22.033
Biofue ls Presen tation
Alex, Lizz y, Ogie, Matt, and Kat hryn October 3, 2011
1
Overview
• Our G oal
• House of Q uali ty
• Comp ariso n of Biomass Sources
• Possibl e Uses & Processes
• Comp ariso n of Inputs
• Comp ariso n of O utputs
• Conclusi on
2
Our Goa l
As a grou p, we inten d t o de sign a bio fuels plan t which:
1. Maximi zes our fuel outpu t
2. Co up les with hydr og en pro du ction
3. Uses t he t he resources (electricit y , heat, etc.) from the nuclear plan t.
3
H ouse of Quality
Cu stom er Requi rem ents
• Ca rbon emissi ons
• Fue l De mand
• Fu el Output (Quantity)
• Co mpetition wi th Foo d Su ppl ie rs
• Co st of F uel Produced
• Quali ty of F uel Produ ce d (Energy Den sity)
HoQ template courtesy of QFD Online. Used with permission.
4
Biomass feedstock compa rison
Cost |
Energy den sity |
A gricul tu re y ield |
Com pet itio n w ith fo od sou rce |
|
Sw itc h grass |
$60/t on |
17 MJ/kg |
1 1.5 t on /acre |
no |
Sorghu m |
$40/ton |
16.9 MJ /kg |
20 to n/acre |
ye s |
Energy cane |
$34/ton |
12.9 MJ /kg |
30 to n/acre |
no |
Energy cane |
$34/ton |
12.9 MJ /kg |
17 to n/acre |
ye s |
Corn |
$40- 50/to n |
13.4 MJ /kg |
3.4 to n/acre |
ye s |
A lgae |
58,700L/ha |
no |
||
5 |
Biomass feedstock compa rison
Biomass
Algae T ransesteri fication
Bio fuels
Microb e Electrolysi s
H gas
Gasification
Hydro lysis
Syngas
Ethanol
Fermentation (Bio)
Catalytic Conve rsion (Thermo)
Ethan ol,
F -T biofuel s
Hydro gen
6
Algae Tr ansesterification
Pros:
• Requ ires low t em pe ratu res be twee n 20 - 30C
• Prod uced with ou t th e use of
hig h -value ara ble la nd
Con s:
• Does no t u tili ze core he at or hydrog en inp uts
• Expe nsive to h arvest
*** http:/ /ww w .oil ga e.com/alg ae /oil /biod/t ra/t ra.htm l
*** Y usuf Ch isti (2007) Bi odi esel fr om Microal g 7 ae . Bi otechno lo gy Ad vance s 25:294 - 306
Electrofuel s
Uses power from the core to drive mic rob ial pro cess es that pro duce hydrog en gas.
1. Mic rob ial Elec trolys is Cell (MEC)
• uses ene rgy to en ha nce t he microbia l proce ssi ng of org anic substrates (e.g. cellulose, acetic acid) in a "bio battery" to pro duce hydrog en gas and oxygen.
2. Microbia l Electrosy nthe sis
Eff iciency d epe nds on pH, sy stem tempera ture, and choice of mic rob e
8
Biochem ical Ethanol Productio n
• Dilute acid p re - treatment (glucos e etc)
• Simultaneous Sacchar ification and Fermentat ion (SSF) (37 ° C, 7 days)
• Ethanol recov ery by dis tillation
• W aste W ater T reatment (WWT ) (methane) 9
Ethanol Inputs and O utputs
Inpu ts
Bioma ss: 65 .6 kg/s Lo w P Stea m: 7.1 kg /s High P Stea m: 23 .0 kg /s
$2 /gall on
( Bransb y , Cell ulos i c biofuel
tec hnol ogi es )
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Therm ochem ical Biofuel Productio n
1. Gasification (Syngas produ ction)
2. Syngas conversion (F - T liqui d produ ction)
3. F -T li quid refining (gasoline, diesel blend)
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F- T Process Overvi ew
Biomas s:
41. 4 k g/s
O2 Stea m: 2 .6 kg /s 240 ° C
Gasifie r
H2S, CO2
F - T
Refini ng
T ar Crack ing
Gaso lin e Ble nd :
2.5 k g/s
Dies el Blen d:
3.8 kg /s
H2:
0.1 k g/s
25 -
40 ° C
Sync ru de
F - T
Synthe sis
Rec yc lin g o f Unc on ve rte d Syng as
Acid Gas Remo val
Cool ing , Filt erin g
Di agram and num bers ad a 1 p 2 ted from Kreutz , Fis her - T ropsc h Fuels from Coal And Bi omas s , 2008
Hydro gen Use in F - T Refinin g
Courtesy of Thomas G. Kreutz. Used with permission.
$1/ga llon
(Bransb y , Cel l ul os i c bi ofuel tec hnol ogi es )
Comp ariso n of processe s
T emp erature of reac tio n |
Hy drog en inp ut |
Steam inp ut |
Biom ass inp ut |
Biof uel O ut pu t rate |
Elec tricit y usag e |
Capit al cost |
|
Electro fu el |
2 5 - 1 00 C |
0 |
0 |
7.2 kg cellulose/1 kg H2 |
1.23 m 3 H2/m 3 reac to r day at op tim al v olt age |
~2.2 kW h/m ^3 - reac to r day |
$ 75 0 ,0 00 |
Bioco nv ersion |
190C |
0.41 kg/sec |
30 kg/sec (100C and 190C) |
65kg/sec (s w itch grass) |
13.2 kg/sec (et han ol) |
$346million |
|
Th ermochem ical bio fu el |
236 |
0.1 kg/sec (25C, 4bar) |
2.6 kg/sec,(236 C) |
41.4 kg/sec (sw itch grass) |
6.3 kg/sec (g asoline blen d) |
32MW |
$541 million |
Phot osy nt he t ic algae |
20- 30 C |
0 |
0 |
carbon dio xide, nit rogen , sulf ur |
226.1 gal/ day |
55kW |
$821,000- $14million |
14 |
Summar y of Products
15
E nergy Density of Biofuel s
Ener gy De nsity of differe nt po ssi ble pro du cts from F - T liquid s Bio - diesel fuel - high est ene rgy to volume ratio
16
B iofuel Carb on Emissions
Bio - diesel Emi ss ions vs. Con ventional Diesel Emi ss ions for :
• 100 % bio - diesel fuel
• 20% bio - diesel fuel and 80% conventional diesel fuel
17
Bio- Fuel Chall enge s
• Low freezing point at 100 % bio - diesel fuel
• Gen era lly mix ed to dispel these qua lities
• Do es no t meet curre nt EN59 0 v eh icle q ua lity st an da rd
• Can be used in s tanda rd cars up to 20% bio - diesel fuel
• Rise in Nitrogen Oxide emis sions, respon sible for sm og
• Decrea se in bio - diversity in energ y crop har vest ing
• DARPA is inter ested in alterna tiv e jet fuels pro duction
• Have grants for $5M that
can help off set capital c ost
18
Conclu sion
• Switc hgrass
• Gasific ation - based F-T process
• Steam requiremen t: (2.6kg/sec , 240C)
• Hydrogen requirement: 0.1kg/sec (25C, 4bar)
• End products: biodi esel and gasoli ne
19
MIT OpenCourseWare http://ocw.mit.edu
22.033 / 22.33 Nuclear Systems Design Project
Fa ll 2011
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