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 American Journal of  
Food Science and Technology (AJFST)

Adaptation and Performance Evaluation Closed Drum 
Type Carbonizer for Waste Biomass

  Getachew Hailu1*

Volume 2 Issue 1, Year 2023
ISSN: 2834-0086 (Online)

DOI: https://doi.org/10.54536/ajfst.v2i1.1508
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Article Information ABSTRACT

Received: March 25, 2023
Accepted: April 11, 2023
Published: June 14, 2023

A nation’s development is frequently driven by its energy industry. It is alarming that 
firewood is still frequently utilized as the main source of  energy for cooking in many nations, 
especially those that see a decline in forest cover. For the carbonization of  biomass waste, 
a drum-type carbonizer adaptation was created. The potential for obtaining a biomass 
carbonization process is the subject of  this research. Various agricultural waste products 
(such as sawdust, coffee husks, peanut shells, and millet stalks) have been heated up in a 
device called a carbonizer. These two residues’ biomass carbonization yields were calculated 
and found to be 37.5% and 60.98%, respectively, for sawdust and coffee husk.

Keywords

Carbonization, Waste Biomass, 
Coffee Busk, Sawdust, 
Temperature

1 Oromia Agricultural Research Institute, P.O. Box 06, Assela Agricultural Engineering Research Center, Oromia, Ethiopia
* Corresponding author’s e-mail: hailufg94@gmail.com

INTRODUCTION
For forestry enterprises, the development of  bioenergy 
offers a singular chance to expand their steady revenue 
streams. By converting ores into metals through a process 
called carbonization, people were able to create charcoal, 
the first biofuel that helped them escape the Stone Age 
(Basu, P.,2006). Charcoal is utilized as a premium solid 
fuel worldwide for domestic cooking, metal refining, and 
chemical manufacture.
Additionally, the market is well defined, the technology 
is well known but still presents opportunities for 
advancements (in terms of  efficiency, costs, and 
environmental impacts), the technology does not present 
a significant risk, the investment is well suited for small 
farmers, and the process and technology provide a great 
opportunity for the development of  small-scale and 
local supply chains. Making charcoal offers favorable 
preconditions for effective biomass-based systems in 
the forestry industry [Basu, P. 2006, Reithmuller, G., and 
Collins, M., 2009).
By converting ores into metals through a process called 
carbonization, people were able to create charcoal, the 
first biofuel that helped them escape the Stone Age. In 
addition to being  
Utilized as a premium solid fuel for domestic cooking, 
metal refining, and chemical manufacturing, charcoal 
has evolved with industrialization to become the most 
valuable reducing agent for the metallurgic industry 
(Borines et al., 2011).
Small-scale farmers, common in Southern Europe 
countries, are typically not set up to deal with problems 
like grid connection and authorizations, emission 
regulation and compliance, administration, and operation 
of  biomass power generation systems, etc. Additionally, 
due to their frequently limited financial resources, most 
of  them find it difficult to invest in bioenergy plants 

or offer financial guarantees in order to obtain a loan, 
which poses a major obstacle to the widespread adoption 
of  these systems. Last but not least, the only way that 
bioenergy production can be financially viable is if  the 
State or the Region provides financial incentives. This 
fact breeds uncertainty among investors and increases the 
risk of  financing because any change in the regulatory 
environment could have a negative impact on the entire 
enterprise. Investments in stationary decentralized 
biomass-based systems face this pertinent challenge. The 
current study in this context concentrated on charcoal 
production as a potential substitute for biopower 
generation for forestry farms (Borines et al., 2011a, 
Borines et al., 2011b).
There are numerous kinds of  carbonization equipment 
that have been created, but the majority of  them were 
made for large capacities, and some of  them also had 
poor performance. Particularly portable metal kilns or 
carbonization, which is more efficient, environmentally 
friendly, and can be used to feed various types of  
biomasses or agricultural refuse (rather than just one type 
of  biomass exclusively). A portable venture drum-type 
kiln with a maximum capacity of  12.45 kg of  coconut 
shells has been developed to enhance kiln performance 
(Virgilio et al., 2015, Nakorn et al., 2018).
With the heat generated during combustion available as an 
additional source of  energy to partly replace the currently 
used kerosene and firewood, the carbonizer allows waste 
heat extraction using exchangers or micro boilers. While 
population growth and current practices (such as using 
kerosene and firewood from unmanaged forests) are 
the main causes of  illegal deforestation, this additional 
energy source from using  agricultural waste in carbonizer 
can play a critical role in protecting the forests in rural 
areas. By reducing the need for firewood and preventing 
deforestation, the adaptation of  carbonizer can increase 

