927

LIFE CYCLE ASSESSMENT FOR THE PRODUCTION AND USE OF PALM BIODIESEL (part 5)

LIFE CYCLE ASSESSMENT FOR THE 

PRODUCTION AND USE OF PALM BIODIESEL 

(part 5)

PUAH CHIEW WEI*; CHOO YUEN MAY* and MA AH NGAN**

Journal of Oil Palm Research Vol. 22 December 2010 p. 927-933

ABSTRACT

In Malaysia, the major consumers of energy are the industrial and transport sectors. The demand is expected 

to increase steadily in tandem with the growth of the economy. As such, alternative sources of energy need 

to be developed, in particular energy from renewable sources, to meet the energy requirements. Fatty acid 

methyl esters, commonly known as biodiesel, derived from oils and fats have long been known as a potential 

diesel substitute. Biodiesel is suitable to be used neat or blended with petroleum diesel in any proportion in an 

unmodified diesel engine. However, the many concerns related to the emissions from the production and use 

of biodiesel have been discussed globally. Thus, this life cycle assessment study was conducted to investigate 

the environmental impacts from the production and use of palm biodiesel produced using MPOB’s production 

technology. The results show that the environmental impact from the production of palm biodiesel is related 

to the use of methanol, while the use of palm biodiesel contributes to the impact categories of respiratory 

inorganics and acidification/eutrophication. In spite of these, the production and use of palm biodiesel is more 

environmental-friendly as compared to petroleum diesel.

* Malaysian Palm Oil Board,

P. O. Box 10620, 

50720 Kuala Lumpur,

Malaysia. 

E-mail: cwpuah@mpob.gov.my

** 39 Jalan 3, Taman Bukit Cantik,

43000 Kajang, Selangor, Malaysia.

to produce biodiesel. However, commercially 

available biodiesel is mainly produced through the 

transesterification process using methanol in the 

presence of sodium hydroxide. In addition, this is 

the most economical approach as it requires only 

a low operating temperature and pressure, yields 

are high (>98% direct conversion to methyl ester) 

and achieved in a short reaction time. According 

to Freedman et al. (1984), the main advantage of 

an alkaline catalyst over an acid catalyst is the 

high conversion under mild conditions in a short 

reaction time. However, acid catalysts are suitable 

for esterification, especially for feedstocks with 

high fatty acids content.

The alternative approach is esterification of 

fatty acids and alcohols in the presence of a solid 

acid catalyst (Choo and Goh, 1987; Choo and 

Ong, 1989). Esterification can also be carried out 

continuously in a counter-current reaction column 

using superheated methanol (Kreutzer, 1984). 

INTRODUCTION

The increase in energy demand worldwide and 

diminishing fossil fuel reserves have driven the 

development of sustainable alternative energy 

sources to progress at a faster pace to ensure energy 

security in every part of the world. To date, the 

most widely used renewable energy for transport 

is the first generation biofuel, namely biodiesel. 

Biodiesel is alkyl esters derived from vegetable 

oils and animal fats. Many pathways are available 

Keywords: biodiesel, environment, palm oil, sustainability.

Date received: 4 October 2010; Sent for revision: 14 October 2010; Received in final form: 18 October 2010; Accepted: 20 October 2010.
Journal of Oil Palm Research 22 (december 2010)

928

Biodiesel can also be produced using supercritical 

methanol without any catalyst (Saka et al., 1986). 

In addition, methanol is not the only alcohol that 

can be used to produce biodiesel. Thus, methyl 

ester is not the only ester that can be considered 

as biodiesel. Other alcohols, such as ethanol, 

butanol and propanol, can also be used. For the 

transesterification process, sodium hydroxide is 

also not the only catalyst that can be used. Other 

usable base catalysts include sodium methoxide 

and potassium hydroxide. Lipases are also potential 

substitutes as the catalyst.

