Biomass as the Renewable Energy Sources in Malaysia

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Biomass as the Renewable Energy Sources in Malaysia: An Overview a

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T.G. Chuah , A.G. K. Wan Azlina , Y. Robiah & R. Omar

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Department of Chemical and Environmental Engineering , Faculty of Engineering, Universiti Putra Malaysia , Serdang, Malaysia Published online: 06 Feb 2007.

To cite this article: T.G. Chuah , A.G. K. Wan Azlina , Y. Robiah & R. Omar (2006) Biomass as the Renewable Energy Sources in Malaysia: An Overview, International Journal of Green Energy, 3:3, 323-346, DOI: 10.1080/01971520600704779 To link to this article: http://dx.doi.org/10.1080/01971520600704779

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International Journal of Green Energy, 3: 323–346, 2006 Copyright © Taylor & Francis Group, LLC ISSN: 1543-5075 print / 1543-5083 online DOI: 10.1080/01971520600704779

BIOMASS AS THE RENEWABLE ENERGY SOURCES IN MALAYSIA: AN OVERVIEW T.G. Chuah, A.G. K. Wan Azlina, Y. Robiah, and R. Omar

Downloaded by [Universiti Putra Malaysia] at 00:18 25 July 2014

Department of Chemical and Environmental Engineering, Faculty of Engineering, Universiti Putra Malaysia, Serdang, Malaysia Past and current economic growths of Malaysia have been primarily energized by fossil fuels. Malaysia has very substantial potential for biomass energy utilization given its equatorial climate that is ideal for dense tropical forest growth and agricultural vegetation. There are five major sectors contributing wastes to biomass energy in Malaysia: forestry (wood products), rubber cultivation, cocoa cultivation, sugar cane cultivation and oil palm cultivation. Biomass in Malaysia contributes about 14% of the approximately 340 million barrel of oil equivalent (boe) of energy used every year. This paper provides an overview on the types of biomass being used, the research works on biomass conversion into energy and the present biomass energy projects in Malaysia. Keywords: Biomass; Renewable energy; Wood fuel; Palm oil biomass; Biogas; Biodiesel; POME

INTRODUCTION Malaysia is blessed with a plentiful and relatively cheap supply of conventional fossil energy resources such as oil, gas, and coal and so far need not to worry about its energy supply. Owing to some large oil fields, the government subsidizes petrol with up to 50 cents per liter to help the local industries flourish. Past and current economic growth in the country has been primarily fueled by fossil fuels and little attention has been paid to other energy sources. However, like most industrial countries, Malaysia too faces the challenges of opening up new sources of energy. Worldwide the supply of fossil fuel will, in not a long period of time, run dry as is commonly acknowledged. Malaysia could very soon experience an energy crisis after the long years of generous energy subsidies if the abundant use of its energy sources continues. Therefore, it is unavoidable that Malaysia also seek renewable sources for future electricity generation. The term renewable energy (RE) has only been in widespread use since the 1981 United Nations Nairobi Conference on New and Renewable Sources of Energy and covers a wide range of natural energy resources, ranging from biomass and hydropower use to the direct and indirect use of solar energy, such as photovoltaic, solar thermal and wind power. The increasing interest in the renewable resources stems from the realization of the

Address correspondence to T.G. Chuah, Faculty of Engineering, Department of Chemical and Environmental Engineering, Universiti Putra Malaysia, Serdang, 43400 Selangor. E-mail: [email protected] 323


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short term nature of the conventional and convenient fossil fuel reserves and the environmental degradation caused by their widespread use. Several industrialized countries promote biomass energy, for both environmental and socio-economic reasons. These countries use locally available wood and biomass fuels as alternatives to oil or coal, taking advantage of recently developed technologies, and thus avoiding CO2 emissions and reduce their own dependency on oil. These countries include Sweden, Finland, Austria, Denmark, European Union and the United State of America. For example, 6% of Denmark’s total energy consumption at present is covered by biomass energy, representing 75% of the country’s renewable energy production. Denmark is an agricultural country and generates large amounts of straw (2.3 mt/a or 46 PJ) and animal wastes (3 Mt/a or 26 PJ), which are increasingly being used as sources of energy. The organic waste is used in biogas which generates heat and electricity. Combustible waste accounts for 10 PJ out of 80 PJ of heat delivered by district heating systems. Malaysia’s target is to generate five percent of its electricity from renewable energy sources by 2005 and decrease reliance on natural gas, which is currently the primary generation fuel. Malaysia currently has approximately 13 gigawatts (GW) of electric generation capacity, of which 84% is thermal and 16% is hydroelectric. Malaysian electricity demand is expected to grow to 15,000 MW by 2005 from 12,975 MW in the year 2000. The Malaysian government expects that investment of $9.7 billion will be required in the electric utility sector through 2010. It is a worry that the day could come when there will be no more gas available, and we will need to look at renewable energy. It could also be cheaper in the long run as natural gas is expensive (Chuah and Azni, 2004). Malaysia already generated nearly 200 MW of power from renewable sources at palm oil plantations as part of the effort of biomass utilisation (PTM, 2004). However, this power was not connected to the national distribution grid. The new plants should feed into the national grid according to the 8th Malaysia Plan (RM8) for the years 2001– 2005. As an incentive, the government was offering tax breaks, investment allowances and would waiver import duties on equipment for renewable energy plants. Figure 1

