Vacuum distillation is a critical part of the refining process. To produce gas oils of acceptable quality, a delicate balance between the vacuum pressure and the heat of the system needs to be maintained.

A southeast refinery was struggling to get it right. The pressure wasn’t low enough and the chiller wasn’t cool enough. The resulting gas oil was off-spec. To fix the problem, the refinery had resorted to blending fire water with the discharge water from the chiller. As a result, operating costs were mounting.