Acoustic studies of the decomposition of hydrogen peroxide process

Dmitry M. Kuznetsov, Piotr N. Kozachenko, Irina A. Luganskaya, Victoria V. Aliluykina

Federal State Budgetary Educational Institution of Higher Vocational Training "Novocherkassk State Land Reclamation Academy"

Don State Technical University, Rostow on the Don, Russia, 344023, ul. Strana Sowietow 1

Possibility of using acoustic emission (AE) method for studying passing in the liquid environment with a gas phase allocation processes is shown by the example of decomposition of hydrogen peroxide process research.

In the case of the heterogeneous process of acoustic waves the nature of its generation is described partially in works [1-5]. The given description can't be considered as being full as, the generation of acoustic emission signals should be added to the described mechanisms of acoustic emission [1,3,5]. Despite the mentioned complexities, the method of AE should be accepted to be interesting due to its decomposition of hydrogen peroxide. The research process is highly informative and universal, allowing the registration of the processes which are passing in the decomposition of hydrogen peroxide.

In connection with the above, the purpose of the present work is to attempt the metrological evaluation of the acoustic emission method’s applicability for the process of research decomposition of hydrogen peroxide in conditions of variable quantity of the catalytic amount. Manganese dioxide catalyses the decomposition of hydrogen peroxide to oxygen and water [6]:

2 H₂O₂ → 2 H₂O + O₂

We will examine the change of evolution of the total acoustic emission signals’ and calculate it at the same time. The acoustic emission activity (for derivative of the total count by time) has an unstable character in the initial stage of the decomposition of hydrogen peroxide process.

This is a result of the simultaneous superposition of the afore-mentioned phenomena: occluded gas release and gas cavitation bubbles process. Approximately 1 minute after the beginning of the decomposition of hydrogen peroxide process, the activity is basically defined by one factor – the reduction of the amount hydrogen peroxide (fig.1). The activity of acoustic emission signals dN/dt naturally decreases and it’s proportional to the speed of gas release :

dN/dt = Kv, (1)

where К –proportionality ratio the speed of the decomposition of hydrogen peroxide; v – speed of the decomposition of hydrogen peroxide, g/s.

The activity dN/dt acoustic emission signals, is naturally proportional to the speed of weight change:

dN/dt = K m/t. (2)

Dividing variables and integrating the equation (2), we receive the equation for the total count of acoustic emission signals (fig.1):

N=Km Ln t – C (3)

A schematic diagram of AE measurement system used in the present work is shown in Fig. 2

In agreement with the given data we can confirm that: in spite of the fact that all registered parameters of the acoustic emission objectively reflect the dissolution process and the value of data spread doesn't make it a possible form to use such acoustic emission parameters such as ‘Duration’, ‘

Rise time’ and ‘the AE oscillations rate’ for the quantitative evolution of the dissolved substance’s weight.

Fig 2. Changes in the acoustic emission signals at the decomposition of hydrogen peroxide process

The most reliable acoustic emission parameter, which can be used for a quantitative evaluation of the dissolved substances is weight ‘the Total account’ of signals

Conclusion. The possibility of using the acoustic emission method for study of the processes, passing in fluid ambience with separation of the gas phase, was considered . In particular, it was shown that in the process of removing gases out from water while decomposition of hydrogen peroxide process several different acousticses-emission pictures are identified. It evidences complexity and multistage character of decomposition of hydrogen peroxide process are. The data obtained allow to forecast the sphere of using the AE method not only for study of the decomposition of hydrogen peroxide process, but also for development of reliable and nondestroying method of controlling the depth and fullness of chemical reactions and physical-chemical processes in liquids.

References

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