hp uiuc part2
TRANSCRIPT
Biorefinery of municipal and industrial wastes: a new paradigm in
waste management leading to biofuels and secondary resources
Héctor M. Poggi-Varaldo
CINVESTAV-IPN, Dept. Biotechnology and Bioengineering, Environmental Biotechnology R&D
Group, Mexico DF, Mexico [email protected]
GBPANAT
Acknowledgements
• Ireri Robles-González, Karla Muñoz-Páez, Alessandro Carmona, Dra. I. Valdez-Vazquez, J. Acevedo-Benítez, Javier, Monserrat from the Environmental Biotechnology R&D Group of CINVESTAV
• Prof. Elvira Ríos-Leal, Mr. Rafael Hernández-Vera, Dr. Fernando Esparza-García, from CINVESTAV
• CINVESTAV for partial financial support
• Dr. Franco Cecchi, Italy; Dr. Richard Sparling, Canada; Dr. Paolo Pavan, Italy
• Agropark
Contents
• Notation• Introduction
– Oil and fossile fuels outlook and impact– Hydrogen advantages and production
technologies• Objective• Intermittently-vented SSAH from paper
mill waste • Intermittently-vented SSAH from
organic waste• Semi-continuous acidogenic SSAD• Conclusions and outlook• Biorefinery from organic wastes
Notation
BES 2-bromoethanesulfonate A-SSAD acidogenic solid substrate anaerobic
digestionHSP or tt heat shock preatreatmentIV-SSAH intermittently vented and flushed, solid
substrate anaerobic hydrogen generationM-SSAD methanogenic solid substrate anaerobic
digestion PH , Pm maximum amount of accumulated H2 (or
CH4) (mmole/reactor)Ri,H, Ri,m initial rate of H2 (or CH4) accumulation
(mole/(reactor.h))
Introduction
GBPANAT
World oil production
Duncan and Youngquist, 1998
Panic button
World Primary Energy Demand
0
1,000
2,000
3,000
4,000
5,000
6,000
1970 1980 1990 2000 2010 2020 2030
Mto
e
Oil
Natural gas
Coal
Nuclear power
Hydro powerNon-hydro renewables
0
1,000
2,000
3,000
4,000
5,000
6,000
1970 1980 1990 2000 2010 2020 2030
Mto
e
Oil
Natural gas
Coal
Nuclear power
Hydro powerNon-hydro renewables
Priddle, 2002
Pollution
Fossil fuel combustion products are causing global problems:
• greenhouse effect,
• ozone layer depletion,
• acid rain
• other pollution effects
Renewable energy
• Sustainable and eco-friendly
• Variety of primary energy sources available– solar energy, – wind energy, – hydropower, – geothermal energy, – ocean currents, tidal and
wave energy– biomass
Fuel candidates
• None of the new primary energy sources can be used directly as a fuel
• There are many candidates, such as – synthetic gasoline– synthetic natural gas (methane)– Methanol/ethanol – and hydrogen
• The fuel of choice must satisfy the following conditions: – Transportation – Versatile – High utilization efficiency– and use should be safe
• In addition, the resulting energy system must be environmentally compatible and economical.
Veziroglu and Barbir, 1992Veziroglu and Barbir, 1992
Hydrogen: the best fuel
When we critically look at the fuel options under the criteria given above, it becomes clear that hydrogen appears to be the best fuel
Veziroglu, 1987; Barbir Veziroglu, 1987; Barbir et al.et al., 1990; Veziroglu and Barbir, 1992, 1990; Veziroglu and Barbir, 1992
(Hydrogen experts and advocates say so.....)
