Abstract:
Disclosed is a method for the integrated production of two different urea products. One is an aqueous urea solution suitable for use in NOx abatement (generally indicated as Diesel Exhaust Fluid – DEF). The other is a solution used as a fertilizer, viz. Urea Ammonium Nitrate (UAN). The production of DEF and UAN are integrated as follows: ammonia recovered from the production of urea is used as a feed to the production of ammonium nitrate. At least part of an aqueous urea stream from urea production, is mixed with ammonium nitrate so as to obtain UAN.
Abstract:
Disclosed is a method of increasing the capacity of an existing urea plant. With reference to the regular components of a urea plant, including a synthess section comprising a a high pressure carbamate condenser and a reactor, and a recovery section, the method comprises installing an additional reactor between the recovery section and the high pressure carbamate condenser. The additional reactor is preferably installed in connection with an ejector, so as to allow ground placement of the additional reactor.
Abstract:
The invention relates to a process for the removal of CO 2 from acid gas by cryogenic distillation performed in two steps. The feed mixture is first distilled at high pressure (at least 45 bar) in a first distillation column. The top product or a part thereof is then, after heating, subjected to a second distillation step at a lower pressure (lower than 45 bar). The top product of the second distillation step is methane of high purity (more than 99 mol.%). The bottom product of the second distillation step is recycled back to the first distillation column. The method according to the invention allows complete separation of methane also at higher level of acidic components, is economical and does not result in solid CO 2 build-up, which is a common problem in cryogenic distillation.
Abstract:
The present application relates to a method of manufacturing a tube sheet (7) and heat exchanger assembly for a pool reactor or pool condenser for use in the production of urea from ammonia and carbon dioxide, wherein the method comprises manufacturing of the tube sheet (7) from a carbon steel material grade and providing said tube sheet (7) with corrosion protective layers (8, 9) of an austenitic- ferritic duplex stainless steel grade, wherein the heat exchanger comprises at least one U-shaped tube (13) of an austenitic-ferritic duplex stainless steel grade, the method further comprises inserting at least two sleeves (11) of an austenitic-ferritic duplex stainless steel grade through the tube sheet (7) such that both ends of the sleeve (11) extend in a direction away from the tube sheet (7), the method further comprises connecting the sleeves (11), at least the opposing ends thereof, to at least the protective layers (8,9) of the tube sheet (7) and finally, connecting both ends of the at least one U-shaped tube (13) to the respective sleeves (11).
Abstract:
Method for the production of urea from ammonia and carbon dioxide in a urea plant containing a high-pressure synthesis section with a horizontal pool condenser, wherein the method comprises exchanging heat from a high pressure process medium received in a shell section of the pool condenser to a medium pressure urea containing solution received in a first heat exchanging section provided in the pool condenser to at least decompose ammonium carbamate into NH 3 and CO 2 , wherein the method further comprises exchanging heat from the high pressure process medium to a low pressure steam condensate received in a second heat exchanging section provided in the pool condenser to produce low pressure steam. The invention also relates to an apparatus for the production of urea from ammonia and carbon dioxide.
Abstract:
Disclosed is a reactor system for the production of polyester pre-condensate. The system comprises at least two reaction zones, operating at substantially different pressure. Reactants fed into the first zone are allowed to initially react and are then allowed to enter a second zone by means of pressure flow. In the second zone, a system of concentric spacers is present so as to ensure a sufficient path length of the reaction mixture to form a pre-condensate, as well as in internal heat exchanger. The pre-condensate is allowed to flow to a next (polymerization) stage by means of gravity flow on account of a standpipe present in the second reaction zone. Said standpipe has an inlet above the internal heating system in the second reaction zone.
Abstract:
Disclosed is a process for the concurrent production of hydrogen and sulphur from a H 2 S-containing gas stream, with reduced, and preferably zero, emissions. The method comprises the catalytic oxidative cracking of H 2 S so as to form H 2 and S 2 . Preferably, the oxidation is conducted using oxygen-enriched air, preferably pure oxygen. The process is conducted in a reaction chamber comprising a bifunctional catalyst material, so as to favor both the partial oxidation of H 2 S and the dissociation thereof.
Abstract:
The invention relates to the production of hydrogen by steam reforming comprising the steps of (i) providing a fossil fuel, preferably methane, and steam, (ii) conducting a steam reforming reaction between the fossil fuel and the steam under heating, wherein a reaction mixture is formed comprising hydrogen and carbon dioxide, (iii) separating hydrogen from the reaction mixture by membrane separation, wherein a permeate is formed comprising hydrogen and a retentate comprising carbon dioxide, (iv) purifying carbon dioxide from the retentate, and (v) using said carbon dioxide as a heat exchange medium to supply heat at least for the steam reforming reaction (ii). The method of the invention can also be used for the production of pressurised carbon dioxide characterised by a high purity. Further, the invention relates to a system for hydrogen production and to the use of pressurised carbon dioxide as heat exchange medium.
Abstract:
The invention is related to a liquid composition comprising (1) a silicon oligomer comprising a group derivable from an alkoxylated silicone, at least two groups chosen from the group consisting of urethane and urea groups obtained from a polyisocyanate and at least one ethylenical unsaturation and (2) at least one polyfunctional cross-linking agent. The liquid composition is suitable in producing ribbon coatings for optical glass fibers.
Abstract:
Process for the polymerization of cyclic esters, using a metal salt as a catalyst, whereby the catalyst consists of a compound with formula (I) where M is a metal ion and n a number from 1 to 4 and being smaller or equaling the valency of the metal ion and where the R and R groups are, independently of each other, alkyl, aryl or cycloaliphatic groups and R is an alkyl, aryl, cycloaliphatic group or a hydrogen atom and where the R -R groups are so chosen that the catalyst has a melting point lower than the desired polymerization temperature. Polymers produced while applying a process or a catalyst according to the invention can be used in numerous fields, but are of particular advantage in biomedical applications as bio-resorbable material, as described in literature.