Optimization of Water Optimization of Water Usage At Petroleum

RefineriesRefineries

Water/Energy Sustainability ForumGround Water Protection Council

Salt Lake City, UtahS t b 15 2009September 15, 2009

AgendaAgenda

• Overview water usage in petroleumOverview water usage in petroleum refineries.

• Discuss drivers for water conservation• Discuss drivers for water conservation.• Review opportunities to reduce water

ticonsumption:– Matching supply quality to the demand need.– Utilization of municipal wastewater.– Zero discharge concepts.

Water Use in Petroleum Refineries

• Adding heat to the processes (steam)Adding heat to the processes (steam).• Removing heat from the process (cooling

water)water).• Removing salt and impurities from crude.• Protecting equipment from corrosion.• Generation of hydrogen (used to remove y g (

sulfur from motor fuels).• Equipment cleaning and maintenanceEquipment cleaning and maintenance.

Water Usage in the Petroleum Refining IndustryRefining Industry

70

40

50

60

20

30

0

10

1 2 3 4 5 6 7 8 9 10 11 12 13

Best in Class(10-20 gal/bbl)

Worst in Class(50-60 gal/bbl)

Water usage varies greatly from facility to facility.

Gallons/bbl Doesn’t Tell the Story…Gallons/bbl Doesn t Tell the Story…• Raw water quality varies:

Target ion concentrations– Target ion concentrations.– Hardness.

• Refinery configuration• Refinery configuration– Water usage very linked to energy efficiency

of the facility.of the facility.• Crude slate

– Poor quality “price advantaged” crude oilPoor quality price advantaged crude oil requires more water.

Some refineries have much greater challenges than others in theirSome refineries have much greater challenges than others in their efforts to control water usage.

Primary UsesPrimary UsesUtility Water Potable Water

5% <1%

Steam42%

Cooling Water53%

The Water Used Is:The Water Used Is:Contained in

Sludges5%

Consumed5%

Vented as Steam

5%Evaporated equates to energy lost

Evaporated38%

11%

Discharged41%

Cost DriversCost Drivers9

7

8

4

5

6

$/10

00 G

al.

2

3

$$$

0

1

S.W. LA Industrial W t

Typical Industrial W ll W t

Midwest Public W t

EBMUD Los Angeles Area ( t)

Los Angeles Area ( j t d)Water Well Water Water (current) (projected)

Other DriversOther Drivers

• Some refineries have had to cut rates dueSome refineries have had to cut rates due to limited water supply.

Direct costs of water may be low– Direct costs of water may be low.– Cost of lost production is very high.

Water Conservation O i iOpportunities

• Matching Water Quality with ProcessMatching Water Quality with Process Requirements.

• Treated Municipal Wastewater Reuse• Treated Municipal Wastewater Reuse Projects.“Z Di h ” C t• “Zero Discharge” Concepts.

Match Water Quality with P R iProcess Requirements

• Many facilities utilize water from more thanMany facilities utilize water from more than one source.

• All facilities generate reusable wastewater• All facilities generate reusable wastewater streams.B tt lit t h ld b• Better quality water sources should be supplied to processes that can benefit f thfrom them.

Cooling Tower ExampleCooling Tower Example

Cooling TowersCooling TowersEvaporation

Raw Water

Process Heat Exchangers

T

Blowdown to Remove Calcium, Magnesium, Silica, etc.

ConsiderationsConsiderations• Cooling towers must be “blown down” to prevent

bl i f i h i h hproblem ions from concentrating to the point that they form scale when heated in process exchangers.

• Depending on water quality, cooling tower blowdown ranges from 10 to 30% of the raw water make up rate.

• Water sources with lower problem ion concentrations result in reduced blowdown rates, resulting in water gsavings.

• Water with higher problem ion concentrations can still be used in processes where the water will not be pheated .

Alternate Sources of Cooling Tower Make-up

• Reverse osmosis unit reject (from boilerReverse osmosis unit reject (from boiler water treatment).

• Cold steam condensate• Cold steam condensate.• Excess boiler feedwater.• Alternate water supplies.

Cooling Tower ExampleCooling Tower Example2500

Savings--638

1500

2000

M

Y-4801

Y-6

Y-5

gpm

500

1000

GPM Y-4

Y-3

Y-2

Y-1

0Current Make-up Rate Sabine River Water as Make-upWater Source #2Water Source #1

By switching to a readily available water source with lower silica concentrations (5 ppm vs. 50 ppm), water demand was reduced by over 600600 gpm.

Reuse of Treated Municipal EfflEffluent

• In some areas, municipal effluent is being p gprovided to industry as a substitute for fresh water.

• California’s East Bay Municipal Utility District has successfully implemented oneDistrict has successfully implemented one project, and is planning others.

• Los Angeles and Anglian Water (U K ) are• Los Angeles and Anglian Water (U.K.) are also planning projects.

Typical Reuse ProcessTypical Reuse ProcessPublic System Industry

Publically Owned Hi h Q lit

S

Wastewater Treatment

System

Reverse Osmosis System

High Quality Water Supply

ZeoliteSoftening

Reject to Disposal or Discharge

BenefitsBenefits

• Proven technologiesProven technologies.• Recovers up to 70% of municipal

wastewaterwastewater.• Provides a very high quality water

l t lsupply—supports low usage.

ConcernsConcerns

• So far economically feasible only withSo far, economically feasible only with subsidies (California and the U.K.).

• Produces waste stream with high• Produces waste stream with high dissolved solids—disposal issues.

Zero Discharge Conceptsg p• The “zero discharge” concept has been

around for many yearsaround for many years.• Serious planning to achieve zero

di h i j t t ti t t kdischarge is just now starting to take place.

• Existing infrastructure, coupled with new technologies can bring facilities close to the zero discharge goal.

Zero Discharge ChallengesZero Discharge Challenges

• Salts and impurities must be removedSalts and impurities must be removed from the system.

• Make up is still required to replace large• Make up is still required to replace large evaporation rates.

Zero Discharge ProcessZero Discharge Process

Evaporation

SummarySummary• Petroleum refining is a water intensive

industry.• Increasing water costs, availability, and g , y,

conservation initiatives are driving the need to re-evaluate usage and supply g pp yalternatives.

• Improved water use strategies, oldImproved water use strategies, old technologies, and newer technologies are providing opportunities.providing opportunities.