To inhibition of methanoarchaea
Hydrogen
Burning hydrogen produces only water with no CO, CO2, hydrocarbons or fine particles
H2 + 1/2 O2 H2O + 141.9 kJ/kg
Yamin Yamin et al.et al., 2000, 2000
Hydrogen production
Hydrogen can be produced
– Chemically or thermo-chemically
– electrochemically
– as a by-product of oil/coal
processing
– by using microorganisms
Biological production of hydrogen
Three main systems to obtain hydrogen with microorganisms
– Photochemical from water:• Algae1 • Photosynthetic bacteria2
– Dark fermentation from organic matter 3:• Facultative anaerobes• Obligate anaerobes
– Phototrophic fermentation from organic matter 3:
• Non sulfur purple bacteria
1.- Ike 1.- Ike et al.et al., 1997; 2.- Melis and Happe, 2001; 3.- Nandi and Sengupta, 1998, 1997; 2.- Melis and Happe, 2001; 3.- Nandi and Sengupta, 1998
Fermentative hydrogen production 1/2
• Pure cultures – Studies on microbial hydrogen
production has been conducted mostly using pure cultures, either natural or genetically modified
– costly organic substrates
• Disadvantages…– cost, and cost, and cost
Asada Asada et al.et al., 2000; Evvyernie , 2000; Evvyernie et al.et al., 2000, 2001; Fabiano and Perego, 2002, 2000, 2001; Fabiano and Perego, 2002
Fermentative hydrogen production 2/2
• Mixed cultures– Hydrogen is a key intermediate in the
anaerobic degradation of organic compounds– In these studies, hydrogen production
resulted from the inhibition of methane fermentation
• Advantages– H2 may be recovered from wastewater or
organic fraction of municipal solid wastes – no aseptic conditions required
Ueno Ueno et al.et al., 1996; Sparling , 1996; Sparling et al.et al., 1997; Lay , 1997; Lay et al.et al., 1999; Mizuno , 1999; Mizuno et al.et al., 2000, 2000
Solid substrate anaerobic digestion (to be DASS is better than being SSAD)
• Methanogenic SSAD is an effective way of reclaiming paper mill sludge and other wastes, for obtaining:1 – CH4 as a fuel
– Soil amender or protein enrichments from the digested solids
• Yet, CH4 or CO2 as its combustion product are greenhouse gases2
1.- Poggi-Varaldo 1.- Poggi-Varaldo et al.et al., 1997 a, b, 1999, 2002; 2.- Dickinson and Cicerone, 1986, 1997 a, b, 1999, 2002; 2.- Dickinson and Cicerone, 1986
Sparling et al., 1997; Brock ,1997; Chidthaisong & Conrad, 2000; Nagar-Anthal, 1996
Hydrogen and anaerobic digestion
Inhibitor
Methanogenesis
Acidogenesis
Hidrólisis Chemical BES Lumazine Acetylene
Physical or Phys-chem pHThermal treatment
Hydrolysis
Acetate
Polymers(polysaccharides, lipids, proteins)
Monomers(sugars, organic
acids, aminoacids)
Important biochemical processes in anaerobic, methanogenic consortia(adapted from Brock and Madigan, 1991).
Gibbs freeenergy
(kJ/reaction)
No Type of reaction Reaction
Go a G' b
1 Fermentation ofcarbohydrates fobutyrate
Glucose + 2H2O -> 2H2 +Butyrate + 2HCO3- +
3H+-135 -284
2 Fermentation ofcarbohydrates toacetate
Glucose + 4H2O -> 4H2 +2Acetate + 2HCO3- +
4H+-207 -319
3 Anaerobic oxidation ofbutyrate (syntrophy) c
Butyrate + 2H2O -> 2H2 +2Acetate + H+ +48.2 -17.6
4 Anaerobic oxidation ofpropionate (syntrophy)d
Propionate + 3H2O -> 3H2 +Acetate + HCO3- + H+ +76.2 -5.5
5 Hydrogenotrophicmethanogenesis
4H2 +HCO3- + H+ -> CH4 + 3H2O -136 -3.2
6 Acetogenesis fromCO2 and hydrogen
4H2 + 2HCO3- + H+ -> Acetate + 4H2O -105 -7.1
7 Sulfate reduction 4H2 + SO4-2 -> HS- + 3 H2O + OH- NA e -165
Notes: a standard conditions: soluble species 1M, gas species 1 ata pressure; b conditionsprevailing in anaerobic ecosystems, i.e., [organic acids] = 1 mM, pH = 7, [HCO3
-] = 20 mM,[Glucose] = 10 mM, and the partial pressures of H2 and CH4 are 10-4 and 0.6 ata, respectively.Negative values of the Gibbs free energy indicate a spontanous, feasible thermodynamicprocess (exoergonic) whereas positive values indicate an impossible process(endoergonic); c typically effected by Syntrophomonas genera; d typically carried out bySyntrophobacter species; e Not available.
