Upgrading of flash pyrolysis tars to synthetic crude oil: 2. Second-stage hydrotreatment using nickel/molybdenum catalysts

Abstract Flash pyrolysis tar, produced from Millmerran coal and pretreated over a packed-bed of steelwool to reduce coking propensity, was hydrotreated in a trickle-bed reactor containing conventional nickel/molybdenum catalyst. The effect of reaction temperature on reactor performance and on the yield and nature of the products was investigated within the range 367–420°C. Increasing temperature resulted in substantial reductions in heteroatom content and coking propensity of the product oil and increased yields of