PDF
Full
Outline
Chemical recycling of polymethyl methacrylate (PMMA) to its monomer, methyl methacrylate (MMA), requires balancing primary depolymerization with the suppression of secondary gas-phase reactions. This study investigates non-oxidative MMA decomposition in a fluidized bed reactor across a temperature range of 623 to 1073 K using online FTIR spectroscopy. Experimental results reveal a significant shift in product selectivity: low temperatures favor a low-energy decarboxylation pathway (yielding CO2 and methanol), while high temperatures promote radical cracking (yielding CO and light hydrocarbons). To describe this, a two-competing-reactions model (CRM) is used, outperforming the traditional single first-order approaches. The CRM identifies two distinct activation energies: Ea,1 = 76.5 kJ mol−1 for decarboxylation and Ea,2 = 269.9 kJ mol−1 for cracking. The research further demonstrates that the classical sequential decomposition model (PMMA → MMA→ light gases) overpredicts monomer yields at low temperatures. By integrating a direct solid-to-gas pathway to account for side-chain break-off and incorporating multi-volume reactor hydrodynamics, the model's predictive accuracy significantly improved. This integrated framework identifies an optimal recovery window near 723 K, achieving MMA yields over 95 %.
PDF
67
12
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |
关闭全屏
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