Research and development of palm biodiesel 

in Malaysia has been carried out since the early 

1980s. The key purpose in the development of 

palm biodiesel then was to provide a safety net to 

enhance and stabilize palm oil price in the country 

in times of over-supply of the commodity. The 

Malaysian Palm Oil Board (MPOB) has developed 

a patented technology for the production of palm 

biodiesel (Choo et al., 1992). The process involves 

mild reaction conditions of transesterification to 

convert palm oil into palm biodiesel by methanol in 

the presence of a base catalyst. The palm biodiesel 

produced has been extensively evaluated through 

engine testing and exhaustive field trials with 

positive results, showing that palm biodiesel is 

a suitable diesel substitute (Choo et al., 1995). 

MPOB’s biodiesel production technology has been 

commercialized with plants operating in Malaysia, 

South Korea and Thailand. The biodiesel produced 

also meets the international specifications for 

biodiesel, such as the EN 14214 and ASTM D6751.

Today, the drivers for biodiesel development, 

besides enhancing commodity prices, are the 

provision of energy security, the mitigation of 

global warming and climate change. However, 

the many concerns related to emissions from the 

production and use of biodiesel have been debated 

by environmentalists worldwide. In some reports, 

biodiesel is described as creating more problems 

instead of solving the existing environment 

problems. In view of this development, this article 

discusses a life cycle assessment (LCA) study 

conducted by MPOB to provide a quantifiable 

measure to evaluate the environmental impacts 

from the production and use of palm biodiesel in 

Malaysia.

METHODOLOGY

System Boundary

Figure 1 shows the system boundary of LCA 

for the production and use of palm biodiesel. The 

production energy, raw materials and auxiliary 

materials were included as the inputs while the 

outputs included the products, by-product and 

wastewater. Subsequently, palm biodiesel is 

transported and used for combustion in diesel 

engine vehicles. The exhaust emissions due to the 

use of palm biodiesel in diesel engine vehicles were 

also taken into consideration for this study.

Functional Unit

The functional unit for this study was the 

production and use of 1 MJ palm biodiesel in diesel 

engine vehicles.

RESULTS AND DISCUSSION

Life Cycle Inventory

Commercially, the most commonly used 

feedstock for the biodiesel production is refined, 

bleached and deodorized (RBD) palm oil. The 

results of the cradle-to-gate study of LCA, i.e. from 

the nursery to the production of RBD palm oil have 

been discussed in the Parts 1 to 4 articles. Figure 

2 shows the detailed process flow chart for the 

production of palm biodiesel. The inventory data 

for the production of palm biodiesel were obtained 

from two biodiesel plants using MPOB’s biodiesel 

production technology through questionnaires. 

Subsequently, validation and verification were 

carried out involving stakeholders from the 

biodiesel industry, and in consultation with 

representatives from the Malaysian Biodiesel 

Association. However, the processing technology 

is being continuously optimized and improved. 

Figure 1. System boundary for the production and use 

of palm biodiesel.

Energy

Auxiliary

materials

Transesterification

Wastewater Palm biodiesel Glycerol

Air emissions

Utilization in diesel

engines vehicles

Raw materials
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LIFE CYCLE ASSESSMENT FOR THE PRODUCTION AND USE OF PALM BIODIESEL (part 5)

In addition, LCA is a site-specific assessment. As 

such, inputs and waste materials may vary from 

plant to plant, even if they were using the same 

production technology. In order to calculate the 

inventory data based on the functional unit, the 

energy values used are shown in Table 1. Thus, 

life cycle inventory (LCI) for this study was based 

on the functional unit as shown in Table 2. LCI 

obtained has been carefully evaluated to ensure the 

reliability of LCA of the present study.

Figure 2. Process flow chart for the production of palm biodiesel.

TABLE 1. ENERGY VALUE (MJ kg-1) FOR SELECTED 

INVENTORY

Material Energy value (MJ kg-1)

