Castor oil and its three derivatives including methyl ricinoleate, sodium ricinoleate and ricinoleic acid were used as the raw material for alkali fusion to prepare sebacic acid. The reaction parameters including catalyst, ratio of oleochemicals/NaOH, reaction time and reaction temperature were optimized. It was found that Pb3O4 (1%) showed the best catalytic performance, and 553 K was considered as the most suitable reaction temperature. The oleochemicals/NaOH ratios of 15:14, 15:14, 15:12 and 15:14 were determined as the optimal ratio for alkali fusion of castor oil, methyl ricinoleate, sodium ricinoleate and ricinoleic acid, respectively. In addition, the optimal reaction time of alkali fusion of castor oil was 5 hours, and that of its derivatives was 3 hours. The maximum yield in sebacic acid of 68.8%, 77.7%, 80.1%, 78.6% can be obtained by using castor oil, methyl ricinoleate, sodium ricinoleate and ricinoleic acid as the raw material, respectively. High purity of sebacic acid was confirmed by GC and melting point analysis. ICP‐OES results illustrated that the content of Pb in sebcic acid was less than 1 mg kg−1. Separating glycerol from castor oil was beneficial for alkali fusion, by which, the yield of sebacic acid was increased of approximately 10%, and the reaction time was reduced from 5 to 3 hours. This study provided guiding significance for the future industrial production of sebacic acid.

A green and environmentally friendly route of no thinning agent was designed to prepare sebacic acid. Sodium ricinoleate was selected as the raw material to carry out solid-phase cleavage in a tubular furnace. The reaction parameters including catalyst, ratio of sodium ricinoleate/KOH, reaction time, reaction temperature, and absolute pressure were optimized to obtain a high yield of sebacic acid. A satisfactory yield (70.2%) of sebacic acid was received in the presence of 1% catalyst (Fe 2 O 3 ) by weight (w/w), with 5:4 (w/w) ratio of sodium ricinoleate/KOH at 543 K under the absolute pressure of 0.09 MPa in 60 min. Sebacic acid was identified by gas chromatography analysis, and the purity (98.1%) of the product was further assessed by its melting point (306.3 K). Alkaline enhancement generates a better cracking effect. The yield of sebacic acid can be improved by a certain absolute pressure as a result of avoiding oxidation of sodium ricinoleate as well as reducing the residence time of hydrogen.

Polyamine chelating adsorbents have a good removal effect on dye wastewater. In this study, small molecule triethylenetetramine and macromolecular poly(ethylene imine) were selected as aminated reagent, and two kinds of aminated chitosan microspheres, TETA-CTSms and PEI-CTSms, were obtained by emulsion cross-linking method. The microspheres were fully characterized by FTIR, SEM, XRD, EDS and TGA. EDS results showed that the N content of the PEI-CTSms and TETA-CTSms microspheres increased significantly after the cross-linking reaction and can reach 5.7 wt% and 7.3 wt%, respectively. Adsorption experiments confirmed that TETA-CTSms and PEI-CTSms showed greater adsorption characteristics for anionic dye reactive yellow (RY) in aqueous solutions compared with CTSms, and the adsorption capacity per unit area was increased by 39.11% and 88.56%, respectively. The adsorption capacity of aminated microspheres for RY decreased with the increase of pH. The adsorption kinetics conformed to the pseudo-second-order model, and the adsorption process was in accordance with the Langmuir isotherm model. The negative value of Δ G confirmed that the adsorption process was spontaneous, and the dye adsorption was a multiple process dominated by chemical chelating and physical adsorption.

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