The RHT technology and the second generation RHT catalysts were applied in design of an 1.7Mt/a VRDS unit at the SINOPEC Changling Branch Co. The commercial application result demonstrated that the RHT catalysts showed good activity and stability in processing low-sulfur and high-nitrogen residue. The ifrst long period run of unit for processing high Fe and high Ca content residue was achieved. The reasons for excessive pressure drop of R-101 were ascribed to Fe and Ca deposition as well as coke formation.