Coal briquette manufacturing technology from coal powder that can cause difficulties at the time of transport was already mostly done in some countries. Things that encourage the use of briquettes for small industry communities and Indonesia, among others:
1. Potential coal Indonesia is very large
2. Most of the population in Indonesia live in rural
3. Can be implemented with simple technology, with low investment
4. Indonesian coal fragile and high caloric value
5. Utilizing coal powder that does not use difficult transported, to be more useful
6. The existence of coal deposits with limited reserves (10 million tons) that can be used in small scale for the surrounding area
7. Government policies to reduce oil consumption and fuel wood
A. Coal briquette Engineering
a. The nature of good briquettes
1. No smoking and no smell at the time of combustion
2. Have certain powers that are not easily broken when appointed and removable
3. Combustion temperature has a fixed (± 3500C) in a period of time long enough (8-10 hours)
4. After combustion still has a certain strength so it is easy to remove from the stove to cook
5. The combustion gases do not contain carbon monoxide gas high
b. Type briquettes
Known briquettes are 2 types:
1. Type yontan (cylinder) for household use
This type is more known and popular, called yontan, a local name cylindrical with diameters of 150 mm, height 142 mm, weight 3.5 kg and has as many holes 22 holes
2. Type egg for industry and households
This type is also used to fuel a small industry such as for burning lime, bricks, tiles, pottery, blacksmith and so on, but also for household use. This type of width 32-39 mm long, 46-58 mm and 20-24 mm thick
c. Technical production
Yontan briquette-making process is quite simple. Coal powder (5 mm) were given water (10%) is pressed by press briquette machine at 120 kg/cm2 pressure so that the briquettes obtained. To type eggs have added molasses (7%) and on roll-type briquette machine
d. Parameters in the manufacture of briquettes
Some of the parameters in the manufacture of briquettes are as follows:
1. Grain size of coal
2. Pressure machine at the time briquette
3. Water content contained in coal
Some experience with a strong briquette press> 6 kg/cm2 quite strong and not easily broken at the time was taken, transported and lifted.
e. Combustion characteristics
The nature of combustion is very important as well depending on the nature of coal. These briquettes combustion characteristics (long and the temperature of combustion) depends also from the amount of burning air (water supply) and the calorific value of coal. The greater the air shorter burned briquettes burn longer and higher calorific value of coal briquettes made longer burning time. The greater the air given (with open air cooking stoves) shorter time briquette combustion temperature obtained despite a higher maximum.
B. Briquette Making Of Coal
Examples of pulverized coal to the size of 5 mm, then added clay (20%) as a binder and water 10%. Analysis of coal samples as follows:
Table of chemical analysis of coal samples korea
Sample properties
Korean
8.19 atoms
39.5
fixed carbon
50.24
53.70
calorific value
7160
4570
S (sulfur)
0.47
0.29
moisture 1.91
3.70
volatile matter 39.66
3.20
subbitumine class
anthracite
Addition of clay is intended to gain strength and size relative to the levels brought closer and briquette ash yontan Korean.
a. Strong press
From the result of the emphasis with the same engine briquette obtained the following data:
Confinement Material Clay
Strong Press (kg/cm2
20%
7.5
30%
10.2
The results provide strong data that the press here are good enough (> 6 kg/cm2)
b. Combustion characteristics
From the result of combustion data obtained as follows:
1. Enough smoky and pungent
2. The highest combustion temperature is slightly higher than the Korean briquettes 6500C - 7000C (6000C Korean briquettes
3. Long time at a temperature of 3500C combustion was much shorter ± 2.5 hours, was briquettes Korean 8 hours
By setting the pipe smaller air openings are expected to be longer burning time.
Note: the addition of clay can absorb the smell of tar and enhance the quality of briquettes, although it can reduce the value of calorie.
We recommend that you use coal with high ash
c. Eliminate smoke and odor
Experiment to reduce / eliminate smoke and the smell of coal briquettes has been done by reducing the volatile matter. This can be done by carbonization of coal at low temperatures and it worked well. Only problem burning time of coal briquettes are still relatively short at around ± 4 hours.
(Source: Coal & Peat, Ir. Sukandarrumidi, MSc. Phd)