Thermal instability of hydrorefined

Thermal Instability of Hydrorefined Products. Thermal instability of hydrorefined product from the reconstituted feed was observed for both Ni-W and Ni-Mo. Comparing the conversion of heptane insolubles for undistilled and distilled materials showed evidence of considerable polymerization for the distilled material. Heptane insolubles conversion for undistilled product from Ni-W was higher than for distilled product as seen in Figure 14. Distilling the product from the 725°F balance reduced the heptane-insoluble conversion from 30% to 16%. For Ni-Mo the reduction for the heptane insolubles was on the same order of magnitude, approximately a 10% decrease in the heptane-insolubles conversion. 

The thermal instability of hydrorefined SRC creates another parameter which requires careful consideration. If, for example, topping operations reverse some of the depolymerization occurring in the SRC process, this equates to a hydrogen penalty. Additional work needs to be done to characterize the asphaltenes generated thermally vs. the starting asphaltenes from coal. 

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