Raising environmental and safety standards, Agar technologies continue to receive industry recognition for their commitment to the advancement of systems which minimize water pollution and accidental hydrocarbon discharge. Additional industries utilizing Agar solutions include: chemical, environmental, and the pharmaceutical industry.
Averaged total hydorcarbon releases to refinery sewers range from 0.5% to 4.0% of the total crude charge. Unfortunately, refiners are losing valuable feedstocks to the sewer and must spend nearly $10/bbl to recover and reprocess lost hydrocarbons.
The desalting system is the largest contributor to wastewater; improving operating methods on this unit can reduce shutdowns and maintenance expenses. Equally important, better operating practices can decrease organic loading on the wastewater treating unit. Several case histories illustrate various source reduction methods to minimize hyrdocarbon emulsion losses to sewer.
Due to a mature and more competitive marketplace, operating companies are re-evaluating fundamental manufacturing strategies. Consequently, the incentive to apply new technologies and improve operations is more compelling than ever before. New measurement technologies, such as energy absorption, have steadily entered the marketplace to meet this need.
Source reduction is an area where innovative technology is being evaluated and used by many major oil and petrochemical companies. The most effective way of reducing the hydrocarbon content in the final effluent is to avoid contaminant losses at their source. Energy absorption (EA) technology has proven to be a useful tool when controlling the amount of hydrocarbons sent to wastewater treatment plants (WWTPs). EA can be applied for monitoring and controlling many separation processes. Additionally, these new control systems help to relieve the pressure from tighter environmental restrictions by reducing the quantity of hydrocarbons released to wastewater pretreatment systems.
Field applications have verified that EA technology enables operators to meet operational goals cost-effectively. Many operating companies worldwide are documenting significant savings through equipment availability, minimized wastewater treatment, lower recovery/reprocessing costs, while still achieving compliance with environmental legislation (such as the U.S. Benzene NESHAPS).
The traditional approach to minimize wastewater contamination does not focus on solving the problem at the source. Instead, wastewater streams are combined into a system, which is then processed through slop tanks, CPI’s, API’s, hydrocyclones, air flotation units and/or benzene strippers. Although, these processes eventually remove hydrocarbons from the wastewater to required levels, treatment costs can be particularly high.
These costs include: specialty chemicals needed to break emulsions at the WWTP and the expense to reprocess recovered hydrocarbons. Many refiners operating their crude units near maximum capacities will suffer significant lost opportunity costs as fresh crude feed is displaced to process recovered oil. This can further exacerbate already poor industry margins.
Typical costs have been documented in an independent study by Wright Killen/Ernst & Young. The consultants surveyed a representative portion of U.S. Gulf Coast refining industry to determine typical industry oily-water treating requirments, crude and product losses, and associated costs.
Study data show that total hydrocarbon releases to plant sewers from all refinery sources normally ranged from 0.5% to 4.0% of total crude charge. Additionally, for an average U.S. Gulf Coast refinery, total costs for recovering and reprocessing these releases is $9.64/bbl. Therefore, if the refinery throughput is 100,000 bpd and it is releasing 1% of this to the sewers, the recovery and reprocessing costs to the refinery are approximately $10,000/day.
Instead of treating the wastewater after it has been contaminated, it is more efficient to identify the stream and use more sophisticated control to prevent contamination at the source. In a typical crude oil refinery, contamination contributors to wastewater (expressed as a percentage of total oil requiring recovery) can be quantified: