Transcript DEMONSTRATION PLAN

Hydrothermally Treated
Biosolids Slurries as a Coal
Cofire Fuel
Dr. John Dooher
Adelphi University
Presented at the International
Technical Conference on Coal
Utilization & Fuel Systems
March 4-7, 2002, Clearwater Beach ,
Florida
What are Biosolids?
•Sewage Sludge
•Agricultural Wastes
•Pig Manure
•Chicken Litter
•Wood Wastes(sawdust)
•Paper Wastes
•Wheat Straw, Switch Grass, etc.
Why Use Biosolids as a Fuel?
•They have Btu content
•They produce less carbon dioxide than fossil fuels
•They are a waste product which can be an economic incentive
•Biosolids are plentiful and tipping fees can offset processing costs
•There are a large number of potential users
•Some biosolids have high ash and metals in the ash, however it may
be possible to remove 50% of ash by applying coal cleaning
technologies which would increase their value
Why Cofire?
•High water content and the expense of direct drying make cofiring with
coal attractive
•Special handling problems of biosolids can be reduced by integration
with existing coal handling systems
•Biosolids can represent a value added factor for coal
Advantages of Hydrothermal Treatment
•Improves fuel quality and handling properties
•Cofiring with coal slurries can be done with simple fluid handling
systems
•Potential reduction in nitrogen oxides via reburning
Requirements for Successful Application of
the Technology
• Determine optimum process
conditions.
• Determine optimum fuel
configuration.
• Develop an implementation
strategy
OPTIMIZATION OF FLOW
PROPERTIES
• Pumpable slurries.
• Slurries should be stable under shearing so
that conventional pumping equipment can
be used.
• Slurry stability sufficient for handling and
transport and must meet user storage
requirements.
Application of Hydrothermal Treatment
•Pressurized dilute slurries are heated to more than 2000C for ten
minutes or less
•Breakdown of water trapping structures
•Formation of CO2 forces liquids out of pores into carrier medium
•Reduction of propensity of biosolids to re-absorb water
•Yields high solids content slurries
•Advantages over conventional drying
Enertech Process Development Unit
Effect of solids content on 100%CMSS(sp2)-max.=40.1%wt.
100% CMSS
Viscosity (mPa-s)
500
400
300
200
100
0
35
36
37
38
Solids Loading (wt%)
39
40
Effect of Additives
100% CMSS + 1/2% DS A-23-S
Viscosity (mPa-s)
500
400
300
200
100
0
38
39
40
41
42
43
Solids Loading (wt% )
Maximum solids content(sp2)=43.1%
50% CMSS/50% COAL + 1/2% DS A-23-S
Viscosity (mPa-s)
500
400
300
200
100
0
42
43
44
45
46
47
48
Solids Loading (wt% )
Maximum solids(with sp2)=48.1%wt.
75% CMSS/25% COAL + 1/2% DS A-23-S
Viscosity (mPa-s)
500
400
300
200
100
0
40.5
41
41.5
42
42.5
43
43.5
Solids Loading (wt% )
Maximum solids(with sp2)=44.8%wt.
Maximum Solids Loading (wt%)
55
50
45
40
0
0.25
0.5
Sludge/Coal Ratio
0.75
1
In Some Ways the Biosolids Fuel Product Behaves as a
Lignite Coal for Combustion
Some TGA Analyses Show This
Proposed Upgraded Biosolids
Slurries
•Carbonized Sewage Sludge/Sawdust Slurries
•Carbonized Sewage Sludge/Paper Waste Slurries
•Beneficiated Carbonized Sewage Sludge
Advantages of Sawdust
•Co-thermal processing with sewage sludge can produce high
solids content slurries with 50% less ash than sewage sludge
alone
•Plentiful sources in mid atlantic region
•Combustion properties are acceptable
•Sludge tipping fees defray processing costs
•Slurry fluid handling can be an advantage
Two Samples Tested
Composition*
75% Biomass/25%
MSS E-Fuel
75% Biomass/25%
MSS E-Fuel
Rxn.
