由于其复杂的结构由10%的铝(Al)和90%的混合塑料薄膜组成,对金属化食品包装塑料废物(MFPW)的单次处理显示出令人失望的结果,回收率<20%,PP,PS,PET,等。此外,它正在产生许多必须填埋的排放物和残留物,这使得它们难以融入循环经济。因此,最近开发了一种多阶段回收(MSR)方法,使用几种顺序机械,热和化学工艺从MFPW回收能源和铝,为回收工厂运营商带来额外收入。热处理有助于将塑料部分分解成蜡或油,气态,和由铝和煤组成的固体残留物(SR),而机械工艺可用作MFPW原料和SR的预处理。最后,化学处理(浸出和官能化)可用于从SR中提取Al并将煤精炼为碳微粒(CP),分别。为了研究拟议的MSR系统的环境性能,这项研究是发展起来的。根据ISO14040/44标准使用SimaPro生命周期分析(LCA)工具进行调查,影响评估方法为ReCiPe2016。在构建的LCA布局中提出了五种不同的方案,即,将MFPW转化为a)蜡和气体(热解),b)蜡,气体,和氯化铝(AlCl)(热解和浸出),c)蜡,气体,AlCl,和CP(热解,浸出,和功能化),andd)oil,气体,AlCl,和CP(催化热解,浸出,和功能化)。此外,催化热解产生的油用于发电(方案e)。结果表明,与焚烧实践相比,蜡和气体回收方案(a)具有更好的环境潜力和环境效益。提取Al和CPs后,结果变化不大(方案b,)有几个在总分中增加了2-4%。虽然升级和利用带来了很多环境负担(场景d,E)被记录,由于使用了大量的催化剂,达到79%。因此,MSR系统具有更大的环境效益,然而,化学和催化过程仍需进一步改进,以减少陆地酸化的影响。
Single treatment of metallised food packaging plastics waste (MFPW) has shown disappointing results with recycling rate <20 % due to its complex structure consisting of 10 % aluminium (Al) and 90 % mixed plastic films made of PE, PP, PS, PET, etc. Besides, it is generating many emissions and residues that must be landfilled making it difficult to integrate them into the circular economy. Therefore, a multi-stage recycling (MSR) approach has recently been developed using several sequential mechanical, thermal and
chemical processes to recover energy and Al from MFPW with additional revenue for recycling plant operators. The thermal treatment helps to decompose the plastic fraction into wax or oil, gaseous, and solid residue (SR) composed of Al and coal, while the mechanical process can be used as a pre-treatment of MFPW feedstock and SR. Finally, the
chemical treatment (leaching and functionalization) can be used to extract Al from SR and to refine coal into carbon microparticles (CPs), respectively. In order to investigate the environmental performance of the proposed MSR system, this research was developed. The investigation was performed using SimaPro life cycle analysis (LCA) tool according to ISO 14040/44 Standards and the impact assessment method is ReCiPe 2016. Five different scenarios were proposed in the constructed LCA layout, namely, conversion of MFPW to a) wax and gas (pyrolysis), b) wax, gas, and aluminium chloride (AlCl₃) (pyrolysis and leaching), c) wax, gas, AlCl₃, and CPs (pyrolysis, leaching, and functionalization), and d) oil, gas, AlCl₃, and CPs (catalytic pyrolysis, leaching, and functionalization). Besides, the oil produced from catalytic pyrolysis is used for generation of electricity (scenario e). The results showed that wax and gas recovery scenario (a) has better environmental potential and environmental benefits compared to incineration practice. The results did not change much after extraction of Al and CPs (scenario b, c), with a few increasing by 2-4% in the total score. While a lot of environmental burdens from upgrading and utilization (Scenario d, e) were recorded, reaching 79 % due to the huge amount of the catalyst was used. Thus, MSR systems have bigger environmental benefits, however, the
chemical and catalytic processes still need to be further improved to reduce the effect of terrestrial acidification.