Synthesis of New Hydrazone Compounds from Natural Grease and Investigation as Flow Improver for Crude Oil

n this work, salicylaldehyde hydrazone (SAH), different from the traditional polymers, was synthesized from natural oils (castor, SAСH, rapeseed, SARH and soybean, SASH), hydrazine hydrate and salicylaldehyde. Firstly, natural grease reacts with hydrazine hydrate to produce hydrazide, and then salicylaldehyde reacts with hydrazide to synthesis salicylaldehyde hydrazone. In this work, SAH were evaluated as viscosity-reducers and pour point depressors for crude oil. The results show that the SAH can significantly reduce the pour point and viscosity of crude oil, with the increase of crude oil fluidity, the viscosity reduction rate of сrude oil from Jinghe Oilfield (QHO) reaches to 80.1% (40°С), the pour point decreases by 12.1°С, the viscosity reduction rate of сrude oil from Xinjiang Oilfield (STO) reaches to 87.5% (15°С), and the pour point decreases by 6.2°С. Based on the efficiency of different SAH, structure-function relationship was discussed. The mechanism of SAH effecting on crude oil is that the long alkyl chain is conducive to inhibiting the growth of crystals when eutectic with wax nuclei in heavy oil, and plays the role of pour point and viscosity reduction.