Figure 1 Energy Potential of Agroprocessing Residues As Percentage of Total Primary Energy Production in ASEAN countries (RWEDP, 1998).

BIOMASS ENERGY SOURCES IN MALAYSIA

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shows the energy potential of agroprocessing residues as percentage of total primary energy production in ASEAN countries. This paper focuses on the progress and development of biomass usage as a renewable energy source in Malaysia. An overview on the types of biomass used, the research works on biomass conversion into energy and present biomass energy projects in Malaysia are also discussed.


BIOMASS FUELS CHARACTERISTICS Biomass is an important renewable source of energy and has been used to provide energy to human activities. Residues obtained from harvesting and milling agricultural produces can be utilised as fuel for energy generation. Biomass differs from coal in many important ways, including organic, inorganic, energy content and physical properties. Relative to coal, biomass generally has less carbon, more oxygen, more silica and potassium, less aluminium and iron, and lower density and friability (Table 1). The typical differences between the properties of coal and biomass are indicated by the proximate and ultimate analyses (Tables 2 and 3). The volatile matter in biomass is generally close to 80%, whereas in coal it is around 30%. Wood and woody materials tend to be low in ash content while the agricultural materials can have high ash contents. It is difficult to establish a representative biomass due to large property variations, but Table 1 Physical, chemical and fuel properties of biomass and coal fuels (Dermibas, 2004). Property

Biomass

coal

Fuel density (kg/m3) Particle size C content (wt% of dry fuel) O content (wt% of dry fuel) S content (wt% of dry fuel) SiO2 content (wt% of dry fuel) K2O content (wt% of dry fuel) Al2O3 content (wt% of dry fuel) Fe2O3 content (wt% of dry fuel) Ignition temperature (K) Peak temperature (K) Friability Dry Heating value (MJ/kg)

~500 ~3 mm 45–54 35–45 Max. 0.5 23–49 4–48 2.4–9.5 1.5–8.5 418–426 560–575 Low 14–21

~1300 ~100 μm 65–85 2–15 0.5–7.5 40–60 2–6 15–25 8–18 490–595 – High 23–28

Table 2 Proximate analyses of coal and selected biomass fuels (wt% of dry fuel). Fuel sample

Ash

Volatile Matter

Fixed carbon

References

Rice husk

18.3

63.5

14.2

3.2 8.4 3.1 0.4

69.5 69.7 70.5 81.7

21.7 18.9 22.0 9.8

Werther and Saenger (2000) Mahlia et al (2001) Mahlia et al (2001) Abelbha et al (2003) Werther and Saenger (2000) Cozzani et al (1995)

Palm kernel shell Palm fibre Coconut shell Wood waste Chicken litter

24.8

68

3.2

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Table 3 Ultimate analyses of selected biomass fuels (wt% of dry fuel with ash). Fuel sample Rice husk Palm kernel shell Palm fibre Coconut shell Wood waste Chicken litter

C

H

N

S

Cl

O

References

38.8 45.6 51.5 51.2 50.7 28.2

4.2 6.2 6.6 5.6 5.9 3.64

35.5 37.5 1.5 0.0 0.2 3.78

0.1 – 0.3 0.1 0.04 0.55

0.1 – – – – 0.6

35.5 37.5 40.1 43.1 43.1 34.4

Werther and Saenger (2000) Mahlia et al (2001) Mahlia et al (2001) Werther and Saenger (2000) Werther and Saenger (2000) Abelbha et al (2003)


Table 4 Inorganic properties of selected biomass fuels. Fuel sample

SiO2

Al2O3

TiO2

Fe2O3

CaO MgO Na2O K2O

SO3

P2O5

References

Rice husk

91.4

0.78

0.02

0.14

3.2

0.01

0.2

3.7

0.7

0.4

0.8 1.6

9.0 0.01

2.8 4.8

2.8 8.8

0.6

0.5

–

2.1

Werther and Saenger (2000) Mahlia et al (2001) Werther and Saenger (2000) Werther and Saenger (2000)

