ISTR Technologies: Feasibility and Limitations, and Overview of SEE
Gorm HeronTerraTherm, Inc.Keene, California, [email protected]
MechanismsTreatment area and volumeThermal technologiesHow to select?
Mechanisms – for VOCs
1 mm
01234567
0 20 40 60 80 100Hen
ry's
law
con
stan
t ( -
)
0.00.20.40.60.81.01.21.41.6
0 20 40 60 80 100
Vapo
r pre
ssur
e (a
tm)
oCoC
TCE
PCE
H2OPCE
TCE
Oils - Viscosity reduction
0
2
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6
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10
12
14
0 20 40 60 80 100 120 140
Temperature (oC)
Vis
cosi
ty (c
St)
0
50
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150
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250
300
350
400
20 60 100 140
Temperature (oC)
Vis
cosi
ty (c
p)
Fuel oil, 14 gravity No. 5 fuel oil
Light ends are removed at 100 oC or higherTypical Soil ChromatogramBefore SEE
Soil Residual ChromatogramAfter SEE
Chromatograms from TPH analysis of soils from Alameda Point, CA (Udell et al. 2000)
Vapor Pressure vs. Temperature
0
100
200
300
400
500
0 50 100 150 200 250 300 350 400 450Temperature (°C)
Vapo
r Pre
ssur
e (m
m H
g)
Vapor pressures increase exponentially with temperature
ERH, SEE, TCH TCH
5
325oC
100oC
70oC
Level 2
Level 3Level 1
Thermally enhanced NAPL recovery
In‐Situ Stabilization/ Solidification
Complete COC removal/destruction
Challenge
• Will make COCs mobile• Steam and COC vapors generated• NAPL may move• Groundwater concentrations may increase• Groundwater permeability increases
• Better treat the right volume• Pneumatic and hydraulic control = capture
Treatment Area and Volume (and goals)
Aerial View of Memphis Site(During Demob)
367 heaters
68 extraction wells
Example: NASA Michoud• Objectives:
– Determine top and bottom of treatment zone– Determine areal extent and shape of treatment zone– Provide a mass estimate for TCE and other CVOCs
Method: MIP with soil and groundwater sampling, variable
Characterization area
Conceptual source area as start
Max ECD response and suggested next pushes
Final MIP results
Original conceptual area
Geological conceptual model
Conceptual model w/MIP profiles
Selection of Treatment Zone
Need quick tools (screening OK) – hundreds of data points
Most widely used:
MIP for screening (LIF if looking for aromatics)GeoProbe w/grab samplesRotosonic drilling w/grab samples
Conceptual model important
Pick TTZ which exceeds the remedial goalsSoil (mg/kg)GW (mg/L)Soil gas (mg/m3)Mass reductionFlux reduction
Thermal Technologies and Providers
ERH/ET‐DSP TRS, CES, McMillan‐McGeeISTD 100 C TerraThermISTD dry and hot TerraTherm, TPSSEE TerraTherm, ERM, others?RF/MW heating Kasevich, ERMSTARS/smoldering SiREMHot water flushing ?Hot air injection ?
Sand
Silt
Silt
GW
19
Example source zone
ISTD/TCH - Heating governed by thermal conductivity (f~3) nearly uniform
ISTD = In Situ Thermal DesorptionTCH = Thermal Conduction Heating
SVE Well
Groundwater Level
Heater Well Source Area
20
TerraTherm ISTD Heaters
Covered by one or more of the following: U.S. Patent Nos. 5,190,405, 5,318,116, 6,485,232 and 6,632,047. International patents (e.g., EPC 1272290).
