Abstract: The present invention provides a fluid-to-fluid through-the-wall heat exchanger for condensation of a vapour in a primary fluid stream, wherein a flow path (5) of the primary fluid stream is defined by an inner cylinder (1), an outer cylinder (2) arranged concentrically to and surrounding the inner cylinder, and a helical space holder (3) arranged between the inner and the outer cylinder. Additionally, the cylinder surfaces delimiting the primary flow path are made of or coated with corrosion resistant material in order to reduce a contamination of the primary fluid. Compared to other condensers with identical ratings, this heat exchanger shows a smaller flow resistance, resulting in a smaller power demand of the blower or pumps, It is therefore particularly suitable for fuel cell systems where the condensed water has to be recirculated in the system and where purity demands are high and parasitic blower power should be minimal.

Abstract: A method of transforming a normally gaseous composition containing at least one hydrogen source, at least one oxygen source and at least one carbon source into a normally liquid fuel, wherein said gaseous composition consists at least in part of carbon dioxide as said carbon source and said oxygen source, and of methane as said hydrogen source and as a second carbon source; the method comprising the steps of feeding the composition into a reactor including a first electrode means, a second electrode means and at least one layer of a normally solid dielectric material positioned between the first and the second electrode means; submitting the composition within the reactor in the presence of a normally solid catalyst to a dielectric barrier discharge, wherein said normally solid catalyst is a member selected from the group of zeolites, aluminophosphates, silicoaluminophosphates, metalloaluminophosphates and metal oxides containing OH groups; and controlling the dielectric barrier discharge to convert the gaseo

Abstract: A method of transforming a normally gaseous composition consisting essentially of methane into a material comprising a major portion, at least, of hydrocarbons containing at least two carbon atoms; the method comprising the steps of feeding the composition into a reactor including a first electrode means, a second electrode means and at least one layer of a normally solid dielectric material positioned between the first and the second electrode means; submitting the composition within the reactor in the presence of a normally solid catalyst to a dielectric barrier discharge; and controlling the dielectric barrier discharge to convert the normally gaseous composition into the material comprising a major portion, at least, of the hydrocarbons containing at least two carbon atoms.

Abstract: So that fuels can be produced efficiently from an undesirable greenhouse gas, the gas is subjected, together with a catalyst gas, preferably nitrogen or nitrous oxide, and a hydrogen-containing gas or vapour, to a silent electric discharge in a 1st reactor (4). In the process, excited or ionized atoms and/or molecules are formed which are converted, in a catalyst reactor (8) comprising a copper-containing 1st catalyst (8'), to H.sub.2 and possibly CO. Via an expansion valve (9), a liquid (13) separates from a fuel in a liquid vessel (11). Gases escaping from the liquid vessel (11) are passed over a thermal reactor (14) containing a 2nd catalyst (15) and expanded via an expansion valve (16). In a downstream liquid vessel (11') CH.sub.3 OH, for example, separates as the desired liquid fuel (13'). The 1st reactor (4) and the thermal reactor (14) may be combined in a container comprising a plurality of reaction chambers which are parallel to one another.

Abstract: A depassivation layer is produced on an electrode for an electrochemical cell by applying one or more layers of a metal salt solution, containing the elements to be applied, to the substrate (1) which is to be coated and is in the form of a porous plate, by means of rolling an elastic roller (2) over the substrate, with the insertion of a solution carrier (3) in the form of felt or paper, and then drying the layer and subjecting it to a chemical/thermal treatment in air (heat treatment at 450.degree. C.). Good depassivation layers with a relatively small noble metal content can be produced in this way. The depassivation layer which, in the form of a homogeneous film, is at least partially coherent contains, as a finely divided, sub-microscopic mixture, electronically conductive sub-oxides/oxides of the substrate (1) in addition to noble metals/noble metal oxides, and it can also contain further components, such as SnO.sub.2.

Abstract: A method for continuous coating of a solid electrolyte (3) with a coating comprised of a catalytically active metal, comprising impregnating the solid electrolyte (3) (present in the form of a film comprised of a plastic polymer) with a solution of a metal salt, and electrolyzing the metal salt in a plurality of passes of the solid electrolyte (3) between two rolls (4, 5) which rolls serve as electrodes, in a water bath, wherewith at first the speed of advance of the solid electrolyte film is a relatively high value of 20 to 30 cm/min and then a lower value of 1 to 2 cm/min, and wherewith the linear current density in the line of contact between the rolls (4, 5) and the solid electrolyte (3) is at least 830 mA/cm.

Abstract: An electrically conductive layer on a solid-body electrolyte (1) is produced by swelling and impregnating an organic ion exchange material (2) with a metal salt solution, drying, converting the metal ions in a gas stream to finely distributed particles (3) which are in electrical contact with one another, renewed swelling in a solvent, converting into a brushable paste and applying same to the surface of the solid-body electrolyte and drying. Preferred embodiment: solid-body electrolyte (1) and ion exchange material (2) made of polymers containing sulphonic acids; and conductive particles (3) made of platinum metals or oxides thereof, in particular ruthenium as electrocatalyst.