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Western Refinery Upgrades Its Boiler Feed Water By Andrew R.

Delgado and Gary Davis Amid the scenic beauty of the Southwest just north of Carlsbad Caverns National Monument along the Pecos River lies the Artesia, N.M., petroleum refinery of the Navajo Refining Company, L.P., a subsidiary of Holly Corp. Dallas-based Holly refines crude oil to produce gasoline, diesel and jet fuel, which it sells in the Southwest, northern Mexico and Montana. It also runs refineries in Utah and Montana, but the Artesia operation has over twice the capacity of those combined. Holly also operates a product distribution system that includes 2,000 miles of pipeline. Customers include refiners, whole- salers, marketers and other retailers, as well as the U.S. military. The Artesia facility, located on a 400-acre site in the petroleum-rich Permian Basin, recently completed an $85 mil- lion expansion and upgrade that expanded its processing capability from 60,000 barrels a day to 75,000 barrels a day. In addition, it upgraded the water treatment equip- ment to improve the quality of boiler feed water as well as waste- water from the facility. The refining company has supplemented its existing RO system with multi-media filters and packed bed sof- teners to produce high-quality effluent. This water generates high-pressure steam for the whole refinery as well as the refin- ery'

s new gas/oil hydrotreater. Navajo also recently replaced two in-ground API separators with two aboveground, steel tank API separators, with granular acti- vated carbon (GAC) adsorber systems for off-gas treatment. An added benefit is that the waste- water treatment systems will help Navajo Refining meet two U.S. Environmental Protection Agency regulations under the Clean Air Act: low-sulfur (clean fuels) emissions standards and New Source P e r f o r m a n c e Standards (NSPS) - Subpart QQQ for wastewater treat- ment for petroleum refineries. Clean Fuels Compliance Installing the gas/oil hydrotreater is part of the strat- egy for Navajo'

s Artesia facility to comply with EPA low-sulfur emis- sions standards. Steam used in the hydrotreater is pro- duced by high- quality effluent treated by multi- media filters, an upgraded RO sys- tem and packed bed softeners from USFilter Corp., a Siemens company. Navajo upgraded the water treatment system after determining the existing RO system'

s capacity was inadequate to meet the new water quality and capacity requirements for steam generation. With the newly online multi-media fil- ters, the refinery'

s capacity is now

900 gpm. The filters provide better pretreat- ment to the refinery'

s RO units, tripling or quadrupling the RO pre-filters'

life and eliminating their costly, daily replacement. Better pretreatment also allows the RO units to operate more efficiently and meet higher flow requirements. Moreover, replacing membranes on the RO units with a higher surface-area membrane increased the capacity without adding any additional equipment. Reject water from the RO system, col- lected in a new storage tank, is used as backwash water for the multi-media fil- ters. This helps the refinery conserve water and minimize wastewater handling. And to meet the new boiler'

s hard- ness specifications, USFilter added packed bed softeners behind the RO system, reducing influent with

640 ppm CaCO3 to less than 0.5 ppm. The filters came online in summer 2003. Cleaner Water and Air Since the early 1990s, the EPA also has required petroleum refineries that collect and treat oil to cover a portion of their wastewater treatment processes. The agency amended the list a few years later, adding VOC emission treatment. To fulfill commitments made pur- suant to a federal consent decree to vol- untarily accept the standard applicable to new petroleum refineries (i.e., NSPS Subpart QQQ), Navajo replaced its two in-ground API separators with two aboveground, steel tank API separators from USFilter Envirex Products also in 2003. Previously, Navajo'

s old API sep- arators were not covered because they pre-dated NSPS Subpart QQQ and care was taken not to trigger QQQ through CASE S S T T U U D D Y Y USFilter provided three softeners rated for

300 gpm each for polishing the effluent from the RO system. As part of the refinery'

s boiler feed water system, USFilter provided four multi-media filters to remove suspended solids from groundwater treat- ed at the refinery. Each filter is

84 diameter x

60 side shell, designed for

300 gpm. Reprinted with revisions to format, from the June

2005 edition of INDUSTRIAL WATERWORLD Copyright

2005 by PennWell Corporation subsequent projects. Covering the existing separators (in- ground concrete tanks) would have been difficult and expensive. This, in addition to concerns of potentially leaking in- ground concrete tanks, factored into Navajo'

s decision to install new above-ground API sepa- rators. The new larger capacity API separators also allowed Navajo to remove from service another uncovered sepa- rator upstream of the wastewater treatment facilities. This provided further emissions reduc- tion and operational benefits. The new explosion- proof units provide positive leak detection and vapor contain- ment, more effective sludge and oil removal and easy routine main- tenance, with each sep- arator effectively pro- cessing a maximum hydraulic flow rate of

600 gpm. Also, GAC systems from USFilter Westates Carbon were installed to adsorb VOCs in the off-gas vented from the covered units. Being a Good Neighbor Navajo Refining is building on past efforts by continu- ing to become more environmentally friendly and more resource efficient. In addition to the environmental ben- efits derived from the installation of the new above- ground API separa- tors, the expansion portion of the clean fuels project is help- ing meet the energy needs of Navajo'

s Southwest........