Questions and Answers - Brian Ahern

  • Brian Ahern taking the time to answer some interesting questions about upcoming replication attempt.


    You can write well-formed questions to him in this thread.


    He will try to answer as best he can. Thanks for that @brian ahern



    Questions


    1. What is the particles size of the Ni and LiAlH4 and purity? Ni ?? LiAlH4 = 97%


    2. Are you going to use mass ratios of Ni- 0.9 gr and LiAlH4-0.1 gr? yes


    3. Where are you going to order the Alumina tubes (who is the supplier?) and what will be you ceramic tube length? I understand that the ceramic tube’s dimensions are in inches?Mcmaster carr. My tube lengths will each be about 8" long


    4. What about the pressure developed inside the chamber? We have no idea. As far as H2 gas,It calculates to 2700psi at 900C, but it may all get absorbed by the nickel


    5. Are you just mix the powders in fume hood manually? yes


    6. What kind of calorimetry are you going to use, is it mass flow with partial water phase change as Parkhomov did? If yes where the water in your system will flow to draw heat from the cell? I will start with simple thermometry. If that shows no gain, I will tyry other sources of nickel


    7. Aren’t you afraid from explosion (Oxygen + Hydrogen inside a sealed cell with flammable alkali metal, Li + O2)? Yes, I am setting up inside an armored box.


    8. Your ceramic chamber will be slightly smaller than Parkhomov, isn’t it? . The quartz outer tube is 10.4 cm OD


    9. What is the quartz cylinder for? Are you going to wind the nichrome wire on the ceramic outside diameter and encapsulate it with the quartz? Why not using another cylinder of ceramic with the same quartz dimensions? Can’t you order ceramic cylinder in which the nichrome wire winded already in, as shown in Parkhomov’s schematic? No.


    10. Are you going to handle the LiAlH4 in the fume hood with Argon or other purge of gas to reduce the concentration of air inside the fume hood? And what about the air inside the cell after loading it with the particles mixture? I have no argon to employ at my home. I will use air.


    11. 5 time cycling of the Ni-LiAlH4 mixture inside the closed/sealed cell? If yes, for what period of time holding it at 700C, are you cooling in a specific profile or naturally ? I will hold at temperature for one hour and shut off power and let cool for an hour.


    Thanks,




    Answers -


    ee below. I will be glad to answer any and all questions.

    1. The LiAlH4 is severely poisonous as well as pyrophoric. People have died from a single breath. You must operate in a hood.

    2. I am just beginning. I will order cement paste from Cotronics Durapot 304

    2, I will order Ni powder from Hunter Nickel Vale-255

    3. I will order LiAlH4 from Alpha Aesar 25 grams, %$55.00

    4. I will order alumina tubes 0.250 OD x 0188 ID

    5. I will order quartz tubes to go over the alumina 10.4mm OD X 7MM ID

    6. I will order 18-gauge nichrome wire from Mcmaster-Carr as the resistance wire.

    This system will only go to 1100C as the quartz softens around that temperature.

    The system must be cycled up and down to 700C at least 5 times to get H into the powders.

    Wrap the tubes with nichrome and then cover that with a tight wrap of Zircar insulation. I will mount thermocouples on the wires with a very thin insulating sheath to avoid short circuiting the heater.

    Wear face shield at all times after you have begun loading LiAlH4.

  • Very valuable and informative post. Thanks to both you, David, and Brian for sharing these questions and answers.


    Below find links to materials Brian specified. I cannot yet guarantee that these are accurate.


    I hope Brian might chime in and correct if needed.


    Hunter Chemical nickel powder


    McMaster-Carr Alumina Tubes


    Alumina Tube Brian chose


    Heating Wire Candidate


    Quartz Tube Candidate


    Quartz Rod Candidate


    Rod for plugs


    I will try to edit this post with more links later. Last edit Monday 1-26-2015.

  • What is the calculated volume of the reactor, Brian? Or, what is the included length? Are you going for the same volume as AGP used?


    Will you use a variac or a stove control? Avoiding rectification?


    Quartz tube as in a tube furnace? Like this NMR tube?


    Is the choice of tube related to your belief that magnetic fields are important to the phenomena?

  • The internal volume will be on th eorder of 2ml.