To Merits
To IV-SSAH OFMSW
To metabolites A-SSAD
Inhibiting methanoarchaea in methanogenic solid substrate
anaerobic digesters
Hydrogen might be produced from organic wastes using microorganisms from M-SSAD, suppressing the activity of hydrogenotrophic methanogens with inhibitors such as:– chemicals: 2-bromoethanesulfonate (BES),
acetylene, lumazine– heat-shock pretreatment (HSP)– acidogenic environment (low pH)
Sparling and Daniels, 1987; Sparling Sparling and Daniels, 1987; Sparling et al.et al., 1997; Valdez-Vázquez , 1997; Valdez-Vázquez et alet al., 2003., 2003
Solid waste in Mexico
• Municipal solid waste: 53 000 tonne/day
• Industrial solid waste: 370 000 tonne/day
• Pulp and paper industry solid waste:
500 000 tonne/year
• Dumping sites, few landfills
CNICP(1993), Poggi-Varaldo CNICP(1993), Poggi-Varaldo et al.et al. (1997a) (1997a)
Pulp and paper industry
• It ranks second in the list of industrial polluters in Mexico
• An important proportion of the solid waste stream is dumped in sites which do not meet actual sanitary landfill design standards and environmental regulations
Objectives
GBPANAT
To review the research efforts of our
Group on biological hydrogen production. This review concentrates on four areas:
(i) the study of batch, repeated fermentation of paper mill waste,
(ii) batch, repeated fermentation of the organic fraction of municipal solid wastes (OFMSW), and
(iii) the semi-continuous, acidogenic fermentation (A-SSAD) of the OFMSW
(iv) development of the concept of Biorefinery of Solid Wastes
To A-SSAD
Intermittently-vented SSAH from paper
mill waste
GBPANAT
Objectives
• To determine the effect of the inhibitor of methanogenesis, i.e., acetylene (non specific), bromoethanesulphonate (BES), and oxygen on batch fermentation of paper mill waste
• To evaluate the influence of venting and flushing with inert gas the headspace of reactors
Response variables:• maximum hydrogen production PH,max (mmole
H2/reactor),
• initial rate of hydrogen generation Ri,H in each cycle of incubation (mmole H2/ (reactor.h))
1.- Poggi-Varaldo et al., 1997 a, 1999; 2.- Valdez-Vázquez, 2003; 3.- Sparling and Daniels, 1987
Waste office paper with 25% w/w dry
matter content (80 g)
glass juice bottlesAnaerobic glove box…
BES (25 mM) orAcetylene ( 1% v/v)3
250ml250ml
250ml
Mesophilic, continuous
M-SSAD Reactors1,2
These were autoclaved and stored until used
20 g of inoculum
flushed with N2. Incubation at
37°C. paper
paperpaper
H2
Organic acidsand
solvents
1.- Poggi-Varaldo et al., 1997 a, 1999; 2.- Valdez-Vázquez, 2003; 3.- Sparling and Daniels, 1987
Waste office paper with 25% w/w
dry matter content (80 g)
Recycled glass juice bottles
In the anaerobic glove box
BES (25 mM) orAcetylene ( 1% v/v)3
Mesophilic, continuous
M-SSAD Reactors1,2
These were autoclaved and
stored until used.