21
ERH/ET-DSP - Heating governed by electrical conductivity (f~200) may require stacked electrodes
ERH = Electrical Resistance HeatingET-DSP™ = Electro-Thermal Dynamic Stripping Process
Silt
Silt
Sand
MPE WellElectrode Well (shown w/3 electrodes)Groundwater
Level
Source Area
23
ET‐DSP™ Electrodes
(McMillan-McGee Corp.) 24
ET‐DSP™ Wellfield
MPEWell
StackedElectrodes
StackedElectrodes
Power Control Unit forElectrodes
Vapor Manifold
Liquid Manifold
25
SEE - Heating governed by hydraulic conductivity non-uniform steam flow
SEE = Steam Enhanced Extraction
Silt
Silt
Sand
Groundwater Level
MPE Well Source Area
Steam Injection Well
26
Steam Enhanced ExtractionNew tools for environmental application
Pressure cycling
Limitations – low K sites and fractured rock
Combinations with TCH and resistive heating
28
Oil field well patterns5‐spot
7‐spot
Line drive
Alameda Point
Creosote DNAPL to +140 ft depth
Alluvial sands and gravels with clays
Both LNAPL and DNAPL
Approaching MCLs in 2002
160,000 gallons removed from subsurface
Superfund Site delisted
UC Berkeley – LLNL - SCE
Visalia Pole Yard ‐SEE
16°C
26°C
36°C
46°C
56°C
66°C
76°C
86°C
96°C
5 days 12 days 30 days 45 days
0 4 8-14.0
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Depth (m
)
Tempe
rature
0 2 4 6-14.0
-12.0
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-8.0
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0.0
0 2 4 6-14.0
-12.0
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0.0
0 2 4 6-14.0
-12.0
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-8.0
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-4.0
-2.0
0.0
0 2 4 6-14.0
-12.0
-10.0
-8.0
-6.0
-4.0
-2.0
0.0
100 kPa
111 kPa
123 kPa
134 kPa
145 kPa
157 kPa
168 kPa
180 kPa
191 kPa
Length (m)
Depth (m
)
Length (m) Length (m) Length (m)
Pressure
Example steam modeling
Guadalupe project – Diluent and crude oil
SEE: Pressure cycling to optimize vaporization and to achieve
diminishing returns
0
1 0
2 0
3 0
4 0
5 0
6 0
1 0 / 1 1 0 / 1 1 1 0 / 2 1 1 0 / 3 1 1 1 / 1 0 1 1 /2 0 1 1 / 3 0 1 2 / 1 0 1 2 / 2 0 1 2 / 3 0 1 / 9 1 / 1 9 1 /2 9 2 /8 2 /1 8 2 / 2 8
Estim
ated
VO
C ra
te (p
ound
s pe
r hou
r)
0
5 0 0
1 , 0 0 0
1 , 5 0 0
2 , 0 0 0
2 , 5 0 0
3 , 0 0 0
3 , 5 0 0
4 , 0 0 0
4 , 5 0 0
5 , 0 0 0
1 0 / 1 1 0 / 1 1 1 0 / 2 1 1 0 / 3 1 1 1 / 1 0 1 1 / 2 0 1 1 / 3 0 1 2 / 1 0 1 2 / 2 0 1 2 / 3 0 1 / 9 1 / 1 9 1 / 2 9 2 / 8 2 / 1 8 2 / 2 8
Inje
ctio
n ra
te (l
bs/h
r)
Time (4.5 months total)
CVOC removal (lbs/day)
Steam injection rate
(lbs/hr)
Pressurization DepressurizationP
T
P
T
Edwards AFB Site 61Fractured granite(quartz monzonite)
39
ERT data planes
VEA-5
VEA-4
VEA-3 VEA-1
VEA-2
ERT data planes
0 0.5 1 1.5 2 2.5 3
DIstance into matrix (m)
0
0.5
1
1.5
2
2.5
Dis
tanc
e fro
m in
ject
ion
hole
(m)
Temperature distribution after 30 days of steam injection into a 100 um fracture at 50 ft depth, using 0.8 psi/ft
Heat conduction into matrix from a steam‐filled fracture
(simulated using a modified Marx‐Langenheim solution; TomHeron et al. 1999)
Q = K x dT/dx
dT/dx = 60 K/m
WHY?
