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In these hard economic times, peo-ple working in troubled businessesmay well envy the situation of Al-bertas oil sands industry. The Ca-

nadian Association of Petroleum Pro-ducers (CAPP, Calgary, Alberta; www.capp.ca) predicts that the productionof synthetic crude from oil sands willreach 3.3-million bbl/d by 2020, upfrom 1.2-million bbl/d in 2007. Much

of this oil will be sent to the U.S. via anexpanding network of pipelines (CE,May 2008, p. 22).

As it happens, though, the industryhas been impacted by the current busi-ness recession causing a number of com-panies to delay their expansion plans.For example, Suncor Energy (Calgary;www.suncor.com) announced a $20.6billion* expansion program a year ago,with the goal of expanding productionfrom 350,000 bbl/d to 550,000 bbl/d by2012. More recently, the completion

date has been pushed back to 2013 andthe company has scaled back its capitalspending plans for 2009 by more thanone-third. Similarly, Fort Hills EnergyL.P., a new venture, has deferred afinal investment decision on miningoperations and delayed indefinitely adecision to build an upgrader (delayedcoker). Petro-Canada (Calgary; www.petro-canada.ca), the majority partnerin Fort Hills, has reduced its capitaland exploration expenditures to about$4 billion this year, down from about $6billion in 2008. Petro-Canadas invest-

ment in oil sands in 2009 is expectedto be about $985 million, down fromabout $1.4 billion in 2008.

Albertas recoverable reserves ofoil sands total about 175-billion bbl,says Greg Stringham, CAPPs vice-president for oil sands and markets.Currently, about half the production isdone by surface-mining the sand and

its associated bitumen, then separatingand upgrading the bitumen to obtain asynthetic crude (syncrude) for refining.However, only about 20% of the re-serves are amenable to surface mining,so the trend is toward increased use ofin situ processing to exploit deposits200 ft or more below the surface.

Process technologyThe main drivers for technology in-novations in oil sands production area desire to reduce costs and environ-mental impacts. Operating costs varywidely, but are currently in the rangeof US$3035/bbl, says Stringham.

Syncrude Canada Ltd. (Fort McMur-ray, Alta; www.syncrude.ca) reportedoperating costs, including purchasedenergy costs, of $24.64/bbl for 2007,down from $26.46/bbl in 2006.

In a surface-mining operation, oilsand is scooped up by huge shov-els, trucked to a crusher, then slur-ried with warm water and piped to

an extraction plant. There, hot water(4050C) is added, air and processaids are injected into the stream, andthe mixture is fed to a conical primaryseparation vessel. Sand settles to thebottom of the vessel and the overflowis a froth that contains about 60% bi-tumen, 30% water and 10% clay.

Naphtha is typically mixed with thefroth to lower the viscosity of the bi-tumen, making it easier to separate itfrom the water and clay by centrifug-ing or settling. Finally, the bitumenand naphtha are separated by distil-lation. The naphtha is recycled andthe bitumen, whose specific gravity is

CHEMICAL ENGINEERING WWW.CHE.COM FEBRUARY 2009 19

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OIL FROM

SAND

*All dollars are Canadian (CAN$1 = US$0.82,January 13)

The oil sands industry

is growing fast,

and so is its impact

on the environment

This portablecrusher works

at the mineface

Suncor

Thousands

ofbarrels

perday

6,000

5,000

Forecast

June '08 moderategrowth forecast

Oil sands production2007 = 1.2 million bbl/d2013 = 2.0 million bbl/d2018 = 3.0 million bbl/d

2020 = 3.3 million bbl/d4,000

3,000

2,000

1,000

0

2002 2004 2006 2008 2010 2012 2014 2016 2018 2020

Convetional oil

Oil sands in productionand under construction

Oil sandsfuture potential

Actual

FIGURE 1. Despite its rapid growth, Western Canadas production of bitumen fromoil sands will actually dip below last Junes moderate growth(MG) forecast over thecoming years. Conventional oil production will decline

CAPP

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about 10 API, is upgraded by delayed-or fluid-coking to obtain a syntheticcrude of 2530 API for refining.

The downside of these operations is

that they use large volumes of waterand have created huge tailings pondsthat contain toxic residues. Air pollu-tion is also a concern, and emissions ofcarbon dioxide are a major issue (seesidebar). In their defense, spokesper-sons for industry point out that theyrecycle at least 90% of the water theyuse, with zero discharge, and the netwater use averages roughly 4 barrelsper barrel of produced oil.

The popular process for in situmin-ing is steam-assisted gravity drainage

(SAGD). A horizontal well is drilledinto the oil formation, and a second,producer well is drilled parallel to itat a lower level. Steam is injected intothe upper well to liberate the bitu-men, which is pumped out from theproducer well.

Benefits of in situmining are thatthe produced bitumen is clean, thereare no tailings, and water use is muchlower than those of operations basedon surface mining. Petro-Canada saysits net water use for SAGD (including

90% water recycling) is about 1/3 bar-rel of water per barrel of product.

