Black Liquor Gasification Design Project GP Wauna Gasifier Design Justin Aldrich, Adam Cooper, Khoa Hua, Jim Jollimore Mill Integration Sean Noste, Steve Ross, John Salvatier, Peter Siedenburg, Nilar Thein-chen Environmental Cody Hargrove, Sonha Pham, Claire Schairbaum, Larissa Zuk Economics Darrow Conley, Ryan McMahon, Vinh Nguyen, Suzy Quach
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Black Liquor Gasification Design Project GP Wauna Gasifier Design Justin Aldrich, Adam Cooper, Khoa Hua, Jim Jollimore Mill Integration Sean Noste, Steve.
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Black Liquor Gasification Design Project
GP Wauna
Gasifier DesignJustin Aldrich, Adam Cooper, Khoa Hua, Jim Jollimore
Mill IntegrationSean Noste, Steve Ross, John Salvatier, Peter Siedenburg, Nilar Thein-chen
EconomicsDarrow Conley, Ryan McMahon, Vinh Nguyen, Suzy Quach
Rick
Slides were generally very good. Not too wordy, most were readable.
Agenda
Gasifier Design
Mill Integration
Environmental
Economics
Rick
For final report you will need introduction to the problem and a brief discussion about the approach. Similar to what was written in the final report.You will also want to present your overall conclusions right up front so we can know what is coming.
the organization needs to be changed. there should 1st be a review of both technologies then a comparison (pros and cons) of each. then you can discuss the gas clean up as they will be similar for both.
High Temperature Gasification
Syngas Properties:Heating Value
Sulfur
Low Temp Gasifier
High Temp Gasifier
Natural Gas
Higher Heating Value (MJ/kg)
20.95 9.32 42.5
Low Temp Gasifier
High Temp Gasifier
H2S in Syngas
(%mol)2.250 1.737
H2S in Syngas values from Larson 2003.
Gasifier values from Larson 2003. Natural gas value from Wikipedia.
High Temperature Gasification
Effect on Causticization Load
ReliabilityWeyerhauser, New Bern, Chemrec Booster 1996.
Low Temp Gasifier
High Temp Gasifier
High Temp Booster
Sulfur (%) ~90% ~50% ~15%
Low Temperature: Pros
Low TemperatureBetter return on energy
Ease of getting chemicals backH2S is in a gaseous form
Proven system that is currently runningNorampac Trenton Ontario
Use heat to produce needed steam and electricity
Rick
We aren't using the syngas for steam or electricity.
Rick
Its not really easier than the high temperature.
Low Temperature: Con
Need additional equipment to recover Chemicals Air scrubbers to recover SO2
Higher initial cost than High Temp ~32% higher initial startup
cost
Rick
Is this unique to the low temperature.
Trim Cooler
Raw Syngas, 40°C
2 Stage Gas
Cooler orHeat
Exchanger
O2 Plant
High Temp
Gasifier1000°C35 bar
165 TPD
GL CondHX
SelexolAbsorber
40 °C~30 bar
SelexolStripper40 °C
~30 bar
To Lime Kiln
BL Solids @ 67% Solids
Air, 20°C
Vent
Cooled Green Liquor132°C
Cooling Water
200°C35 bar
Raw Syngas
Raw Syngas, 122°C
Clean Syngas
40°C~30 Bar
LP Steam
WL Scrubber
H2S and CO2
High Sulfidity White Liquor
95% O2, 20°C
LP Steam?
Cooling Water?
White Liquor
Rick
this is a great figure but you need to use darker lines.
Raw Syngas, 40°C
Raw Syngas, 600°C
Trim Cooler
SelexolAbsorber
40 °C~25 bar
SelexolStripper40 °C
~25 bar
Clean Syngas
40°C
LP Steam
WL Scrubber
H2S and CO2
High Sulfidity White LiquorOr Green Liquor
White Liquor
Low Temp
Gasifier650°C1.2 bar
165 TPD
Low Pressure
Superheater
BL Solids @ 67% Solids
Mix Tank & Filter
Na2CO3
Dregs
Clean Syngas
PC Heater Flue Gas
HX
Steam
Superheated Steam
Heat Exchanger
Cooling Water
LP Steam or Warm Water
Compressor
Claus PlantConverts H2S gas into elemental sulfur
Has two parts: thermal stage and catalytic stages
Operates at moderate temperatures (340° C to 200° C)
Uses Titanium Dioxide or Alumina as a catalyst94 to 97% efficiency depending on the number
of catalytic stages
2H2S + O2 → S2 +2H2O
Rick
Did we decide to use this despite the fact we can't produce enough sulfur to make polysulfide??
Liquor Scrubbing
Product gas stream contains CO2 and H2SScrubbing CO2 generates Na2CO3 which increase the
lime kiln load
Use the NaOH in the liquor to regain the pulping chemical Na2S
A lot of contaminant removal is required to recover the pulping chemicals from the gas
Rick
Should have intro slide for each group. bullet points on what you are to discuss.
Air Emissions: High Temp vs. Low Temp
3.439 tpd (averaged from over a year)
2.507 tpd (averaged from over a year)
0.017 tpd (averaged from over a year)
Emissions (Low T) Emissions (High T)
0.014 tpd (averaged from over a year)
0.074 tpd (averaged from over a year)
3.014 tpd (averaged from over a year)
2.807 tpd (averaged from over a year)
0.275 tpd (averaged from over a year)
0.238 tpd (averaged from over a year)
Pollutant/Parameter
1.402 tpd (averaged from over a year)
1.272 tpd (averaged from over a year)
0.088 tpd (averaged from over a year)
SO2
TRS
PM
NOX
VOC
CO
Figure 1. Emissions estimated for low temperature and high temperature gasifiers. The values were calculated using a 353 day operating schedule per year. Source: Larson, E.D., & Consonni, S., & Katofsky, R.E. (2003). A Cost-Benefit Assessment of Biomass Gasification
Power Generation in the Pulp and Paper Industry.
