The invention discloses a waste
mineral oil multistage
coupling heat exchange and gradient
cooling energy-saving cooperative treatment method, which belongs to the technical field of
heat energy engineering and
energy conservation, and comprises the steps of pretreatment refining,
fractionation cutting, molecular
distillation, hydrofining, gradient cooling and
intelligent control. By constructing a multi-stage
coupling heat
exchange network, hydrofining high-temperature
waste heat is used for preheating
fractionation feed, and fractionating
tower top steam
waste heat is used for preheating molecular
distillation feed; cooling the high-temperature
material flow according to the temperature by stages through a three-stage gradient cooling
system, and recycling the low-temperature cold energy of the molecular
distillation unit for a pretreatment process; and dynamically optimizing heat exchange and cooling operation based on an
energy balance model through the central
control system. According to the method, the technical problems of energy utilization splitting and serious
waste heat waste in a waste
mineral oil regeneration process are solved, the yield and the quality of a
base oil product are greatly improved while the
system energy consumption and the cooling
water consumption are remarkably reduced, and an innovative solution is provided for efficient regeneration of the waste
mineral oil.