One kilogram of unheated oil was set aside for additional
20 measurements.
Once the measurements of the vegetable oil were complete, the gas burner was turned on to a temperature of about 270° C, and the temperature of the vegetable oil in the small container was monitored using the thermocouple and temperature gauge. After the
temperature of the vegetable oil was stabilized at about 260° C ถึงประมาณ 270° C, a 1-Kg 25 sample of densified wood pellets was loaded into the wire strainer basket and submerged in
the heated vegetable oil in the small container เป็นเวลาประมาณ 5 นาที. The wire strainer basket
with the densified wood pellets contained therein was then removed from the vegetable oil in
the small container, and allowed to drain and drip dry over the small container for 5 นาที.
The ชีวมวล อัดทีที was retrieved from the wire strainer basket and its weight
measured, without submersing in a cold water, to avoid any water absorption by the ชีวมวล อัดทีที and contamination of the results. The net weight loss or gain of the sample was then calculated by comparing to the starting weight of the densified wood pellets, on a
dry basis. The net weight of the used oil was also measured by measuring the small container 5 containing the used oil and subtracting the weight of the small container. Oil loss by
absorption and mass loss of pellets was calculated. This process was repeated another 8
times, each with a 1 kilogram sample of densified wood pellets. The total weight of the small
container containing the oil was measured prior to each experiment. One kilogram of the used
vegetable oil in the small container was collected for additional testing purposes.
10 The resulting ชีวมวล อัดทีที from all 9 test experiments were collected
and mixed together to form a sample batch. One kilogram of the sample batch was collected for testing.
Results:
The results from two sample batches prepared according to the process described for 15 Example 1 are shown in Table 1. The test results indicated that with about 5 นาที in a
vegetable oil heated ถึงประมาณ 260°C ถึงประมาณ 270°C, densified wood pellets increased in
weight by an average of about 10% and increased in BTU value by an average of 15%. In
addition, the torrefied wood pellets were found to be hydrophobic and to have increased
grindability (i.e., high Hardgrove Grindability Index) as compared to untorrefied wood 20 pellets. "Hardgrove Grindability Index" ("HGI") is a measure for grindability of coal.
Grindability is indicated using the unit °H, for example, "40°H" or "55°H." A higher HGI
value indicates a more easily pulverized or more grindable product.
As shown in Table 1 below, the lower heating value (LHV) of two sample batches of
torrefied pellets obtained from the process were 23.11 and 22.76 GJ/ton, respectively. This 25 represents an increase in LHV of approximately 14.8% for sample 1 and approximately
16.1% for sample 2. Those skilled in the art will know that an average LHV for wood pellet fuel ranges from a low of 18.14 GJ/ton to a high of 19.72 GJ/ton, making torrefied wood pellets of the disclosed process to be approximately 17.5% higher in heat value compared to good quality biofuel.
36
Table 1:
Measurements Starting Densified Wood Torrefied Wood Pellet
Pellet #1 #1
As Received Dry Basis As Received Dry Basis
Basis Basis
Weight 1 kg 1 kg
% Moisture 7.00 1 0 2.78 I 0
Calorific Value (Gross)
Btu/lb 8336 I 8963 9786 10066
Kcal/kg 4631 I 4979 5437 '5592
Torrefied Wood Pellet
#2
As Received Dry Basis
Basis
1 kg
0.59 0
9934 9993
5519 5552
I
GJ/ton 19.39 I 20.85 22.76 I 23.41 23.11 23.24
% Carbon 1 55.46 55.79
% Hydrogen 6.58 6.62
(excludes H in
36.92moisture)
% Nitrogen 0.09 0.09
% Sulphur 0.02 0.02
% Ash 0.56 0.56
%Oxygen 1 36.70 36.92
% Hydrogen 6.65 ---
(includes H in moisture)
"% Moisture" for the "Torrefied Wood Pellets" refers to the amount of water in the
torrefied wood pellets immediately after the กระบวนการทอร์รีแฟกชัน process (i.e., after drip drying for 5 นาที).
5 "Starting Densified Wood Pellet" is the sample that was initially set aside for testing
purposes.
37
Example 2:
Materials and Methods
In this example, a coastal hemlock ก้อน was quartered and each quarter was used
for testing. Three of the quarters were used in the กระบวนการทอร์รีแฟกชัน process and one quarter was set 5 aside. The initial weight of the quartered ก้อน used in the กระบวนการทอร์รีแฟกชัน process is set out
in Table 2 below.
The small test unit, as described above for Example 1, was used in this example. As
an initial step, the small container was placed on a scale and the net weight of the empty
small container was measured. Vegetable oil was then poured into the small container and the 10 total weight of the small container plus vegetable oil was measured, thereby providing a net
weight for the vegetable oil.