"A two-staged fluidized-bed reactor for the energy-efficient, thermal recovery of bitumen from Utah tar sands has been constructed. This reactor is a scaled-up version of an earlier system investigated at the University of Utah, and involves the use of three liquid-potassium heat pipes which thermally couple an upper pyrolysis is bed with a lower combustion bed. The reactor has been studied to determine the effect of multiple heat pipes, increased feed rate, and longer duration run times. The process consists essentially of three steps. In the first step, mined and suitably sized tar sand, being fed into the reactor at a constant rate, is pyrolyzed at temperatures of 440'C to above 500'C in an inert atmosphere to volatilize and partially crack most of the contained bitumen. The vaporized products of the pyrolysis section are condensed and coalesced to give a synthetic crude oil. In the second step, coked sand, formed as a by-product in the pyrolysis reactor, is combusted with air at temperatures between 550 and 600·C. In the third step, heat is recovered from the hot spent sand leaving the combustion bed by a fluidized-bed heat exchanger using vertical copper cooling tubes. Three heat pipes are used to transfer 100% of the energy required to maintain the required temperature of pyrolysis in the upper bed. This energy is provided by the lower, combustion bed. Air is used to fluidize the combustion bed and the heat recovery bed. The pyrolysis bed is fluidized with nitrogen. In a commercial unit, recycled gas from pyrolysis could be used in place of nitrogen to fluidize the pyrolysis bed. The process is equipped with a digital control and data acquisition system to permit a more efficient method of process study. The current reactor is capable of processing over 30 lbs of tar sand per hour, and has successfully operated on a continual basis for over 6 hours. Over 30 runs, with tar sand from the Sunnyside, PR Springs, and Whiterocks deposits, have been made to study controllability of the process , heat requirements , and liquid product yield with respect to process variables such as pyrolysis-bed temperature and average solids residence times. The highest liquid yield obtained was 71 weight percent of the original tar sand bitumen. Typically, coke yield is from 15 to 20 weight percent, with gas yield making up the difference."