Air Emissions: Mill Limits
Figure 2. These are emission standards for the Georgia-Pacific mill in Wauna. Source: Oregon Department of Environmental Quality. (2005). Oregon Title V Operating Permit (Permit Number 04-0004). Portland, OR.
0.218 tpd (averaged from over a year)
NOX
VOC
CO
4.266 tpd (averaged from over a year)
5.147 tpd (averaged from over a year)
2.317 tpd (averaged from over a year)
6.133 tpd (averaged from over a year)
13.78 tpd (averaged from over a year)
Pollutant/ParameterTRS
Limit
PM
SO2
Rick
Now that you have some data from the milll on the magnitude of the emissions you can assess whether the gasification will help or hurt the mill. This will be a critical part of the final reprot.
Water Emissions & Usage Two water issues associated with the addition of gasifier:
Water Usage Thermal Pollution
Secondary treatment facility has a maximum capacity of 42 million gal/day.
In 2007, GP Wauna averaged 27.3 million gal/day. There is no way the gasifier will cause the mill to
increase its water consumption by 15 million gal/day.
Thermal Pollution
Maximum allowable discharge temperature from secondary treatment plant is 20 °C.
In 2007, GP Wauna’s secondary treatment was fed waste water at a temperature of 29.3 °C.
The addition of 7.2 million gpd at 40 °C from the gasifier could potentially raise the temperature of the discharge waste water stream by 2 °C.
Syngas ExposureCarbon Monoxide – PEL 50 ppm
EXTREMELY toxicFlammable
Hydrogen – No PELNot toxic; excessive exposure may lead to
asphyxiationEXTREMELY flammable
Carbon Dioxide – PEL 5,000 ppmToxic
Syngas StorageStore in well ventilated areas.Store where temperature is less than 50 °CRemove sparking and ignition hazardsStainless steel is satisfactory
• Risk of embrittlement with hydrogen• Syngas is not pure hydrogen, so
embrittlement risk is minimal
Rick
This should be syngas handling materials as we won't be stroring the syngas.
Natural Gas Usage
Natural gas
(Therms/year)Total CO2 Emissions
(metric tons/year)
Lim Kiln 4,029,600 3,641
PM 1,2 1,825,000 1,649
PM 5 4,197,500 3,792
PM 6 8,030,000 7,255
PM 7 9,125,000 8,244
Bed Boiler 1,314,000 1,187
LVHC 36,500 33
Total 28,557,600 25,802
Raw Syngas Component
Component Volume %
CO 13.1
H2 13.7
CH4 0.75
H2O 63.7
CO2 7.6
H2S 0.67
COS 0.03
N2 0.14
Ar 0.37
Raw Syngas Produced
BL enter Gasifer
(dry lbs/hour)Raw Syngas
(kg/year)Raw Syngas
(Therms/year)Natural Gas Needed
(Therms/year)
High Temp 13800 84,738,715 7,485,923 21,071,677
Low Temp 13800 110,549,826 21,952,785 6,604,815
Rick
You need to revisit this calculation. It should be based on the clean syngas. Much of the raw syngas is H2S which we will remove.
Natural Gas only 28,557,600 70,890,042 40,508,596 25,801,653 25,802
Total 25,802
Social ImpactBenefit
Improve the economics Greenhouse gases reduction
Lower net emission of CO2
Possible downsideWater thermal discharge
Economics: Agenda Major Equipment Summary of Calculation Capital Cost Analysis Cost Reduction Conclusions
Major Equipment and Components
Gasifier Air Separation Unit Sulfur Recovery Unit (SRU)
Selexol/RectisolGreen Liquor Scrubber
Gas Cooler (Heat Exchangers)
Summary of Calculation
Capital cost adapted from Eric Larson’s A Cost-Benefit Assessment of
Biomass Gasification Power Generation in the Pulp and Paper Industry
Adjustment made with High Temp
2002$ inflated to 2008$
Scaled to Wauna specifications using 6-tenths factor
2576.8 tons BL/day 165.6 tons BL/day
Lang factor used to estimate indirect costs from direct costs
Capital Cost AnalysisCost From Larson Article $ Million $ MillionDirect Cost Low Temp High TempGasifier Island and Green Liquor Filter 9.680 11.607Air Separation Unit 7.935Process gas handling 6.997Gas clean up and sulfur recovery 9.713 3.188Auxiliaries 1.321Total Direct 27.711 22.729
The expectation for the final report is that there will be costs for major capital items and indirect costs will be estimated using appropriate scaling factors from the major equipment costs.
Cost Reduction AnalysisLow Temp High Temp
Flow Syngas (kg/s) 23.76 24.24
Heating value (MJ/kg) 20.95 9.32
NG Heating Value (MJ/kg) 42.50 42.50
Syngas Energy Production (Therm/Day) 407,632 185,006
NG replacement (Therm/Day) 9,591.55 4,353.18
Savings by using Syngas ($ Million/Yr) 3.081 1.398
Total Installed ($ Million) 87.966 66.300
ROI (%) 6.54 4.27
ConclusionsLow Temp Gasification
Higher up front costHigher ROIBetter at replacing natural gas with Syngas
High Temp Gasification Lower up front costLower ROI
Consult with design teamStability against Natural Gas Increase
Rick
Sensitivity to gas prices, carbon prices, capitol cost. We will want to use more sophisticated ecomomic analysis such as net present value of discounted rate of return. Talk to Briggs.