Transcript Biomass pyrolysis and gasification

30th ISTC Japan Workshop
on Advanced Catalysis Technologies in Russia
Fluidized bed catalytic pyrolysis and gasification
of biomass for production of fuel out of renewable
resources
Prof. Z.R.Ismagilov
Laboratory of Environmental Catalysis,
Boreskov Institute of Catalysis SB RAS,
Novosibirsk, Russia, www.catalysis.ru/envicat
BIOMASS YEARLY WORLD GROWTH - UP TO 200*109 t
TO DATE YEARLY BIOMASS CONSUMPTION (FOOD,
CONSTRUCTION, FUEL PRODUCTION) - 3-4 %
ADDITIONAL INVOLVING OF 3 % OF BIOMASS FOR
FUEL PRODUCTION IS EQUIVALENT TO 3*109 t OF
CRUDE OIL REPLACEMENT
Diagram of biomass processing and utilization
Catalytic fluidized bed for biomass pyrolysis and gasification
1. Increase of the process rate and decrease of the temperature
to 600-700оС
2. Increase of the content of H2 and CO in the products to 10-15
vol.% and regulation of H2/CO ratio
3. Decrease of the yield of liquid and solid products of pyrolysis
4. Production of low tar or tar free synthesis gas.
Experimental
• For the studies semolina was taken as a biomass model object, with the following
chemical composition (wt. %): hydrogen 6.92; carbon 39.18; nitrogen 1.81; ash 1.17.
• The combustion catalyst CuxMg1-xCr2O4/-Al2O3 (IC-12-73) was used in the
experiments. The inert bed material used in the setups 2 and 3 was granulated -Al2O3.
• All setups were equipped with the system for on-line continuous gas sampling for GC
analysis.
• The goal of this work was to study the processes of biomass pyrolysis and
gasification in experimental facilities containing fluidized bed reactors. Three setups
used in this work were different by the way of conducting the pyrolysis and gasification
processes.
Experimental setup 1
In the setup 1 the reactor contains
fluidized bed catalyst in lower part
for catalytic combustion of fuel.
The height of the fluidized bed
being 50 cm and biomass was fed
directly to the hot fluidized bed at
the height of 40 cm.
Experimental setup 2
The setup 2 contains two fluidized bed
reactors. Lower reactor is for fuel
catalytic combustion and upper
reactor loaded by inert bed material
(-Al2O3). The biomass was fed into
the fluidized bed of the upper reactor.
Scheme of experimental setup 1
1,2 – reactor: 1 – lower part with fluidized bed of catalyst; 2 – upper part; 3 - high-temperature cyclone; 4 - lowtemperature cyclone; 5 – biomass feeder; 6 - rotameter; 7 - valve; 8 – reservoir with fuel; 9 - multi channel
temperature control system; 10 - plunger micro pump for fuel injection; 11 - grid filter and fine filter; 12 - ejector
Characteristics of the setups.
Characteristics
Dimensions, mm
Reactor type
material
diameter, mm
Catalyst
loading, dm3
fraction, mm
Inert bed
loading, dm3
fraction, mm
Temperature of working zone, oC
Air flow, m3/h
Fuel flow, l/h
Biomass flow, kg/h
Setup 1
1800 x 600 x 600
FB
stainless steel
50
IC-12-72
0.5
1.6-2.0
-
650-800
2.5
0.2
0.3
Value
Setup 2
2500х2500х600
FB
stainless steel
50
IC-12-72
1.0
1.6-2.0
-Al2O3
0.3
2.0-2.5
650-800
6.0
0.3
0.5
Setup 3
4000 x 3000 x 1500
FB
stainless steel
300
IC-12-72
4.0-5.0
0.4-0.8
-Al2O3
3.0
0.2-0.4
650-800
30
1-1.5
10
The experimental conditions and results of GC analysis of reaction products.
Temperature in the biomass feeding zone – 750oC.Setup 1.
Products, % vol.
