Apparatus and process for preparing polyalpha-olefins

A process for preparing polyalpha-olefin synthetic base oils in a reaction apparatus comprising a mixing unit, a microchannel reaction unit comprising a plurality of microchannel reactors, a high-pressure separation unit, a low-pressure separation unit, a post-treatment unit, and a gas circulation unit that are fluidly connected, comprising:

• S1:
• forming a mixed stream comprising an olefin raw material and an auxiliary feed in the mixing unit;
• S2:
• mixing the mixed stream and a BF3 gas in a plurality of mixing channels in a mixing zone of each microchannel reactor to form a reactant mixture, wherein a number of the plurality of mixing channels is 2-10;
• S3:
• introducing the reactant mixture into a reaction zone of each microchannel reactor, wherein the olefine raw material undergoes polymerization in a plurality of reaction channels in the reaction zone of each microchannel reactor to form an intermediate stream, wherein a number of the plurality of the reaction channels ranges from 2 to 500;
• S4:
• feeding the intermediate stream into the high-pressure separation unit, in which the intermediate stream undergoes a first gas-liquid separation to form a first liquid phase and a first gas phase;
• S5:
• feeding the first liquid phase into a low-pressure separation unit, in which the first liquid phase undergoes a second gas-liquid separation to form a second liquid phase and a second gas phase;
• S6:
• feeding the second liquid phase into a post-treatment unit for a post-treatment to obtain a polyolefin product;
• and
• S7:
• feeding the first and the second gas phases comprising BF3 into a gas circulation unit to be recycled, wherein a recycled BF3 is a portion of the BF3 being fed into the microchannel reactor,
• wherein the post-treatment is one or more selected from adsorption, extraction, distillation, centrifugation, sedimentation, alkaline washing, and water washing, and
• wherein, in S2, each of the plurality of mixing channels has an inlet adapted to receive the mixed stream and an outlet fluidly connected to the reaction zone, wherein the BF3 gas is introduced into the plurality of mixing channels in each microchannel reactor through a fluid distribution pipe having a plurality of branch pipes, each branch pipe has one or more fluid distributors and extends into one of the plurality of mixing channels through the inlet thereof so that the BF3 gas is introduced into the mixed stream inside each mixing channel through the one or more fluid distributors.