Effect of Water-to-Vacuum Residue Ratio

The iuCTeased H2O/VR ratio increases the amount of water, which reduces the temperature of the gasification reactor. To maintain the temperature at the desired level, an additional combustion is needed through additional supply of oxygen. This additional combustion causes higher consumption of the fuel components of the vacuum residue. Hence, the amount of CO2 is increased by the complete combustion when the H2O/V7 ratio is inCTeased and the rate of the gasification reaction (C + HjO CO + Hj), which is an endothermic reaction, decreases. The reason behind the greater reduction of CO as compared with H2 is attributed to the additional consumption of CO by the water-gas conversion reaction. Theoretically, it is estimated that almost no methane is produced. 

With the increase in the H20/VP ratio, carbon conversion increases and reaches 100% due to the carbon-steam reaction. In the carbon-steam reaction and the conversion of CO, when the amount of water increases, both reactions proceed in such a direction that the amount of Hj is increased. These two reactions occur on the left-hand side of the dotted vertical line, so after all the solid carbon is depleted, only the CO conversion reaction continues. The changes in the synthesis gas composition 

Modeling of Processes and Reactors for Upgrading of Heavy Petroleum 

FIGURE 4.11 Effect of on carbon conversion and synthesis gas composition 

The changes in the H2O/V7 ratio are usually done to limit the temperature of the reaction or to adjnst the H2/CO ratio of the synthesis gas by means of the water-gas reaction. 

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