The invention relates to a method for treating fluoride-containing, in particular HF containing wastewater to remove fluoride and to a corresponding apparatus. In the new method calcium carbonate is reacted in a reaction step at an acidic pH4 with the fluoride in the wastewater to form calcium fluoride particles. Then, in a subsequent filtration step said calcium fluoride particles are separated by a porous membrane from the treated wastewater. The inventive apparatus comprises at least one reaction container/tank for reacting calcium carbonate at an acidic pH4 with fluoride in the wastewater to form calcium fluoride particles, as well as at least one porous membrane, in particular at least one porous ceramic membrane for separating calcium fluoride particles from the treated wastewater in a filtration step.

A chemical reactor for use in a chemical process wherein a reactant and/or a target product is prone to produce undesirable byproducts through secondary reactions. The reactor is configured with a first flow passage for passing a flow of an overly reactive reactant; a permeable first wall for controlled flow of the overly reactive reactant into a second flow passage providing a flow of a second reactant; a permeable second wall having a catalyst supported on an inner surface thereof for catalyzing reaction of the reactants flowing in the second flow passage; the permeable second wall passing through a flow containing the target product; and a non-permeable third wall defining a third flow passage for exiting the product mixture. The reactor can be employed in selective oxidation, oxidative dehydrogenation, and alkylation processes to reduce the formation of byproducts.

The invention relates to a thermal conversion vessel (200) used during amidification step of acetone cyanohydrin (ACH), in the industrial process for production of a methyl methacrylate (MMA) or methacrylic acid (MAA). The thermal conversion vessel (200) is used for converting an hydrolysis mixture of -hydroxyisobutyramide (HIBAM), -sulfatoisobutyramide (SIBAM), 2-methacrylamide (MACRYDE) and methacrylique acid (MAA), into a mixture of 2-methacrylamide (MACRYDE). at least one compartment (C1, C2, C3, . . . Ci) comprising an inner wall (206a, 206b, . . . 206i) separating said compartment into two communicating parts (C1a, C1b) by a passage provided between the bottom of said vessel and said inner wall, said compartment having a space above said inner wall, for separating gas phase from liquid phase during thermal conversion, said compartment being connected to an outlet valve (204a, 204b, . . . 204i). Such vessel allows obtaining a high yield thermal conversion in very safe conditions.

A chemical reactor is implemented on a substrate. The chemical reactor has multiple ducts for transporting a fluid and/or gas during use of the chemical reactor, in which the ducts optionally include pillar structures and at least one connection duct connected between two of the multiple ducts for transporting the fluid and/or gas from one duct to another. In the connection duct, a series of individual pillar structures are positioned behind each other in the longitudinal direction of the connection duct.

A combined reformer and purifier for converting a hydrogen-rich feedstock into purified hydrogen is described. The combined reformer and purifier can include at least one compression plate as an assembly comprising at least one first cavity comprising a catalyst effective to liberate hydrogen from said hydrogen-rich feedstock and forming a hydrogen-rich mixed gas. The compression plate assembly can also include at least one second cavity enclosing a burner or oxidative catalytic reactor to oxidize said hydrogen-depleted raffinate or said hydrogen-rich feedstock to supply heat to the at least one first cavity containing said catalyst. The compression plate assembly can also include an interior surface proximal to said membrane and an exterior surface distal to said membrane. The compression plate assembly can also include a third cavity effective to preheat said hydrogen-rich feedstock prior to being delivered to said catalyst.

A chemical reactor for use in a chemical process wherein a reactant and/or a target product is prone to produce undesirable byproducts through secondary reactions. The reactor is configured with a first flow passage for passing a flow of an overly reactive reactant; a permeable first wall for controlled flow of the overly reactive reactant into a second flow passage providing a flow of a second reactant; a permeable second wall having a catalyst supported on an inner surface thereof for catalyzing reaction of the reactants flowing in the second flow passage; the permeable second wall passing through a flow containing the target product; and a non-permeable third wall defining a third flow passage for exiting the product mixture. The reactor can be employed in selective oxidation, oxidative dehydrogenation, and alkylation processes to reduce the formation of byproducts.

The invention relates to a thermal conversion vessel (200) used during amidification step of acetone cyanohydrin (ACH), in the industrial process for production of a methyl methacrylate (MMA) or methacrylic acid (MAA). The thermal conversion vessel (200) is used for converting an hydrolysis mixture of -hydroxyisobutyramide (HIBAM), -sulfatoisobutyramide (SIBAM), 2-methacrylamide (MACRYDE) and methacrylique acid (MAA), into a mixture of 2-methacrylamide (MACRYDE). It comprises: at least one compartment (C1, C2, C3, . . . Ci) comprising an inner wall (206a, 206b, 206i) separating said compartment into two communicating parts (C1a, C1b) by a passage provided between the bottom of said vessel and said inner wall, said compartment having a space above said inner wall, for separating gas phase from liquid phase during thermal conversion, said compartment being connected to an outlet valve (204a, 204b, . . . 204i).

Such vessel allows obtaining a high yield thermal conversion in very safe conditions.

A reactor and method for seeded growth of nano-products such as carbon nanotubes, wires and filaments in which selected precursors are introduced into the reactor which is heated to a temperature sufficient to induce nano-product formation from interaction between the precursor gases and a nanopore templated catalyst. The selected precursors are segregated in the reactor through a plate defining two chambers which are sealed off from each other except for a void space provided in the plate. The void space is closed off by a membrane having nanopores and a catalyst formed as a layer. Atomic transfer of material from the selected precursors to form the nano-products on the catalyst layer in the other of the chambers occurs by diffusion through the catalyst layer to form the nano-product on the other of the chambers absent a pressure drop between the two chambers.

A multiple adiabatic bed reforming apparatus and process are disclosed in which stage-wise combustion, in combination with multiple reforming chambers with catalyst, utilize co-flow and cross-flow under laminar flow conditions, to provide a reformer suitable for smaller production situations as well as large scale production. A passive stage by stage fuel distribution network suitable for low pressure fuel is incorporated and the resistances in successive fuel distribution lines control the amount of fuel delivered to each combustion stage.

A reaction assembly has an elongate vessel defining a reaction chamber. Planar supports within the reaction chamber have surfaces for supporting a solid catalyst. The planar supports are mounted transversely to an elongate axis of the vessel, forming a series of spaced-apart barriers. A conduit introduces gas through openings between successive barriers such that gas flow through the conduit causes gas to flow along the support surfaces. With selection of an appropriate metal nanoparticle catalyst that may be seeded on the support surfaces. the reaction assembly may be used to produce carbon nanofibers from carbon monoxide and hydrogen, wherein the nanofibers may be subsequently removed via injection of a fluid.