Improved water management in a petroleum refinery can potentially reduce the volume and cost of raw water used in refinery operations, as well as resulting in reduced wastewater flow and/or contaminant load, in turn reducing operating and maintenance costs for wastewater treatment,.
With critical shortages of fresh water in most areas of the world, (and in particular the Gulf), and a requirement for relatively high volumes of raw water in a refinery, the pressure to recycle and/or reuse water is increasing. In evaluating recycle/reuse issues in a refinery, potential uses of water should be evaluated along with recycle/reuse of refinery wastewater as well as external sources of wastewater (such as treated wastewater from municipal treatment plants) and the opportunities and risks of water exchange.
This paper will identify key areas in a refinery where water can be reused or substituted, where water minimization practices can be employed, and where opportunities for implementation of internal and external water exchange practices exist.
The paper will catalogue the technologies applicable to water upgrading for large volume uses (e.g. Boiler/Utility feedwater) and the techniques for matching effluent from one source to input water for another use on the facility.
Finally the paper will look ahead to the "holy grail" of Zero Liquid Discharge (ZLD) from a refinery and discuss the techniques employed, as well as look at the trade-off between reducing effluent discharges and increased energy use and emissions.
When compared to other industries, refineries are relatively large user of raw water. In many regions of the world there is a shortage of water and frequently refineries are restricted on the quantity of raw water that can be imported from outside sources. As a consequence many refineries are considering water recycle and reuse while taking into account local site conditions. This paper takes a holistic view of the water use in refineries and presents the options available for both in-process reuse as well as reuse of treated wastewater.