 |
 |
|
|
| Author/s: | Francesco Celani, A. Spallone, P. Marini, V. Di Stefano, M. Nakamura, V. Andreassi, A. Mancini, E. Righi, G. Trenta, E. Purchi, U. Mastromatteo, E. Celia, F. Falcioni, M. Marchesini, E. Novaro, F. Fontana, L. Gamberale, D. Garbelli, P.G. Sona, F. Todarello, G. D’agostaro, P. Quercia |
| Title: | Electrochemical Compression of Hydrogen inside a PD-AG Thin Wall Tube, by Alcohol-Water Electrolyte | Report: | LNF - 06 / 20(P) |
| Date: | 17-07-2006 |
| PACS: | |
| Pubblished on: | Invited Paper at JCF7 Kagoshima University-Japan, April 26-28 2006 |
| PDF File: | LNF-06-20(P).pdf |
| Url: | |
| Abstract: | Yoshiaki Arata (Osaka University) has since 1955 developed and on 1994 patented in Japan (also USA, N° 5647970, 1997) a procedure for producing ultrahigh pressure H/D gas, based on the electrolytic loading of a hollow cathode made of a Hydrogen and/or Deuterium absorbing material (Pd). The truthfulness of Arata’s results and even the real existence of Arata’s device have been recently challenged by an influent Italian scientist and suspected to be merely a “computer simulation experiment”. Accordingly, we decided to replicate the Arata experiment in order to confirm his results. A further reason for such a replication is due to the consideration that the electrolytic compression of Deuterium (D) is the basic for most of the Cold Fusion experiments. Moreover, the experiment allows for a direct evaluation of the D2 (or H2) pressure inside the hollow cathode, without making use of indirect measurements, like those based on the well-known “Baranowsky curve” (change of the Pd electrical resistance, versus D or H absorption). The cathode was a Pd-Ag (75%-25%) tube, closed at one end (diameter 10mm, total length 10cm, useful length exposed to electrolyte 9cm) with a very thin wall (thickness about 50μm), previously used as a Hydrogen purifier (home-made by Dr. Silvano Tosti: ENEA, Frascati, Italy). The effective volume of the Pd-Ag tube (partially filled with a porous ceramic tube, in order to avoid the vacuum collapse of the Pd-Ag tube), pipes, valves and pressure gauges was about 18ml. The anode was a Pt (purity >99.99%) wire (diameter 0.25mm) wounded as a pseudo-cylindrical spiral of radius about 4cm. The total length of the Pt wire was about 200cm, number of turns about 5. The volume of the electrolyte was about 2000ml. The cell was commercial glass (Pyrex type). The solution, according to our long experience in this field, was alcohol-water type (C2H5OH 85-90%, H2O 15-10%) electrolyte. Th(NO3)4 (in 5% wt HNO3), SrCl2 and Hg2SO4 salts were added. Th and Sr salts were added at an amount of some tens of micromoles, and the Hg ion at an amount of only a few micromoles. The electrolytic current density was as low as 2-10mA/cm2. The anode-cathode voltage was 20-136Volts. During the experiment the cell temperature ranged between 20 and 60°C. The Pd-Ag tube surface was previously mechanically cleaned (by fine, silica based, sandy soap), acetone rinsed, washed several times with distilled water, and finally treated at a temperature of about 450°C for a complete degassing. Before the cathodic H loading operations, the surface was “activated” by proper cycles of anodic oxidation. Vacuum was made inside the tube cavity, connecting pipes, pressure gauges and valves. We reached a maximum value of pressure inside the hollow cathode of about 8.5atm (absolute 9.5). The maximum value of 8.5atm was imposed by the mechanical strength limit of the 50μm wall of the tube. We would like to note that the faradic efficiency, i.e. the amount of hydrogen gas produced by the electrolytic current (collected and pressurised inside the tube) reached values as large as 15--20%; the efficiency strongly depends on the Pd surface conditions, type of electrolyte, current density, and temperature. In comparison, the device invented by Arata (using usual D2O - LiOH 0.1M electrolyte, tube 2.5mm thick) had efficiency on the order of 0.5--2.5%. Arata was able to reach pressures as high as several hundred atmospheres; up to now, we can’t say anything regarding the capability of our electrolyte in obtaining such a high pressures. In a further set of experiments we are going to use a thicker (0.250mm) ultra-pure (99.99%) Pd tube, specially developed for this purpose by ORIM SpA Company (Italy). In conclusion: 2 The effectiveness of the original device developed by Yoshiaki Arata since 1955 was fully confirmed; 3 The surprisingly high Faradic yield for H-D loading in hydro-alcoholic electrolyte might open some ways toward practical applications; 4 The measurement of H2 pressure in the hollow cathode directly confirms our previous results (H/Pd-D/Pd close to one, measured by the change in resistivity of the Pd cathode, and high faradic efficiency), obtained by electrochemical loading of long (typically 60cm) and thin (diameter 50μm) Pd wires in C2H5OH-H2O or C2H5OD-D2O electrolytes. Following the positive results of our experiment we received the acknowledgement of a large part of the Italian scientific community formerly sceptical about all that concerns Cold Fusion. Moreover, one of the most diffuse and influential (in Italy) INTERNET blog about environment & clean energy (http://www.vglobale.it) has adopted, as front page for 3 months, the photo of the experimental apparatus build at INFN-LNF. The number of down-loads of such photo (and 2 pages of explanations/comments) was quite large (increases of over 500 access/day of the blog, up to now). Such blog is certified by “spazio RP” and was established about 9 years ago. |
Comments, Complaints, Queries, Suggestions to |