages with a same sectional area are formed inside the bulk filler body. The present invention has the characteristics of small pressure drop, large specific surface area, low liquid holdup and large void ratio. The annular wall surface is provided with the corrugated angle group to increase the disturbance and reduce a double-membrane thickness of vapor and liquid phase mass-transfer resistance, thereby improving the mass-transfer coefficient and separation efficiency. Meanwhile, by adopting the bell-mouth shape, the stability and natural stacking regularity of the bulk filler can be improved.

The present disclosure relates to a single shell open interstage reactor (SSOI). The SSOI comprises a first reaction stage, an interstage heat exchanger, an open interstage region, and a second reaction stage. The SSOI may be configured for upflow or downflow operation. Further, the open interstage region of the SSOI may comprise a supplemental oxidant feed. When the open interstage region comprises a supplemental oxidant feed, the SSOI may further comprise a supplemental oxidant mixing assembly. Processes for producing acrylic acid through the oxidation of propylene are also disclosed.

In a fixed-bed flow reaction using a multitubular heat exchange type reactor, an object of the present invention is to provide a novel packing for a reaction tube, which can control the reaction ratio in the vicinity of the reaction tube inlet, reduce the load unevenly placed on the catalyst in the reaction region, and distribute the load on the entire catalyst layer, a heat exchange type reactor, and a reaction method using the reaction tube. The packing for a reaction tube of the present invention is characterized in that the volume is continuously or step-by-step decreased from one end part or midway toward the other end part.

The present disclosure relates to a single shell open interstage reactor (SSOI). The SSOI comprises a first reaction stage, an interstage heat exchanger, an open interstage region, and a second reaction stage. The SSOI may be configured for upflow or downflow operation. Further, the open interstage region of the SSOI may comprise a supplemental oxidant feed. When the open interstage region comprises a supplemental oxidant feed, the SSOI may further comprise a supplemental oxidant mixing assembly. Processes for producing acrylic acid through the oxidation of propylene are also disclosed.

Described herein are expandable center arrangements for use in a tubular reactor, such as a reformer, for enhancing heat transfer and reactor efficiency. The expandable center arrangement can include a cone being expandable in the radial direction and an expansion weight for promoting expansion of the cone. The cone and expansion weight can be slidably arranged on a center support. Expansion of the cones in the radial direction forces reactor components radially outward to an outer tube that houses the reactor components and expandable center arrangement. Expansion of reactor components towards the outer tube promotes heat for carrying out catalytic reactions.

The present disclosure relates to a single shell open interstage reactor (SSOI). The SSOI comprises a first reaction stage, an interstage heat exchanger, an open interstage region, and a second reaction stage. The SSOI may be configured for upflow or downflow operation. Further, the open interstage region of the SSOI may comprise a supplemental oxidant feed. When the open interstage region comprises a supplemental oxidant feed, the SSOI may further comprise a supplemental oxidant mixing assembly. Processes for producing acrylic acid through the oxidation of propylene are also disclosed.

A packing (200, 300, 400, 500) for a rotating packed bed (RPB). The packing includes an elongate central aperture (210, 340, 440, 540). The elongate central aperture (210, 340, 440, 540) extends along at least part of the length of the packing (200, 300, 400, 500). The packing (200, 300, 400, 500) is configured to rotate about an axis (220, 350, 450, 550) which extends along the length of the central aperture (210, 340, 440, 540). A packing body (230, 360, 430, 530) extends around the central aperture (210, 340, 440, 540). The packing body (230, 360, 430, 530) includes a first body portion (240, 310, 420, 520) having a first side profile (250, 320, 410, 510). The packing body (230, 360, 430, 530) further includes a second body portion (260, 370, 460, 560) having a second side profile (270, 380, 470, 570), wherein the second side profile (270, 380, 470, 570) is different from the first side profile (250, 320, 410, 510).