[en] A method is described enabling the separation of radioactive krypton and xenon isotopes from the waste gases of nuclear facilities and then the separation of both of these. The waste gas at constant pressure and constant temperature is passed through an absorber filled with activated carbon; after the breakthrough of krypton, the activated carbon is pumped out to a pressure between 1 and 100 torr, the gas fraction added to the waste gas, the absorber washed at 30-760 torr with an inactive carrier gas (e.g. helium, nitrogen, air) and this fraction separated off for processing. The regenerated absorber is used again. Of advantage are the two parallel-connected absorbers in the system. Further advantageous details of the method are described. (HP)

[en] The method uses activated carbon as adsorption medium for ⁸⁵Kr and Xe isotopes in waste gases. The activated carbon is flowed through at normal pressure and temperature until the break through of the Kr. The adsorber is regenerated in three steps. The first consists of an evacuation at a pressure between 10 and 50 mm.Hg and at constant temperature as well as the addition of desorption gases to the waste gas. The second step involves a counter current washing with inert gas at a pressure under 760 mm.Hg and at a temperature of 150⁰C where a Kr and Xe enriched gas fraction of the product gas is kept. As soon as the washing gas exhibits a Kr and Xe concentration corresponding to the concentration in the impure waste gas, a second washing gas fraction is removed. This is introduced into the non-purified starting gas. A third step follows which is a recycling of the adsorption medium to the pressure of the adsorption medium to the pressure of the adsorption step by suction or pressing an inert gas, e.g. air. In the regeneration step (stage 2), the gas products can be freed from the washing gas by condensation or freezing out. (DG/LH)

[en] The steam gasificaton of coal requires a large amount of energy for endothermic gasification, as well as for production and heating of the steam and for electricity generation. In hydrogasification processes, heat is required primarily for the production of hydrogen and for preheating the reactants. Current developments in nuclear energy enable a gas cooled high temperature nuclear reactor (HTR) to be the energy source, the heat produced being withdrawn from the system by means of a helium loop. There is a prospect of converting coal, in optimal yield, into a commercial gas by employing the process heat from a gas-cooled HTR. The advantages of this process are: (1) conservation of coal reserves via more efficient gas production; (2) because of this coal conservation, there are lower emissions, especially of CO², but also of dust, SO², NO_x, and other harmful substances; (3) process engineering advantages, such as omission of an oxygen plant and reduction in the number of gas scrubbers; (4) lower gas manufacturing costs compared to conventional processes. The main problems involved in using nuclear energy for the industrial gasification of coal are: (1) development of HTRs with helium outlet temperatures of at least 950₀C; (2) heat transfer from the core of the reactor to the gas generator, methane reforming oven, or heater for the hydrogenation gas; (3) development of a suitable allothermal gas generator for the steam gasification; and (4) development of a helium-heated methane reforming oven and adaption of the hydrogasification process for operation in combination with the reactor. In summary, processes for gasifying coal that employ heat from an HTR have good economic and technical prospects of being realized in the future. However, time will be required for research and development before industrial application can take place. 23 figures, 4 tables. (DP)

[en] Starting from the present situation in the final energy consumption of the Federal Republic of Germany, it is shown that the High Temperature Nuclear Reactor due to its high coolant outlet temperature of 950⁰ C has the great chance to replace the classical energy sources such as mineral oil and natural gas that are declining and becoming more expensive. This can be performed via the processes of nuclear district energy supply (NFE) and nuclear coal gasification (HKV and WKV) in the large field of application of the heat-market. The development of the heat exchange equipment in which the heat of the Helium-loops of the reactor systems is transfered to the chemical processes of the NFE-, HKV- an WKV-systems, e.g. steam reformer and gas generators, as well as the development of the subsequent process stages are about to change over from the half technical to the pilot plant level. As there is also the development of the High Temperature Reactor with the successful operation of the AVR in the Nuclear Research Center of Juelich having achieved an advanced level, the relation of the described chemical processes with a HTR in form of a Prototypanlage Nukleare Prozesswaerme (PNP) can be pushed. (orig./RW)

[en] The industrial application of nuclear process heat for coal gasification is practicable in the light of existing knowledge both from a technical point of view and from economical aspects. Since 1970, appropriate methods are being developed. The investigations in the field of nuclear technology are based on the state of the AVR reactor in Juelich, the reactor supplying helium with a temperature of 950⁰C for almost two years. The gasification plant is in a semi-commercial state (carbon flow rate of 100-200 kg/h). The operation of a pilot plant with a carbon flow rate of 1-2 t/h from 1979 onwards, is to be followed in 1985 by a prototype of a nuclear reactor coupled with a gasification plant. The advantages of the process in prospect are compared with conventional methods: Production of more gas from less coal and thus reducing the strain on the coal reserves, better utilization of the hauled coal, lower emissions of CO₂ and SO₂, and a reduced dependence of the gas production costs on the price of coal. (orig.)

[en] The off-gas containing Krypton and xenon is passed through a delay bed with activated carbon of defined porous structure. In order to achieve greater retention factors, one must make the methanol adsorption isotherm of the activated carbon in such a manner that the difference of the methanol charges at the relative saturations p/ps = 0.025 and p/ps = 0.007 is above 15 x 10^-3 cm³ methanol per cm³ activated carbon bulk volume. The bulk density is also adjusted to 450 to 650 g/l and the linear flow rate to 1000 cm/ min for Xe and 10 000 cm/min for Kr. (DG)

[en] Survey of the production, the properties and the definition of the three types of adsorbents activated carbon, activated coke and carbon molecular sieves and their applications in keeping air and water clean and in gas separation processes. (IHOE)

[en] After a presentation of the development of gaseous energy carriers up to now, the present situation of the coal gas as well as the state and the aims of the coal gasification are reported. The cost structure of the gas economy changes with the application of coal gasification. Furthermore the article describes: a) the gasification of coal by steam-reforming using process heat from high-temperature nuclear reactors, b) the thermal efficiencies of the production of the different synthetic fuels dependent on the helium outlet temperature of the high-temperature nuclear reactors, c) the layout of a plant for the production of town gas using process heat, and d) the state of development of the application of nuclear process heat to coal gasification. (GG)

No abstract available

No abstract available