FID
TCD
Fuel
*
inject
CH4 C2H6 C3H8 C4H10 iso- C5H12
CO
N2
O2
H2
Air,
C4H10
m3/h
experiments with variation of air flow (in fluidized bed)
0
0
0.01
0.01
0.01
0.03
0.01
78.4
11.3
0.2
0.87
0.375 0.175
0.02
0.01
0.06
0.09
0.08
0.1
0.6
77.6
8.9
1.2
0.83
0.375 0.175
0.09
0.06
0.4
0.5
0.4
0.6
1.8
78.1
6.3
2.7
0.79
0.375 0.175
0.3
0.3
0.7
0.9
0.8
1.2
4.3
79.9
3.2
4.1
0.71
0.375 0.175
0.6
0.7
0.8
1.3
1.2
1.8
6.3
77.8
1.0
5.2
0.63
0.375 0.175
experiments at fixed air flow (checking stability of the process)
0.4
0.5
0.8
1.0
0.9
1.3
5.1
78.2
2.8
4.6
0.67
0.375 0.175
0.3
0.4
0.8
0.9
1.0
1.2
4.9
78.1
2.7
4.4
0.67
0.375 0.175
0.3
0.5
0.7
0.9
0.8
1.1
5.2
77.9
2.9
4.0
0.67
0.375 0.175
0.4
0.4
0.7
0.9
0.8
1.3
4.7
77.9
3.0
3.9
0.67
0.375 0.175
0.4
0.4
0.7
0.8
0.8
1.3
5.0
78.0
2.7
4.3
0.67
0.375 0.175
experiments with variation of air flow (at fixed total gas flow in fluidized bed)
0.2
0.3
0.7
1.4
1.5
2.1
7.2
78.2
0.5
5.6
0.51
0.375 0.175
0.15
0.3
0.5
1.1
1.3
1.6
6.5
77.5
0.9
5.0
0.63
0.375 0.175
0.1
0.1
0.2
0.07
0.9
1.3
5.1
77.3
2.9
4.5
0.71
0.375 0.175
0.01
0.01
0.02
0.4
0.05
0.4
1.5
78.4
7.8
2.3
0.83
0.375 0.175
0
0
0
0.01
0.01
0.01
0.1
78.5
8.8
0.3
0.95
0.375 0.175
Feed conditions
Fluidized Ejector
bed
N2,
N2,
Air,
m3/h m3/h m3/h
Fuel,
l/h
Semo
lina,
kg/h
0.1
0.1
0.1
0.1
0.1
0.3
0.3
0.3
0.3
0.3
1.5
1.4
1.3
1.1
0.9
0
0
0
0
0
0.1
0.1
0.1
0.1
0.1
0.3
0.3
0.3
0.3
0.3
1.0
1.0
1.0
1.0
1.0
0
0
0
0
0
0.1
0.1
0.1
0.1
0.1
0.3
0.3
0.3
0.3
0.3
0.6
0.9
1.1
1.4
1.7
1.6
1.3
1.1
0.8
0.5
* is oxygen to fuel equivalence ratio, i.e. the ratio of the actual amount of
supplied oxygen to that of oxygen required for complete combustion of biomass and fuel
Experimental setup 2
The setup 2 contains two fluidized bed
reactors. Lower reactor is for fuel
catalytic combustion and upper
reactor loaded by inert bed material
(-Al2O3). The biomass was fed into
the fluidized bed of the upper reactor.
Pyrolysis and gasification of semolina in fluidized beds with different materials.
Setup 2.
No.
Gases content
О2,
Н2 ,
СО,
СН4,
NOx,
Примечание
% vol.
% vol.
% vol.
% vol.
mg/m3
Fuel (without semolina) 850-900oC
1
2.6
0.51
41
2
2.7
0.50
32
Experiment 1; fuel – 300 ml/h, semolina - 1000 g/h, quartz – 300 ml, 700oC
6
0.1
1.53
10.12
0.35
961
Н2 - 1.44%
СО – 10.02%
7
0.0
1.48
9.98
0.35
1084
СН4 – 0.35%
8
0.0
1.33
10.12
0.35
1043
Experiment 2; fuel – 300 ml/h, semolina - 1000 g/h, quartz – 300 ml + catalyst – 100 ml, 700oC
11
0.0
5.84
10.64
0.89
890
Н2 - 5.84%
СО – 10.54%
12
0.0
5.84
10.63
0.98
974
СН4 – 0.92%
13
0.0
5.84
10.46
0.88
986
Experiment 3; fuel – 300 ml/h, semolina - 950 g/h, Al2O3 – 300 ml, 750oC
11
0.0
4.8
5.96
0.71
1865
Н2 - 4.7%
СО - 5.79%
12
0.0
4.6
5.87
0.73
1838
СН4 - 0.72%
13
0.0
4.7
5.64
0.71
1874
Conversion of biomass upon the variation of specific biomass flow.
