Double Green Process: a low environmental impact method for recycling of CdTe, a-Si and CIS/CIGS thin-film photovoltaic modules

Figures & data

Figure 1. Scheme of the recycling process developed by Giacchetta, Leporini, and Marchetti (2013).

Figure 2. Scheme of the recycling sub-process DGPa-1.

Figure 3. Scheme of the recycling sub-process DGPa-2.

Figure 4. Scheme of the recycling sub-process DGPb-1.

Figure 5. Scheme of the recycling sub-process DGPb-2.

Table 1. Input and output in terms of materials and power of the DGPa-1 and DGPa-2 processes.

Process	Process steps	Material IN	Power IN	Material OUT
DGPa-1	Automatic feed	12 kg MIN=	0.00263 kWh	12 kg MOUT=
		11.52 kg Glass		11.52 kg Glass
		432 g EVA		432 g EVA
		28.8 g CdTe		28.8 g CdTe
		2.16 g CdS		2.16 g CdS
	Hammer mill	12 kg MIN	0.000185 kWh	12 kg MOUT
			0.018 kWh
			0.0264 kWh
	Dimensional reduction	12 kg MIN	0.0216 kWh	12 kg MOUT
			0.018 kWh
			0.000518 kWh
	Wet mechanical treat	12 kg MIN	0.0002035 kWh	13.2 kg Mixed fraction
		1.2 l H2O	0.020 kWh
	Flotation	13.2 kg Mixed fraction	0.006 kWh	Photoactive materials
			0.000168 kWh	25.9 g CdTe
				1.9 g CdS
				0.6 kg material to incinerate
				1.2 l H2O to treat
				10.9 kg Glass fraction
	Washing	10.9 kg Glass fraction	0.001262 kWh
		12.4 l H2O
DGPa-2	Automatic feed	12 kg MIN=	0.00263 kWh
		11.52 kg Glass
		432 g EVA
		28.8 g CdTe
		2.16 g CdS
	Hammer mill	12 kg MIN	0.000185 kWh
			0.018 kWh
			0.0264 kWh
	Dimensional reduction	12 kg MIN	0.0216 kWh
			0.018 kWh
			0.000518 kWh
	Wet mechanical treat	12 kg MIN	0.0002035 kWh
		1.2 l H2O	0.020 kWh
	Centrifugal extractor	13.2 kg Mixed fraction	0.01221 kWh	Photoactive materials
			0.000168 kWh	23.31 g CdTe
				1.971 g CdS
				3.4 kg material to incinerate
				1.2 l H2O to treat
				10.9 kg Glass fraction
	Washing	10.9 kg Glass fraction	10.9 kg Glass fraction	0.001262 kWh
		12.4 l H2O

Table 2. Input and output in terms of materials and power of the DGPb-1 and DGPb-2 processes.

DGPb-1	Automatic feed	24.18 kg MIN=	0.0111 kWh	24.18 kg MOUT=
		23.77 kg Glass		23.77 kg Glass
		225.542 g Photoactive materials		225.542 g Photoactive materials
		189.36 g Copper		189.36 g Copper
	Hammer mill	24.18 kg MIN	0.048 kWh	24.18 kg MOUT
			0.0225 kWh
			0.0004 kWh
	Dimensional reduction	24.18 kg MIN	0.033 kWh	24.18 kg MOUT
			0.0225 kWh
			0.0011 kWh
	Depression sandblasting	24.18 kg MIN	0.00022 kWh	7.133 kg Glass
		3.6 kg Abrasives	0.00015	9.606 kg Dust + Abrasives + Photoactive materials
			0.000415 kWh
			0.00017 kWh	10.8 kg Glass + Encapsulant
	Flotation	9.606 kg Dust + Abrasives + Photoactive materials	0.0146 kWh	5.624 kg Glass
			0.0000874 kWh
	Vibrating screen	10.8 kg Glass + Encapsulant	0.00075 kWh	10.791 kg Glass
			0.000165 kWh	0.1015 kg Encapsulant
	Washing	26.7 l H2O	0.00323 kWh	26.7 l Wastewater
		5.624 kg Glass		23.45 kg Glass
		7.133 kg Glass
		10.791 kg Glass
DGPb-2	Automatic feed	24.18 kg MIN=	0.0111 kWh	24.18 kg MOUT=
		23.77 kg Glass		23.77 kg Glass
		225.542 g Photoactive materials		225.542 g Photoactive materials
		189.36 g Copper		189.36 g Copper
	Hammer mill	24.18 kg MIN	0.048 kWh	24.18 kg MOUT
			0.0225 kWh
			0.0004 kWh
	Dimensional reduction	24.18 kg MIN	0.033 kWh	24.18 kg MOUT
			0.0225 kWh
			0.0011 kWh
	Rotating drum	24.18 kg MIN	0.00133 kWh	26.7 kg Mixed fraction
		3.6 kg Chemical additives	0.0000034 kWh
	Centrifugal extractor	9.606 kg Dust + Abrasives + Photoactive materials	0.055 kWh	3.62 kg Liquid to treat
			0.0000068 kWh	23.9796 kg Glass + Encapsulant
	Vibrating screen	23.9796 kg Glass + Encapsulant	0.00075 kWh	22.495 kg Glass
			0.000165 kWh	1.4846 kg Encapsulant
	Washing	25.6 l H2O	0.00039 kWh	25.6 l H2O
		22.495 kg Glass	0.015 kWh	22.495 kg Glass
	Precipitation	3.62 kg Liquid to treat	0.0000675 kWh	4.34 kg Mud
			0.001 kWh	25 l H2O
		25.6 l H2O
		0.721 l H2O
	Filterpress	4.34 kg Mud	0.038 kWh	4.135 kg Waste
				169.13 g Copper mixture
				32.79 g Silicon mixture

Figure 6. Scheme of DGPa-1 process.

Figure 7. Scheme of DGPa-2 process.

Figure 8. Scheme of DGPb-1 process.

Figure 9. Scheme of DGPb-2 process.

Figure 10. LCA results of DGPa-1 process.

Figure 11. LCA results of DGPa-2 process.

Figure 12. LCA results of DGPb-1 process.

Figure 13. LCA results of DGPb-2 process.

Figure 14. NPV and PBP for DGPa-1 and DGPa-2 processes.

Figure 15. NPV and PBP for DGPb-1 and DGPb-2 processes.

Table 3. Estimation of costs and revenues for DGPa and DGPb processes.

	Design life (years)	Capital cost (CAPEX) (€)	Annual cost (OPEX) (€/year)	Revenues from material selling (€/year)
DGPa-1	25	640000	481920	996968
DGPa-2	25	640000	481920	942580
DGPb-1	25	700000	532120	17130284
DGPb-2	25	750000	491960	17664492

Figure 16. Scheme of the entire high value recycling Double Green Panel (DGP) process.

Giacchetta, G., M. Leporini, and B. Marchetti. 2013. “Evaluation of the Environmental Benefits of New High Value Process for the Management of the End of Life of Thin Film Photovoltaic Modules.” Journal of Cleaner Production 51: 214–224.10.1016/j.jclepro.2013.01.022

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