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European Journal of Applied Sciences – Vol. 10, No. 5

Publication Date: October 25, 2022

DOI:10.14738/aivp.105.13085. Quartey, G. A., Eshun, J. F., Marfo, E. D. (2022). Calorific Values of Rubberwood Biomass Along the Tree. European Journal of Applied

Sciences, 10(5). 11-14.

Services for Science and Education – United Kingdom

Calorific Values of Rubberwood Biomass Along the Tree

Gladys A. Quartey

Department of Interior Design and Technology

Faculty of Built and Natural Environment

Takoradi Technical University. P. O. Box 256. Takoradi

John Frank Eshun

Department of Interior Design and Technology

Faculty of Built and Natural Environment

Takoradi Technical University. P. O. Box 256. Takoradi

Eric Donkor Marfo

Department of Interior Design and Technology

Faculty of Built and Natural Environment

Takoradi Technical University. P. O. Box 256. Takoradi

ABSTRACT

Rubberwood is one of the major plantation crops grown mainly in the Western

Region of Ghana. They are mostly utilised for their latex. Rubber trees that are aged

and low yielding can be cut down and properly utilised as fuelwood. In Ghana, there

is a high demand for fuelwood in most domestic homes and rubberwood is one of

the tree species with potential use as fuelwood. Even though gas has been promoted

as an energy source for heating and cooking activities in Ghana, it remains

expensive, and its affordability, therefore, remains out of reach of many people.

Rubberwood, which is plantation grown can, therefore, be considered as fuelwood.

In this study, the calorific values of rubberwood biomass from a plantation were

determined using samples from the bottom, middle, branch, and top parts of the

stem. The calorific values of rubber wood biomass from different sections of the

tree were determined in accordance with standard laboratory methods using a

bomb calorimeter. The calorific values obtained were 17.194 MJ/kg for the branch,

17.225 MJ/kg for the top, 17.595 MJ/kg for the middle, and 17.702 MJ/kg for the

bottom. The trend of the values shows that the calorific value decreases from the

bottom through the top of the stem to the branch. The calorific value of rubberwood

was comparable to other high-performing tree species used for fuelwoods and

therefore has the potential to be used for fuelwood.

Keywords: Rubberwood, Biomass, Calorific Value, Fuelwood, Renewable

INTRODUCTION

Biomass is one of the renewable energy sources which was used even in ancient times by

people. Until the 18th century biomass was considered an important source to ensure the

necessary energy for cooking, and heating, among other sources and it was one of the most

widely spread energy sources on earth. The provision of biomass energy started developing in

the year 2000 and in the year 2010, it was already providing some percentage of the energy

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European Journal of Applied Sciences (EJAS) Vol. 10, Issue 5, October-2022

Services for Science and Education – United Kingdom

worldwide, the equivalent of 1.5 % of the energy provided globally (Scarlat et al., 2015).

Presently biomass continues to have an important role in a number of countries and represents

the main source providing the energy needed.

Energy from biomass can be used for various purposes from room heating, to fuel for cars and

to producing electricity (Astbury, 2008). Wood biomass is a source of renewable energy which

increases every year, is widely available worldwide, and presents low costs, as compared to

fossil fuel. Biomass is one of the renewable energy sources that can be converted into solid,

liquid, and gaseous energetic fuel, and that can generate energy in the form of heat by means of

its burning, as well as electricity, by conversion processes (Garcia, 2004). The combustion of

wood biomass is an ecological one, with a minor impact on the environment (Wilkins and

Murray 1980).

Rubberwood is a light-colored medium-density tropical hardwood obtained from the rubber

tree (Hevea brasiliensis), usually from trees grown in rubber plantations. Rubberwood can be

used for almost anything once it has served its primary function. It is commonly referred to as

an environmentally friendly wood (Wengert, 2019).

The main objective of this study was to determine the calorific value of the biomass of the

bottom, middle, branch, and top of the stem and to evaluate the heating value of rubber wood

along the tree.