Temp
(oC)
Production
Unit
75% Biomass/25%
292 Autoclave
MSS E-Fuel
75% Biomass/25%
325 Autoclave
MSS E-Fuel
*(Biomass used was wheat straw)
Ultimate/Proximate Analysis
75% Biomass/25% MSS E-Fuel
Ultimate Analysis (%Dry Basis)
Dry Basis)
Carbon
Hydrogen
Nitrogen
Sulfur
Ash
Oxygen
62.80
4.91
3.91
0.32
21.10
6.96
Proximate Analysis (%
Ash
Volatile Matter
Fixed Carbon
21.10
43.94
34.96
Rheology Results – 75% Biomass/25% MSS E-Fuel (Rxn Temp 292 C)
Concentration
(wt%)
54.3
57.0
59.7
Viscosity
(mPa-s)
141
306
563
PLI
(n)
Yield Stress
(dPa)
0.8
0.8
0.8
-
m- exp = 60.7 wt%
Viscosity (cP)
1000
800
600
400
200
0
50.0
55.0
60.0
65.0
Concentration (wt% )
70.0
Rheology Results – 75% Biomass/25% MSS E-Fuel (Rxn Temp 325 C)
Concentration
(wt%)
Viscosity
(mPa-s)
58.0
60.4
63.0
66.0
PLI
76
141
332
882
(n)
Yield Stress
(dPa)
0.8
0.9
0.9
0.9
-
m- exp = 66.6 wt%
Viscosity (cP)
1000
800
600
400
200
0
50.0
55.0
60.0
65.0
Concentration (wt% )
70.0
Other Biosolids Mixtures
• Paper Mill Wastes
• Recycle Paper
• Carbonized Sewage Sludge With Selective
Agglomeration to Remove Ash
Implementation Strategy
A source study to determine the optimum suppliers of
sawdust and paper waste will be performed to ensure
successful implementation of the new slurry
composition. This study will be centered on sources
within economical transportation distance of the
hydrothermal treatment plant located in Kearny, NJ.
• Several options are considered for the
potential users.
 Direct spray of high concentration carbonized
biosolids/water slurry into the coal flame.
 Co-fired with coal in a combined coal/ carbonized
biosolids slurry.
 Used as a reburn fuel either as a direct carbonized
biosolids/water slurry or a combined coal/
carbonized biosolids slurry.
Coal Burning Power Plants Within 100 mi Radius of Kearny,N.J.
Company
Unit
City
State
Public Service Electric and Gas Co. HUDSON2
Jersey City,NJ
PG&E Generating Co.
LOGAN TOWNSHIP1 Bridgeport,NJ
Public Service Electric and Gas Co. MERCER1
Hamilton NJ
Public Service Electric and Gas Co. MERCER2
Hamilton NJ
N.States Power-Xcel Energy
B.L.England
Beesley's Point,NJ
Deepwater Operating Co.
Deepwater
Pennsville,NJ
US Generating Co.
Carney's Point
Carney's Point,NJ
Vineland Electric Utility
HM Down
Vineland,NJ
Central Hudson Gas&Electric
DANSKAMMER3 NewburghNY
Central Hudson Gas&Electric
DANSKAMMER4 NewburghNY
Southern Energy Inc
LOVETT4
Tomkins
Newburgh
cove,NY
NY
Southern Energy Inc
LOVETT5
Tomkins
Newburgh
cove,NY
NY
Bethlehem Steel Corp
BETHLEHEM WORKS1 Bethlehem,Pa
Tractebel Power Inc
CHESTER1
Chester Pa
PECO Energy Co
CROMBY1
Phoenixville,Pa
PECO Energy Co
EDDYSTONE1
Chester Pa
PECO Energy Co
EDDYSTONE2
Chester Pa
Intra-Power Dev.Corp
GIBRALTER1
Gibralter Pa
PP&L
MARTINS CREEK1
Martins Creek,Pa
PP&L
MARTINSCREEK2Martins
CREEK1
Creek,Pa
Tractebel Power Inc
NEPCO1
McAdoo
Pa
PG&E Generating Co.