Palm fibre Coconut shell

63.2 69.3

4.5 6.4

0.2 0.01

3.9 1.6

– 8.8

3.8 2.5

Wood waste

12.8

4.1

5.2

5.2

45.2

0.9

Table 5 Calorific values (CV) of various biomass fuels. Fuel sample Rice husk Palm kernel shell Palm fibre Coconut shell Wood waste

CV (MJkg−1)

References

15.8 18.0 15.4 14.0 18.41

Werther and Saenger (2000) Mahlia et al (2001) Mahlia et al (2001) Werther and Saenger (2000) Werther and Saenger (2000)

eight examples are included here for comparison. The composition variations among biomass fuels are larger than among different coals, but as a class biomass has substantially more oxygen and less carbon than coal. Less obviously, nitrogen, chlorine, and ash vary significantly among biomass fuels. These components are directly related to NOx emissions, corrosion, and ash deposition. The wood and woody materials tend to be low in nitrogen and ash content while the agricultural materials can have high nitrogen and ash contents. The inorganic properties of coal also differ significantly from biomass (Table 4). Inorganic components in coal vary by rank and geographic region. As a class, coal has more aluminium, iron, and titanium than biomass. Biomass has more silica, potassium, and sometimes sodium than coal. Furthermore, one important difference between coal and biomass is the net calorific value (Table 5). Biomass fuels often have high moisture content, which results in relatively low net calorific value. BIOMASS ENERGY SOURCES IN MALAYSIA Biomass in Malaysia contributes about 14% of the approximately 340 million barrels of oil equivalent (boe) of energy used every year. There are five major sectors that contribute wastes to the biomass energy in Malaysia: forestry (wood products), rubber


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cultivation, cocoa cultivation, sugar cane cultivation and oil palm cultivation. Tables 6 and 7 present the estimation of biomass energy productivity, biomass production, utilization and energy potential in Malaysia.


Wood Fuel Malaysia is one of the major wood processing countries in the region. Generally, generation of electrical power using wood waste material is considered cost-competitive with the tariffs charged by the electric utility companies. The supply of excess power to the grids is not yet practised. Basically, there are four types of forest residues: logging, saw milling, plywood and veneer, and secondary processing residues. According to national statistics, Malaysia generates about 2.18 million tonnes of wood waste per year, with the potential to generate 598 GW-hours, with a total installed capacity of 68 MWs (Chuah and Azni, 2004). Wood energy only accounts for 7% of total renewable energy (RE) consumption in Malaysia. Statistics shows that most biomass energy is consumed by industries. Table 8 Table 6 Estimates of the energy productivity and biomass production and utilization (PTM, 1999). Crops/Activities

Oil Palms

Energy productivity (boe/ha/year) 88.7

Rubber trees

29.5

Paddy plants

11.54

Coconut trees

28.21

Cocoa trees

Sugarcane Logging Timber processing

Current Annual Amount Used for Energy Purposes Fruit shells Fruit fibres Effluents

23.609 13.630 0.022

Wood

4.967

80.33

Fronds Shells N.A.

1.578 0.785 N.A.

54.9 – –

Bagasse – Sawdust & waste

0.421 3.733

Current Annual Energy Potential of Utilised Biomass (million boe) Pruned fronds Empty Fruit Bunches (EFB) Effluents Replanting wastes Wood Effluents Rice husks Rice straws Fronds

77.665 11.444 2.928 12.94 3.707 0.210 1.025 2.541 0.164

Pruning wastes Pod husks Replanting wastes Leaves and tops Residues Tree bark and sawdust

16.850 0.085 0.630 0.298 19.060 1.0

Table 7 Energy Potential from Biomass/Biogas (PTM, 1999). Sector

Rice Mills Wood industry Palm oil mills Bagasse Total Palm Oil Mill Effluent (POME)

Quantity (kton/yr)

Potential Annual Generation (GWh)

Potential capacity (MW)

424 2117 17980 300 20881 31500

263 598 3197 218 4276 1587

30 68 365 25 488 177

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Table 8 Wood wastes fueled power plants in Malaysia under ASEAN-EC COGEN Programs (PTM, 1999). Wood waste

Homet Raya Sdn. Bhd., Sarikei, Sarawak

Ib Timber Sdn. Bhd., Bentong, Pahang

Bekok Kiln Dryer Sdn. Bhd., Gemas, Negeri Sembilan


Guthrie Wood Products Sdn. Bhd., Kulim, Kedah Guthrie MDF Sdn. Bhd., Kulim, Kedah

The Cogen plant is designed to produce 30 tons per hour or 22 bar saturated steam. The steam is supplied to 1.65 MW condensing turbine and the kiln dryer for drying of saw timber. Cogen plant produce 1.5 MW from backpressure turbine and condensing turbine, supplied to kiln dryer. Sawdust, wood shaving and off cuts are used as boiler fuel. Wood shavings and sawdust are used in the 5 tons per hour fire tube boiler. Steam is used to dry wood furniture. Sawdusts and wood shavings are stored in silo before fed into the boiler. The saturated steam at 6 bar is supplied to kiln dryer and furniture industry. The furnace is designed to produce heat capacity 22 Gcal/hour, for drying of fibres and heating thermal oil heather. The residues are used in the combustion chamber as fuel.

