A process for synthesis of urea from CO.sub.2 and NH.sub.3 wherein a steam flow (13) produced in the condenser (3) of a high-pressure synthesis loop is compressed to raise its pressure and temperature before using the steam as a heat source for a downstream step of the process.

A system for processing fuel to remove sulfur species through the oxidation of the sulfur species is described which includes one or more (and preferably two or more processing units). Additionally, a method of removing sulfur species through the oxidation of the sulfur species is also described. The system and the method rely on the use of aqueous feed and does not require the removal (through sorption or the like) at each or between each processing unit. Such a configuration for numerous reasons is economically advantageous.

Reagents and solvents used for polymer synthesis are reused or recycled rather than discarded. The outflow from each step of polymer synthesis may be collected separately in one of multiple dedicated containers. Reuse returns the outflow from a step of polymer synthesis back to an input of a polymer synthesizer for subsequent use in that same step. Recycling processes the outflow from one or more steps of polymer synthesis to restore original concentrations or purity levels for use in a later synthesis run. Quality control analysis may determine if outflow collected from a polymer synthesizer is reused or recycled. These techniques reduce reagent cost and waste quantity. These techniques may be used with phosphoramidite or enzyme-based synthesis of deoxyribonucleic acid (DNA).

A reactor for performing a gas/liquid biphasic high-pressure reaction with a foaming medium, comprising an interior formed by a cylindrical, vertically oriented elongate shell, a bottom and a cap, wherein the interior is divided by internals into a backmixed zone and a zone of limited backmixing, wherein the backmixed zone and the zone of limited backmixing are consecutively traversable by the reaction mixture, wherein the backmixed zone comprises means for introducing gas and liquid and a gas outlet and also comprises at least one mixing apparatus selected from a stirrer, a jet nozzle and means for injecting the gas, and the zone of limited backmixing comprises a reaction product outlet, a first cylindrical internal element which in the interior extends in the longitudinal direction of the reactor and which delimits the zone of limited backmixing from the backmixed zone, backmixing-preventing second internal elements in the form of random packings, structured packings or liquid-permeable trays arranged in the zone of limited backmixing and a riser tube whose lower end is arranged within the backmixed zone and whose upper end opens into the zone of limited backmixing so that liquid from the backmixed zone can ascend into the zone of limited backmixing via the riser tube, wherein flow into the zone of limited backmixing enters from below. The reactor is configured such that the high-pressure reaction space is optimally utilized and contamination of workup steps or subsequent reactions arranged downstream of the high-pressure reaction with foam is substantially avoided. The invention further relates to a process for performing a continuous gas/liquid biphasic high-pressure reaction in the reactor.

A submerged propylene hydration micro-interface strengthening reaction system and a method are proposed. The system includes a reactor, a first micro-interface generator and a second micro-interface generator. Through the micro-interface generators, the propylene is broken to form micron-scale bubbles, which are mixed with reactants and deionized water to form a gas-liquid emulsion, so as to increase a phase boundary area between gas and liquid phases, and achieve a strengthening mass transfer effect under a lower preset operating condition. The micro-scale bubbles can be fully mixed with the deionized water to from a gas-liquid emulsion. By fully mixing gas and liquid phases, it can ensure that the deionized water in the system is in full contact with propylene, and they are fully in contact with the catalyst, which effectively improves the efficiency of preparing isopropanol.

A micro-interface strengthening reaction system and method for preparing polyethylene by using a solution process are provided. The system includes a pre-polymerization reactor and a polymerization reactor connected in sequence. The pre-polymerization reactor is provided with a pre-polymerization micro-interface generators, and the polymerization reactor is provided with a micro-interface generator. The system further includes a desolvation tower for removing solvents and impurities from the polyethylene product. A polyethylene inlet is disposed at a middle part of the desolvation tower, and the polyethylene inlet is connected with the flash tank bottom outlet. A nitrogen micro-interface generator for dispersing and breaking high-temperature nitrogen into micro-bubbles is disposed within the desolvation tower. Through installing the micro-interface generators on the pre-polymerization reactor and the micro-interface and on the polymerization reactor, the mass transfer area between gas phase and liquid phase is increased, the reaction efficiency is improved, and energy consumption is reduced.