Palm oil 39.0

Methanol 19.7

Palm biodiesel 40.3 

TABLE 2. LIFE CYCLE INVENTORY BASED ON 

FUNCTIONAL UNIT OF USE OF 1 MJ PALM BIODIESEL

Inputs and outputs Unit Amount

Raw materials

RBD palm oil

Methanol

Sodium hydroxide

Hydrochloric acid

MJ MJbiodiesel-1

MJ MJbiodiesel-1

kg MJbiodiesel-1

kg MJbiodiesel-1

1.006

0.055

0.0001

0.0004

Utilities

Electricity

Water

Steam

Instrument air

MJ MJbiodiesel-1

kg MJbiodiesel-1

MJ MJbiodiesel-1

kg MJbiodiesel-1

0.0022

0.009

0.0144

0.00008

Products

Biodiesel

Glycerol

Wastewater

MJbiodiesel-1

kg MJbiodiesel-1

kg MJbiodiesel-1

1.00

0.0030

0.009
Journal of Oil Palm Research 22 (december 2010)

930

Assumptions

There are limitations and assumptions used in 

the present study because palm biodiesel has yet 

to be used commercially as a diesel substitute in 

this country; thus, some data on infrastructure and 

facilities are not available for the use of biodiesel.

Co-product allocation. The transesterification 

process produces biodiesel and glycerol as the 

co-product (Figure 2). Thus, glycerol which is 

produced in its crude form is not treated to higher 

purity. In addition, glycerol with different degrees 

of purity has different applications, especially in the 

oleochemicals industry. As such, mass allocation 

was carried out to distribute the environmental 

impact due to glycerol as it is not a waste material. 

Biodiesel and glycerol were allocated based on 

mass at a ratio of 89.3: 10.7.

Wastewater. In the biodiesel production process, 

water is mainly used for washing purposes. The 

wastewater generated is treated and recycled to 

be reused in the process. In general, the chemical 

oxygen demand (COD) is in the range of 15 000 

to 30 000 mg litre-1 while the biochemical oxygen 

demand (BOD) is in the range of 10 000 to 20 000 

mg litre-1. The discharged BOD and COD are 50 mg 

litre-1 and 100 mg litre-1, respectively. In addition, 

the wastewater generated in the production of 1 MJ 

of palm biodiesel is 0.009 kg (Table 2). The amount 

is relatively small as compared to other stages of 

biodiesel production.

Transportation. Currently, palm biodiesel is not 

used in the domestic market but is mainly for 

export purposes. As such, there is no inventory data 

available on the transportation of palm biodiesel 

from the factory to the distribution terminal, and 

subsequently to the diesel kiosk to be used in 

diesel engine vehicles. In the present study, the 

transportation of RBD palm oil to the biodiesel 

factory was assumed to be negligible.

Energy for the transportation of methanol and 

the catalyst was also considered to be low and 

was not taken into consideration in the present 

study. Excess methanol is recycled and reused in 

the process, and therefore methanol recovery and 

intermediate tanks are more important to be taken 

into account. In addition, the catalyst used is in the 

range of 2 to 5 kg for every tonne of palm biodiesel 

produced; thus, transportation of the catalyst was 

also not taken into consideration.

Capital goods. The determination of capital goods 

was conducted by taking into account the total 

materials used to construct a 60 000 t biodiesel plant 

using MPOB’s biodiesel production technology. 

These comprise mainly stainless steel for vessels 

and tanks, pumps and agitators as well as pipes. 

Replacement factors based on annual replacement 

requirements were used to indicate the need to 

replace the equipment based on their shelf-lives. 

Table 3 shows a breakdown of the materials with 

their corresponding replacement factor. All vessels 

and tanks for the production of palm biodiesel at 

the processing plant were taken into consideration. 

A replacement factor of 10% was assigned to these, 

taking into consideration major vessels and tanks 

which are constructed with stainless steel are 

expected to last for more than 10 years.

A replacement factor of 5% was allocated to all 

pumps and agitators, taking into account the higher 

wear and tear that is expected to occur with these 

equipment. The assumption was made that the main 

material to assemble these pumps and agitators is 

stainless steel. In addition, the total amount of 

stainless steel used in pumps and agitators is 

relatively low as compared to vessels and tanks. It 

was estimated that pumps and agitators made up 

20% of the total amount of steel required for vessels 

and tanks. However, the construction materials 

are for a plant producing 60 000 t of biodiesel per 

year, and the contribution due to capital goods was 

expected to be insignificant when it was translated 

into the functional unit of the present study. Thus, 

the materials for the construction of the factory 

building were not included. They were expected 

to be insignificant, taking into account that the 

structure will last for at least 20 years.

