Abstract: PEG-Na reagents were prepared by polyethylene glycol (PEG) with different molecular weights and NaOH. Chitosan-PEG (Na) desulfurization materials (CS-PEG (Na)) were prepared by PEG-400Na reagent and chitosan. The test sample with dibenzyl disulfide (DBDS) in the fresh transformer oil was prepared. The effect of CS-PEG (Na) on desulfurization of the corrosive sulfur in the test oil was investigated to obtain the best reaction conditions: the mass fraction of CS-PEG (Na) of 20%, the treatment temperature of 60℃, and the treatment time of 2 h. Under the optimal conditions, the corrosive sulfur in the test oil was almost completely removed by CS-PEG (Na). The desulfurization effect of CS-PEG (Na) for waste transformer oil was comparable to that of PEG-400Na reagent, but better than other desulfurizers, the removal rate of corrosive sulfur reached 84.6%. However, the electrical performance of waste transformer oil after desulfurization treatment decreased slightly.

Key words: transformer oil, chitosan, polyethylene glycol, desulfurization rate