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Am. J. Food. Sci. Technol. 2(1) 21-25, 2023

carbon sequestration. Using biochar for fertilizer further 
reduces net emissions in the area by storing carbon in 
the soil (Virgilio et al, 2015, Gutu Birhanu and Duresa 
Tesfaye, 2021).The current utilization strategy of  burning 
agricultural byproducts to recover heat is considered 
inefficient and bad due to the low heating value and issue 
with air emissions. Agricultural residues are typically made 
of  low-density materials and have poor heating values. 
Apart from these, their combustion cannot be readily 
maintained or controlled effectively for the intended use. 
Therefore, turning it into a more valuable energy supply 
is a recurring problem.

MATERIALS AND METHODS
Materials 
The materials used in the test included  stopwatch, spring 
balance, sack, waste biomass of  sawdust and coffee husk, 
anemometer, thermometer, Digital moisture, hygrometer, 
infrared thermometer, and digital  multi-meter.

Assessment of  Existing Carbonizer  
After different carbonizer were gathered from various 
locations and fully analyzed  regarding their technical and 
financial limitations. The following carbonizer designs 
and kinds were evaluated in order to choose the best 

Figure 1: a) BAECR corncob-type Carbonizer, b) JAERC Closed drum-type carbonizer

carbonizer for waste sawdust and coffee husks: pyrolysis 
of  wood JAERC’s drum-style carbonizer and BAECR’s 
corncob-style carbonizer.

Manufacturing of  Carbonizer
Based on a prepared design standard, the residual 
carbonizer for waste biomass was manufactured first. The 
part was improved, and the process proceeded as follows. 
As a result, a 620 mm diameter drum body was made from 
sheet metal that was pressed to a thickness of  1.5 mm. 
The exhaust chimney and coal tar box were made from 
sheet metal and assembled individually. The carbonizer is 
a cylindrically shaped reactor that was created to provide 
efficient carbonization in an atmosphere with little 
oxygen. It was constructed using the aforementioned 
materials, with a drum that was 620 mm in circumference 
and 2100 mm tall. The upper opening of  the drum was 
covered by a suitable metal plate, which was used to fire 
feedstocks. Finally, the entire unit was put together to 
create the full waste biomass carbonization apparatus 
and was ready for experimental testing. Only 42 kg of  
raw waste biomass per lot could fit in the waste biomass 
carbonizing drum.

Biomass Preparation 
We gathered the necessary raw coffee husk and sawdust 
from our center, which is considered to waste, from 
the fields of  private investors and well-known farmers. 
The collected feedstocks were sorted out to guarantee 

a successful carbonization process and placed over the 
sun to reduce the moisture content of  waste biomass. 
To provide more surfaces or contact areas for the 
carbonization activity, sawdust residues, in particular, 
were classified based on their different sizes.

Performance Evaluation of  the Carbonizer
Whether a system is used for conversion or transportation, 
its efficiency determines how well it can carry out 
its duties. Additionally, it contrasts a system’s real 
performance with the best or most ideal performance it is 
capable of. Calculating combustion helps determine how 
effective a carbonization procedure is. Before and after 
the procedure, various parameters were collected. The 
values of  these parameters were then used to measure the 
performance of  the carbonizer. Some parameters that will 
be obtained or measured before and after the operation 
are moisture content, the material’s initial weight, the 
charcoal recovered, and weight of  the container. Other 
values, like the weight of  the volatile matter, will be 
obtained from computations. 
These data are needed in order to compute the actual 
and maximum recovery of  the system. Percent actual 
recovery, Ractual represents the actual weight of  charcoal 
produced over the initial weight of  the sample expressed 
in percentage, while percent maximum recovery, Rmax 
shows the maximum weight of  carbonized that can 
be recovered over the initial weight of  the sample 
expressed in percentage. The weight of  fixed carbon and 

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Am. J. Food. Sci. Technol. 2(1) 21-25, 2023

