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Biomass gasification in supercritical water: II. Effect of catalyst
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Transcript of Biomass gasification in supercritical water: II. Effect of catalyst
BIOMASS GASIFICATION IN BIOMASS GASIFICATION IN SUPERCRITICAL WATER: SUPERCRITICAL WATER:
EFFECT OF CATALYSTEFFECT OF CATALYST
Jale Yanik, S.Ebale*, A. Kruse*, M. Saglam, M. Yüksel
Department of Chemistry, Faculty of Science, Department of Chemistry, Faculty of Science, Ege University, 35100Ege University, 35100
Izmir,TurkeyIzmir,Turkey
*Institue for Technical Chemistry*Institue for Technical ChemistryDivision of ChemicalDivision of Chemical--Physical ProcessingPhysical ProcessingForschungszentrum Karlsruhe,GermanyForschungszentrum Karlsruhe,Germany
Objective of the investigation;
Hydrogen production from biomass by supercritical water gasification
Evulation of experimental findings with respect to:
- Product distribution
-Yields of major liquid products
- Gas product composition depending on:
biomass type
catalyst type
Gasification of Biomass in SCW
Feed stock:
- agricultural wastes: tobacco stalk(B1), corn stalk (B2), cotton stalk(B3), sunflower stalk (B4), corncob(B5), oreganum stalk (B6)
- leather wastes: chromium- tanned(B7) waste and vegetable-tanned(B8) waste
Thermal Gasification
Gasification of Biomass in SCW
B1B1tobaccotobacco
B2B2corn stkcorn stk
B3B3cot. stkcot. stk
B4B4sun. stksun. stk
B5B5corncobcorncob
B6B6oreg.stkoreg.stk
Ash,%Ash,% 7.37.3 6.76.7 4.54.5 11.211.2 2.12.1 4.04.0
CC 40.6040.60 39.7039.70 42.2042.20 36.1036.10 42.9042.90 42.5042.50
Ultimate analysis, dry wt%Ultimate analysis, dry wt%
HH 5.705.70 5.905.90 6.006.00 5.305.30 6.406.40 6.006.00
NN 0.080.08 1.501.50 0.700.70 1.301.30 0.600.60 0.700.70
0.290.29
2.42.40.10.1--
SS 0.490.49 0.290.29 0.390.39 0.590.59 0.290.29
KK 7.57.5 3.53.5 2.92.9 7.97.9 5.25.2CaCa 3.43.4 0.90.9 0.70.7 4.94.9 1.41.4MgMg 0.10.1 0.10.1 0.10.1 0.20.2 0.20.2
Properties of lignocellulosic biomasses
Gasification of Biomass in SCW
B1B1tobaccotobacco
B2B2corn stkcorn stk
B3B3cot. stkcot. stk
B4B4sun. stksun. stk
B5B5corncobcorncob
B6B6oreg.stkoreg.stk
CelluloseCellulose 48.5 48.5 27.0 27.0 47.1 47.1 43.1 43.1 31.7 31.7 33.8 33.8
LigninLignin 11.111.1 3.03.0 11.011.0 9.7 9.7 3.4 3.4 9.39.3
HemicelluloseHemicellulose 16.2 16.2 27.1 27.1 13.113.1 7.4 7.4 31.731.7 10.910.9
Properties of lignocellulosic biomasses
Gasification of Biomass in SCW
B7B7chromiumchromium--
tannedtanned
B8B8vegetablevegetable--
tanned tanned Ash,%Ash,% 9.09.0 4.14.1
Ultimate analysis, dry wt%Ultimate analysis, dry wt%CC 37.237.2 46.2046.20
HH 6.406.40 5.505.50
NN 13.6013.60 6.606.60
SS 1.791.79 1.291.29
KK 0.10.1 0.9810.981CaCa 0.20.2 0.5920.592CrCr 4.44.4 nilnil
Properties of leather wastes
Gasification of Biomass in SCW
Batch Reactor- Autoclavewith 1 L of volume,
3 °C min-1
500 °C, 1 h
8.3 g of lignocellulosic or
1.6 g of leather wastes and
140 ml of water
Thermal Gasification
Gasification of Biomass in SCW
MaterialsMaterials B1B1(tobac)(tobac)
B2B2(corns)(corns)
B3B3(cotton)(cotton)
B4B4(sunflow)(sunflow)
B5B5(cornc)(cornc)
B6B6(oreg)(oreg)
Max. Pressure, barMax. Pressure, bar 278.5278.5 335.8335.8 275.8275.8 308308 287.6287.6 241.2241.2ProductsProductsGas, Gas, (g gas/kg biomass)(g gas/kg biomass) 247247 534534 418418 592592 340340 390390
21.721.7Coke, Coke, (g coke/kg biomass)(g coke/kg biomass) 55.455.4 66.366.3 104.8104.8 19.319.3 113.3113.3
Product distribution from SCWG of agricultural wastes
Thermal Gasification
Gasification of Biomass in SCW
Some parts of aromatic compounds such as lignin or other unsaturated species, are eventually polymerized to tar and char materials.