20 g of inoculum
Venting and flushing with N2.
Incubation at 37°C.
Organic acids
H2
Glass juice bottles with waste
office paper
Hydrogen production
Effect of 1% acetylene on CH4 and H2 production:Preliminary experiments
• A batch minireactor exposed to air at the start-up and spiked with acetylene.
Hollow squares: CH4 ; Black squares: H2
• In an non-exposed, non-inhibited batch minireactor
Hollow circles: CH4 ; Black circles: H2
0
2
4
6
8
10
12
0 500 1000 1500
Time(h)
H2
or
CH 4
accu
mu
lati
on
(m
mo
le/r
eacto
r)
Acetylene
0
2
4
6
8
10
12
0 500 1000 1500
Time(h)
H2
or
CH 4
accu
mu
lati
on
(m
mo
le/r
eacto
r)
Acetylene CH4, non-inhibited culture
CH4, inhibited culture
H2, inhibited culture
Acetylene
• Acetylene was a very effective inhibitor of the methanogenesis and facilitated the hydrogen accumulation
• Exposure of batch minireactors to air had a slight inhibitory effect on the methanogenic microflora. The effect was reversible:
it has been reported that methanogenic Archaea in anaerobic, methanogenic consortia can tolerate the exposure to O2,1
and the protective effect increased with increasing concentrations of sucrose.2
1.- Estrada-Vázquez 1.- Estrada-Vázquez et al.et al., 2001, 2002; 2.- Estrada-Vázquez , 2001, 2002; 2.- Estrada-Vázquez et al., et al., 20032003
Intermittently vented solid substrate anaerobic hydrogen generation (IV-SSAH)
• Hollow circles: CH4 from non-inhibited minireactors• Black circles: H2 from minireactors spiked with BES• Black triangles: H2 from minireactors spiked with acetylene
0
3
6
9
12
15
18
0 1000 2000 3000 4000 5000
Time (hour)
CH
4 o
r H
2 (m
mo
le/r
eact
or) N2
N2
N2
Hydrogen and methane accumulation and initial rates of hydrogen andmethane production in batch minireactors loaded with anaerobic solidinoculum plus paper waste substrate.
Cycle of incubation1 2 3 TotalParamete
r C2H2 a BES b C2H2
a BES b C2H2 a BES b C2H2
a BES b
PH c 17±1.2 14.4±1.4 11.1±1.0 9.6±0.8 5.9±0.7 5.2±0.4 34.0±1.7 29.2±1.6
Ri,H*10-3 d
[r, P(F)] e10.6±0.8
[0.96;10-5]9.6±0.9
[ 0.95; 10-4]9.1±0.4
[0.98; 10-6]8.0±0.3
[0.98; 10-6 ]6.7±0.2
[0.99; 10-6]5.4±0.4
[0.98; 10-5]NA f NA f
Pm g 12.1± 0.8 h < 0.2 < 0.2 12.1± 0.8 h
Ri,m *10-3 i
[r, P(F)] j17.3±1.2 h
[0.99; 2*10-4]--- --- NA f
Notes: a acetylene; b bromoethanesulfonate; c maximum amount of hydrogen accumulated atthe end of the incubation period (mmole H2/reactor) in inhibited minireactors, the methaneproduction was null; d initial rate of hydrogen accumulation (mmole H2/(reactor.h)); e
correlation coefficient and probability of the F statistics for the regression of the initial rateof H2 (significance level of the regression); f
not applicable; g maximum amounto of methaneaccumulated at the end of the incubation period (mmole CH4/reactor) in non-inhibitedminireactors, the hydrogen production was null; h the methanogenic batch reactor was notspiked with acetylene or BES (that is, it was not inhibited); i initial rate of methaneaccumulation (mmole CH4/(reactor.h)); j correlation coefficient and probability of thestatistics F for the regression of the initial rate of CH4 (significance level of the regression).