RF Heating• Preferentially heat polar molecules• Limited full-scale applications• Cost?• Limited to small sites?• Gentle heating (40-50°C) to
enhance hydrolysis, biodegradation, and ISCO?
Figures courtesy of JR Technologies, LLC42
Gas Thermal Remediation (GTR©)
• New TCH/ISTD kid on the block• Limited in-situ applications • Limited application in US• Permitting concerns
– Air discharge– City building/fire
• Hundreds of gas connections and fittings
• Natural gas availability• Advantage? Fuel cost?
Figures courtesy of TPS Tech America, Inc. 43
ComparisonTCH/ISTD ‐ Heating governed by thermal conductivity
ET‐DSP/ERH ‐ Heating governed by electrical conductivity
(max temp = boiling point)
SEE ‐ Heating governed by hydraulic conductivity
(max temp = boiling point)
How to Select Heating Method?
Are the COCs volatile?
Is there a high-flow aquifer?
ISTD, ERH or ET-DSPTM
(100oC)
ISTD 100oC
ISTD >100oC
SEE combined with ISTD, ERH or ET-DSPTM (100oC)
Is there a thick clay layer?SEE
Simplified decision tree for identifying applicable thermal technologies for a site
No
No
No
No
Yes
Yes
Yes
No
Yes
YesStringent COC soil treatment criteria?
Start
Is bedrock present in the treatment zone?
Primary Factors Affecting Selection of Treatment Technology/Approach
- BP/VP of COCs- Cleanup Criteria - GW flux- Bedrock- Stratigraphy
45
Fill
Sand/silt
Clay
Gravel/weathered rock aquifer (v>1 ft/d)
Fractured bedrock
Example source area DNAPL and VOC distribution
Fill
Sand/silt
Clay
Fractured crystalline bedrock
TCH/ERH/ET‐DSP
SEE/TCH/ERH/ET‐DSP
SEE
TCH, ET‐DSP?
Applicable technologies in each zone
Gravel/weathered rock aquifer (v>1 ft/d)
TCH CVOC BTEXChloro-
benzenes Gasoline DieselOils > 50
cpCreosote, 10-100 cp
MGP coal tar,
viscous
Sand, vadose EffectiveSand, saturatedSilt, vadose Promising/site specificSilt, saturatedClay, vadose Problematic/unprovenClay, saturatedCrystalline rock Will not be effectiveCemented sedimentary rockOrganic rock
ERH/ET-DSP CVOC BTEXChloro-
benzenes Gasoline DieselOils > 50
cpCreosote, 10-100 cp
MGP coal tar,
viscous
Sand, vadose EffectiveSand, saturatedSilt, vadose Promising/site specificSilt, saturatedClay, vadose Problematic/unprovenClay, saturatedCrystalline rock Will not be effectiveCemented sedimentary rockOrganic rock
SEE CVOC BTEXChloro-
benzenes Gasoline DieselOils > 50
cpCreosote, 10-100 cp
MGP coal tar,
viscous
Sand, vadose EffectiveSand, saturatedSilt, vadose Promising/site specificSilt, saturatedClay, vadose Problematic/unprovenClay, saturatedCrystalline rock Will not be effectiveCemented sedimentary rockOrganic rock
TCH+SEE CVOC BTEXChloro-
benzenes Gasoline DieselOils > 50
cpCreosote, 10-100 cp
MGP coal tar,
viscous
Sand, vadose EffectiveSand, saturatedSilt, vadose Promising/site specificSilt, saturatedClay, vadose Problematic/unprovenClay, saturatedCrystalline rock Will not be effectiveCemented sedimentary rockOrganic rock
Extraction
Top soil/clay
Permeable zone
Clay
Power
Vapor cap
Steam Power Power Steam
TCHTCH
SteamSteam
ISTD+SEE or ET-DSP+SEE in Complex Stratigraphy
49
Knullen site, Denmark
Cla
yey
till
Fill
Sand
/gra
vel
BuildingDepth bgs
0 m / 0 ft1 m / 3 ft
11 m / 36 ft
14 m / 46 ft
Vertical temperature profiles
Jord & Grundvand
0,00
2,00
4,00
6,00
8,00
10,00
12,00
14,00
16,00
0,0 20,0 40,0 60,0 80,0 100,0 120,0
Temperatur (C)
Dyb
de (m
)
01-07-2008 03-07-2008 07-07-2008 10-07-2008 17-07-2008 24-07-2008 31-07-2008 08-08-200814-08-2008 25-08-2008
Clay till
Aquifer
Jord & Grundvand
0,00
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6,00
8,00
10,00
12,00
14,00
16,00
0,0 20,0 40,0 60,0 80,0 100,0 120,0
Temperatur (C)
Dyb
de (m
)
01-07-2008 03-07-2008 07-07-2008 10-07-2008 17-07-2008 24-07-2008 31-07-2008 08-08-200814-08-2008 25-08-2008
Clay till
Aquifer
Temperature (C)
Dep
th (m
)
52
0
25
50
Depth (ft)
TCH heater boring
Steam injection well
Multiphase extraction well
Horizontal vapor extraction well
Surface cover
Confidential site, Florida
How to choose?
