Department of Earth Resources and Environmental Engineering, Hanyang University, Seoul 04763, Republic of Korea.
Department of Environmental Engineering & Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung, Taiwan.
J Hazard Mater. 2022 May 15;430:128454. doi: 10.1016/j.jhazmat.2022.128454. Epub 2022 Feb 9.
Conventional disposal processes (incineration and landfilling) of agricultural plastic wastes release harmful chemicals and microplastics into our ecosystems. To provide a disposal platform not releasing harmful chemicals, pyrolysis of a representative agricultural plastic waste was proposed in this study. Spent plastic mulching film (SMF) was used as a model waste compound. To make pyrolysis process more environmentally benign, CO was used as a raw material in pyrolysis of SMF. H and hydrocarbons were produced from pyrolysis of SMF under the inert (N) and CO conditions, because SMF is composed of polyethylene. To enhance conversion of hydrocarbons into H, catalytic pyrolysis of SMF was conducted over Ni/SiO. Compared to non-catalytic pyrolysis, total concentration of pyrolytic gases was enhanced up to 3.1 and 11.3 times under N and CO conditions, respectively. The gas phase reactions between CO and hydrocarbons led to formation of CO, which enhanced production of pyrolytic gases under the CO condition. Moreover, gas phase reactions resulted in less production of pyrolytic oil from CO condition (15.9 wt%) in reference to the N condition (22.6 wt%). All experimental results confirmed that CO and SMF can be used as useful feedstocks to produce value-added products. ENVIRONMENTAL IMPLICATION: Plastic waste used from a sector of agriculture is incinerated or/and landfilled, generating hazardous microplastic and volatile compounds into the environment. Thus, an environmentally friendly process for plastic waste materials in the agricultural industry is required. This study converted a spent plastic mulching film (SMF), broadly used for plastic greenhouse, into value-added syngas through catalytic pyrolysis. CO was used as a reactant. We found that concentration of CO was key to improve syngas formation from pyrolysis of SMF. Thus, this study suggested that CO/SMF are used as useful feedstocks through catalytic pyrolysis, while they were previously discarded as waste materials.
传统的农业塑料废弃物处理方法（焚烧和填埋）会将有害化学物质和微塑料释放到我们的生态系统中。为了提供一个不释放有害化学物质的处理平台，本研究提出了一种农业塑料废弃物的热解方法。用过的塑料地膜（SMF）被用作模型废物化合物。为了使热解过程更加环保，在 SMF 的热解中使用 CO 作为原料。由于 SMF 由聚乙烯组成，因此在惰性（N）和 CO 条件下，SMF 的热解会产生 H 和碳氢化合物。为了提高碳氢化合物转化为 H 的效率，在 Ni/SiO 上进行了 SMF 的催化热解。与非催化热解相比，在 N 和 CO 条件下，热解气体的总浓度分别提高了 3.1 倍和 11.3 倍。CO 和碳氢化合物之间的气相反应导致 CO 的形成，从而在 CO 条件下增强了热解气体的生成。此外，气相反应导致 CO 条件下热解油的生成量（15.9wt%）比 N 条件下（22.6wt%）少。所有实验结果均证实，CO 和 SMF 可用作生产增值产品的有用原料。环境影响：农业部门使用的塑料废物被焚烧或/和填埋，将危险的微塑料和挥发性化合物释放到环境中。因此，农业行业的塑料废物需要一种环保的处理方法。本研究通过催化热解将广泛用于塑料温室的废旧塑料地膜（SMF）转化为增值合成气。使用 CO 作为反应物。我们发现，CO 的浓度是提高 SMF 热解合成气形成的关键。因此，本研究表明，CO/SMF 可作为有用的原料通过催化热解使用，而它们以前则被作为废物丢弃。
