The present invention is directed to the upgrading of heavy petroleum oils
of high viscosity and low API gravity that are typically not suitable for
pipelining without the use of diluents. It utilizes a short
residence-time pyrolytic reactor operating under conditions that result
in a rapid pyrolytic distillation with coke formation. Both physical and
chemical changes taking place lead to an overall molecular weight
reduction in the liquid product and rejection of certain components with
the byproduct coke. The liquid product is upgraded primarily because of
its substantially reduced viscosity, increased API gravity, and the
content of middle and light distillate fractions. While maximizing the
overall liquid yield, the improvements in viscosity and API gravity can
render the liquid product suitable for pipelining without the use of
diluents. This invention particularly relates to reducing sulfur
emissions during the combustion of byproduct coke (or coke and gas) and
to reducing the total acid number (TAN) of the liquid product. The method
comprises introducing a particulate heat carrier into an up-flow reactor,
introducing the feedstock at a location above the entry of the
particulate heat carrier, allowing the heavy hydrocarbon feedstock to
interact with the heat carrier for a short time, separating the vapors of
the product stream from the particulate heat carrier and liquid and
byproduct solid matter, regenerating the particulate heat carrier in the
presence of the calcium compound, and collecting a gaseous and liquid
product from the product stream.