Thermal Gasification
Gasification of Biomass in SCW
Although B6 and B4 have similar lignin content, the amount of coke obtained from B6 was five times more than that of from B4.Similarly, B3 gave two times more coke than that of from B4even their lignin contents were identical.
Coke formation in biomass gasification due to the lignin not only depends on the lignin amount and also strongly depends on the structure of lignin and interactions between other components in biomass.
MaterialsMaterials B7B7 B8B8
Max. Pressure, barMax. Pressure, bar 249.3249.3 314.5314.5ProductsProductsGas, Gas, (g gas/kg biomass)(g gas/kg biomass) 165165 519519
Coke, Coke, (g coke/kg biomass)(g coke/kg biomass) 175.0175.0 237.5237.5
Product distribution from SCWG of leather wastesThermal Gasification
Gasification of Biomass in SCW
B8 produced more amount of coke, because vegetable tannin agent consists of phenolic compounds.
4,65 4,12 4,13 3,65 2,094,09
1,444,05
02468
101214161820
B1 B2 B3 B4 B5 B6 B7 B8
Yiel
d, m
ol g
as/k
g bi
omas
s CH4CO2H2
Gas yields from different biomass feedstocks.
Thermal Gasification
Gasification of Biomass in SCW
water–gas shift reaction CO + H2O⇋ CO2 + H2
methanation reaction CO + 3H2⇋ CH4 + H2O
Thermal Gasification
Gasification of Biomass in SCW
Although B1 and B4 have similar potassium content as well as the cellulose, hemicellulose and lignin content, the yields and composition of gases obtained from B1 and B4 are significantly different from each other.
These findings indicate that organic materials other thancellulose, hemicellulose and lignin may have also effect theyield and composition of gas products
Thermal Gasification
Gasification of Biomass in SCW
Proteins
The degradation of organic acid produce mainly CO, CO2, H2 and H2O
Thermal Gasification
Gasification of Biomass in SCW
Amino acids
carbonic acids/amines
carboxylic acids/ammonia
cellulose
glucose/fructose
acids/aldehydes
gases
furfurals
phenols
higher molecular weight products
I II III
decomposition of cellulose in supercritical water
Gasification of Biomass in SCW
0
2
4
6
8
10
12
14
B1 B2 B3 B4 B5 B6 B7 B8
g liq
uid
prod
uct /
kg
biom
ass acetic acid
formic acidfurfuralsphenols
Yields of major products in aqueous phase from SCWGof different biomasses.
Thermal Gasification
Gasification of Biomass in SCW
CONCLUSION
Thermal Gasification
Gasification of Biomass in SCW
- The gasification of lignocellulosic and tannery wastesleads to formation of gases consisting of mainly H2,CO2 and CH4.
-The gas obtained from tobacco stalks contained the highest amount H2(39.47%), although it produced relatively lowgas yield.
-The lowest total gas yield was obtained from chromium tanned waste.
