Abstract:

Photovoltaic power generation has gradually become one of the core strengths of renewable energy. A large number of crystalline silicon photovoltaic modules are facing retirement in the near future and the recycling of photovoltaic modules holds great significance in terms of resource circulation and environmental protection. In crystalline silicon photovoltaic modules recycling technology, the separation of laminated parts especially stripping of ethylene-vinyl acetate (EVA) encapsulant films has been a persistent challenge for the industry. Traditional pyrolysis methods for EVA films suffer from high energy consumption, high costs, emissions of toxic gases and substantial carbon emissions. As a novel approach for EVA film separation, the solvothermal method boasts advantages such as environmentally friendly, recyclability of the film, low energy consumption and adjustable solvents. This paper investigated the interaction between EVA films and various solvents under solvothermal reaction conditions using laminates from which the glass and back sheet were removed to reveal the visual changes in the films induced by different solvents. Experimental results indicated that solvents such as anhydrous ethanol and citric acid could achieve the separation of the rear EVA film after treatment at 200℃ for 30min. The mechanism of EVA films separation under solvothermal conditions was initially explored, providing theoretical guidance and methodologies for the sustainable, green and efficient recycling of decommissioned silicon-based photovoltaic modules.

Key words: photovoltaic module recycling, silicon-based photovoltaic modules, solvothermal, EVA adhesive film, solar cells

摘要：

光伏发电已逐渐成为可再生能源的中坚力量之一，在不久的将来大量晶硅光伏组件将面临退役，光伏组件回收在资源循环与环保方面有极大意义。在晶硅光伏组件回收技术中，层压件的分离尤其是聚乙烯-醋酸乙烯酯（EVA）封装胶膜的剥离一直是行业的难点，传统热解胶膜的方法存在能耗高、成本高、有毒气体排放、碳排放量大等问题。溶剂热法作为一种新的分离EVA胶膜的方法，具有绿色环保、胶膜可回收、低能耗和溶剂可调控等优势。本文研究了EVA胶膜与不同溶剂在溶剂热法反应条件下的相互作用，使用已经去除玻璃和背板的层压件来揭示由不同溶剂所引起的胶膜的直观变化。实验结果表明无水乙醇、柠檬酸等溶剂在200℃下处理30min可以实现背面EVA胶膜的分离。初步探讨了在溶剂热条件下EVA胶膜分离的机理，为退役硅基光伏组件的可持续、绿色、高效回收提供了理论指导与方法。

关键词: 光伏组件回收, 硅基光伏组件, 溶剂热, EVA胶膜, 太阳能电池