Presentation given at 2013 California Air Pollution Control Officer's meeting.

1. 2 1 M a y , 2 0 1 3
C o l i n M u r p h y M . S .
P h D C a n d i d a t e , I n s t i t u t e o f T r a n s p o r t a t i o n
S t u d i e s , U C D a v i s
Current Research on Air Pollutant
Emissions from Bioenergy

2. 1 . CURRENT STATUS OF BIOENERGY IN CA
2. ADVANCED TECHNOLOGY
3. MULTI-OUTPUT SYSTEMS
4. MODELING COST EFFECTS AT NATIONAL SCALE
Overview

3.  5.8 TWh of in-state biopower production
 17% of in-state renewable power
 2% of full California power mix
 SB 1122 adds FIT for 250 MW, SB 489, 594 improve net-metering
Current Biopower Capacity in California
* Includes: (a) LFG: 12 direct-use or CNG/LNG facilities; (b) WWTF: 8 heat or
pipeline application; (c) AD: 12 Direct-use heat or fuel
Biopower Facilities
Facility Type Net (MW) Facilities
Solid Fuel (forest, urban & ag) 574.6 27
LFG Projects (a) 371.3 79
Waste Water Treatment Facilities (b) 87.8 56
Farm AD (c) 3.8 11
Food Process/Urban AD (c) 0.7 3-5
Totals 1038 175
Solid Fuel (MSW) (mass burn facilities /
organic fraction only)
63 3

4. Current Bioenergy Facilities

5. Current Solid Fuel
Biomass Power
 Like politics, all biomass
is local. Feedstock and
technology combinations
reflect local conditions.
 Many existing facilities
idled or inoperative.
 May be opportunities to
repower or increase
output through
improved efficiency.
Mayhead G, Tittmann P. 2012. Outlook:
Uncertain future for California's biomass power
plants. Calif Agr 66(1):6. DOI:
10.3733/ca.v066n01p6

6. Advanced Technology

7. Overview
 No silver bullets for exhaust aftertreatment.
 Focus generally on combustion technology, to reduce
pollutants entering gaseous phase
 Lots of interest in integrating CCS or
biofuel/bioproduct production

8. SCR Still the Standard
 Orange County Sanitation District
 Using SCR on biogas from WWTP, achieving ~7-8 ppmv NOx,
some reliability problems.
 http://www.casaweb.org/documents/2013/03-ocsd_rothbart.pdf
 Fresno Dept of Public Utilities
 Gas turbines burning 60/40 DG/NG, achieving ~3 ppmv NOx.
 http://www.casaweb.org/documents/2013/05-fresno_scr_turbine_hogg.pdf

9. Activated Carbon w/ Microwave Regen
 CHA Corporation – SMUD Testing / Demo project on
dairy digester biogas.
 http://www.epa.gov/region9/organics/symposium/2010/5Lemes2010-PorsPres.pdf

10. Gasifier Project Examples
Phoenix Energy Authority to Construct (SJVAPCD)
Emission Limits
NOx
(ppm)
CO
(ppm)
VOC
(ppm)
PM10
(g/hp-hr)
SOx
(g/hp-hr)
9 75 25 0.05 0.03
NOx
(ppm)
CO
(ppm)
VOC
(ppm)
PM10
(gr/dscf)
SO2
(ppm)
Permit 98.8 2823 14.1 0.012 28.2
Source
Test
58 362 ND 0.0005 <0.4
CPC 50 kW at Dixon Ridge Farms (Winters, CA) [Yolo-Solano AQMD]
Emission Limits and Test Results
New 3-way Catalytic converter just prior to source test
Ankur derivative downdraft gasifier, gas
scrubbing/filtering, recip. engine-generator
(~500 kWe)
Downdraft gasifier, gas filtering,
automotive V-8 engine-generator (~50
kWe)

11. UC Test Platform

12. Partial-Oxidation Gas Turbine
 Partially oxidize NG at high pressure to generate
excess H2, which allows ICE operation under ultra-
lean conditions, to minimize NOx, <20ppm.
 Demonstration project at San Bernadino WWTP.
 http://www.casaweb.org/documents/2013/07-san_bernardino_mwd_-_claus.pdf