CONCLUSION
- tannery waste containing no chromium gave the similargas yields and composition with the lignocellulosic materials.
in the case of real biomass, the gasification reactions were more complex and the whole biomass contents are expected to effect on the results.
Thermal Gasification
Gasification of Biomass in SCW
Catalysts: Red mud, Trona, Ni, K2CO3
Feedstock:- agricultural wastes: sunflower stalk, corncob
- leather wastes: vegetable-tanned
Catalytic Gasification
Gasification of Biomass in SCW
Red mud:Fe2O3 (37.72%), Al2O3 (17.27%), SiO2 (17.10%), TiO2 (4.81%), Na2O (7.13%), and CaO (4.54%).
Trona: Na3H(CO3)2.2H2O
Ranney nickel:(as suspension containing 50 wt% water and 50 wt% Raney nickel)
Catalytic Gasification
Gasification of Biomass in SCW
Batch Reactor- Autoclave with 1 L of volume,
3 °C min-1
500 °C, 1 h
8.3 g of biomass and 0.8 g of catalyst and 140 ml of water
(biomass-catalyst suspension -5 wt% biomass + 0.5 wt% catalyst-)
Catalytic Gasification
Gasification of Biomass in SCW
CatalystCatalyst nonenone KK22COCO33 TronaTrona Red MudRed Mud RaRa--NiNi
Max. Pressure, barMax. Pressure, bar 308308 311311 360360 314314 314314ProductsProductsGas, Gas, (g gas/kg biomass)(g gas/kg biomass) 592592 420.8420.8 461.06461.06 446.75446.75 477.3477.3
357.8357.8Coke, Coke, (g coke/kg biomass)(g coke/kg biomass) 19.319.3 90.290.2 160.2160.2 31.331.3
Product distribution from SCWG of sunflower stalks
Catalytic Gasification
Gasification of Biomass in SCW
Used catalysts promote the condensation reactions
0
5
10
15
20
25
none K2CO3 Trona Red mud Ra-Ni
yiel
ds, m
ol g
as /
kg b
iom
ass
CH4CO2H2
Gas yields from sunflower stalkCatalytic Gasification
Gasification of Biomass in SCW
- Hydrogen yields were extremely increased by using of catalysts.
- Trona showed similar activity with K2CO3 in hydrogen production.
Catalytic Gasification
Gasification of Biomass in SCW
K2CO3 + H2O ...........KHCO3 + KOH
KOH + CO ....... HCOOK
Formate reacts with water to produce hydrogen
HCOOK + H2O ..... KHCO3 + H2
CO2 is produced by the decomposition of KHCO3
2KCO3..............H2O + K2CO3 + CO2
However in this study
CO2 content decreased by using of catalyst
Reason may be
- CO2 may be consumed by the reaction with organic materials
- CO2 may partly be present in the liquid phase.
Catalytic Gasification
Gasification of Biomass in SCW
- CH4 formation was decreased to the same extent for all catalysts.
CH4 + 2H2⇋ CO2 + H2
Catalytic Gasification
Gasification of Biomass in SCW
0
2
4
6
8
10
12
none K2CO3 Trona Red mud Ra-Ni
g liq
uid
prod
uct /
kg
biom
ass
acetic acidformic acidfurfuralsphenols
Yields of major products in aqueous phase from SCWGof sunflower stalk
Catalytic Gasification
Gasification of Biomass in SCW
-The addition of alkaline catalysts increased the formic acid yield
• probably due to the formation of potassium formate
-The phenol amount was decreased by addition of catalyst.
• catalysts used enhanced the cross-linking reactions
between phenols and lower-molecular-weight fragments or
• suppressed the phenol formation.
Catalytic Gasification
Gasification of Biomass in SCW
CatalystCatalyst nonenone KK22COCO33 TronaTrona Red MudRed Mud RaRa--NiNi
Max. Pressure, barMax. Pressure, bar 287.6287.6 312.0312.0 317.0317.0 357.3357.3 403.1403.1ProductsProductsGas, Gas, (g gas/kg biomass)(g gas/kg biomass) 340340 614.9614.9 412.1412.1 426426 448.1448.1
28.928.9Coke, Coke, (g coke/kg biomass)(g coke/kg biomass) 21.721.7 21.721.7 40.940.9 16.916.9
Product distribution from SCWG of corncobCatalytic Gasification
Gasification of Biomass in SCW
catalysts led to an increase in gas yield where as no significant effect of catalyst on coke formation was observed.
