MONO-METHYL PARAFFIN ADSORPTIVE SEPARATION PROCESS

摘要

A process for the recovery and purification of mono-methyl branched C_(10) - C_(15) paraffins from kerosene or n-paraffin depleted kerosene through an adsorptive separation has been developed. Two complimentary adsorptive separation-operating modes were demonstrated for efficient mono-methyl paraffin production. The first method uses simulated moving-bed adsorptive separation with a silicalite adsorbent and a mixture of C_5 and/or C_6 n-paraffin and iso and/or cyclo-paraffin as the desorbent. The second method, which provides enhanced mono-methyl paraffin recovery, uses the pre-pulse technique in combination with the first operating method. Pulse tests (chromatographic separation) with both techniques showed good performance in the laboratory. Both methods were demonstrated successfully in a continuous counter-current chromatographic separation pilot plant using commercial n-paraffin depleted kerosene feedstock. Better than 90% normal and mono-methyl paraffin purity with greater than 70% recovery of normal and mono-methyl paraffins was achieved from the pilot plant. Detailed information on the process development including feed composition, desorbent composition, temperature, diffusion rates, and model simulations will be discussed.