es7b03756_si_001.pdf (3.84 MB)
Influences of Temperature and Metal on Subcritical Hydrothermal Liquefaction of Hyperaccumulator: Implications for the Recycling of Hazardous Hyperaccumulators
journal contribution
posted on 2018-01-27, 00:00 authored by Feng Qian, Xiangdong Zhu, Yuchen Liu, Quan Shi, Longhua Wu, Shicheng Zhang, Jianmin Chen, Zhiyong Jason RenWaste Sedum plumbizincicola, a zinc (Zn) hyperaccumulator
during phytoremediation, was recycled via a subcritical hydrothermal
liquefaction (HTL) reaction into multiple streams of products, including
hydrochar, bio-oil, and carboxylic acids. Results show approximately
90% of Zn was released from the S. plumbizincicola biomass during HTL at an optimized temperature of 220 °C, and
the release risk was mitigated via HTL reaction for hydrochar production.
The low-Zn hydrochar (∼200 mg/kg compared to original plant
of 1558 mg/kg) was further upgraded into porous carbon (PC) with high
porosity (930 m2/g) and excellent capability of carbon
dioxide (CO2) capture (3 mmol/g). The porosity, micropore
structure, and graphitization degree of PCs were manipulated by the
thermal recalcitrance of hydrochar. More importantly, results showed
that the released Zn2+ could effectively promote the production
of acetic acid via the oxidation of furfural (FF) and 5-(hydroxymethyl)-furfural
(HMF). Fourier transform ion cyclotron resonance mass spectrometry
(FT-ICR MS) with negative electrospray ionization analysis confirmed
the deoxygenation and depolymerization reactions and the production
of long chain fatty acids during HTL reaction of S. plumbizincicola. This work provides a new path for the recycling of waste hyperaccumulator
biomass into value-added products.