The application provides in an aspect a process for producing urea in a urea plant comprising a high pressure synthesis section comprising a reactor, wherein the process comprises reacting NH.sub.3 feed and CO.sub.2 feed under urea formation conditions in said reactor to form a urea synthesis solution comprising urea, water, carbamate and ammonia, wherein the process further comprises contacting a carbamate-containing liquid stream with an equipment part of said high pressure synthesis section that is made of a ferritic steel alloy.

A method is described for shutting down a Fischer-Tropsch reactor fed with a reactant gas mixture comprising a synthesis gas and a recycle gas recovered from the Fischer-Tropsch reactor in a synthesis loop, said Fischer-Tropsch reactor containing a Fischer-Tropsch catalyst cooled indirectly by a coolant under pressure, comprising the steps of: (a) depressurising the coolant to cool the reactant gas mixture to quench Fischer-Tropsch reactions taking place in the Fischer-Tropsch reactor, (b) stopping the synthesis gas feed to the Fischer-Tropsch reactor, and (c) maintaining circulation of the recycle gas through the Fischer-Tropsch reactor during steps (a) and (b) to remove heat from the Fischer-Tropsch reactor. The method safely facilitates a more rapid return to operating conditions than a full shut-down.

A combined reforming apparatus is provided. The combined reforming apparatus includes a body, a first catalyst tube disposed inside the body and reacting at a first temperature to reform hydrocarbons (C.sub.xH.sub.y) having two or more carbon atoms into methane (CH.sub.4), a second catalyst tube disposed inside the body, connected to the first catalyst tube, and reacting at a second temperature higher than the first temperature to reform methane (CH.sub.4) into synthesis gas comprising hydrogen (H.sub.2) and carbon monoxide (CO), and a combustion unit configured to supply heat to the first and second catalyst tubes.

A chemical vessel utilizing induction heating elements and useful for preparing polyamides, such as nylon. The vessel can utilize an array of induction heating elements located inside a process chamber. Also described are a vessel, a heat exchanger, a process, and an apparatus useful for polyamide preparation.

A solar-driven methanol reforming system for hydrogen production includes a water storage tank, high-temperature solar collector tubes, a thermocouple, valves, preheaters, an evaporator, a reactor, a heat exchanger, a mixed solution (methanol and water) storage tank, a gas separator, a pump, a carbon dioxide storage tank, a hydrogen storage tank, and pipes; the present invention utilizes solar energy to provide heat required for hydrogen production by methanol reforming, and stores some heat in a phase change material to supply heat for the methanol reforming reaction when sunlight is weak; the system does not need additional energy supply, thus saving energy consumption from traditional electric heating or fuel heating.

A depolymerization system with a tube-wound heat exchanger (4) comprises a heat exchange device for heating a material, having a material output; a gas-liquid separation device (1) having an inlet and a gas output, connected to the material output of the heat exchange device; and a depolymerization device (2) connected to the gas output of the gas-liquid separation device (1); the heat exchange device comprises at least one tube-wound heat exchanger (4). The depolymerization rate is greatly improved and the service period of the whole depolymerization system can be greatly improved.

Current chemical batch processing technology is based on batch reactors, which typically consist of a vessel, in which reactants are processed. The batch reactor comprises a reactor vessel having at least one first thermal transfer element; a removable top cover for sealing the reactor vessel; a baffle component having at least one second thermal transfer element; and an agitator component, wherein each of the at least one first thermal transfer element and the at least one second thermal transfer element is independently controllable, and wherein the batch reactor comprises a thermal transfer surface-to-volume ratio of at least 6:1. This increases the thermal transfer potential and the thermal energy transfer efficiency of the batch reactor, thereby to increase production speed and throughput.

The application provides in an aspect a process for producing urea in a urea plant comprising a high pressure synthesis section comprising a reactor, wherein the process comprises reacting NH.sub.3 feed and CO.sub.2 feed under urea formation conditions in said reactor to form a urea synthesis solution comprising urea, water, carbamate and ammonia, wherein the process further comprises contacting a carbamate—containing liquid stream with an equipment part of said high pressure synthesis section that is made of a ferritic steel alloy.

A dehydrogenation chemical reactor includes: a housing; a catalyst part made of a thermally conductive material and disposed in the housing, where the catalyst part has a panel shape, and a catalyst is coated on a surface of the catalyst part to separate hydrogen from an organic hydrogen carrier; a heat transfer pipe which is installed to contact the catalyst part, and conducts latent heat to the catalyst part while pressurized and saturated fluid is supplied therein; and an organic hydrogen carrier line which is connected to the housing to form a passage in which the organic hydrogen carrier is introduced into the housing, contacts the catalyst part to separate hydrogen, and then is discharged.

Shell-and-tube strippers for stripping a urea/carbamate mixture, related systems, methods, and uses. The stripper includes a shell, a plurality of tubes disposed within the shell, and a heating fluid distributor for homogenizing the flow of a heating fluid near a heating fluid inlet. The heating fluid distributor includes an edge wall and a laterally disposed heating fluid distribution plate. Related systems, methods, and uses are also provided.