OPPORTUNITY TO INCREASE THE SHARE OF UNCONVERTED VACUUM TOWER BOTTOM FROM RESIDUE HYDROCRACKING (H-OIL) IN PAVING GRADE BITUMEN PRODUCTION

摘要

The restrictive factor for maximisation of Unconverted vacuum tower bottom (UVTB) from ebullated bed hydrocracking process - H-Oil technology in bitumen production is its low resistance to hardening, determined by using a Rolling thin film oven (RTFO). The limitation in LUKOIL Neftohim Burgas (LNB) industrial production is up to 37% UVTB in blends with air blown straight run vacuum residue (SRVR). The intention to increase UVTB content in bitumen blend passes through a dedicated evaluation of available approaches for their effectiveness and contribution for redirecting hydrocracking residue from low cost, hard to produce, high sulphur fuel oil to more valuable bitumen production. Several chemical components are tested and neither Heavy vacuum gas oil (HVGO) from hydrocracking of vacuum residue, nor slurry oil from Fluid catalytic cracking (FCC), nor asphaltene fraction from solvent deasphalting, nor antioxidant can inhibit softening point (SP) measured by the ring and ball (R&B) method increase due to resistance to hardening at 163°C test. A slightly positive result is assigned to SRVR addition but even that it can not lower the SP increase of UVTB to bellow specification required value of 9°C. Two substances reveal significant reduction in UVTB SP increase: 8% atactic polypropylene (aPP) is capable to obtain 5.4°C and elemental sulphur - 6°C with only 0.23% additionally bonded sulphur.