Exhaust emission. The first exhaustive field trial on 

the use of palm biodiesel in diesel engine vehicles 

was conducted by MPOB from 1986 to 1989. A 

wide range of diesel engines such as stationary 

engines, passenger cars, lorries, tractors, taxis 

and vans in Malaysia was included in the study. 

Subsequently, palm biodiesel was evaluated in 

bench endurance tests by Mercedes Benz AG, 

Germany. This exhaustive and comprehensive 

field trial involved 30 buses covering more than 

10 million kilometres in total (each travelling 

more than 300 000 km, the life time of the engine 

as recommended by the engine manufacturer). 

Results have shown that the exhaust emissions of 

TABLE 3. MATERIALS BREAKDOWN OF BIODIESEL 

PLANT

Item Unit Replacement 

factor Amount

Vessels and 

tanks

tonne 10% 56.5

Pumps and 

agitators

tonne 5% 12.3

Pipes tonne 5% 16.7
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LIFE CYCLE ASSESSMENT FOR THE PRODUCTION AND USE OF PALM BIODIESEL (part 5)

the engines were cleaner with less hydrocarbons, 

nitrogen oxides (NOx), carbon dioxide and sulphur 

dioxide (Choo et al., 2005).

Table 4 shows the tailpipe emissions (per km) 

for the use of ultra low sulphur diesel (ULSD) as 

compared to palm biodiesel blends (Beer et al., 

2007). It is shown that the use of palm biodiesel 

contributes to lower emissions of carbon dioxide, 

carbon monoxide and particulate matter. However, 

the use of biodiesel increases the emissions of 

NOx, while there are similar emissions of methane, 

nitrous oxide and non-methanic hydrocarbon as 

from ULSD.

Life Cycle Impact Assessment

The life cycle impact assessment (LCIA) was 

carried out using the SimaPro software, version 

7.1 with the methodology Eco-indicator 99. The 

foreground biodiesel production data based on 

MPOB’s production technology were obtained 

directly from the commercial biodiesel plants while 

the foreground capital goods data were obtained 

directly from the biodiesel technology provider. 

However, the background data were obtained 

from the Ecoinvent database under SimaPro. These 

included the production of capital equipment and 

various chemicals used in the transesterification 

process. LCIA for the use of 1 MJ of palm biodiesel 

in diesel engine vehicles was presented in this 

study based on two case studies: continued land 

use for oil palm plantations with biogas emission at 

palm oil mills, and continued land use for oil palm 

plantations with biogas capture at palm oil mills. 

LCIA that was conducted incorporated results from 

the nursery to the refinery as are presented in the 

Parts 1 to 4 articles.

Figure 3 shows the weighted LCIA results for 

continued land use for oil palm plantations with 

biogas emission at palm oil mills. The processing 

step for the conversion of RBD palm oil to palm 

biodiesel contributed to two impact categories, 

namely fossil fuels and respiratory inorganics. 

Impact on fossil fuels was due to the use of nonrenewable sources of materials, including methanol 

which is produced from natural gas and fuel oil for 

the boiler to generate steam. Impact on respiratory 

inorganics is associated with emissions to the 

atmosphere, and therefore was due to emission 

from the boiler.

The use of palm biodiesel contributed 

to respiratory inorganics and acidification/ 

eutrophication as both impact categories are related 

to emissions to atmosphere. Based on the latest 

findings reported by Beer et al. (2007), the use 

of 100% palm biodiesel contributes to greater 

reductions in emissions of total carbon dioxide, 

particulate matter and carbon monoxide (100%, 

58% and 36%, respectively) (Table 4).

The effects of acidification/eutrophication were 

due to a higher emission of NOx from the use of 

biodiesel. The presence of the oxygen component in 

biodiesel increases the formation of NOx. Currently, 

the use of B5 which is a blend of 5% biodiesel with 

95% petroleum diesel is being implemented in the 

country. Thus, the emission from NOx is similar to 

that of petroleum diesel (Table 4). In this context, 

the adverse effects of acidification/eutrophication 

were not significant due to the use of 5% blends of 

palm biodiesel. More importantly, the results show 

that the production and use of palm biodiesel did 

not contribute significantly towards the impact 

category on climate change (Figure 3).

