Effect of Transesterification with Kupang Natural Zeolite on VCO

Biodiesel Characteristics and Diesel Engine Performance

Aris Palinggi, Lukas Lantang and Thomas A. Fongo

State Politecnic of Kupang, Adi Sucipto, Kupang, Indonesia

Keywords: Transesterification, Zeolite, VCO, Biodiesel, Characteristic, Performance.

Abstract: This study aims to improve the characteristics of VCO biodiesel so that when mixed with dexlite it can meet

the fuel requirements of diesel engines in order to improve engine performance . The expected better

characteristics of VCO biodiesel are viscosity, calorific value and density. The method used is the

transesterification of biodiesel VCO using Kupang natural zeolite catalyst and methanol with a percentage of

50% catalyst and 50% VCO which is processed at a temperature of 60 ºC. Then the results of

transesterification of VCO in its use are mixed with dexlite fuel with a percentage of 30% and 40%. The load

used in the test was 35 kgf, and was tested at a high speed of 3000 to 4000 rpm. Diesel engine performance

measured is effective power, fuel consumption, thermal efficiency and CO and HC exhaust gases. The results

showed that the transesterification process with Kupang natural zeolite could improve the characteristics of

VCO biodiesel by lowering the viscosity from 24 Cst to 14,5 Cst. when used as a dexlite mixture, the

performance of the diesel engine produced is close to the use of pure dexlite fuel at a mixture of 30%. in the

40% mixture the exhaust emissions are reduced but the engine power is also reduced.

1 INTRODUCTION

The availability of energy is the key to the progress

of human civilization because all sectors require

energy to carry out their activities in order to meet the

growing needs. The use of fossil energy that

continues to increase as fuel in the industrial and

transportation sectors as well as the agricultural sector

has caused global warming and environmental

pollution to become increasingly severe. Biodiesel

from palm oil (CPO) is one of the alternative

renewable energy options and available and

environmentally friendly raw materials are the main

choice to be developed, but until now its use has not

been fully utilized because it still has to be mixed with

fuel from diesel or the like. to maintain the

characteristics of the fuel to match the standard diesel

engine. In addition to palm oil, the raw material for

biodiesel which is abundant and has not been used as

fuel for diesel engines is local coconut which has just

been used as food and medicine. Local coconut

processing is carried out by heating and a natural way

without heat called VCO, because without heat

processing, the results are clear and have low

viscosity, so they can be used as biodiese

To improve the characteristics of biodiesel so that

it can be used as fuel for diesel engines, esterification

and transesterification are carried out to reduce acids

and fats in biodiesel materials. This process uses

several choices of materials such as KoH, methanol,

and zeolite as a catalyst to facilitate the improvement

of characteristics. Several studies to improve the

characteristics of biodiesel by esterification and

transesterification have found that the use of these

processes can improve the characteristics of biodiesel,

especially at a decreased flash point and viscosity

( Suleman, 2019 ) Several catalysts used in the

transesterification process show that the use of zeolite

can produce more acid from biodiesel materials, this

occurs in palm oil and used cooking oil ( Pasae, 2019 )

The main problem that will be discussed in this

study is whether the transesterification process with

Kupang natural zeolite will improve the

characteristics of biodiesel from VCO so that when

used as diesel engine fuel it can increase engine

power and reduce exhaust emissions. Can the

percentage of VCO in dex fuel be increased by more

than 30% and still produce high performance? This

research really needs to be done because the need for

renewable energy is very urgent to reduce air

pollution due to the use of fuel.

Palinggi, A., Lantang, L. and Fongo, T.

Effect of Transesteriﬁcation with Kupang Natural Zeolite on VCO Biodiesel Characteristics and Diesel Engine Performance.

DOI: 10.5220/0012058900003575

In Proceedings of the 5th International Conference on Applied Science and Technology on Engineering Science (iCAST-ES 2022), pages 1067-1071

ISBN: 978-989-758-619-4; ISSN: 2975-8246

1067

Transesterification and esterification are two

processes that are often used to make biodiesel from

vegetable oils, and are sometimes used to improve the

quality of biodiesel so that it has characteristics that

meet the requirements of diesel engine fuel ( Aunillah,

2012 ). Esterification is carried out with the aim of

reducing the acid content in biodiesel so that it is easy

to burn, usually by heating more than 100 degrees

Celsius and using KOH, CaO, H2SO4 and methanol

catalysts while stirring for a few minutes and then

depositing so that the acid content will dissolve to the

bottom and biodiesel will be above. ( Handayani,

2016 ). Meanwhile, the transesterification process is

carried out after the esterification process is complete,

the purpose of transerification is to reduce the

viscosity of biodiesel by reducing the fat content in

biodiesel. Transesterification was carried out by

heating below 100 degrees celsius while stirring at

slow speed for several hours, the catalysts used were

KoH Cao and Zeolite. ( Hadrah, 2018 ). Research

shows that from several catalyst materials used for

transesterification, the zeolite catalyst produces good

characteristics and more biodiesel, such as lower

viscosity and lower flash point or more flammability

( Salim, 2016 ).