1. Conceptual site model crucial
2. Let the site conditions dictate
3. Request feasibility screening info from expertsWill it work?
Preliminary design
Cost estimates
4. Move to RFP or final proposal stage for viable alternatives
SEE
ERH/ET‐DSP
ISTD
Performance monitoring during thermal
1. Operate equipment per specs (performance based; energy in, rates out, compliance)
2. Hydraulic and pneumatic control3. Subsurface temperatures4. Mass removal5. Soil concentrations6. Groundwater concentrations
Operational range Other
ISTD system 1000‐1500 kW Safety checks OK
Vapor treatment system
1250 scfm vapor750 non‐condensable
Comply with air discharge std
Liquid treatment system
30 gpm water1 gpm NAPL
Comply with water discharge std
Monitoring system 95% up‐time on sensors
Data web‐site current
Hydraulic control
0 20 40 60 80 100 120 140 1600
20
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160
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0 20 40 60 80 100 120 140 160
EE‐2
EE‐3
EE‐1
EE‐5
EE‐4
EE‐6
EE‐7
EE‐8
EE‐9
EE‐10
EE‐11
EE‐12EE‐13
EE‐14
EE‐15
EE‐16
EE‐17
EE‐18EE‐19
EE‐20
EE‐21
EE‐22
EE‐23
EE‐24
EE‐25
EE‐26
EE‐27
EE‐28
05600561
0563
056205640565
05660567
Hydraulic control
Pneumatic control
Subsurface temperatures
Mass Removal During Treatment
0.0
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6.0
8.0
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18.0
0 15 30 45 60 75 90 105 120 135 150
Days after Initial Startup (Jan 29, 2007)
Rem
oval
Rat
e (lb
s/hr
)
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
Tota
l Rem
oved
(Ton
s)
Removal Rate Total Removed
~12,000 lbs ofTCE
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
18.0
0 15 30 45 60 75 90 105 120 135 150
Days after Initial Startup (Jan 29, 2007)
Rem
oval
Rat
e (lb
s/hr
)
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
Tota
l Rem
oved
(Ton
s)
Removal Rate Total Removed
~12,000 lbs ofTCE
30 4515 60 75 90 105 120 135 1500
62
Soil sampling
ISTD Results: CVOCs (100°C)
Site Volume (yd3)
Major Contam-
inant
Concentration (mg/kg)
Pre-Treatment
Remedial Goal
Mean Post-
Treatment
Portland, IN 5,000 PCE 3,500 8.0 0.53
Midwest #1 7,882 TCE 4,130 1.0 0.07
Midwest #2 1,730 TCE 20.7 1.0 0.48
Midwest #3 1,338 TCE 12.6 1.0 0.10
Richmond, CA 7,000 PCE 34.2 2.0 0.012