13. Oxy-Fuel Combustion
 Use gas or gasified
biomass in pure-oxygen
environement to produce
highly-efficient
combustion and minimal
NOx formation.
 CO2 can be recovered for
EOR or CCS
 Clean Energy Systems
demonstration plants at
Kimberlina and Placerita
http://www.westcarb.org/pdfs_Lodi/Devanna.pdf

14. Multi-Output Systems

15. Biomass is Not Just Energy
 Current research often emphasizes integrating
systems to take advantage of local synergies
 CHP
 Nutrient Reovery
 Bio-Product Production
 Biomass systems often struggle to be cost
competitive on a purely energy basis, coproducts
may be key to economic viability

16. Example – Dixon Ridge Farms
 50 kW gasifier utilizing walnut shells (adding
another 100kW)
 50 kW gasifier displaces:
 20% of facility electricity demand
 15% of propane demand for heaters
 Biochar is incorporated into soil
 Nutrient management
 Carbon sequestration
 N2O reduction?

17. Dixon Ridge

18. Dairy Digesters
 Currently in limited deployment for energy purposes
 NOx permitting difficult
 Some reliability concerns
 Opportunities to better capture nutrients (N, P, K)
from effluent
 Reduce burden on surface water
 Displace fertilizer produced elsewhere
 Additional revenue

19. Digester Energy / Nutrient Recovery Concept

20. Modeling the Effects of Air
Pollution Regulation on Biofuel
Industry Development

21. Geospatial Bioenergy Systems Model
 Nationwide technoeconomic model
 Feedstock: Forest residue, MSW, corn stover, energy crops
 Biofuel demand: Based on county-level VMT
 Scope: Nation wide, county-by-county basis
 Biomass transport: Network model of road, rail and barge
 Conversion technology: Multiple biochemical and
thermochemical pathways
 Produces spatial model of where conversion facilities
locate and which feedstock sources they utilize
 Produces cost curves for biofuel supply under
various market conditions

22. Spatial Results

23. Supply Curves

24. Next Steps
 Improve site selection heuristic
 Incorporate existing environmental policy
 Improve feedstock production model
 Competition with existing crops
 Anecdotally – Air pollutant emission regulations
major obstacle to successfully developing a project

25. Cost Estimates
Cost factors for SCR and ESP systems on biochemical and thermochemical conversion
facilities. All costs are in thousands of 2002 dollars
• Costs modeled on EPA
guidance document for
various technologies.
• Costs are intended to be
reasonable proxies for
actual costs of achieving
BACT or equivalent, rather
than technological
proscriptions.
• Typical capital cost for a
biorefinery of this size:
$400-500 million.

26. Effect of Air Quality Costs – High Ethanol Case

27. Effect of Air Quality Costs – Low Ethanol Case

28. Preliminary Results
 About 1 cent/gge difference in average ethanol cost.
 Less than that in California
 Generally, very little response to the costs of air
quality
 Most facilities are outside of nonattainment zones
 Those that are, are uniquely positioned close to a market or
feedstock supply
 Current model may be too location-agnostic
 Next generation – adding state-by-state cost factors

29. For more information:
 California Biomass Collaborative
 Biomass.ucdavis.edu
 UC Davis Policy Institute for Energy, Environment
and the Economy
 Policyinstitute.ucdavis.edu
 Colin Murphy
 cwmurphy@ucdavis.edu
 Twitter: @Scianalysis
 Rob Williams
 rbwilliams@ucdavis.edu

30. 0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
CO NOx SO2 PM THC
(lbs/MWh)
Chowchilla-Permit Chowchilla-Actual
El Nido-Permit El Nido-Actual
Madera-Permit Madera-Actual
Woodland-Permit Woodland-Actual
Ely,UK-Permit Ely,UK-Actual
Permitted and actual emissions for several solid fuel biomass plants.
Williams, R.B. (2005). Technology assessment for advanced biomass power generation - Final Report for SMUD ReGen program. University of
California, Davis. CEC PIER Contract 500-00-034.