Recycling of CIGS flexible solar cells: Investigation of organic acids leaching
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Innovative and sustainable chemical engineering (MPISC), MSc
Publicerad
2023
Författare
Somani, Parth
Liang, Hanxiang
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
The Photovoltaic market has been rising sharply in recent years and is expected to
grow steadily in the upcoming years. The copper-indium-gallium diselenide (CIGS)
solar cell has become a more and more significant role in the photovoltaic industry,
and its application in the second generation of solar cells has increased in recent
years, which means photovoltaic waste will be prominent in the future. To reduce
resource consumption and recycle valuable materials from an economical and environmental
perspective, further research on metal recovery should be carried out.
Currently, from an economic point of view, recycling CIGS solar cells is not feasible
on an industrial scale, and research is limited. The current end-of-life module recycling
is done using thermal decomposition, pyrolysis treatment, and dry etching in
the presence of Chlorine gas at high temperatures, which could require high energy
demand and high effort for the purification of metals. Moreover, due to the drawbacks
of inorganic acid leaching, such as toxic gas production and low selectivity of
the metals. The viability of organic acids as an alternative leaching agent needs to
be investigated. The project aims to extract the valuable metals present in CIGS
solar cells by comprehending the influence of leaching variables through utilizing
organic acids in an environmentally friendly way. Citric acid and tartaric acid were
employed for the leaching process, as well as nitric acid leaching was studied to
compare the results. Some leaching conditions such as concentration, surface area
to liquid ratio, temperature, and agitation method are considered to find the optimum
condition for the metal recovery from CIGS solar cells. The results show that
different division methods have an impact on extracting silver with nitric acid. The
mass of silver in the whole solar cell is 44% more than in the divided cell sample.
For 1M citric acid with a surface area to liquid ratio of 1:3 cm2/ml, temperature
of 50◦C and 100 rpm stirring speed, a high selectivity of Zn and In at 8 hours was
observed.
Beskrivning
Ämne/nyckelord
Recycling , acid leaching , CIGS solar cells , PV