project poster - Joint Institute for Strategic Energy Analysis

The Joint Institute for Strategic Energy Analysis is operated by the Alliance for Sustainable Energy, LLC, on behalf of the U.S. Department of Energy’s National Renewable Energy Laboratory, the University of Colorado-­‐Boulder, the Colorado School of Mines, the Colorado State University, the Massachusetts Institute of Technology, and Stanford University. Impact of Alkalinity Sources on the Life Cycle Energy Efficiency of CO2 Mineraliza?on Technologies Collaborators: Stanford University (PI-­‐Jennifer Wilcox, Adam Brandt, Abby Kirchofer) Imperial College (Sam Krevor) MassachuseGs InsHtute of Technology (PI-­‐Charles Harvey and Kurt House) Project Descrip?on A holisHc, transparent life cycle assessment model of a variety of aqueous mineral carbonaHon processes was built using a hybrid process model and economic input-­‐output life cycle assessment approach (hybrid EIO-­‐LCA). In this study we seek to evaluate the tradeoffs in using various reacHon enhancement process schemes while considering the larger life cycle impacts on energy use and material consumpHon. While previous studies have idenHfied process condiHons opHmal for enhancing the chemical rates of reacHons, no study has yet performed a scheme that opHmizes these condiHons with respect to engineering and economic consideraHon for the goal of producing a viable carbonaHon process. Results of this work will help to determine the miHgaHon potenHal of CO2 mineralizaHon. Accomplishments and Current Status The LCA model allows for the evaluaHon of the tradeoffs between different reacHon enhancement processes while considering the larger lifecycle impacts on energy use and material consumpHon. The net CO2 storage potenHal of aqueous mineral carbonaHon has been evaluated for serpenHne (Se), olivine (Ol), cement kiln dust (CKD), fly ash (FA), and steel slag (SS) across a range of reacHon condiHons and process parameters. •  8 generic process stages comprise the process-­‐model core of the LCA tool (Figure 1). •  The contribuHon to CO2 emissions for select mineral carbonaHon processes reveals that mixing, heaHng, and grinding are the main energy drivers (Figure 2). AddiHonally, the geographic relaHonship between carbonaHon resources (i.e., industrial alkaline sources) and products (i.e., syntheHc aggregate), CO2 point-­‐
sources, and aggregate markets has been invesHgated (Figures 3, 4). 1200
1000
Disposal
CO2 Emissions (t/d)
Product Transportation
Post-reaction processing
800
Mixing
Capital investment
600
Fresh water demand
Heat loss through tanks
Heating solid
400
Heating recycled water
Heating fresh water
energy
solid
water
CO2
OUTPUTS
Extraction
Reactant
transportation
Preprocessing
Chemical
conversion
Postprocessing
Product
transportation
Disposal
or reuse
Inputs
Figure 1
. L
ife c
ycle p
rocess m
odel s
chemaHc f
or a
queous m
ineral c
arbonaHon o
f 1
,000 t
C
O
, b
ased o
n t
he O
livine 2
Energy (GJ)
188
52
1,350
3,610
6
150
223
– 1Solid
55 ˚C case; (t)line t1,944
hickness is s caled and mass fluxes. 1,924 to the energy 1,866
1,848 2,819
2,791 2,707
material
Water (t)
Recycled water (t)
Carbon dioxide (t)
0
0
0
0
0
0
Outcomes and Applica?ons 0
0
0
6,659
731
1,000
The life cycle assessment of aqueous mineral carbonaHon Outputs
1,866
1,848
Solid material t(t)
suggests hat a1,924
variety of alkalinity sources and process 2,819
0
0
0
7,317
Water (t)
configuraHons Water for recycle (t) 0are capable o
0 f net CO
2 reducHons. 0
0
Waste material (t)
19
58
19
102
The esults of t188
his work provide guidance for the Wasterenergy
(GJ)
52
1,350
3,610
CO emissions (t) a11
3
100
205
development nd opHmizaHon of viable m
ineral carbonaHon technologies. For example: •  Process efficiency is maximized by increasing extent reacted through the most energeHcally favorable enhancement measure •  Mixing, heaHng, and grinding are the main energy drivers across all processes •  Reuse of carbonate as aggregate does not necessarily improve life cycle energy efficiency •  Not all alkalinity sources benefit from high reacHon temperatures •  Any steps to increase reacHon rates would dramaHcally improve process efficiency. The total CO2 storage potenHal for the alkalinity sources considered in the United States ranges from 1.3% to 23.7% of U.S. CO2 emissions, depending on the assumed availability of natural alkalinity sources and efficiency of the mineral carbonaHon processes. 2
7,317
0
0
2,791
0
0
2,707
0
0
2,791
2,791
731
3,822
6
0
2,707
2,707
0
168
150
10
2,707
2,707
0
0
223
13
Figure 3. Industrial alkaline sources and CO2 point-­‐sources in the conterminous United States. 200
Physical preprocessing Transportation
SS - 100˚C
SS - 25˚C
FA - 75˚C
FA - 25˚C
CKD - reuse
CKD - 25˚C
Se - 155˚C
Ol - reuse
Ol - 155˚C
Extraction
Ol - 105˚C
0
INPUTS
Figure 4. Comparison of absolute mined to potenHal syntheHc producHon of aggregate. Figure 2. CO2 emissions per 1,000 t-­‐CO2/d sequestered for the carbonaHon processes with net CO2 miHgaHon potenHal. Joint Ins?tute for Strategic Energy Analysis 1617 Cole Blvd. Golden, CO 80401-­‐3393 Contacts Jennifer Wilcox wilcoxj@stanford.edu Adam Brandt abrandt@stanford.edu
Samuel Krevor s.krevor@imperial.ac.uk Abby Kichofer abby.kichofer@stanford.edu
Acknowledgments ValenHna Prigiobbe, Noemi Alvarez, Wenny Ng, and Emilia Dicharry contributed to this research. Joint Institute for Strategic Energy Analysis Annual Meeting
March 2012