NUS Environmental Research Institute, National University of Singapore, Singapore 138602, Singapore.
Energy and Environmental Sustainability Solutions for Megacities (E2S2), Campus for Research Excellence and Technological Enterprise (CREATE), Singapore 138602, Singapore.
Environ Sci Technol. 2022 Jun 21;56(12):8953-8963. doi: 10.1021/acs.est.2c01645. Epub 2022 Jun 1.
Converting plastic waste into valuable products (syngas) is a promising approach to achieve sustainable cities and communities. Here, we propose for the first time to convert plastic waste into syngas via the FeAlO-based chemical looping technology in a two-zone reactor. The FeAlO-based redox cycle was achieved with the pyrolysis of plastic waste in the upper zone, followed by the decomposition and thermal cracking of hydrocarbon vapors, and the oxidation and water splitting in the lower zone (850 °C) enabled a higher carbon conversion (81.03%) and syngas concentration (92.84%) when compared with the mixed feeding process. The iron species could provide lattice oxygen and meanwhile act as the catalyst for the deep decomposition of hydrocarbons into CO and the accumulation of deposited carbon in the reduction step. Meanwhile, the introduced water would be split by the reduced iron and deposited carbon to further produce H and CO in the following oxidation step. A high hydrogen yield of 85.82 mmol/g HDPE with a molar ratio of H/CO of 2.03 was achieved from the deconstruction of plastic waste, which lasted for five cycles. This proof of concept demonstrated a sustainable and highly efficient pathway for the recycling of plastic waste into valuable chemicals.
将塑料废物转化为有价值的产品（合成气）是实现可持续城市和社区的有前途的方法。在这里，我们首次提出在两区式反应器中通过基于 FeAlO 的化学循环技术将塑料废物转化为合成气。在 850°C 的下部区域中，通过塑料废物的热解实现基于 FeAlO 的氧化还原循环，随后进行烃蒸气的分解和热裂化，以及氧化和水分解，与混合进料工艺相比，实现了更高的碳转化率（81.03%）和合成气浓度（92.84%）。铁物种可以提供晶格氧，同时在还原步骤中充当将烃类深度分解为 CO 和沉积碳积累的催化剂。同时，引入的水将在随后的氧化步骤中被还原的铁和沉积的碳分解，进一步产生 H 和 CO。从塑料废物的解构中获得了 85.82mmol/gHDPE 的高氢气产率，H/CO 的摩尔比为 2.03，持续了五个循环。这一概念验证为将塑料废物高效且可持续地转化为有价值的化学品提供了一种途径。
