"Selected processes potentially applicable to primary conversion of Utah tar sand bitumen were examined. Effect of variables on product yields and structure were determined for visbreaking, coking, catalytic cracking and hydropyrolysis. Results are interpreted in terms of efficiency of conversion and utilization of available hydrogen. Hydropyrolysis produces the highest yields of liquid and gaseous products and the highest conversion of >538°C material to distillable liquids of the various processes studied. Catalytic cracking produces higher quality products than coking at similar yields and conversion. This probably results from the beneficial effect of the catalyst on cracking selectivity. Coking produces high yields of heavy products at low pressures and lower yields of higher quality products at higher pressures. The improvement in products with increased pressure does not appear to justify the loss in yields experienced. The potential of virgin bitumen for production of paving asphalt was examined and the bitumen possesses highly attractive technical and economic features for this use. The various processing and utilization options will be amenable to preliminary economic evaluation as related to developing recovery technology. This study forms a basis for further work on the quantitative correlation of structure with heavy ends and resid thermal and catalytic processing."