Parameter
IV-SSAH 1/2
• The plateau and initial rates of H2 accumulation decreased in each subsequent cycle of incubation
• Yet, the total cumulative H2 harvested in the three cycles was nearly double than that in the first cycle alone
• The total H2 accumulated in the batch minireactors spiked with acetylene was slightly better than that corresponding to the minireactors spiked with BES
IV-SSAH 2/2
Venting and flushing the headspace with N2 would have released the product inhibition effected by the H2 on the activity of some fermentative microorganisms in the consortia (for instance, syntrophic bacteria)
Brock and Madigan, 1991Brock and Madigan, 1991
Organic acids
• Another cause contributing to the biochemical inhibition might be the accumulation of organic acids
• A conservatively low estimate of butyric (HBu) and acetic acid (HAc) final concentrations can be made based on the biochemical equations 1 and 2 in the latter Table
To Table Biochemical Reactions
Organic acids We made the following simplifying
assumptions: – 95% of the paper is degradable cellulose– cellulose is approximately equal to glucose– half of the consumed substrate is fermented
according to Eq 1 and the other half to Eq. 2
– the H2 harvested is directly related to consumed substrate
Organic acids
Final concentration of short chain volatile organic acids approx.
• 6 800 mg HAc/kg wet basis (34 000 mg HAc/kg dry initial substrate)
• 6 000 mg HBu/kg wet basis (25 000 HBu/kg dry inittal substrate)
can be expected in the solid phase at the end of the 3rd cycle
IV-SSAH merits with respect to other biological alternatives
I. More cost-effective than processes working with pure microbial strains
II. More attractive than processes that ferment soluble carbohydrates to H2
III. No light is needed as compared to photobiological H2 production
IV. The inhibitor used (acetylene) is a cheap gas that will exit the bioreactor with the H2-rich gas stream
However…
I. The kinetics of H2 accumulation is slower than reported rates for liquid fermentation processes
II. There is a potential for lower H2 yields than those of processes using pure cultures
III. There is an upper limit for the amount of H2 that can be obtained via anaerobic fermentation of carbohydrates To table Biochem. Reactions
Intermittently-
vented SSAH from
organic waste
GBPANAT
Objectives To determine the effect of:
– origin of inocula (from meso- and thermophilic methanogenic SSAD reactors; M and T, respectively),
– inhibition of the methanogenesis (acetylene and heat shock pretreatment, Ac or tt, respectively), and
– incubation temperature (37 oC and 55 oC, M and T, respectively)
on batch fermentation of organic fraction of municipal solid waste
Response variables: • maximum hydrogen production PH,max (mmole H2/reactor),• initial rate of hydrogen generation Ri,H (mmole H2/(reactor.h)),• lag time, and • accumulation of organic acids and solvents
1.- Poggi-Varaldo et al., 1997 a, 1999; 2.- Valdez-Vázquez, 2003; 3.- Sparling and Daniels, 1987
Organic fraction of MSW
with 25% w/w dry matter content (80 g)
glass juice bottlesAnaerobic glove box…
Heat-shock pretreatmentor Acetylene ( 1% v/v)3
250ml250ml
250ml
Meso- and thermophilic continuous
M-SSAD Reactors1,2
These were autoclaved and stored until used
20 g of inoculum
flushed with N2. Incubation at 37°C or 55oC.
