Upgrading technology, hydrogen

Process schemes and auxiliary operations as already done, the coupling of several complementary processes or steps will remain essential, and the overall economics may thereby be greatly improved. Preliminary treatments such as filtration and desalting should also be improved due to their growing importance, especially if fixed bed systems are used. The availability of cheaper hydrogen is also a key factor in the overall cost of all upgrading technologies. 

Upgrading technologies from syngas to hydrogen, biofuels, and high-value chemicals... 

Figures 2.8 and 2.9 illustrate some of the process schemes of technologies based on carbon rejection and hydrogen addition that can be combined. Figure 2.10 shows other possible combinations between the different upgrading technologies.

To improve selectivity and conservation of hydrogen over present liquefaction technology in the conversion of coal to high quality liquids, we believe that thermal reactions should be kept as short as possible. Catalytic processes must be used for upgrading but should be used in a temperature regime which is optimal for such catalysts. 

In the cracker, heavy oil cracking and the steam-iron reaction take place simultaneously under conditions similar to thermal cracking. Any unconverted feedstock is recycled to the cracker from the bottom of the scrubber. The scrubber effluent is separated into hydrogen gas, liquefied petroleum gas (LPG), and liquid products that can be upgraded by conventional technologies to priority products. 

Technologies for upgrading heavy crude oils such as heavy oil, bitumen, and residua can be broadly divided into carbon rejection and hydrogen addition processes (Chapter 8). Briefly, carbon rejection processes are those processes in which a carbonaceous by-product (coke) is produced along with distillable liquid products. On the other hand, hydrogen addition processes involve reaction of the feedstock with an external source of hydrogen and result in an overall increase in H/C ratio of the products as well as a decrease in the amount of coke produced. 

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