Abstract: The solubility of the active matter in MPTR demetallization agent for crude oil in DMF solvent and mixed solvent of DMF and TB at low temperature was investigated. The applicability of demetallization agent solutions with different composition at low temperature was discussed. Experimental results illustrate that the active matter in MPTR can well dissolve in DMF solvent when the MPTR/ DMF mass ratios are 1.05：0.95, 1.06：0.94, 1.07：0.93, and 1.08：0.92 at low temperature. In the dosage range of 120-180 μg/g of MPTR, single solvent TB cannot improve demetallization rate. Among the concentrations of the active matter in the range of 50-54% in solutions without TB, the performance of demetallization agent solutions with 53.5% of active matter is the best, the calcium removal rate reaches the maximum value of 55.8%.

Key words: demetallization agent, crude oil, solvent, low temperature solubility, demetallization performance