H2
Organic acidsSolvents
H2 production for batch solid substrate anaerobic hydrogen production with intermittent ventingand flushing of the headspace fed with organic fraction of municipal solid waste
Incubation Cycle
1 2 3 4
Minireactor a
PH,max b PH,max PH,max PH,max
Overall H2
production
4
1,,
jjmaxHP
M-tt-M 10.17 ± 4.45 c 5.21 ± 0.51 3.07 ± 1.02 2.58 ± 0.60 21.03 ± 5.38
T-tt-M 11.89 ± 1.90 4.95 ± 0.26 2.46 ± 0.57 1.89 ± 1.62 21.20 ± 0.03
M-tt-T 0.67 ± 0.67 2.23 ± 1.03 1.80 ± 0.59 0.01 ± 0.01 4.71 ± 1.13
T-tt-T 0.34 ± 0.34 3.05 ± 3.05 1.21 ± 1.21 0.11 ± 0.11 4.71± 4.02
M-Ac-M 8.01 ± 3.55 5.39 ± 1.32 2.25 ± 0.23 1.77 ± 1.77 17.42 ± 6.86
T-Ac-M 10.19 ± 2.00 7.24 ± 0.89 3.02 ± 0.52 1.08 ± 0.50 21.53 ± 3.16
M-Ac-T 5.82 ± 4.51 3.76 ± 0.83 2.37 ± 1.09 0.10 ± 0.10 12.05 ± 6.53
T-Ac-T 3.85 ± 2.87 5.88 ± 1.22 1.62 ± 0.37 0.00 ± 0.00 11.35 ± 4.46
Notes: a for the codes of minireactors, see section Experimental Design, Second Experiment above; b
maximum hydrogen production in the incubation cycle in mmole H2/reactor; c average plus minus standarddeviation of two replicates
0
4
8
12
16
0 100 200 300 400 500 600 700 800
Time (h)
H2 p
rod
uct
ion
(mm
ol H
2/m
ini-
reac
tor)
M-tt-M M-tt-T T-tt-M T-tt-T
0
4
8
12
16
0 100 200 300 400 500 600 700 800
Time (h)
H2 p
rod
ucti
on
(mm
ole
s H
2/m
ini-
reacto
r)
M-Ac-M M-Ac-T T-Ac-M T-Ac-T
Kinetics of H2 production from organic fraction of municipal solid waste fermentation by anaerobic consortia:First cycle of incubation
(a) heat-shock pretreated mini-reactors; (b) mini-reactors treated with acetylene; M mesophilic; T thermophilic.
0
4
8
12
H2 p
rod
uct
ion
(m
mo
l H2/m
ini-
reac
tor)
0
100
200
300
400
500
Lag
tim
e (
h)
0
10
20
30
40
H2 p
rod
uct
ion
rat
e (m
mo
l H2/(
min
i-re
acto
r h
))
0
4000
8000
12000
16000
Met
abo
lites
acc
um
ula
tio
n(m
g C
OD
/kg
wet
bas
is)
VOA
Solvents
Main effect of inhibition treatment on performance of first cycle of incubation
tt: heat-shock pretreatment; Ac: acetylene; VOA volatile organic acids (sum of acetate, butyrate and propionate); solvents sum of acetone and ethanol
0
4
8
12
H2 p
rod
uct
ion
(mm
ol H
2/m
ini-
reac
tor)
0
100
200
300
400
500
600
Lag
tim
e (h
)
0
10
20
30
40
H2 p
rod
cuti
on
rat
e(m
mo
l H2/(
min
i-re
acto
r h
))
0
4000
8000
12000
16000
Met
abo
lites
acc
um
ula
tio
n(m
g C
OD
/kg
we
t b
as
is)
VOA
Solvents
Main effect of incubation temperature on performance of first cycle of incubation
M: mesophilic incubation; T: thermophilic incubation; VOA volatile organic acids (sum of acetate, butyrate and propionate); solvents sum of acetone and ethanol
Semi-continuous
acidogenic SSAD
GBPANAT
Objectives
To evaluate the effect of the temperature regime (meso- and thermophilic ) on semi-continuous acidogenic SSAD of organic fraction of municipal solid waste
Response variables:• hydrogen percentage in biogas, • biogas productivity,
• H2 yield (NmL H2/gVSrem),
• organic acids and solvents concentrations in spent solids
1.- Poggi-Varaldo et al., 1997 a, 1999; 2.- Valdez-Vázquez, 2003; 3.- Sparling and Daniels, 1987
Organic fraction of MSW
with 35% w/w dry matter content
Mesophilic, continuous
A-SSAD Reactors1,2
Biogas H2
Spent solids: Organic acidsand solvents
Thermophilic continuous
A-SSAD Reactors1,2
Biogas H2
Spent solids: Organic acidsand solvents
Reactors setup for semi-continuous hydrogen production
0
1000
2000
3000
4000
0 10 20 30 40 50
T ime (days)
Bio
ga
s p
rod
uc
tiv
iy (
Nm
L/(
kg
d))
0
100
200
300
400
500
Hy
dro
ge
n y
ield
(m
L H 2
/ g
VS
rem
)
Typical performances of acidogenic, semi-continuous reactors fed with the organic fraction of municipal solid
waste
Black symbols: biogas productivity; hollow symbols: H2 yield; squares: Thermophilic reactor 1; circles: Mesophilic reactor 1. The methane contents in both reactors were less than 0.5%.