Setup 3.
Dependencies of the content of gaseous products of air conversion of biomass and initial gases on the value of
specific biomass flow.
Height of the stationary bed - 0.32 m, height of fluidized bed - 0.5 m, loading of -Al2O3 (d=1mm) - 2.5 dm3, T = 720-780oC, residence
time - 0.45 c.
Conversion of biomass upon the variation of contact time with reaction
medium. Setup 3.
Dependencies of the content of gaseous products of air conversion of biomass and initial gases on the biomass
contact time with reaction medium. Light dots – inert packing -Al2O3; dark dots – catalyst IC-12-72.
Height of fluidized bed - 0-0.5 m, loading of -Al2O3 (d=1mm) - 0-2.4 dm3, T = 670-700oC, biomass flow - 5.8-7.2 kg/h, specific
biomass flow - 0.71-0.88 kg/m3.
Conversion of biomass upon the variation of additional steam flow
Setup 3.
Technological characteristics of the process of steam-air biomass conversion upon the variation of additional steam
flow (experiments 1-3) and of the biomass pyrolysis process (experiment 4).
No.
1
2
3
4
5
6
7
8
9
10
1
2
3
4
5
6
7
8
9
Parameters
Meas.
units
No. of experiment
Steam-air conversion
Pyrolysis
1
2
3
4
Technological parameters of the process
Air flow
m3/h
8.2
8.2
8.2
Nitrogen flow
m3/h
8.2
Biomass flow
kg/h
6.7
6.7
4.1
8.3
Specific biomass flow
kg/m3
0.8
0.8
0.5
1.0
Water flow
kg/h
0.5
1.1
1.8
0
3
Specific water flow
kg/m
0.06
0.13
0.22
0
Water flow/biomass flow
g/kg
75
160
435
0
o
Initial bed temperature
C
615
630
625
620
o
Operating bed temperature
C
705
700
710
570
o
Temperature in CHG
C
660
670
670
650
Composition of the steam-air conversion and pyrolysis products
H2
vol.%
9.0
9.0
5.5
0
O2/Ar
vol.%
4.0
3.0
4.9
2.8
N2
vol.%
57.2
52.0
62.3
72.8
CH4
vol.%
1.5
2.0
0.9
0.9
CO
vol.%
12.4
15.0
7.4
7.0
CO2
vol.%
9.4
13.0
10.0
3.5
C2H4
vol.%
1.0
1.0
0.5
0.4
C2H6
vol.%
0.1
0.l
0
0.1
H2O
vol.%
2.0
2.0
2.0
2.0
Balance
vol.%
96.8
97.1
93.5
89.5
Results of the GC/MS analysis of liquid fraction of the biomass pyrolysis
and gasification products. Setup 1.
No.
1
Name
Acetic acid
Formula
C2H4O2
2
Acetohydroxamic
acid
3
Structure
No.
7
Name
2,5-Hexanedione
Formula
C6H10O2
C2H5NO2
8
2,5-Furandione, 3methyl-
C5H4O3
Propanoic acid
C3H6O2
9
Phenol
C6H6O
4
Pyridine
C5H5N
10
2-Cyclopenten-1one, 2-hydroxy-3methyl
C6H8O2
5
Pyridine, 2methyl-
C6H7N
11
1,4 : 3,6-Dianhydroalpha-dglucopyranose
C6H8O4
6
2(5H)-Furanone
C4H4O2
12
Unidentified highmolecular
oxygen-containing
compounds
-
Structure
-
Conclusions:
1. Main products of biomass conversion are the gases: H2, CO and CH4 . The maximum
quantaties of these products are: H2 - 8-11% vol., CO - 18-20%vol., CH4 - 2-2.5%vol.
2. Conducting pyrolysis in the inert atmosphere, or conversion with the addition of water
vapor into the reaction zone do not have any advantages over the conventional catalytic
process
3. At the values of oxygen excess ratio >0.60-0.65 the process proceeds with
preferential formation of the gaseous conversion products, while at the values <0.60
the evolving of liquid and solid products is also noticeable; at <0.50 the evolving of
liquid and solid products becomes very abundant, while that of the gaseous products,
on the contrary, decreases. Most optimal is to conduct the process at ~0.5-0.65. In this
case, the values of the yields of gaseous products of biomass pyrolysis and gasification
are maximal, and evolving of liquid and solid products is minimal.