FRELP: progress in October 2014
The four steps of the plan of development, the situation is as follows:
Action B3 – DETACHMENT
In September it was tested in continuous the prototype for detachment, trying to optimize performance.
There are some problems in the gluing system of the panels head to head because, in transit in the high temperature area, before the detachment of the glass from the sandwich, we had some problem of loosening of the joint due to the fact that the adhesive is very sensitive to temperature changes, and therefore, when the temperature rises beyond a certain limit, the disconnect occurs.
Let adhesives that are resistant to conditions of temperature higher than the operating temperature in order to have a certain margin of safety and to avoid problems in the continuity of the process of detachment.
Action B4 – PYROLYSIS
Have been performed various tests on pyrolysis on centimeter portions of sandwiches to mediate the quantitative results of residual ashes on which we made of the chemical analyzes.
Have been analyzed different types of ashes of pyrolysis and the results of the chemical analyzes are quite variable, in particular depending on the presence of silver that is present in an amount ranging from 0,05% to 0,15% with respect to the total weight of entire panel.
Even the other metal components have a high variability according to the type of the panel and, for the same panel, depending on the portions of the wafer.
We have finalized the study of the ashes and in particular to the recovery of silver and copper, which are the elements to be recovered by electrolysis after dissolving in acid leaching through.
For aluminum, it is seen that, by milling and subsequent sieving thrust of the ash, it is possible to recover most of the aluminum as a residual overscreen.
Action B5 – ACID LEACHING
In September it was also tested the process of acid leaching with different acids and mixtures of acids.
After numerous tests based on sulfuric acid, nitric acid, hydrochloric acid, hydrofluoric acid and various mixtures of the same, considering the environmental problems relating to different dangerousness of the same, it was decided, also in function of the encouraging early results, to focus primarily on leaching with hot nitric acid.
Therefore we will proceed in this direction also in function of the subsequent stage of electrolysis, which will be object of study in the month of November and December when we have established the most suitable dilution ratios of the acid solution to be used for the selective electrolysis at different potentials.
Action D2 – DISSEMINATION
September 23 took place simultaneously two conventions to which Sasil and SSV participated by presenting the project FRELP:
• 29th Conference on Solar Energy and Photovoltaic (EU PVSEC 2014) in Amsterdam in the “PV life cycle management & recycling”;
• 12th ESG (European Society of Glass) Conference, in Parma.
Both have attracted much interest because, in the recovery of the panels with silicon technology, there are currently no active treatment processes at industrial level; also at the level of research is still in the recovery phase little selective for the enhancement of the individual components.