The diesel engine ignition system is compression

ignition, therefore the fuel used must meet several

characteristics suitable for compression ignition so

that biodiesel must first be treated so that it can be

used as diesel engine fuel. Biodiesel produced from

the transesterification process has characteristics that

must be measured to determine whether the biodiesel

meets the requirements as diesel engine fuel, such as

viscosity, calorific value, flash point, cetane number,

lubricating properties, and specific gravity. Diesel

engines require fuel with a high cetane number to

avoid knocking in the combustion chamber ( Palinggi,

2020 ).

Biodiesel is one of the main options to replace fuel

for diesel engines because raw materials are abundant

and have long been managed for food. Biodiesel from

palm oil has begun to be developed in bulk because

its characteristics are close to those of fuel and lower

exhaust emissions because the combustion products

do not contain carbon. ( Elma, 2016 ). VCO as

biodiesel has not been widely used and is only limited

to laboratory research with results showing that VCO

can be mixed with fuel with a percentage of up to 30%

producing power that is almost the same as pure fuel

and low exhaust emissions ( Rizal, 2015 ).

Virgin cocnut oil (VCO) is oil produced from

local coconut (Cocos Nucifera) which is processed

without heating and chemicals so it is not harmful to

engine components and when used as a diesel mixture

it can increase engine performance at medium speed.

( Nazir, 2017 ) . The natural processing produces

VCO that is durable, fat-free and clear and can

significantly reduce exhaust emissions. Previous

research found a problem with VCO biodiesel,

namely the viscosity is still high even though it has

been mixed with fuel, so it needs further treatment

such as transesterification to reduce viscosity.

( Bhikuning, 2013 )

2 MATERIAL AND METHOD

The research method used is an experimental method

by transesterifying VCO biodiesel using a Kupang

natural zeolite catalyst and methanol with a ratio of

50% VCO and 50% catalyst processed at a

temperature of 60 degrees Celsius. The transesterified

biodiesel is then mixed with dexlite type diesel engine

fuel. The VCO biodiesel used is taken directly from

small industries, while the dexlite is a product of

Pertamina. The diesel engine used for the experiment

is a Nissan brand with 4 cylinders and 4 strokes

equipped with a fuel heater. The engine was tested at

a maximum allowable load of 35 kgf and engine

speed at 3000, 3200, 3400, 3600, 3800 and 4000 rpm.

The engine was tested first using pure dexlite fuel

then a mixture of 30% VCO and finally a mixture of

40% VCO. The results of the study were then made

in tabular form and then graphed using excel

software. engine performance to be analyzed is the

power consumption of fuel, effective power, thermal

efficiency and exhaust emissions of carbon dioxide

and hydrocarbons.

3 RESULT AND DISCUSSION

3.1 Result and Analysis

Table 1: Physical Properties of Material fuel.

Fuel

Material

Heating Value

(Calori/gram )

Viskosity

( cSt ) 40ºc

Density

(gram/ml)

100%

Dexlite

11245

3.6

0.83

100 % VCO

9579.5

14,5

0.917

30 % VCO

10745,8

6,87

0.85

40 % VCO

10578,8

7,96

0.86

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Table 1 shows the results of testing the

characteristics of VCO biodiesel that has been

processed by transesterification, there is an

improvement in the characteristics of the heating

value and viscosity before transesterification, the

calorific value of VCO is 8979.5 cal/gram and the

viscosity is 24.3 cSt to 9579.5 cal/gram and 14, 5 cSt.

Effective Power

If we look at Figure 1, the use of pure dexlite

produces greater power, but as the engine speed

increases, the power generated at a mixture of 30%

VCO approaches the power produced by the use of

pure dexlite. at 3000 rpm the pure dexlite produces

32.6 HP of power and a mixture of 30% 31.9 HP, but

at 4000 rpm the power produced by pure dexlite is

36.9 HP and a mixture of 30% produces 36.3 HP of

power. This happened because the VCO viscosity

was getting smaller after the transesterification

process, and the fuel heater installed added to the

improvement in the quality of the VCO and dexlite

mixture. For a 40% mixture the power produced is

lower than the 30% mixture, but if the engine speed

is increased the power produced also increases

Figure. 1: Effective Power of blend diesel fuel VCO and

pure dexlite.

Thermal efficiency

The thermal efficiency produced by the use of a

mixture of VCO and dexlite at a mixture of 30% is

still lower than the use of pure dexlite, but if the

engine speed is increased, the 30% VCO mixture is

closer to the efficiency produced by pure dexlite. In

Figure 2 it can be seen that the transesterification

process in VCO can improve the characteristics so as

to increase engine efficiency. This happens because

the viscosity of the fuel has decreased to near the

viscosity of pure dexlite and as a result of the addition

of a heating device so as to maximize fuel atomization

and better combustion. in the 40% mixture, it can be

seen that the resulting efficiency is still lower than the

30% mixture.

