Thermochemical Behavior of Tris(2-Butoxyethyl) Phosphate (TBEP) during Co-pyrolysis with Biomass

Abstract

Co-pyrolysis of plastic waste and wood biomass to recover valuable chemicals is a cost-effective waste-recycling technology. However, widely used organophosphate ester additives in plastic, such as tris(2-butoxyethyl) phosphate (TBEP), can form diverse phosphorus (P)-containing species. These P-containing compounds can pose new environmental challenges when the biochar is reused. In this study, a mixture of TBEP and lignin was used to simulate the feedstock of plastic waste and wood biomass, and the thermochemical behavior of TBEP in slow pyrolysis (20 K min(-1)) and fast pyrolysis at 400-600 °C was investigated. The results show that low temperature in fast pyrolysis favors the enrichment of P in char. Up to 76.6% of initial P in the feedstock is retained in the char resulting from 400 °C, while only 51% is retained in the char from 600 °C. Slow pyrolysis favors the formation of stable P species regardless of the temperature; only 7% of the P retained in the char is extractable from char from slow pyrolysis, while 20-40% of P can be extracted from char resulting from fast pyrolysis. The addition of CaCl2 and MgCl2 can significantly increase the fraction of P retained in the char by the formation of Ca, Mg-P compounds. Online TG-FTIR-MS analysis suggests that TBEP undergoes decomposition through different temperature-dependent pathways. The P-containing radicals react with the aromatic rings produced by the pyrolysis of lignin to form Ar-P species, which is an important factor influencing the distribution and stabilization of P in char.

Phosphorus-Assisted Biomass Thermal Conversion: Reducing Carbon Loss and Improving Biochar Stability

“…5 ). Qian et al (2014) pointed out that the P-containing radicals react with the aromatic rings produced by the pyrolysis of lignin to form P-containing species, which is an important factor influencing the distribution and stabilization of P in char [36] . Uchimiya and Hiradate (2014) indicated that orthophosphate such as CH 3 −O−PO 3 2− and phenyl−O−PO 3 2− formed in pyrolysis were stable [37] .…”

Lifestyle chemistries from phones for individual profiling

“…5C and Dataset S1). A flame retardant [tris(2-butoxyethyl) phosphate] usually used in plasticizers (61) and textiles was also detected on individual 21 ( Fig. 5C and Dataset S1).…”

Transformation of phosphorus in sewage sludge biochar mediated by a phosphate-solubilizing microorganism

“…As the short chain metaphosphates with poor crystal structure were more vulnerable than the long chain metaphosphates with stable structure in the solution [26,31], more P could be released from B400 than B700. The cleavage of the organic matter in the sludge could lead to the formation of C-O-P [32,33]. At 400 o C, the main carbon evolution was the decomposition/evaporation of labile organic matter [34,35].…”