Abstract: The development and application of environment-friendly LPG deep desulfurization（LDS）technology were introduced. Through Higee process intensification，the oxidation reaction of mercaptan sodium to disulfide and the separation process of disulfide from caustic were coupled into one step，while both high oxidation conversion rate as above 95% and high separation ratio as above 98% were achieved. Results of commercial application in a 0.3 Mt/a LPG sweetening unit in Company A of PetroChina showed that FCC LPG after amine washing with 80 μg/g of mercaptan was taken as the feed, low sulfur content of LPG product with less than 10 μg/g is gained，while the amount of fresh caustic is reduced by more than 90% compared with the Merox process and nearly zero spent caustic is discharged. The economic benefit of the whole factory increases by nearly ￥ 11 million yuan /a

Key words: LPG, sweetening, spent caustic, Higee