ash present in the sample, which can be calculated by 
deducting the weight of  water and volatile matter from 
the original weight of  the sample, together make up the 
maximum weight of  carbonized material that can be 
recovered (Virgilio et al., 2015). Eqs (1), (2), and (3) show 
the equations for actual recovery, maximum recovery, and 
efficiency, respectively.     
Ractual= (Wcarbonized/Winitial ) × 100%  (1
)                                                                                                                                                                                                                                                                                             
where: Ractual is the actual recovery of  the system (%), 
Wcarbonized is the weight of  charcoal recovered (kg) and 
Winitial is the initial weight of  samples (kg)
Rmaximum= ((Winitial-Wm-Wvm ))/Winitial  100%      (2
)                                                                                                                                                  
where: Rmax is the maximum recovery of  the system (%), 
Winitial is the initial weight of  wet samples (kg), Wvm is the 
weight of  the volatile matter (kg) and Wm is the weight of  
water in the sample (kg)
Esystem= (Ractual/Rmax) * 1000                           (3)                                                                                                    
where: Esystem is the system efficiency (%), Ractual is 
the actual recovery of  the system (%) and Rmax is the 
maximum recovery of  the system (%
According to Schenkel (2006), the mass yield was 
calculated by the ratio of  the mass of  carbonized product 
to the mass of  the raw product initially introduced.                                                                                                 

Where: Wt = total weight of  material loaded into the 
carbonizer and t= total time of  operation 

Total Time of  Operation 
This spans the period from when the carbonizer was first 
fired up until it was completely emptied of  carbonized 
substance.  The following practical tasks are included 
in this, and their time requirements are also tracked 
separately: (a) loading/reloading of  hopper, (b) collecting 
the charcoal, and (c) agitating/stirring the hopper 
contents.

Temperature 
The temperatures of  the ignition compartment would 
be measured using thermocouple probes and a multi-
thermometer data recorder with thermocouple wires. 
The tips of  the probes, which were placed at the top 
and bottom of  the ignition chamber, were roughly at 

Where: Cy: Mass yield (%) Mc: Mass of  carbonized 
product (kg) and Mb: Mass of  raw product (kg)

Carbonizer Capacity 
The amount of  material that was carbonized by the 
prototype carbonizer per unit time (Ricardo F. Orge, 
2012), is computed as follows,  

Figure 2: Carbonizer prototype during performance testing

the chamber’s longitudinal line. At ten-minute intervals, 
temperatures were measured at each location, and the 
data were recorded.

RESULTS AND DISCUSSION
Carbonizer Selection
Based on an evaluation of  the various carbonizer designs 
already in existence, the best design of  carbonizer for 
the carbonization of  refuse sawdust and coffee husk was 
chosen. The carburizer’s ability to contain and manage 

sawdust and coffee husk during operation, as well as 
the expense of  fabrication, was the primary design 
consideration. The BAERC-type corncob carbonizer, 
which uses biomass pyrolysis, was not chosen because it 
can only be used for raw materials with large particulate 
sizes. This was considered because the JAERC drum-type 
carbonizer can handle refuse materials the size of  sawdust 
and coffee husks. The JAERC drum-type carbonizer was 
adjusted as a result.

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Performance Testing of  the Drum-Type Carbonizer 
The primary components of  biomass materials were 
thermally degraded once a pyrolysis gas flame was created 
by heat transfer from the central tube burner, which raised 
the reactor chamber temperature to a high of  250–400 
o C (Nakorn et al., 2018). The charring procedure was 
seen to be finished in two to three hours. The range of  
charcoal yields for sawdust and coffee husk, respectively, 

was determined to be 36.1- 37.5 and 58.07-60.98% by 
dry weight. (Table1). We can determine the bulk yields 
using the information from   sawdust and coffee husk 
carbonization. (table 1 and table 2). (Cocosnucifera) 
Wastes yielded the highest test for 8 openings in the drum-
type carbonizer for Young Coconut quantity of  charcoal, 
8.15 kg, or 33.13% actual charcoal recovery (Virgilio 
et al., 2015). The efficiency of  a corn cob carbonizer 

Table 1: Carbonization of  the two residues of  sawdust and coffee husk of  100% loaded
Wastes of  
Biomass

Time of  
treatment (min)

Mass of  
biomass (kg)

Mass of  
char (kg)

Loss in other 
forms (kg)

Mass yield (%) Carbonizer 
capacity

Sawdust 130 32 12 20 37.5 15kg/hr
Coffee husk 180 41 25 16 60.98 14kg/hr

measured on a volume basis was 86.36%, and one batch 
charring took 90 to 110 minutes for better carbonization 
as opposed to 3 to 4 hours for the former (Gutu Birhanu, 
Duresa Tesfaye, 2021).