The impact on climate change as contributed by 

RBD palm oil has been discussed in the Parts 1 to 

4 articles. The impact category on climate change 

was also reduced with palm oil mills installed 

with biogas capture facilities. Figure 4 shows the 

weighted LCIA results for continued land use for 

oil palm plantations with biogas capture at palm 

oil mills.

For biodiesel production, the environmental 

impacts associated with the production of capital 

equipment had been included and found to be 

TABLE 4. TAILPIPE EMISSIONS (per km) FOR ULTRA LOW SULPHUR DIESEL (ULSD) BIODIESEL BLENDS USING 

PALM OIL

Impact category Tailpipe emission (g km-1)

ULSD BD2 BD5 BD10 BD20 BD100

Carbon dioxide 692 679 659 626 560 0

Methane 0.01 0.01 0.01 0.01 0.01 0.01

Nitrous oxide 0.016 0.016 0.016 0.016 0.016 0.015

Carbon monoxide 2.81 2.78 2.75 2.69 2.57 1.79

Nitrogen oxides 8.68 8.71 8.76 8.84 8.99 10.33

Non-methanic hydrocarbon 0.72 0.71 0.71 0.71 0.71 0.71

Particulate matters (PM 10) 283 278 271 260 238 119
Journal of Oil Palm Research 22 (december 2010)

932

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0

mPt

Biodiesel – revised oil palm and emission (Oct 2010)

Methanol, at plant/GLO U (biodiesel)

NaOH ETH U

Electricity Malaysia

Water, completely softened, at plant/RER U

RPO Sept 2010 (OP to OP, without biogas capture, with capital) reviewer

X5CrNI18 (304)

Steam on Site A

Carcinogens Resp.

organics

Resp.

inorganics

Climate

change

Radiation Ozone layer Ecotoxicity Acidification/

eutrophication

Land use Minerals Fossil fuels

insignificant. However, the impact due to the 

construction of the factory building was excluded 

based on results from earlier studies which indicate 

that their contribution is small. In addition, land 

occupation by the biodiesel factory have been 

excluded in this study.

The use phase of biodiesel was the major 

contributor towards the impact on respiratory 

inorganics and acidification/eutrophication. The 

exhaust emissions based on published data show 

that the use of palm biodiesel contributes towards 

lower emissions as compared to petroleum diesel. 

The greater reductions in emissions shown in a 

more recent study are mainly due to the 

advancement in technological development in 

diesel engine manufacture. Based on the LCIA 

results, it was found that the production of palm 

biodiesel using MPOB’s technology does not 

contribute significantly towards to overall life 

cycle while the use of palm biodiesel is more 

environmental-friendly as compared to petroleum 

diesel in terms of emissions.

Figure 3. Weighted life cycle impact assessment of cradle to grave for production and use of palm biodiesel based on 

continued land use for oil palm plantations with biogas emission at palm oil mills.

Figure 4. Weighted life cycle impact assessment of cradle to grave for production and use of palm biodiesel based on 

continued land use for oil palm plantations with biogas capture at palm oil mills.

28

26

24

22

20

18

16

14

12

10

8

6

4

2

0

Pt

Biodiesel – revised oil palm and emission (Oct 2010)

Methanol, at plant/GLO U (biodiesel)

NaOH ETH U

Electricity Malaysia

Water, completely softened, at plant/RER U

RPO Sept 2010 (OP to OP, without biogas capture, with capital) reviewer

X5CrNI18 (304)

Steam on Site A

Carcinogens Resp.

organics

Resp.

inorganics

Climate

change

Radiation Ozone layer Ecotoxicity Acidification/

eutrophication

Land use Minerals Fossil fuels
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LIFE CYCLE ASSESSMENT FOR THE PRODUCTION AND USE OF PALM BIODIESEL (part 5)

CONCLUSION

LCIA of this study shows that the environmental 

impact from the production of palm biodiesel is 

related to the use of methanol, while the use of 

palm biodiesel contributes to the impact categories 

of respiratory inorganics and acidification/

eutrophication. In spite of these, the production 

and use of palm biodiesel is more environmentalfriendly as compared to petroleum diesel.

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CHOO, Y M and ONG, S H (1987). Transesterification 

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