Jing Yang,Liang Zhao,Shaotong Liu,Yuanyuan Wang,Liyi Dai
Catalytic hydrocracking of kraft lignin was carried out in isopropanol system and an orthogonal array design (OAD) was employed to optimize the experimental conditions. GC–MS/FID, elemental analysis, GPC and 1 H- 13 C HSQC NMR were carried out for entire investigation of the liquid products. The results indicated that the hydrocracking process was thermally controlled and catalysts showed significant influences on the product distributions. Comparing with Pd/C, Pt/C and Ru/C, Rh/C inhibited the self-condensation of isopropanol and reduced the formation of oxygenic-chain compounds. The excellent catalytic activity for phenols conversion was obtained over Rh/C. The routes of oxygenic-chain compounds formation and phenol conversion were proposed in detail. The least oxygenic-chain compounds formation, the highest phenols conversion (93.4%), the lowest O/C ratio (0.094) and the highest HHV (37.969 MJ/kg) provided the possibility of the high quality bio-oil obtained over Rh/C in isopropanol medium.
The industrial utilisation of Fischer–Tropsch synthesis (FTS) products, particularly the valuable C5–C9 linear α-olefins, has been hindered by the high energy-intensive separation of olefins and alkanes with identical carbon numbers. This study presents a comprehensive process integrating the selective dimerisation of linear α-olefins to α-olefin dimers, enabling their separation from paraffins in FTS products. These dimers are subsequently converted into branched-chain aldehyde intermediates through heterogeneous hydroformylation using Rh/C as the catalyst. Notably, optimising the reaction conditions achieved the main product aldehyde of α-olefin dimers with excellent selectivity (up to 86.66 %) at 65 °C, compared to linear α-olefins, which exhibited only 49.31 % selectivity. In-situ IR spectroscopy was used to monitor the entire reaction process. The resulting branched aldehyde intermediates were further transformed into branched acids or branched alcohols through oxidation or reduction reactions, respectively. These products have diverse applications as surfactants, coal flotation agents, and cutting fluid additives. The synthesised compounds were characterised using FT-IR, GC, GC–MS, and NMR. In addition, a comprehensive evaluation of their physicochemical properties was conducted. This study provides a versatile design strategy for developing high-value intermediates from α-olefins in the FTS.
危险品化学品经营许可证（带存储）