MATERIALS AND METHODS

Study Area

The study was carried out in a rubber tree plantation in the Ahanta West District which is

located in the wettest region of Ghana. It lies between 0. 0 latitudes 4 .45''N and longitude 1 .58”

W and within the south-western equatorial climatic zone marked by a double-maximum

rainfall with mean annual rainfall of over 1,700mm. The climate here is tropical. During most

months of the year, there is significant rainfall. There is only a short dry season with the average

annual temperature around 25.8 °C | 78.5 °F. The rainfall is around 1366 mm | 53.8 inches per

year. The soil types range from loose sand to clay and are suitable for crops such as oil palm,

rubber, cocoa, coffee, and citrus (UNDP Human development report, 2007).

Preparation of samples

The diameter distributions (diameter at breast height, DBH) of five rubber wood trees were

measured. The samples of rubber wood used for the study were selected from an acre of rubber

plantation 25 years of age. The density of rubber trees was 550 trees per hectare. Five trees

were selected based on their average DBH of 1.0 meters. Altogether, five trees of varied sizes

(10–30 cm in DBH) were sampled from an acre, as described by Hytönen et al. (2019). Three

sample discs (thickness 5–8 cm) were cut with a chainsaw from the butt, middle, and top

sections of the sample trees, and also a disc from the branches. The samples were placed in

sealed plastic bags and were later turned into particles.

Laboratory work

Control Measures: Benzoic acid reference was used to determine whether the calorimeter was

in good working condition.

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Quartey, G. A., Eshun, J. F., Marfo, E. D. (2022). Calorific Values of Rubberwood Biomass Along the Tree. European Journal of Applied Sciences,

10(5). 11-14.

URL: http://dx.doi.org/10.14738/aivp.105.13085

Determination of Biomass: The samples were weighed and dried to a constant weight at 105oC

and combusted in a PARR 6400 Calorimeter. The results were displayed on a screen on the unit

and recorded. Determination of calorific value by the PARR 6400 Calorimeter is according to

ASTM D5468, “Standard Test Method for Gross Calorific and Ash Value of Waste Materials”.

RESULTS AND DISCUSSION

Calorific Value of Rubberwood sections

The calorific values of the rubber wood sections were presented in Table 1. The value for the

branch was the lowest at 17.194 MJ/Kg, followed by the top with a value of 17.225MJ/Kg, to the

middle with a value of 17.595 MJ/Kg and the highest value was at the bottom with a value of

17.702 MJ/Kg. The trend observed was that the calorific value decreases from bottom to top

and then to the branches. Duruaku et al. (2016) explain the low calorific value of the branch

due to the effect of the carbon content being stronger in the case of the trunks than in the

branches. They further explained that results showed that carbon content contributed

positively to the experimental gross heat value of wood biomass. Other factors such as the

extractive contents which will mainly be found in the trunk could also raise the heating value.

In this research, the bottom of the tree had the highest calorific value which is confirmed by the

literature. The age of the tree has also an effect on the heating value as confirmed by Hytönen

et al. (2019).

Table 1. The calorific value of the rubber wood along the tree

S/N Sample ID Calorific value MJ/Kg

1 TIBr 17.194 ± 0.132

2 TIT 17.225 ± 0.067

3 TIM 17.595 ± 0.268

4 TIB 17.702 ± 0.144

Key: TIBr- sample from BRANCH, TIT – sample from TOP, TIM – sample from MIDDLE, TIB- sample from BOTTOM

CONCLUSION

The calorific value of rubber wood biomass is affected by a number of factors. Key among them

is the section or part of the tree that the biomass is taken from. The bottom of the tree has a

higher calorific value than any part of the tree. The heating value of the biomass obtained in this

research shows that rubber trees can be used as fuelwood. This research has thus highlighted

the importance of considering such factors as environmental impacts, health issues, and tree

parts in the selection of a species for use as fuelwood.

ACKNOWLEDGMENT

The staff at the Department of Chemical Material Engineering at Kwame Nkrumah University

of Science and Technology at Kumasi in Ghana is acknowledged for their support during the

laboratory works.