    I will use an uncontrolled variac 120 V AC


    I am mounting the alumina tube inside a quartz tube and melting it closed with an acetylene torch. It will be hermetic, but capable of a large explosion.. I will do it inside an armored steel box of 1meter3 dimensions.


    I think Magentism is important, but it is unrelated to using the quartz tube.


    I do not understand the role of magnetism herein.

  • Ecco: see https://en.wikipedia.org/wiki/Lithium_aluminium_hydride


    "...


    Thermal decomposition
    LAH is metastable at room temperature. During prolonged storage it slowly decomposes to Li3AlH6 and LiH.[12] This process can be accelerated by the presence of catalytic elements, such as titanium, iron or vanadium.


    When heated LAH decomposes in a three-step reaction mechanism:[12][13][14]


    3 LiAlH4 → Li3AlH6 + 2 Al + 3 H2 (R1)2 Li3AlH6 → 6 LiH + 2 Al + 3 H2 (R2)2 LiH + 2 Al → 2 LiAl + H2 (R3)R1 is usually initiated by the melting of LAH in the temperature range 150–170 °C,[15][16][17] immediately followed by decomposition into solid Li3AlH6, although R1 is known to proceed below the melting point of LiAlH4 as well.[18] At about 200 °C, Li3AlH6 decomposes into LiH (R2)[12][14][17] and Al which subsequently convert into LiAl above 400 °C (R3).[14] Reaction R1 is effectively irreversible. R3 is reversible with an equilibrium pressure of about 0.25 bar at 500 °C. R1 and R2 can occur at room temperature with suitable catalysts.[19]


    ..."

  • According to an online calculator here: internal pressure stress calculator it appears if the LAH simply decomposes the quartz tube will burst.


    The calculator disallows pressure above 100 psi (approximately 6.89 bar).


    So either the hydrogen does something other than pressurizing the vessel, or it leaks out, thereby relieving pressure. Here I mean that in Parkhomov's apparatus either it leaks or it bursts or something else occurs. Since he stated he detected no leaks, and it did not burst, something needs investigating. Something we as yet do not understand.


    On a chemistry forum I visit a poster theorized that a Rossi reactor got hot simply because monatomic hydrogen reacted with moisture in the air at the outer surface of the alumina as it leaked out. Long run times and small amounts of available hydrogen seem to rule this out, but for short runs calculations are essential. You might think steam would be easy to see outside the tube. Perhaps.

  • @brian ahern


    Will you rely on the Quartz Tube alone to contain the reactor contents in the sense of this schematic drawing?



    So the alumina tube is *not* sealed before placing it inside the quartz tube?


    Notes to others viewing this image: The CAD drawing assumes a closed end alumina tube which is commonly sold. The left end of the schematic shows such a tube. The right end of the drawing depicts a cross-section of a melted quartz tube and an open end of an alumina tube. This drawing is proportional in the x-axis but truncated in the y-axis --- to better visualize the ends. I started with a tube length of eight inches and cut out a section in the middle to produce this drawing for convenient posting to this forum.


    If Brian is using an open ended alumina tube, just imagine both ends are like the right hand end in the drawing.

  • Have you considered using a "real" calorimeter? For example, this elegant example of a liquid flow calorimeter from associates of Dr. Giancarlo, which has been shown to work very well at the heat flux and temperature values which you can expect if you replicate Rossi's claimed results:


    https://gsvit.wordpress.com/20…te-calorimetria-a-flusso/
    The original is in Italian however Google translate does a good job with it, especially within the Chrome browser.

  • You (and others looking to replicate) may try contacting this company
    http://kanthal.com/en/products…wire-and-resistance-wire/


    Kanthal and Alkrothal FeCrAl alloys*High-resistivity iron-chromium-aluminium alloys for use up to 1400ºC (2550ºF).


    I suspect that to reach the phononic level required to run the reaction in the manor that the "dog bone" runs, may require temperatures even above this level. Note the outside temp of the Rossi device was 1200C.

  • brian ahern


    I wonder Brian, if you have received a clarification about the ratio of nickel powder to LAH?


    AGP wrote that one gram of nickel powder accompanied 10% LAH.


    Does this make the total mass 1.10 grams? Or is it 0.90 grams of nickel and 0.10 grams of LAH?


    For experimenters concerned about getting these tiny weights under control, please see my blog - http://ni.comli.com - where a homemade microgram balance makes measuring quick, easy, and cheap.