On the other hand, energy use ishigh and there are air emissions fromthe steam boilers. Several new tech-nologies are being developed and im-plemented to alleviate these problemsand to cut costs (see below).

Companies whose operations startwith mining are striving to improve ef-ficiency throughout the process train.

At the beginning of the train, Suncorhas been using a mobile crusher at the

mine face for more than a year. Builtto Suncors specifications by MMD(Summercotes, England), the trackedunit can process 5,000 metric tonsper hour (m.t./h) and is linked to amobile slurry unit, thus reducing thecost of truck haulage and reducingair emissions. Suncor expects to havetwo more mobile crushers operatingwithin three years.

Syncrude has designed a compactslurrying unit for use with a mobilecrusher at the mine face and field-tested a 4,000-m.t./h prototype, whichis about half the size of a commer-cial unit. The company is now doing

engineering design for a commercialsystem, says Alan Fair, manager ofresearch and development. The equip-ment will be moved every few weeksby commercially available crawlertransports. Fair notes that haulagetrucks cost about $5 million each, soits a costly way to move ore.

An improved froth treatment pro-cess, for separating bitumen from thefroth after primary separation, has

been developed by Shell Canada Ltd.(Calgary; www.shell.com). Naphtha isnormally mixed with the froth to lowerthe viscosity of the bitumen and easethe separation, as noted earlier. Shell,in contrast, has for several years usedparaffinic technology developed incooperation with Natural ResourcesCanadas CanmetEnergy (Devon,

Alta.; www.nrcan.gc.ca).Shell has now developed an im-

proved paraffinic process, called ShellEnhance, and plans to start up a com-

mercial plant at its Muskeg River Minein 20102011. The new process oper-ates at above 60C, versus 2535Cfor the earlier process. The advantagesof paraffin over naphtha, according toShell, are that the bitumen producthas a lower solids and water contentand there is partial deasphalting of thebitumen. Shell Enhance is an improve-ment over the earlier process in that itimproves energy efficiency by 10%, uses10% less water and requires less space.

CokingIn contrast with the situation in a con-

ventional petroleum refinery, coking is

an important unit operation in oil sandsprocessing. Most petroleum refinersuse the coker as a garbage can to pro-cess the bottoms and heavy oil, but inour case most of our feed goes througha coker, says Alan Fair, manager of re-search and development for Syncrude.The company has three fluidized-bedcokers two older ones with name-plate capacities of 107,000 bbl/d anda 95,000-bbl/d unit that started up in

2006. These are the largest fluid cok-ers in the world, says Fair.

Syncrude has installed baffles inthe reactor product-recovery sectionof one of the cokers to improve prod-uct fractionation. The company plansto make similar modifications to theother cokers during future scheduledshutdowns. The cost is about $1 mil-lion for each project, but Syncrudesays the potential savings could reach$9 million/yr through longer runtimes and improved product quality.

The baffle was developed by the com-panys R&D department, with helpfrom ExxonMobil (Fairfax, Va.; www.exxonmobil.com), licensor of the fluidcoking technology.

Syncrude is also investing $1.6 bil-lion to retrofit lime spray dryers onthe two older cokers for sulfur emis-sions control. Scheduled for startup in2010 or 2011, the project is expectedto reduce emissions from the twounits by about 60%, reducing the totalsulfur emissions at the site to lessthan 100 m.t./d.

The newer coker uses an aque-ous ammonia scrubbing process from

OIL SANDS AND THE ENVIRONMENT

Toward mid-year, Alberta Energy (Edmonton, Alta.; www.gov.ab.ca) the provincial gov-ernments energy department, will award three to five contracts for pilot projects forcarbon capture and storage (CCS). Total funding is $2 billion (Canadian) and the goalis to capture 5 m.t./yr of CO2and develop a pipeline network to transport the gas foruse in enhanced oil recovery (EOR) or injection deep underground.

The CO2initiative is welcomed by Stephen Kaufman, chairman of ICO2N (Calgary),a group of some 20 industrial companies that studies CCS. In a recent report ICO2Noutlined a scheme for a CCS system to reduce CO2emissions by 20 million m.t./yr, atan estimated cost of more than $100/ton.

Last year was the first full year of an Alberta regulation that requires companiesemitting more than 100,000 m.t./yr of CO2to reduce their emissions by 12%. Thosethat dont meet their targets may buy offsets or pay $15 for each ton over the limit. The

Alberta government was the first in North America to issue such a regulation.Environmentalists complain that the regulation is based on intensity (for example, per

barrel or kWh), rather than placing a cap on plant emissions. The oil sands industryproduces about 4% of Canadas greenhouse gas emissions and this is set to triple to 12%by 2020, says Simon Dyer, director for oil sands with the Pembina Institute (Calgary;Pembina.org), a sustainable energy think tank. He adds that the regulation does notencourage polluters to use CCS. Paying $15 a ton, when CCS may cost around $100/ton, is a perverse incentive not to use CCS, he says.

Dyer notes that current oil sands operations cover about 600 km2of land in north-eastern Alberta and have the highest environmental impact of any oil production in the

world. As for land reclamation, he says that so far virtually no land has been certified as

reclaimed, nor any tailings ponds, which comprise about 130 km2

of toxic liquids.

