Nuclear steam reformer

Reformer tube heating with a high-temperature nuclear reactor is performed with helium, typically at 950 °C, as the heat source. The aim of reaching a heat flux density similar to that of the conventional method can be achieved by employing a helium-heated counterflow heat exchanger (see Fig. 2-11). Helium under pressure shows excellent heat transfer properties. Furthermore, precautions must be taken to minimize the effects of asymmetry or hot gas streaks in the helium flow as well as a non-uniform process gas flow. The materials of a helium-heated steam reformer should be selected such that the 

Experience in construction and operation was gained with the EVA-I and EVA-n facilities at the Research Center Jiilich (see section 4.3.2. and appendix B.I.). The replacement of the catalyst is difficult because of the presence of the internal return pipe ( pigtail ). Using a vacuum cleaner was found to be inefficient. A new hydraulic system developed at Jiilich reduced the replacement time down to a few minutes [38]. 

On the secondary side, a steam-methane gas mixture with a ratio of 4 1 enters the reformer at a temperature of 330 °C and is distributed to all reforming tubes. The feed 

Product gas return pipe outside reformer tube inside reformer tube 

Maximum pressure difference across tube wall [MPa] 0 - 2.5 0.1 (hot part) 0.4 (cold part) 

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Allothermal steam reforming of methane Nuclear steam reforming... 

Figure 3 Schematic of the EVA nuclear steam reformer (left) and the SOLASYS solar reformer (right)...

To overcome the perceived disadvantages of a nuclear steam reformer with its comparatively low heat transfer and its high system pressure, improvements of the Japanese design of the HTTR nuclear reformer have been proposed (Fig. 2-12) ... 

Nuclear reformer tube heating with a high-temperature reactor is performed with helium, typically at 950 °C, as the heat source. A counterflow scheme allows the use of internal return pipes for the product gas. Experience in construction and operation was gained with the EVA-I and EVA-II facilities at the Research Center Jiilich. The perceived disadvantages of a nuclear steam reformer with its comparatively low heat transfer and its high system pressure can be overcome by design optimization to increase heat input into the process gas and its conversion rate. 

Nuclear energy can produce hydrogen in several ways (1) nuclear heated steam reforming of natural gas, (2) electrolysis of water using nuclear power, (3) HTE using minor heat and major electricity from nuclear reactor, and (4) thermochemical splitting of water using... 

In evaluation of the potential objects which are to define respective options to be taken into a consideration there are 99 objects. In this exercise we will focus our attention on the following hydrogen energy systems Fossil-Reforming-Intemal Combustion Engine System, Natural Gas Steam Reforming-Fuel Cell System, Nuclear Power-Electrolysis-Fuel Cell System, Solar Power-Electrolysis-Fuel Cell System, Wind Power-Electrolysis-Fuel Cell System, Biomass-Reforming-Gas Turbine System. 

Oil/fuel industry Upgrading of bitumen from oil sands using hydrogen produced by the nuclear-heated steam reforming of a portion of the product. 

In the intermediate term, nuclear-heated steam reforming of natural gas could be utilised, using medium-temperature reactors, in spite of some carbon dioxide emissions, because of its advantages in economic competitiveness and in technical feasibility. Also, high-temperature reactors could be used to carry out high-temperature steam electrolysis, with higher conversion efficiency and fewer materials problems. 

Figure 2 is an example of applying nuclear hydrogen to the SCO production process from bitumen of oil sands, where a portion of product (11% of product SCO) is fed back to the steam reforming part to produce hydrogen (Hori, 2005 Numata, 2006). 

The nuclear heat production plant consists of the high-temperature gas cooled nuclear reactor as heat source as well as the steam reformer and the steam ge-... 

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