Carson, CA 6,700 1,2-DCA 902[1.0]
(pilot)0.23
SC 8,230 TCE 10,000 0.06 0.01
64
0
1
2
3
4
5
6
7
8
0 1 10 100 1,000 10,000 100,000 1,000,000 10,000,000
Soil Concentration - g/kg
Dep
th B
elow
Gro
und
Surf
ace
- m
Pretreatment - PCEPost Treatment - PCE
Bottom of Treatment Zone
Bottom of Heated Zone
Point Richmond TCH Site, CASoil PCE Concentration (g/kg)
Treatment Objective: 2,000 ug/kg 65
Groundwater samplingExample: Young‐Rainey STAR Area A (SEE‐ETDSP combo)
NAPL Remediation GoalsGroundwater MCLS:
Date Apr 16-17 May 13-14 July 23-24 Apr 16-17 May 13-14 July 23-24 Apr 16-17 May 13-14 July 23-24 Apr 16-17 May 13-14 July 23-24 Apr 16-17 May 13-14 July 23-24
PIN15-CS-01 ND 3.3 76 ND 0.40 JB ND ND ND 0.20 J ND 0.58 J 12 ND ND NDPIN15-CS-02 ND 0.74 J 52 ND 0.49 JB ND 0.24 J 0.38 J ND ND 0.13 J 8.0 ND 320 NDPIN15-CS-03 ND ND 16 ND 1.2 JB 11 1.3 ND ND ND ND 1.2 340 510 2000PIN15-CS-04 0.3 J 0.45 J 0.18 J ND 1.3 JB ND 4.1 2.5 ND ND ND ND 120 J 970 910PIN15-CS-05 23 9.9 8.6 13 3.8 JB ND 1.5 0.83 J ND 0.63 J 0.35 J ND 3,200 6,800 1300PIN15-CS-06 0.5 J 36 27 4.2 J 150 B 12 0.59 J ND ND ND 2.7 3.6 120 J 140 J NDPIN15-CS-07 ND .22 J 0.83 J 0.48 J 1.2 JB ND 1.4 7.0 6.8 ND ND ND 1,000 6,700 9500PIN15-CS-08 2.4 1.8 2.1 ND 1.8 JB ND 17 8.3 7.6 ND 2.0 0.44 J 210 J 580 1700PIN15-CS-09 ND ND ND 0.52 J 1.4 JB ND 1.4 1.8 ND ND ND ND 400 740 260 JPIN15-CS-10 ND ND 0.65 J 0.82 J ND 0.62 J 1.4 1.2 1.7 ND ND ND 180 J 340 1200PIN15-CS-11 ND ND ND ND ND ND 0.49 J 1.5 1.1 ND ND ND 110 J 270 J 140 JPIN15-CS-12 0.43 J 0.45 J 0.24 J 0.74 J 1.1 JB 0.51 J 4.5 2.5 3.2 0.28 J 0.42 J ND 490 980 1300PIN15-CS-13 ND ND ND 0.62 J 1.7 JB 0.30 J 1.3 0.85 J 0.58 J ND ND ND 240 J 580 NDPIN15-CS-14 ND 0.30 J 0.16 J 0.78 J 1.7 JB ND 1 ND 0.75 J ND 0.11 J ND 120 J 400 NDPIN15-CS-15 ND ND ND 0.68 J ND ND 4.7 ND 1.1 ND ND ND 1,000 2,400 2600PIN15-CS-16 1.3 1.2 7.5 0.8 J 0.75 JB ND 4.5 38 23 ND 29 6.8 ND 190 J 110 J
(µg/L)
50,0005,000*
Samples Inside Remediation Area A
(µg/L)cis-1,2-Dichlorethene
70
Methylene Chloride(µg/L)
20,0005
Toluene TCE
50,000 5,500 11,0001,000 3
(µg/L) (µg/L)Florida Petroleum Range
Location TCEToluene
MeCl2Cis‐1,2‐DCE FL‐PRO
Conclusions
Conceptual model crucialTreat right volumePick heating method to matchCapture mobilized COCsData quality/metrics