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Marsulex Inc. (Toronto; www.mar-sulex.com). The NH3 reacts with SO2to form an ammonium-sulfite slurry,then air is bubbled through the slurry

to obtain ammonium sulfate, which issold to the fertilizer industry.

Syncrude chose this process becauseammonia is generated as a byproductin the hydrotreating plant, says PaulIbbotson, a process engineer. However,trace compounds in the gas caused anodor, so the company has been buyingNH3until it finds a way to deal withthe offending compounds.

Suncor will install three trains ofpaired delayed cokers for its planned200,000-bbl/d expansion. The project,

dubbed Voyageur, will process bitumenfrom a combination of surface- and insitu-mined sources (Figure 2). Thecompany has been using some SAGDfor about five years, says a companyspokesman, but in the next 57 yearswe expect it to account for about 50%of our bitumen recovery.

Tailings treatmentSurface-mining operations producetailings that are a mixture of water,clay, sand, residual bitumen and

naphthenic acids. The problem is thatthe clay stays suspended, settling to amaximum of only 3040% solids con-tent after 35 yr, says Randy Mikula,team leader for the extraction andtailings group with Canmet.

Indeed, Suncor is only now reclaim-ing its first tailings pond after decadesof operation. Suncor pioneered the useof consolidated tailings technology, de-

veloped in association with Canmet,in which tailings are consolidated bychemical treatment. In Suncors case,

gypsum (from SO2scrubbing) is addedto the tailings to accelerate the releaseof water. Suncors Pond 1 is now beinginfilled with sand, after which thecompany will contour the surface andplant vegetation.

A process in which CO2 is injectedinto the tailings pipeline is being com-mercialized by Canadian Natural Re-sources Ltd. (CNRL, Calgary; www.cnrl.com). CNRL developed the processin collaboration with Canmet. The in-

jected CO2

forms carbonic acid, whichchanges the pH and coagulates theclay, thereby increasing the settlingrate of the tailings, says Theo Paradis,

lead operations engineer. CNRL isusing the process to treat the tailingsfrom its new 110,000-bbl/d oil sands

plant, now starting up. Paradis expectsit will permit settlement of the tailingswithin weeks, rather than years.

An improved process will be used inthe projects second stage, when theplant will increase oil production to232,000 bbl/d. The tailings volume willbe reduced by thickeners and cyclones.Warm water will be recycled to the pro-cess from the thickener, and waste heatfrom the coker will be used to heat theprocess water, eliminating the use ofnatural gas. About 26 m.t./h of CO2will

be obtained from the onsite H2plant.The deposited tailings may be traffica-ble almost immediately, says Paradis.

In another process, developed by Syn-crude in collaboration with Canmet,organic polymers are added to tailings,which are then centrifuged to separatethe clay from the water. Syncrude hastested the process at a scale of 20 m.t./hand increased the solids content of thetailings from 1720% to 5560%. Theseparated water was returned to thebitumen-extraction process.

As an alternative to consolidatingtailings, Syncrude has piloted a watercapping method, in which lakes havebeen built in former mines, with softtailings forming sedimentary bottoms.Syncrude says its research indicatesthat the lakes will, over time, supportplant and wildlife.

In situprocessesThe conventional in situmining pro-cess is SAGD, as noted earlier, but thismethod uses large volumes of naturalgas to raise steam, and there are airemissions from the steam boilers. Anumber of companies are working on

new technologies that reduce or avoidthese problems.

Petrobank Energy and Resources

Ltd. (Calgary; www.petrobank.com) ispiloting a process called THAI (Toe-to-Heel Air Injection). A horizontal pro-ducer well with a slotted liner is drilledat the base of the oil sands formation,which may be 2030 m thick, then a

vertical injector well is drilled to theend (toe) of the producer well. Steamis injected for 2-3 months to raise thereservoir temperature to about 100C.Finally, air is injected at 450550 psi,initiating a combustion front thatmoves along the axis of the producer

well, causing oil to flow into the well.The oil just rises to the surface by

gas lift, without pumping, says BarryNoble, a management adviser withPetrobank. Asphaltenes remain in thesand to provide fuel, he says, so theproduced bitumen has an API gravityin the middle teens, versus eight forraw bitumen. Compared with SAGD,there are substantial savings in capi-tal costs and water and energy, headds, because steam is used only at thebeginning of the cycle. Petrobank has

piloted the process and plans to build a10,000-bbl/d demonstration plant.

Shell is developing anIn situUpgrad-ing Process (IUP) in which the oil isheated by electrical resistance heatersthat are inserted in wells. The heat up-grades the bitumen into a lighter crudeand gas that can be recovered, leavingcoke in the ground. Shell has been field-testing IUP for several years, using 18heaters and three producer wells. Sofar, more than 100,000 bbl of light oilhas been produced at the site, but Shellsays further work is necessary beforethe process can be commercialized.

Gerald Parkinson

Suncor

FIGURE 2.The drawing showsthe layout of Suncor'splanned expansion