I
promised a couple of months ago to dig out our conversion tables for
biomass and engines we developed at Fluidyne for our own use.
Biomass
is a fickle fuel and there are always variations to consider in
making calculations. If you just use these basic figures you won't go
wrong, unless that is you crib them to replace laboratory tests, so consider
them real world values!
The
engine tables are not found in existing literature and have been tested
over thousands of hours using various engines. Use them sensibly and you
can do all sorts of cross calculations , that is with normally aspirated
engines. No references apply to turbo charged engines.
If
you choose to include these tables in published literature, then extend
the courtesy of acknowledging their source.
Regards
Doug Williams
Fluidyne Gasification.
Engine Tables
WOOD TO ENERGY CONVERSION DATA
BEFORE GASIFICATION
Based on wood moisture content of 15% wet basis
Woods gross heat energy content: 15,490kJ per kg
Woods gross heat energy content: 6,600 BTU per lb
Or 4.3kW heat per kg. Or 2.615HP per lb
Gasifiers energy conversion efficiency: 73.57% HOT GAS
Gasifiers energy conversion efficiency: 70.95% COLD GAS
AFTER GASIFICATION
Gas produced from 1kg of wood: 2.185 standard cubic metres
Gas produced from 1lb of wood: 35 standard cubic feet
Energy content of 1 standard cubic metre of gas: 5,030kJ
Energy content of 1 standard cubic foot of gas: 135 BTU
After gasification 1kg wood yields 2.185 cubic metres of gas
which has a nett heat energy content of 3.05kW heat.
After gasification 1lb wood yields 35 cubic feet of gas which
has a nett heat energy content of 1.8566HP heat. (Or 4,725 BTU)
1kg of wood produces 2.185 cubic metres of gas
or 3.165kW heat from burning gas direct
or 0.837kW of shaft power i.e engine
or 0.754kW of electric power generated
1lb of wood produces 35 cubic feet of gas
or 4,900 BTU heat from burning the gas direct
or 1.925HP heat from burning the gas direct
or 0.51 HP of shaft power i.e engine
or 0.459HP of electric power generated
or 0.342kW of electric power generated
1 litre of diesel has a heat energy content of 9.630 kW heat (or 32,895 BTU)
1 litre of petrol as a heat energy content of 8.79 kW heat (or
30,023 BTU)
1 litre of diesel has the same heat energy content as the cold gas from 3.1579kg
of wood
1 litre of petrol has the same heat energy content as the cold gas from 2.882kg
of wood
INDICATIVE, WOOD WEIGHTS AND GAS VOLUMES REQUIRED
AND
INDICATIVE, SHAFT AND ELECTRIC POWER OUTPUTS
FOR ENGINES AND GENERATOR SETS
Fuelled with PRODUCER GAS from biomass (wood)
(tabulated values are per litre of swept volume (4 cycle))
Engine RPM
1200
1400
1500
1600
1800
2000
2200
2300
Spark Ignition Engines
Wood required in kg/hr
5.1
5.939
6.363
6.787
7.636
8.484
9.332
9.757
Gas required in m³/hr
11.2
13
14
14.932
16.8
18.665
20.532
21.465
Shaft power in kW
4.266
4.977
5.332
5.688
6.4
7.11
7.821
8.176
Electric power in kW.e
3.732
4.354
4.666
4.977
5.6
6.22
6.843
7.154
Dual fuel, diesel engines fuelled with diesel plus producer
gas NOTE: Wood and gas required is the same as for spark ignition
engines
Shaft power in kW
5.332
6.221
6.665
7.11
8
8.887
9.776
10.22
Electric power in kW.e
4.665
5.443
5.832
6.221
7
7.776
8.554
8.942
To obtain wood and gas required plus power output
values for a particular engine:
Select the required RPM column
Extract the required tabulated ‘per litre’
value
Multiply that value by the particular engines
swept volume in litres
INDICATIVE, WOOD WEIGHTS AND GAS VOLUMES REQUIRED
AND
INDICATIVE, SHAFT AND ELECTRIC POWER OUTPUTS
FOR ENGINES AND GENERATOR SETS
Fuelled with PRODUCER GAS from biomass (wood)
(tabulated values are per 100 cubic inches of total cylinder
displacement (4 cycle))
Engine RPM
1200
1400
1500
1600
1800
2000
2200
2300
Spark Ignition Engines
Wood required in lbs/hr
18.426
21.457
22.989
24.521
27.588
30.652
33.715
35.251
Gas required in cu'ft'/hr
648.1
752.26
810.127
864.06
972.153
1080.07
1188.11
1242.1
Shaft horse power
9.375
10.937
11.717
12.5
14.065
15.625
17.187
17.968
Electric power in kW.e
6.116
7.135
7.646
8.156
9.177
10.193
11.214
11.724
Dual fuel, diesel engines fuelled with diesel plus producergas NOTE: Wood and gas required is the same as for spark ignition
engines
Shaft horse power
11.718
13.671
14.647
15.625
17.581
19.53
21.484
22.46
Electric power in kW.e
7.645
8.92
9.557
10.195
11.471
12.743
14.018
14.654
To obtain wood and gas required plus power output values for a particular engine:
Select the required RPM column
Extract the required tabulated 'per 100 cubic inches' value
Multiply that value by the particular engines swept volume in whole 100s
and decimals of 100 cubic inches. For example: 350 cubic inches = 3.5
Air Dry Wood Fuel Gross Heat Energy Content = 4.3kW per kg of wood
Wood > Gas > Energy Heat Yield (Hot Gas) = 3.165kW per kg of wood
Wood > Gas > Energy Heat Yield (Cold Gas) = 3.05kW per kg of wood
Wood to Gas Volume Yield = 2.185m³ gas per kg wood
Gas > Energy Heat Yield (Hot Gas) = 1.45kW per cubic metre hot gas
Gas > Energy Heat Yield (Cold Gas) = 1.4kW per cubic metre cold gas
Wood > Gas > Shaft Power Spark Ignition Engine (Petrol) = 0.837kW shaft
per kg of wood
Wood > Gas > Shaft Power Spark Ignition Engine (Gas) = 0.82kW shaft per
kg of wood
Wood > Gas > Shaft Power Dual Fuel Diesel Engine = 0.86kW shaft per kg
of wood
Wood > Gas > Electricity Spark Ignition Petrol – Engine
Generator = 0.754kW/hr electricity per kg wood
Wood > Gas > Electricity Spark Ignition Gas – Engine
Generator = 0.697kW/hr electricity per kg wood
Wood > Gas > Electricity Dual Fuel Diesel – Engine
Generator = 0.731kW/hr electricity per kg wood
Wood > Gas > Process Heat (Direct) = 3.17kW heat per kg wood
Wood > Gas > Process Steam = 4.465kW steam per kg wood
Wood > Gas > Power Steam = 3.93kW steam per kg wood
Petrol engines run on Producer Gas at recommended, maximum continuous RPM.
High compression engines derate 37.3% approx to recover power including capacity
x 1.6 times
Average high compression engines derate 42.5% approx to recover power including
capacity x 1.74 times
Medium high compression engines derate 47.0% approx to recover power including
capacity x 1.9 times
Low compression engines derate 56.3% approx to recover power including capacity
x 2.3 times
Diesel (Dual Fuel) engines on pilot diesel plus Producer Gas at recommended,
maximum continuous RPM – derate 20% approximately. To recover power including
capacity x 1.25 times
Gas engines run on Producer Gas at recommended, maximum continuous RPM –
companion ratio: 10 to 1 - derate 10% approximately. To recover power including
capacity x 1.1 times
