Dr. Case's Experiment: Run 1b 1MAY98
Scott R. Little, EarthTech International, Inc.
*** This test was conducted with a substitute catalyst ***
This experiment employed the apparatus described here.
The procedure involves first evacuating the chamber, then charging it with 50 psi of H2 gas and then heating the chamber so that the catalyst inside reaches about 180° C. This temperature and pressure are maintained for an hour or so and then the chamber is vented, evacuated and filled again for another cycle. Each of these H2 cycles cleans the catalyst by removing adsorbed oxygen and volatile contaminants. After the catalyst is cleaned, the chamber is filled with D2 gas, also at 50 psi, and an "excess temperature" is observed....i.e. the catalyst runs hotter (~10° C) in D2 gas than it did in H2 gas...for the same heater input power.
The purpose of our investigation is to determine whether or not an excess heat accompanies the excess temperature.
Yesterday we assembled the apparatus and performed the first H2 cycle (Run 1a). During that cycle, a significant decrease in H2 gas pressure was observed while the system was soaking at temperature. This decrease was probably due to consumption of the H2 gas as it reacted with oxygen in/on the catalyst. Today we completed two more H2 cycles (in which little or no pressure decrease was observed) and then switched to D2 hoping to see some sign of Dr. Case's effect. The plot below depicts the data collected during today's experimentation.
The horizontal scale is 8 hours and the vertical grid lines are 1 hour apart. The traces are color coded according to the displays above the plot. The three K thermocouples in the catalyst bed are Tbtm, Tmid, & Ttop and their traces are plotted on a 0-250° C scale.
The input power, measured with a Clarke-Hess 2330 power analyzer, is represented by the Pin trace on a 0-50 watt scale. The measured heat output power is shown as Pout on the same scale.
The run starts off with about 30 minutes of no heater power, then the heater is adjusted to 35-37 watts to warm things up rapidly. During the first 2 hours of this run the heater power was gradually stepped downward until the target 25 watts was reached. Due to the peculiar behavior of the Pout trace, we thought some strange endo/exothermic reactions were happening in the chamber...but it turned out just to be a loose connection in the thermistor circuitry which we corrected 2.5 hours into the run (where the Pout trace suddenly quits wandering downwards and heads smartly up to match the Pin trace).
This run started out with the chamber filled (for the 2nd time) with 50 psi of H2 gas. At 2.0 hours into the run, we vented, evacuated, and filled a third time with H2 gas to 50 psi....all within about 5 minutes.
At 3.3 hours into the run, I tried to "improve" the experiment by inserting a large SOLA voltage regulator into the heater power line. As luck would have it, plugging in the SOLA, crashed the system computer!. I restarted ASAP but the result was the bipolar excursion in the Pout trace that lasts from 3.3 hours to about 3.7 hours. Moral: Don't try to improve things that are already working satisfactorily in a running experiment.
By 4.0 hours into the run, Pout and Pin were agreeing very closely...within 0.5 watt.
At 4.3 hours into the run we vented, evacuated, and filled with 50 psi of D2 gas (note the "bobble" in the catalyst temperature traces). The Tmid trace went up a few degrees (from 198° C to about 202° C) but nothing significant happened to the power traces.
At 6.4 hours into the run we vented, evacuated, and filled with 50 psi of H2 gas again. There was a slight tendency for Tmid to return to its previous H2 value but it didn't go all the way...?
At 7.2 hours, with a virtually perfect match between Pin and Pout for the past 4 hours, we turned off the heater and ended the run.
The catalyst used in this run was not the one recommended by Dr. Case but rather a 1% Pd on activated carbon (fine powder) available from Aldrich Chemical Co. We already had this catalyst on hand and at least it has served to prove out our experimental setup and to confirm our calorimetry. We expect to receive the correct catalyst (G75-E from United Catalysts) early next week.
We are considering modifying our apparatus to more closely approximate the thermal gradients that exist in Dr. Case's apparatus.
One notable difference between our conditions and those at Gene Mallove's place where Dr. Case recently demonstrated his experiment is the room temperature. Troom is plotted in white on the graph. Note that it slightly exceeded 31° C towards the end of this run! The Texas summer is coming....
Comments are most welcome.