Figure. 2: Thermal Effeciency of a mixture of VCO with

diesel fuel and pure dexlite.

Fuel Consumption: Specific fuel consumption is

the mass flow rate of the fuel compared to the power

generated by the engine. In Figure 3 it can be seen

that with a VCO percentage of 30% in the fuel, the

specific fuel consumption is higher than pure dexlite.

shows that the use of pure diesel is more efficient than

the use of biodiesel. This is due to the calorific value

of a mixture of 30% VCO with dexlite is lower than

the calorific value of pure dexlite. This causes the

load and high engine speed to flow more fuel to run

the engine. For a mixture of 40% VCO it is more

wasteful than the use of pure diesel and a mixture of

30%

Figure. 3: Spesific fuel consumtion of mixture VCO with

pure dexlite and pure dexlite.

2900 3100 3300 3500 3700 3900 4100

Effective Power (HP)

Rotation (rpm)

Diesel Fuel 30% vco 40% vco

2900 3100 3300 3500 3700 3900 4100

Thermal Efficiency (%)

Rotation (rpm)

Diesel Fuel 30% vco 40% vco

0,245

0,25

0,255

0,26

0,265

0,27

0,275

0,28

2900 3100 3300 3500 3700 3900 4100

SFCe (kg/HP./h)

Rotation (rpm)

Diesel Fuel 30% vco 40% vco

Effect of Transesteriﬁcation with Kupang Natural Zeolite on VCO Biodiesel Characteristics and Diesel Engine Performance

1069

Exhaust gas emissions of HC: HC are

hydrocarbons and are one of the dominant

combustion residues, so that an increase in engine

speed causes HC to also increase, in Figure 4 when

viewed on each fuel, pure dexlite fuel produces the

highest HC, while the lowest HC is at 30% VCO Mix.

This is because the characteristics of the VCO have

been improved by the transesterification process and

the presence of a fuel heater installed in the engine to

reduce the viscosity of the fuel before use so that

atomization becomes better which causes better fuel

combustion. for a 40% mixture there is still more HC

because the increase in VCO in the fuel causes the

viscosity to increase.

Figure. 4: The amount of HC in exhaust gas from mixture

of VCO with pure dexlite and pure dexlite.

CO exhaust emissions: if the engine operates at

low speed, the CO produced is also low, the opposite

is true, namely the higher the engine speed, the

greater the CO. in Figure 5 it can be seen that by

adding transesterified VCO to dexlite fuel, exhaust

gas emissions will be reduced when compared to the

use of pure dexlite. This happens because VCO does

not contain materials that can form CO in the exhaust

gas. At a mixture of 40% exhaust emissions are

almost the same as a mixture of 30% and if the engine

speed is increased, the exhaust emissions will also

increase but the CO exhaust emissions are less than

30% if the maximum speed is increasing. VCO in

diesel will reduce exhaust emissions significantly, so

the percentage of VCO in diesel needs to be increased

Figure. 5: Percentage of CO exhaust gas of mixture VCO

with pure dexlite and pure dexlite.

3.2 Discussion

The transesterification process in VCO biodiesel can

improve characteristics, especially on viscosity and

calorific value, so that when used as a dexlite mixture,

the resulting performance is close to the performance

of pure dexlite use. the transesterification process is

able to reduce saturated fat in VCO so that the

viscosity decreases and increases the calorific value.

on the use of transesterified VCO with a mixture of

30% VCO and 70% dexlite, the power generated is

still lower than pure dexlite but if the rotation is

increased then the power is closer to the use of pure

dexlite as shown in Figure 1. 30% mixture is close to

the efficiency of pure dexlite and for 40% mixture the

resulting efficiency is lower. For fuel consumption in

Figure 2, the use of pure dexlite is more efficient

because of its high calorific value, while the 30%

mixture requires more fuel to produce large power.

very good results are produced from exhaust gas

emissions of HC and CO, where the use of VCO as a

dexlite mixture can reduce levels of HC and CO

significantly because VCO does not contain materials

that can produce carbon.

4 CONCLUSIONS

After doing research and testing, it can be concluded

as follows:

1. The transesterification process with

Kupang natural zeolite catalyst and methanol can

improve the characteristics of VCO biodiesel, namely

reducing viscosity and increasing calorific value

2900 3100 3300 3500 3700 3900 4100

HC ( PPM)

Rotation(rpm)

Diesel Fuel 30% vco 40% vco

0,2

0,225

0,25

0,275

0,3

0,325

0,35

2900 3100 3300 3500 3700 3900 4100

CO (%)

Rotation(rpm)

Diesel Fuel 30% vco 40% vco

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2. The use of transesterified VCO as a dexlite

mixture produces performance that is close to the

performance of using pure dexlite

3. The resulting cleaner exhaust emissions,

namely hydrocarbons and carbon monoxide,

decreased significantly.

ACKNOWLEDGMENT

This research was funded by the State Polytechnic of

Kupang, therefore we are grateful its contribution.

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