Converting polycarbonate and polystyrene plastic wastes intoaromatic hydrocarbons via catalytic fast co-pyrolysis

Jia Wang; Jianchun Jiang; Xiaobo Wang; Ruizhen Wang; Kui Wang; Shusheng Pang; Zhaoping Zhong; Yunjuan Sun; Roger Ruan; Arthur J Ragauskas

doi:10.1016/j.jhazmat.2019.121970

Converting polycarbonate and polystyrene plastic wastes intoaromatic hydrocarbons via catalytic fast co-pyrolysis

J Hazard Mater. 2020 Mar 15:386:121970. doi: 10.1016/j.jhazmat.2019.121970. Epub 2019 Dec 24.

Authors

Jia Wang¹, Jianchun Jiang², Xiaobo Wang³, Ruizhen Wang⁴, Kui Wang⁴, Shusheng Pang⁵, Zhaoping Zhong⁶, Yunjuan Sun⁷, Roger Ruan⁸, Arthur J Ragauskas⁹

Affiliations

¹ Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Longpan Road 159, Nanjing 210037, China; Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry (CAF), No. 16, Suojin Five Village, Nanjing, Jiangsu 210042, China; Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University, No.2 Sipailou, Xuanwu District, Nanjing, Jiangsu 210096, China; Department of Chemical & Biomolarcular Engineering, the University of Tennessee, Knoxville, TN 37996, USA.
² Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Longpan Road 159, Nanjing 210037, China; Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry (CAF), No. 16, Suojin Five Village, Nanjing, Jiangsu 210042, China. Electronic address: jiangjc@icifp.cn.
³ School of Environmental Science, Nanjing Xiaozhuang University, Nanjing, Jiangsu 211171, China.
⁴ Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Longpan Road 159, Nanjing 210037, China; Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry (CAF), No. 16, Suojin Five Village, Nanjing, Jiangsu 210042, China.
⁵ Department of Chemical and Process Engineering, University of Canterbury, Christchurch, New Zealand.
⁶ Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University, No.2 Sipailou, Xuanwu District, Nanjing, Jiangsu 210096, China.
⁷ Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry (CAF), No. 16, Suojin Five Village, Nanjing, Jiangsu 210042, China. Electronic address: bioenergy@seu.edu.cn.
⁸ Center for Biorefining and Department of Bioproducts and Biosystems Engineering, University of Minnesota, 1390 Eckles Ave., St. Paul, MN 55108, USA.
⁹ Department of Chemical & Biomolarcular Engineering, the University of Tennessee, Knoxville, TN 37996, USA; Department of Forestry, Wildlife and Fisheries, Center for Renewable Carbon, the University of Tennessee, Institute of Agriculture, Knoxville, TN 37996, USA; Joint Institute for Biological Science, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.

PMID: 31887562
DOI: 10.1016/j.jhazmat.2019.121970

Abstract

Thermochemical conversion of plastic wastes is a promising approach to produce alternative energy-based fuels. Herein, we conducted catalytic fast co-pyrolysis of polycarbonate (PC) and polystyrene (PS) to generate aromatic hydrocarbons using HZSM-5 (Zeolite Socony Mobil-5, hydrogen, Aluminosilicate) as a catalyst. The results indicated that employing HZSM-5 in the catalytic conversion of PC facilitated the synthesis of aromatic hydrocarbons in comparison to the non-catalytic run. A competitive reaction between aromatic hydrocarbons and aromatic oxygenates was observed within the studied temperature region, and catalytic degradation temperature of 700 °C maximized the competing reaction towards the formation of targeted aromatic hydrocarbons at the expense of phenolic products. Catalyst type also played a vital role in the catalytic decomposition of PC wastes, and HZSM-5 with different Si/Al molar ratios produced more aromatic hydrocarbons than HY (Zeolite Y, hydrogen, Faujasite). Regarding the effect of Si/Al molar ration in HZSM-5 on the distribution of monocyclic aromatic hydrocarbons (MAHs), a Si/Al molar ratio of 38 maximized benzene formation with an advanced factor of 5.1. Catalytic fast co-pyrolysis of PC with hydrogen-rich plastic wastes including polypropylene (PP), polyethylene (PE), and polystyrene (PS) favored the production of MAHs, and PS was the most effective hydrogen donor with a ∼2.5-fold increase. The additive effect of MAHs increased at first and then decreased when the PC percentage was elevated from 30 % to 90 %, achieving the maximum value of 32.4 % at 70 % PC.

Keywords: Bisphenol A polycarbonate; Catalytic thermochemical conversion; HZSM-5; Monocyclic aromatic hydrocarbons; Plastic polymers.

Publication types

Research Support, Non-U.S. Gov't