Partial oxidation Soot recycle

Partial oxidation of heavy Hquid hydrocarbons requires somewhat simpler environmental controls. The principal source of particulates is carbon, or soot, formed by the high temperature of the oxidation step. The soot is scmbbed from the raw synthesis gas and either recycled back to the gasifier, or recovered as soHd peUetized fuel. Sulfur and condensate treatment is similar in principle to that required for coal gasification, although the amounts of potential poUutants generated are usually less. 

The soot formed as a byproduct in the partial oxidation process has to be scrubbed out with water and recycled in a fairly complex process. 

If the partial oxidation unit is integrated in a coal gasification complex - as suggested in Chap. 7 - and the liquid products of coal gasification are used as a feedstock, the ash content of this feedstock will be extremely low and gasification can be performed in such a way that even less than 0.5 wt % of soot occur in the reformed gas. In this case, the expenditure for a carbon recycling system can be saved as the small carbon quantities can be more easily and with less expenditure be removed in the waste water treatment system of the complex. 

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