NORTHAMPTON1Northampton,Pa
Constellation Power Inc
PANTHER CREEK1
Nesquehoning,Pa
Sithe Energies
PORTLAND1
Portland ,Pa
Sithe Energies
PORTLAND2
Portland ,Pa
Merck Chemical Co
RIVERSIDE MERCK1 Riverside
Pa
Sithe Energies
TITUS1
Reading Pa
Sithe Energies
TITUS2
Reading Pa
Sithe Energies
TITUS3
Reading Pa
Hydrothermal Treatment Cost Breakdown
EER
5,344 dry ton/yr
Total Plant Investment
Category
Cost($)
Major Equipment
305,500
Construction Labor
79,000
Construction Indirects
100,000
Engineering
89,930
Project Management/Owners cost
68,770
Freight
21,385
Taxes/Other
23,070
Startup
17,192
Subtotal
704,867
Project Contigency@25%
171,919
Total Plant Investment(TPI)
876,786
Projected Annual Operating Costs
(assume 1 man/shift requirement for sludge processing system)
Utilities:
Electricity
195,[email protected]$/kWhr
9,798
Steam
6,[email protected]$/Klb
30,835
Water
5,[email protected]$/Kgal
2,313
Fixed Charges@12%of TPI
105,214
Labor:
Operating
9,080mnhrs@20$/mnhr
181,600
Maintenance@60%of25%of
f 2%of TPI
TPI
10,521
Supervision@20% of Maint.Labor
2,104
Supplies:
Operating@30%of Operating Labor
54,480
Maintenance@40%of 2%of TPI
7,014
Admin. And Gen.Ovhd.(60%of total labor)
116,535
Insurance and Taxes(2.7%of TPI):
23,673
Total Operating Cost
544,087
Total First Year Costs
1,420,873
Costs/ton of processed sludge (1st year )
265.8819
(after plant paid off) 101.8127
Tip. Fees>150$/dry ton yield payback and profitable operation within 6 years
Analysis by Enertech of Comparitive Drying and
Pelletizing Show that Starting With 25% Solids
Sewage, Applying the Slurrycarb Process Results
in a 30% Cost Savings per ton to Produce 5% Moisture
Pellets
Based on some recent tests Enertech has found that running
the process at lower temperatures(450oF)
•Increases the BTU yield
•Reduces overall capital and operating costs
•Yields a product with acceptable flow properties
Particle Size Distribution
100.00
90.00
Cum . We ight %, [r e taine d]
80.00
70.00
60.00
Avg. Feed
50.00
450-Product +8-12m
550 Product +8-12m
40.00
30.00
20.00
10.00
0.00
0
100
200
300
400
500
Particle Size, [microns]
600
700
800
900
Progress of Kearny, NJ plant
Plant construction was held up for several months because of
local zoning problems.
These issues were resolved in court two weeks ago and
construction is back on target
CONCLUSIONS
• Biosolids Slurries Flow Properties
Enhanced by Processing at Elevated
Temperatures and Pressures
• Stability of Slurries is Acceptable and
Storage in Aggitated Tanks is
Recommended
• There are a Sufficient Number of Potential
Utility Users(Over20) Within Economical
Tranportation of Kearny Plant
CONCLUSIONS(cont.)
• Inexpensive Additives are Available to
Enhance Handling Properties of Sewage
Slurries and Coal/Sewage Slurries
• Tax Benefits are Feasible(.015$/kWh)
• Startup in 2002 of NJ Plant Allows for Near
Term Implementation
• Since Sewage Will not Exceed 10% Heat
Input Plants Should Remain Under Coal
Regulations.