A chemical looping process for the production of hydrogen and the co-production of carbon dioxide comprising: a first redox loop that comprises: feeding of a first solid oxygen carrier to a first reaction zone (R1) in which a first carbonaceous fuel is also fed, which reacts with the first solid oxygen carrier fed at its maximum oxidising state (fully-oxidised form), leading to the formation of the combustion products carbon dioxide and water and the solid oxygen carrier at a lower oxidising state (reduced form); and feeding of the first solid oxygen carrier in reduced form to a second reaction zone (R2) into which air is also fed, obtaining, from the oxidation of the first solid oxygen carrier, heat and the solid oxygen carrier in fully-oxidised form to be recycled to the first reaction zone (R1); and a second redox loop that comprises: feeding of a second solid oxygen carrier to a third reaction zone (R3) in which a second carbonaceous fuel is also fed, which reacts with the second solid oxygen carrier fed at its an intermediate oxidising state (oxidised form), leading to the formation of the combustion products carbon dioxide and water and the solid oxygen carrier at a lower oxidising state (reduced form); and feeding of the second solid oxygen carrier in reduced form to a fourth reaction zone (R4) into which steam is also fed, which reacts with the reduced form of the solid oxygen carrier, producing hydrogen and the solid oxygen carrier at an intermediate oxidising state (oxidised form) to be recycled to the third reaction zone (R3) and/or the first reaction zone (R1), wherein the first reaction zone (R1) and the third reaction zone (R3) are interconnected allowing transfer of at least a portion of the first solid oxygen carrier from the first reaction zone (R1) to the third reaction zone (R3).

In a urea synthesis process, temperature distribution in a submerged condenser is reduced. The process includes: synthesizing urea from NH.sub.3 and CO.sub.2 to generate a urea synthesis solution; by heating the solution, decomposing ammonium carbamate and separating a gaseous mixture containing NH.sub.3 and CO.sub.2 from the solution to obtain a solution higher in urea concentration than the solution obtained in the synthesizing; with use of a submerged condenser including a shell and tube heat exchange structure including a U-tube, absorbing and condensing at least a part of the gaseous mixture in an absorption medium on a shell side, and generating steam on a tube side with use of heat generated during the condensation; and recycling at least a part of liquid, obtained from the shell side, to the synthesizing, wherein water is supplied to the tube side of the condenser at a mass flow rate that is three times or more of the steam generation rate.

A process for the hydroformylation of olefins to aldehydes is disclosed. The process comprises: hydroformylating one or more olefins with hydrogen and carbon monoxide in the presence of a ligand-rhodium catalyst in a reaction zone; recovering a reactor effluent from the reaction zone, the reactor effluent comprising product aldehyde and the ligand-rhodium catalyst; passing the reactor effluent and a strip gas to a vaporiser, wherein the strip gas comprises carbon monoxide and is formed from a recycle strip gas stream and a make-up strip gas stream, wherein the product aldehyde is vaporised into the strip gas in the vaporiser resulting in a vapour mixture, comprising the strip gas and the product aldehyde, and a liquid mixture, comprising the ligand-rhodium catalyst; recovering the liquid mixture and recycling the ligand-rhodium catalyst to the reaction zone; recovering the vapour mixture and separating the product aldehyde from the vapour mixture.

There is described a method of using a feedstock gas reactor. Reaction of feedstock and combustion gases in the reactor produces hydrogen through pyrolysis of the feedstock gas. At least some of a mixed product stream extracted from the reactor may be recycled to the reactor to drive further pyrolysis of the feedstock gas. A portion of the recycled mixed product stream may be recirculated back to a combustion chamber of the reactor, and a portion of the recycled mixed product stream may be recirculated back to a reaction chamber of the reactor.