ENV-17-30 Refinery Water Use Study

Description:

JBE performed a comprehensive evaluation of a refinery to identify major contributors to water use, to allocate usage to refinery products, and to identify target areas for usage reductions strategies. Results of the study showed some alignment with results obtained in a detailed study recently performed by Jacobs Consultancy using a linear program to approximate unit yields 1. This review also identified some key issues with the Jacobs study:  The water use to produce steam could be quite a bit larger than a portion of the 20% of cooling water evaporation that was assumed by Jacobs based on our study inventory if condensate is not recovered (thus making the overall predicted water usage low);  Cooling tower blowdown was not included in the Jacobs water use estimate because wastewater was not assumed to be “used” based on their definitions; and this could be at least half 0.5% of the cooling tower water circulation rate;  Jacobs performed a heat balance and arrived at an average annual circulated water evaporation rate of 1.7% but indicated that variations could push this to 2.0%; whereas our calculations for this study estimated 2.6% of circulating water rate;  Allocation of water use to a major unit product (or to all products based on unit yields) could be an over-simplification, whereas a detailed look at equipment services may suggest different product allocations. Regardless of the results obtained, the process developed can be used to develop a better understanding of refinery water uses at a facility with a minimum of effort.