Thermophilic A-SSAD
Mesophilic A-SSAD
2
4
6
8
10
0 10 20 30 40 50
T ime (days)
pH
Evolution of pH in acidogenic semi-continuous reactors fed with the organic fraction of municipal
solid waste Black symbols: Thermophilic reactor 1; hollow symbols: Mesophilic reactor 1
Thermophilic A-SSAD
Mesophilic A-SSAD
0
3600
7200
10800
14400
18000
T hermophilic Me sophilic
Pro
du
ct
dis
trib
uti
on
(m
g C
OD
/kg
wet
bas
is)
Acetone Ethanol Acetate Propionate Butyrate
Average distribution of volatile organic acids and solvents in the spent solids of the acidogenic, solid substrate reactors fed with the organic fraction of
municipal solid wasteHAc
HAc
HBu
HBu
To Table
Comparison of biological hydrogen production from organic fraction of municipal solid waste by anaerobic
culturesSubstrate Seed
Temperature
(ºC)pH
H2
(% v/v)
Cultivation
method
H2
yield aRef
Cabbage 37 55 62
Carrot 37 47 71
Rice
Pretreated
digested sludge b
37
No
control46
Batch
96
[20]
OFMSW c
Pretreated
digested sludge b
and H2-producing
bacteria
37 5.2 60 Batch 180 [21]
37 5.5 d 42 eSemi-
continuous165 f
OFMSW cAnaerobic
digestates55 6.4 g 58 h
Semi-
continuous360 i
This
study
Notes: a NmL/g VS; b inoculum boiled at 100 oC/15 min; c OFMSW: organic fraction ofmunicipal solid waste; d 5.5 0.1; e 42 3; f 165 15; g 6.4 0.2; h 58 3; i 360 48. d,e,f
average and standard deviations of duplicate reactors; g,h,i average and standarddeviations of triplicate reactors.
