School of Engineering, Design and Built Environment, Western Sydney University, Penrith, NSW 2751, Australia.
School of Engineering, Design and Built Environment, Western Sydney University, Penrith, NSW 2751, Australia.
Waste Manag. 2024 Oct 1;187:306-316. doi: 10.1016/j.wasman.2024.07.021. Epub 2024 Jul 31.
Plastic waste poses a critical environmental challenge for the world. The proliferation of waste plastic coffee pods exacerbates this issue. Traditional disposal methods such as incineration and landfills are environmentally unfriendly, necessitating the exploration of alternative management strategies. One promising avenue is the pyrolysis in-line reforming process, which converts plastic waste into hydrogen. However, traditional pyrolysis methods are costly due to inefficiencies and heat losses. To address this, for the first time, our study investigates the use of microwave to enhance the pyrolysis process. We explored microwave pyrolysis for polypropylene (PP), high-density polypropylene (HDPE), and waste coffee pods, with the latter primarily comprising polypropylene. Additionally, catalytic ex-situ pyrolysis of coffee pod pyrolysis over a nickel-based catalyst was investigated to convert the evolved gas into hydrogen. The single-stage microwave pyrolysis results revealed the highest gas yield at 500 °C for HDPE, and 41 % and 58 % (by mass) for waste coffee pods and polypropylene at 700 °C, respectively. Polypropylene exhibited the highest gaseous yield, suggesting its readiness for pyrolytic degradation. Waste coffee pods uniquely produced carbon dioxide and carbon monoxide gases because of the oxygen present in their structure. Catalytic reforming of evolved gas from waste coffee pods using a 5 % nickel loaded activated carbon catalyst, yielded 76 % (by volume) hydrogen at 900 °C. These observed results were supported by elemental balance analysis. These findings highlight that two-stage microwave and catalysis assisted pyrolysis could be a promising method for the efficient management of waste coffee pods, particularly for producing clean energy.
塑料废物对世界构成了严峻的环境挑战。废塑料咖啡胶囊的大量出现加剧了这一问题。传统的处理方法，如焚烧和填埋，对环境不友好，因此需要探索替代的管理策略。一种有前途的方法是热解在线重整过程，它可以将塑料废物转化为氢气。然而，传统的热解方法由于效率低下和热损失而成本高昂。为了解决这个问题，我们首次研究了使用微波来增强热解过程。我们探索了微波热解聚丙烯（PP）、高密度聚乙烯（HDPE）和废咖啡胶囊，后者主要由聚丙烯组成。此外，还研究了在镍基催化剂上进行咖啡胶囊热解的催化异位热解，以将产生的气体转化为氢气。单级微波热解的结果表明，HDPE 在 500°C 时气体产率最高，而废咖啡胶囊和聚丙烯分别在 700°C 时产率为 41%和 58%（按质量计）。聚丙烯表现出最高的气态产率，表明其易于进行热解降解。废咖啡胶囊由于其结构中存在氧气，因此独特地产生了二氧化碳和一氧化碳气体。使用负载 5%镍的活性炭催化剂对废咖啡胶囊产生的气体进行催化重整，在 900°C 时产生了 76%（体积）的氢气。这些观察结果得到了元素平衡分析的支持。这些发现表明，两级微波和催化辅助热解可能是一种很有前途的方法，可以有效地管理废咖啡胶囊，特别是用于生产清洁能源。