0
5
10
15
20
25
none K2CO3 Trona Red mud Ra-Ni
yiel
ds, m
ol g
as /
kg b
iom
ass
CH4CO2H2
Gas yields from corncob
Catalytic Gasification
Gasification of Biomass in SCW
Trona showed the highest activity in both
water-gas shift reaction and reforming of methane.
Catalytic Gasification
Gasification of Biomass in SCW
0
5
10
15
20
25
none K2CO3 Trona Red mud Ra-Ni
g liq
uid
prod
uct /
kg
biom
ass
acetic acidformic acidfurfuralsphenols
Yields of major products in aqueous phase from SCWGof corncob
Catalytic Gasification
Gasification of Biomass in SCW
The effect of catalyst on gasification varied according to the type of agricultural wastes. The differences is resulted from the composition of lignocellulosic materials.
Catalytic Gasification
Gasification of Biomass in SCW
-Sunflower stalk contained more amount of cellulose and much less amount of hemicellulose than corncob.
-Besides, the organic constituents other than cellulose and lignin might be different in each material.
CatalystCatalyst nonenone KK22COCO33 TronaTrona Red MudRed Mud
Max. Pressure, barMax. Pressure, bar 314314 309309 311311 299299ProductsProductsGas, Gas, (g gas/kg biomass)(g gas/kg biomass) 331.26331.26 411.8411.8 343.9343.9 322.5322.5
10.910.9Coke, Coke, (g coke/kg biomass)(g coke/kg biomass) 33.7333.73 50.9650.96 68.4368.43
Product distribution from SCWG of leather
Catalytic Gasification
Gasification of Biomass in SCW
Raney-Ni has very high gasification affect in SCWG of proteins.
Only K2CO3 considerably affected the gas yield.
0
5
10
15
20
25
none K2CO3 Trona Red mud
yiel
ds, m
ol g
as /
kg b
iom
ass
CH4CO2H2
Gas yields from leather
Catalytic Gasification
Gasification of Biomass in SCW
Proteins
The degradation of organic acid produce mainly CO, CO2, H2 and H2O
Thermal Gasification
Gasification of Biomass in SCW
Amino acids
carbonic acids/amines
carboxylic acids/ammonia
0
1
2
3
4
5
6
7
none K2CO3 Trona Red mud
g liq
uid
prod
uct /
kg
biom
ass
acetic acidformic acidfurfuralsphenols
Yields of major products in aqueous phase from SCWE of leather waste
Catalytic Gasification
Gasification of Biomass in SCW
• The amount of acetic acid decreased in presence of catalysts.
• Because the tanning agent in leather waste consists ofphenolic compounds, the phenols content in aqueous phase was increased by catalytic degradation of tanningagent.
Catalytic Gasification
Gasification of Biomass in SCW
In this study, the catalytic gasification of real biomasses (lignocellulosic and proteinous materials) in supercritical water was investigated.
Trona (a natural mineral) and red-mud (a by-product) were used as catalyst besides K2CO3 and Raney-Ni,
CONCLUSION
Catalytic Gasification
Gasification of Biomass in SCW
The effect of catalysts on gasification varied according to the type of biomass.
Catalysts have significantly increased the hydrogen yield. The all used catalysts enhanced the water-gas shift reaction and reforming of methane which due to the formation of H2 rather than methanation.
Catalytic Gasification
Gasification of Biomass in SCW
CONCLUSION
Trona showed similar gasification activity with K2CO3.
Although, the yield of hydrogen with red mud was lower than that with alkaline catalysts for all biomass tested, the present findings established that iron based catalysts show activity for the production of hydrogen from biomass.
Catalytic Gasification
Gasification of Biomass in SCW
CONCLUSION