Conclusions
GBPANAT
To Conclusions A-SSAD
Preliminary experiments:
• Similar final H2 productions were obtained for reactors spiked with acetylene and BES, although a slightly lower for the minireactors spiked with BES
• O2 as methanogenic inhibitor was not successful
• Acetylene and BES OK. Acetylene has a lower cost than BES and does not accumulate in the solid materials
IV-SSAH from paper mill waste:
– Plateaux and initial rates of H2 accumulation decreased in each subsequent incubation cycle
– Total cumulative H2 harvested in the three-cycle incubation was double than that in the first cycle alone (17 and 34 mmole/bottle)
– Kinetics of H2 accumulation is very slow
– Acetylene and BES work OK as inhibitors of methanogenesis. Acetylene has a lower cost than BES and does not accumulate in the solid materials
IV-SSAH from organic fraction of municipal solid waste:
– Acetylene was more effective than HSP – Incubation at 37 oC gave the highest hydrogen
accumulation in the batch reactors
– Origin of inocula did not have a significant effect on hydrogen production
– Units with thermophilic inocula that were treated with HSP and thermophilic incubation gave the poorest hydrogen production in the first cycle, but interestingly, they somewhat improved the hydrogen production in the subsequent cycles
Semi-continuous acidogenic SSAD of organic fraction of municipal solid waste:
– Higher percentage of H2 in the biogas of thermophilic reactors than that in mesophilic ones (60 and 43%, respectively)
– Hydrogen yield of the thermophilic A-SSAD was significantly higher than that of the mesophilic reactors (470 versus 150 NmL/gVS)
– Higher concentrations of volatile organic acids in the spent solids of the thermophilic reactors than in the corresponding solids of the mesophilic units
• Our results point out to a feasible strategy for obtaining higher H2 yields from the fermentation of industrial and municipal solid wastes, and a possible combination of waste treatment processes A-SSAD and M-SSAD
• Useful products of this approach would be– H2– organic acids and solvents– CH4
– and anaerobic digestates that could be used as soil amenders or protein enrichments for animal feed
Lo que vendrá (Tango, Astor Piazzolla)
Biorefinery from
organic solid wastes
Cuando el destino nos alcance…
Organicsolid
waste
H2
IV-SSAH or
A-SSAD
Spent solids
Extracts
Photo-heterotrophic fermentation
Microbial fuel cells Electricity
Downstream processing
AcidsSolvents
M-SSAD
CH4Animal feed
Fertil-izer
Adapted from Poggi-Varaldo, H.M. (2006)
CH4
Sustainable development in Mexico City =Biorefinery of solid wastes
1 ton OFMSW
•47 kW-h biohydrogen
•1050 kW-h methane
•50 to100 kg of organic acids and solvents
•600 kg fertilizer
Recyclables
0.3 ton
Biofuels from food or from wastes?
In the world in which we live, each year millions of people die from the lack of food.
However, none dies for not having a car to drive.
Carlos Escamilla-Alvarado, Mexico, 2008
First International Congress of Biotechnology
and Bioengineering
1ICBB
Mexico City, Mexico, CINVESTAV
Novembre 5-7, 2008
3rd International Meeting on Environmental Biotechnology and
Engineering
3IMEBE
Palma de Mallorca, Baleares Islands, Spain
September 2008
Subjects:Microbial Ecology Molecular Biology Applications
Soil Remediation Environmental Risk Assesm.
Groundwater remediation Sustainable Development
Phytoremediation Wastewater Treatment
Solid and Hazardous Wastes Process Modelling and Control
Environmental Chemistry Atmospheric pollution
Information:
www.cinvestav.mx/2IMEBE
Shadow
I am just the shadowof my echo.I go back and treasuremy yesterday,and I abhor of tomorrowand its treachery.Yet, I fade away, prisoner of a perverse gameof blind mirrorsand blind doors.Now, I am justa shiverof the echo of my shadow.
Sombra
Soy tan solo la sombra de mi eco.Regreso y me abrazoa aquel mi ayer,y abjuro horrorizdodel mañana y sustraiciones.Sin embargo, desaparezcoprisionero de un perversojuego de espejos ciegos y puertas falsas.Ahora, soy tan soloun temblor del ecode mi sombra.
HMP-V, Mexico, 2006
Despedida FarewellMe miro al espejo I look at myself in the
mirror
y sólo veo but I can only see
la desnuda pared a mis espaldas. the bare wall behind me.
Me estremezco y me pregunto: I shiver and mutter:
¿quién llorará nuestras derrotas? Who will cry for our defeats?
¿quién soñará nuestros sueños? Who will dream our dreams?
¿quién peleará nuestras batallas? Who will fight our battles?
¿quién ganará nuestras victorias? Who will win our victories?
HMP-V, March 2003