Abstract: A variable impedance device comprises a coil (10) and an associated magnetic circuit (16) having a gap receiving a plate (20) of superconducting material which acts as a shield or barrier so that, while the plate (20) is in its superconducting state, magnetic flux is caused to traverse the gap via pathways substantially greater in length than the width of the gap. If a large current is passed through the coil (10), the plate (20) becomes resistive thereby presenting a substantially increased impedance to the current. The device may be used in current limiting applications, or other applications where a variable impedance is required.

Abstract: Process and apparatus for catalytic combustion in which a combustible gas stream is mixed with part of the recycled hot product stream and then fed to a combustion zone containing a combustion catalyst, and from which the hot pressurized product is obtained. The recycle is preferably effected by means of a constriction at the end of the inlet gas supply producing a region of lower pressure than the pressure of the product gas.

Abstract: At least during some part-load operation of a gas turbine wherein a fuel gas is combusted with air with the formation of a flame and the combustion products are let down through a turbine, the fuel gas comprises the product of a stage of catalytic autothermal steam reforming of a light hydrocarbon feedstock gas and the amount of air fed to the gas turbine combuster, relative to the amount of hydrocarbon fed to the catalytic autothermal steam reforming stage, is greater than the maximum amount of air that enables a flame to be sustained in said combustor if that amount of hydrocarbon were to be fed directly to the combustor.

Abstract: Process and apparatus for catalytic combustion in which a combustible gas stream is mixed with part of the recycled hot product stream and then fed to a combustion zone containing a combustion catalyst, and from which the hot pressurized product is obtained. The recycle is preferably effected by means of a constriction at the end of the inlet gas supply producing a region of lower pressure than the pressure of the product gas.

Abstract: A catalytic partial oxidation or secondary reforming process wherein a flame is established at a burner upstream of the catalyst is started-up by catalytic combustion of a suitable combustible material to produce a hot gas stream and directly, or indirectly, using the heat from the gas stream to heat the reactants fed to the burner to the autoignition temperature. After a flame has been established at the burner, production of the hot gas stream by combustion of the combustible material is discontinued.

Abstract: Shaped articles, especially ones containing a plurality of fine through passages, are made from a composition containing a refractory particulate material by extrusion, cutting the extrudate, while vertically hanging or suspending into lengths while in the green deformable state by a high velocity water jet, and then calcining to bind the refractory particles together. Depending on the nature of the refractory material, the articles are of use as catalyst supports or precursors, adsorbents, or absorbents. The extrudate is extruded horizontally and allowed to sag into a gap between the extrusion die and a transport device, which is driven positively to maintain the degree of sag within predetermined limits, and the frequency of cutting depends on the rate of movement of the transport device.

Abstract: Catalyst precursor units, e.g. for ammonia synthesis catalysts, comprise an iron oxide composition in the form of sintered shaped units of substantially uniform cross section having a plurality, e.g. 13 to 50 or more, through passages of substantially uniform cross section. The passages preferably have a diameter of less than 1.5, particularly less than 0.7, mm.

Abstract: A heat and mass exchange, pressure and/or thermal swing adsorption process using an adsorbent bed which consists of at least one unit having substantially parallel passages through it. Each unit has at least 20 passages per cm.sup.2 of its cross-sectional area, the number and cross-sectional area of the passages being such that each unit has a geometric void of not more than 0.45. The bed may be random packed or a close packed assembly or stack of units.

Abstract: A self-supporting structure, particularly for use as a support for a catalyst, e.g. for secondary steam reforming of hydrocarbons, comprises an assembly of interlocking units, preferably of prismatic polygonal, e.g. hexagonal, configuration. Each unit is provided with projections in its upper part enabling the unit to be supported on a complementary projection in the lower part of an adjacent unit and/or on a supporting member of a vessel containing the assembly. As the structure heats or cools, expansion and contraction of the units relative to the containing vessel is accommodated by the structure bowing.

Abstract: A bed packing material, e.g. for use as a catalyst precursor, in the form of regular, preferably cylindrical, units having a multiplicity of through passages of small cross section so that the units have a low voidage, GV, a high ratio of the geometric surface area, GSA, to the volume V, of the equivalent cylindrical unit having no passages, and a high ratio of GSA to the product of GV and the surface area, A, of the equivalent cylindrical unit having no passages.

Abstract: A process and apparatus for contacting a fluid with the walls of a vessel are characterized by flow of the fluid alternatingly (a) through a structure within the vessel and having passages angled to the general direction of flow in the vessel and (b) through a space between the structure and the vessel walls. The structure can be for example a cross flow ceramic or metal honeycomb or a stack of profiled plates or of apertured plates such as expanded metal. The structure can carry a catalytic coating and then affords high activity and low pressure drop. The process and apparatus are especially suitable for endothermic tubular steam hydrocarbon reforming.

Abstract: This invention relates to catalytic hydroformylation of internal olefins. In particular the invention relates to a process for the production of a straight chain aldehyde from an olefin comprising reacting said olefin in a liquid reaction medium with hydrogen and carbon monoxide in the presence of a complex of Rh(I) in solution in the said medium as catalyst and a heterogeneous co-catalyst comprising a catalytic metal deposited upon a solid particulate support.

Abstract: This invention relates to catalytic hydroformylation reactions, for example the hydroformylation of internal olefins. In particular the invention relates to a process for the production of a straight chain aldehyde from an olefin comprising reacting the said olefin in a liquid reaction medium with hydrogen and carbon monoxide at a total pressure of less than 500 psig in the presence of a complex of Rh(I) in solution in the said medium and a homogeneous co-catalyst dissolved in said reaction medium comprising a co-ordination complex of a transition metal other than rhodium selected from Group 6 or Group 8 of the Periodic Table.The transition metal is, preferably, selected from the group consisting of Cr, Mo, W, Fe, Co, Pd, Pt and Ru.