The open‐circuit voltages of the cell normalLifalse(1false)/normalLiI‐KI‐normalLiCl/LixnormalAlfalse(normalsfalse) were measured over the composition range of 6.9–50 a/o (atom per cent) Li in LixnormalAl alloy in the temperature range 282°–389°C. The composition of the LixnormalAl alloy was varied by coulometrically charging and discharging the cell. The emf values of the cell are independent of the composition up to 47 a/o lithium in the alloy and their temperature dependence follows the relationship E=451.07−0.2202T false(σ=0.3false) , where E is in millivolts, T normalin°K , and σ is the standard deviation. The constant potential exhibited by the alloy is ascribed to the formation of β‐normalLiAl phase on the alloy surface. The standard free energies of formation for β‐normalLiAl are estimated to be −7.49, −7.24, and − 7.09 kcal/mole at 300°, 350°, and 380°C, respectively. The standard enthalpy and entropy of formation are constant, −10.40 kcal/mole and −5.08 cal/mole · deg, respectively, in this temperature range. Since the electrochemically prepared lithium‐aluminum alloy has a constant potential over a wide composition range and exhibits good electrochemical behavior, it can serve as a good reference electrode as well as a high energy density anode in molten salt systems containing lithium.

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The distribution of hydrogen types in the soluble fractions from the depolymerization of a series of coals has been determined by NMR analysis. The aromatic hydrogen content varies from 20 to 32% of the total hydrogen, and no simple relationship exists with coal rank. β-Paraffinic plus naphthenic hydrogens, the major type, exceed the α-hydrogens and comprise 38-66% of the nonaromatic hydro gens. The most striking variation in the structure of the six coals is the number of methylene bridges. The degree of depolymerization with phenol-BF 3 can be correlated directly with the number of methylene bridges found in the soluble fractions. A general coal structure in accord with our results consists of large units (MW > 4000) and smaller units (MW, 300-600) connected by methylene bridges.Jhe distribution of hydrogen types in coals continues to be a subject of con siderable interest in coal structure studies. Published data indicate that the fraction of aromatic hydrogens usually increases with increasing rank, but the absolute values depend on the specific analytical method used (7). Hydrogen type analysis of a single coal based on the application of NMR spectroscopy to the soluble fraction from depolymerization with phenol-BFa has been re ported by us (3). The conversion of coal to soluble fragments in substantial yields under very mild conditions permits a reliable determination of the hydrogen types by NMR analysis, and these results can be extrapolated to the parent coal with considerable confidence.This procedure has now been extended to a series of coals varying in rank from lignite (70% C) to a low volatile bituminous coal (91% C). In addition to determining the amount of aromatic and aliphatic hydrogens, the aromatic group will be further subdivided into monocyclic and polycyclic types. A more 493 Downloaded by KTH ROYAL INST OF TECHNOLOGY on August 11, 2015 |

Three bituminous coal samples were extracted at 350°C. with phenanthrene, labeled in one series with tritium, in another with C 14 . The extract yield was 80-90%. Results: converting coal to soluble products breaks C-H bonds; 10-15% of the hydrogen content of the coal exchanged with that of the phenanthrene during extraction; 3-8% chemically linked phenanthrene was found in the extracts; less than 1% hydrogen exchange took place between pure model compounds (anthracene, p-benzyl--phenol) and tritiated phenanthrene under similar experimental conditions. Thus, chemical reactions take place during phenanthrene extraction of bituminous coals. The role of phenanthrene in this process is probably an interaction with the free radicals which are formed in the thermal decomposition of coal.jy|ost solvents which have been used for coal extraction can be divided into two groups. Extraction with the first group of solvents is based on purely physical effects and gives low extract yields. Most monocyclic aromatic compounds belong to this group. On the other hand, the extract yield is high when coal is treated with hydroaromatic solvents at higher temperatures. In that process chemical interactions take place, and hydrogen is transferred from the solvent to the coal substance. The higher yields with hydroaromatic solvents result from the hydrogenative cleavage of carbon-carbon and carbonoxygen linkages in the coal polymer and the formation of lower molecular weight, more soluble materials. The results of Orchin and co-workers (I, 2) on the extraction of coal with phenanthrene and other polynuclear aromatic compounds do not fit into this classification. They reported that at a temperature of about 350°C. phenanthrene and other related angular condensed aro-1

The chemical and electrochemical characteristics of sodium amalgam galvanic cells were studied. A static electrode cell, contained in a stainless steel pressure vessel, was operated at temperatures from 477 to 510°C. under 140 to 180 psig argon cover gas pressure. A molten eutectic mixture of sodium salts was used as the electrolyte. Current densities as high as 200 ma./sq. cm. were achieved without appreciable electrode polarization. A flowing electrode cell with a tubular electrode matrix was designed, built, and tested. In this cell the anode and the cathode compartments were supplied with continuous streams of concentrated and dilute amalgam, respectively. A complete thermally regenerative system (a flowing electrode cell coupled with a regeneration loop) was successfully operated for a period of 1200 hrs. at a cell temperature of about 490°C.'T'he application of thermally regenerative fuel cells for the conversion A of heat into electrical energy has been discussed recently (9). Thermally regenerative systems using liquid metal electrodes and fused salt electrolytes appear to be particularly promising because energy losses through electrode polarization and electrolyte resistance can be much 1 Work performed under company-sponsored, independent research and development program.