Deuterium production

The very low D/H natural abundance ratio (0.015% = 150 ppm) is responsible for the high cost of heavy water. Materials balance requires a minimum of 7x 103 mol feed per mol of product, and that increases even more for reasonable values of tails analysis (in some plants the feed/product ratio has reached nearly 4 x 104). At peak Canadian production, 800t year-1, this amounted to feeds of 3 x 107t year-1. Clearly that figure demands a cheap and easily accessible feed (i.e. water), or alternatively, requires deuterium production to be parasitic on some large industrial process, for example the production of NH3 for fertilizer, or petrochemical processing. 

Then, in the 1990 s, the accurate determination of the primeval deuterium abundance changes the strategy. Schramm and his collaborators introduced the deuteronomy (see Schramm Turner, 1997). Also, because the Big Bang deuterium production decreases rapidly with baryon density and its post Big Bang history (or chemical evolution) is simple - stars only destroy D - primordial deuterium became the best baryometer. It pegged the baryon density and led to accurate predictions for the other fight elements. 

All of the previously mentioned plants except those employing distillation of water were parasitic to a synthetic anunonia plant. Their deuterium-production rate is limited by the amount of deuterium in ammonia synthesis gas. To produce heavy water at a sufficient rate, a growing industry of heavy-water reactors requires a deuterium-containing feed available in even greater quantity than ammonia synthesis gas. Of the possible candidates, water, natural gas, and petroleum hydrocarbons, water is the only one for which an economic process has been devised, and the dual-temperature hydrogen sulfide-water exchange process is the most economic of the processes that have been developed. 

Because of the complexity of the GS process flow sheet, there are a number of opportunities for making improvements in the process that, taken together, should increase deuterium production, reduce the number of separate pieces of equipment, improve energy utilization, and reduce costs. U.S. work on improvements in the early 1960s was described by Proctor and Thayer [P4] and has been used in the first Canadian plants. Later improvements patented by Thayer [T3] have been considered for the newer Canadian plants. 

Analysis of the increased deuterium production made possible through use of supplementary hot water feed will be made by reference to Fig. 13.35. Here it is assumed that the flow rate of supplementary feed F to the top of stage number of the hot tower and the product rate P are so adjusted that the deuterium content of water flowing from stage rtg -I-1 to stage ng equals that of natural water feed Xp, to prevent mixing loss at the supplementary... 

When the quantity / exp(- 5/T) 1, the rate for deuterium destruction (D + y — p + n) finally falls below the deuterium production rate and the nuclear chain begins at a temperature T 0. IMeV. 

In this reaction, the e is a positron and the Ve is an electron-type neutrino. Significantly, this reaction depends on the weak force since it requires one of the two reacting protons to convert into a neutron in the brief moment the two protons are in close contact. This is rare, so the vast majority of proton-proton scatterings in a star do not result in deuterium production. The deuterium, that is, the H, produced by the pp reaction quickly captures a proton to become He ... 

TABLE 8.3. Reaction of 1,2-Butadiene with Hydrogen and Deuterium Product Composition and D Content of Pool ... 

The hmiting factor in the a-(i theory appears to be the time of 700 seconds required to turn half the available neutrons into protons for deuterium production. As a possible remedy it was suggested that electron-positron pair production at T > 10 °K t < 2s) could speed up the formation of protons by the fast process... 

Since some authors did not report information on the above cited side reactions, we carried out some catalytic deuterations of methyl dimorphecolate (methyl 9-hydroxy-octadeca-trara-lO, tra s-12-dienoate), an optically pure precursor of (9/ )-9-HSA. We used an in situ deuterium production method, and we report the new results obtained in section 4 of this Chapter. 

In order to improve the protocol and to deuterate higher amounts of unsaturated material, we designed the deuterium production apparatus shown in Figure 13 that was then built in a Pyrex glass suitable to resist moderate pressure (as the glass used for bottles in Parr hydrogenator). 

It is instructive to use the case of enriched deuterium production to describe distillation and exchange distillation isotope separation. To begin, the historical background of the need for... 

While Volmer was not a follower of the Nazi system, and consequently e.g., his election to the Prussian Academy of Science was blocked, he had to spend 10 years in the Soviet Union after 1945. He was invited as several other German scientists to the USSR. He worked on deuterium production and nuclear waste processing in the research group of Gustav Hertz (1887-1975, Nobel prize 1925). As many other colleagues, he was released in 1955 and was permitted to return to GDR. He became professor of physical chemistry at Humboldt University (East-Berlin) and president of the East-German Academy of Sciences between 1956 and 1958. 

Arias, F.J., Parks, G.T., 2015. On the feasibility of self-sustainable deuterium production in fusion reactors using an ionization chamber. Journal of Fusion Energy (2), 5—7. 

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