Temperature Variation Inside the Carbonizer 
The yield of  charcoal produced, the characteristics of  the 
charcoal produced, and the reactor temperature profile 
have all been used to describe the performance of  the 
carbonizer system. The graph below illustrates how the 
sawdust and coffee husk temperature profiles changed 
inside the carbonization container. We have also made an 
effort to monitor the homogeneity of  the temperature 
in the carbonizer during carbonization. For this, the 
temperature inside the carbonizer is measured using a 
computerized multi-meter every ten minutes. Examples 
of  temperature fluctuation during the carbonization of  

sawdust and coffee husk are shown in the figure below. 
These graphs demonstrate that during the carbonization 
procedure, the temperature inside the carbonizer is not 
uniform.Because the carbonization is accompanied by 
partial combustion processes.  It is observed that there is 
a loss of  matter at the beginning of  the carbonization of  
the charred matter), the temperature variability can affect 
the mass yield. We also observed that for 130 minutes, 
sawdust is carbonized at a high temperature (roughly 445 
°C), before cooling to temps below 209 °C. In a carbonizer, 
the temperature inside a corn cob quickly reached 200 
°C, and heat transmission from the surrounding flue 
gas significantly raised that temperature to about 400°C, 
where the majority of  the biomass residues were thermally 
degraded (Nakorn et al., 2018). The major components 
of  the cassava rhizome were thermally decomposed at 
temperatures between 250 and 300°C once a stable flame 

Table 2: Carbonization of  the two residues of  sawdust and coffee husk of  75% loaded
Wastes of  
Biomass

Time of  
treatment (min)

Mass of  
biomass (kg)

Mass of  
char (kg)

Loss in other 
forms (kg)

Mass yield (%) Carbonizer 
capacity

Sawdust 100 24 9 15 37.5 14.4kg/hr
Coffee husk 160 31 18 13 58.07 11kg/hr

Figure 3: a) Sawdust temperature distribution around pyrolysis chamber

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from the pyrolysis gas was realized (Nakorn et al., 2017).
Where Bp is bottom of  pyrolysis chamber, Mp is middle 
of  pyrolysis chamber and Tp is top of  pyrolysis chamber.

CONCLUSION
The efficacy of  the sawdust and coffee husk pyrolysising 
carbonizer was measured by the reaction temperatures 
reached, the total processing time, and the yields of  
carbonized material. Reactor temperature profile, 
charcoal yield, and charcoal quality all affected how 
well the carbonizer device worked. Because partial 
combustion occurs alongside carbonization, which is why 
there is a loss of  matter at the outset of  the carbonization 
of  the charred matter, temperature variability had an 
impact on the mass yield. Less educated rural and per 
urban populations will benefit from this design and 
process because it will enable them to create small- or 
medium-sized businesses with minimal resources and 
training. Additionally, it will benefit rural women who rely 
on inexpensive fuel sources, such as charcoal made from 
trees, to cook and who apply regular manure to farms to 
increase crop yields. Other than coffee husk and sawdust, 
other waste biomass and agricultural residues can also 
be carbonized using this technique. For farming residue 
and waste biomass to be used effectively, ultimate and 
proximate analyses of  that biomass must be conducted.
 
REFERENCE
Basu, P. (2006). Combustion and gasification in 

fluidized beds.(1st edition), CRC press, https://doi.

org/10.1201/9781420005158
Borines, M. G., De Leon, R. L., and McHenry, M. P. 

(2011a).  Bioethanol production from farming non-
food macroalgae in Pacific island nations - Chemical 
constituents, bioethanol yields, and prospective 
species in the Philippines. Murdoch research repository, 
15(9), 4432-4435.

Borines, M. G.; McHenry, M. P., and de Leon, R. L. 
(2011b).Integrated macroalgae production for 
sustainable bioethanol, aquaculture and agriculture in 
Pacific island nations. Murdoch research repository 5(6), 
599-608.

Gutu Birhanu Oli, Duresa Tesfaye Muleta, (2021) 
.Fabrication and Performance Evaluation of  
Improved Corn Cob Residual Carbonizer to Produce 
Bio-Charr for Energy. IJSRMS, 7(5), 27-33

Nakorn T., Prasert R., Pruk A., Adisak P. (2018). 
Characterization of  Biochar from Pyrolysis of  Corn 
Residues  in a Semi-continuous Carbonize, CRt, 70. 
https://doi.org/10.3303/CET1870232

Nakorn T., Prasert R., Pruk A., Adisak P. (2017). Biochar 
Production from Cassava Rhizome in a Semi-
continuous Carbonization System. Energy Procedia, 
141. 109–113.

Reithmuller, G., and Collins, M. (2009). Biochar application 
to soil, for environmental management,(1st edition) 
Routledge, 207-226. 

Virgilio S. MORALE, Jessie C. ELAURIA and Marilyn M. 
ELAURIA (2015) Carbonization of  Young Coconut 
(Cocosnucifera) Wastes. J. Jpn. Inst. Energy, 94(10). 

Figure 3: b) Coffee husk temperature distribution around pyrolysis chamber 

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