shows several wood wastes fuelled cogeneration power plant projects in Malaysia. A comprehensive study on utilization of woodfuel (biomass) was also reported by Ali and Hoi (1990). However, data on woodfuel use by households are not available. In the domestic sector biomass energy is mainly used for cooking. Table 9 gives the total production and trade statistics of fuelwood and charcoal in Malaysia for the period 1985–1993. Currently, with the emergence of alternative uses for wood waste materials (e.g. fibre board), wood residue volumes as a source of fuel are decreasing. Emphasis in this sector will be not so much on expansion of capacities, but rather on higher efficiencies in existing industries. The other reason biomass waste from forestry, logging and timber industries in Malaysia has not been highlighted as a potential fuel is the difficulty of interesting wood mill owners in diversifying their businesses to include power generation. There is also a problem in securing long-term supply agreements from the mills.

Table 9 Total production and trade statistics of fuelwood and charcoal in Malaysia for the period 1985–93 (Thomas et al., 1997). Year

1985 1986 1987 1988 1989 1990 1991 1992 1993

Fuelwood (’000 m3)

Charcoal (’000 MT)

Production

Production

Import

Export

5537 5687 5842 600 6159 6319 6478 6637 6795

351 360 370 380 390 400 410 420 430

61 52 47 47 47 47 15 15 9

19 13 13 13 13 13 21 28 18


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Rubber Cultivation Waste generated by the rubber industry can come from three sources (PTM, 1999):


1. Generated from fallen leaves, branches, twigs and rubber seeds. There are 6.5 dry tones of wood and leaves and 0.036 dry tones of seed per hectare per year. The total energy potential available is 20.7 boe. 2. Effluents produced after latex processing. If converted into biogas, the energy potential of this effluent is about 210,000 boe per year 3. Rubber wood from replanting activities. It is estimated that the amount of dry rubber wood available from 1999 until 2007 is an average of 3.3 million dry tones annually. Out of this, 1.47 million dry tonnes is used as fuel, which has an energy content of 4.97 million boe per year (see Table 6). The relatively small amount of in-place waste in rubber processing activities means that it is a fairly low priority area for biomass based renewable energy development. The major waste stream—from replanting—involves a variety of issues regarding transport to a central generation facility, which will negatively impact the potential for this component. In Malaysia, Heaveafil Sdn. Bhd., Batang Kali, Selangor, is the pioneering company reported to produce biogas from rubber effluent via anaerobic process and used it as fuel (PTM, 1999). Rice Paddy Cultivation In 1996, 639,000 ha of land were used for paddy cultivation, which is mainly located in the state of Kedah and Selangor. The amount of rice produced was 2.128 million tones. Paddy cultivation leaves two types of residue: paddy straw and rice husk. Based on 1996 production statistics, 1.06 million tones of paddy straw were produced giving an energy potential of 2.54 million boe; meanwhile 1.03 million tones of rice husk were produced with an energy potential of 3.04 million boe. The total energy potential for rice straw and rice husk is 3.56 million boe, which would account for 1.5% of the country’s energy consumption in 1996. It is estimated that rice mills produce 424,000 tonnes per year, with the potential to produce 263 GW hours, with a capacity of 30 MWs (see Table 7). One successful energy project that developed in rice sector in Malaysia is at Ban Heng Bee rice mill, Alor Setar. The total investment, excluding civil and structural works, for equipment is about RM 330,000 (USD 92,000). Based on the consumption and price of fuel oil, the annual savings from reducing fuel oil purchases amounts to an astonishing RM 75,000 (USD 21,000) (Ibrahim et al., 2002). Another rice husk cogeneration plant, Titi Serong Edar Sdn Bhd., located in Parit Buntar, Perak, is also reported to successfully generate between 700 and 1500 kW of electricity. The 1.5 MWe plant is designed to cover the steam and electricity requirements of the drying process of rice milling (COGEN3, 2004). Even though the energy potential from rice straw and rice husk is relatively high, it is not well developed due to the difficulty of handling paddy wastes. Another problem is seasonal supplies because rice is only produced 1 to 3 times a year. Coconut Cultivation Waste from coconut cultivation can be divided into three categories (PTM, 1999):

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1. Coconut fronds and debris that are shed throughout the year. It is estimated that based on 1995 data, 0.583 million tonnes of fronds with a potential energy of 1.747 million boe is produced annually and about 0.528 million tones of these are being used for fuel in rural villages by burning. 2. Shell, husk and copra wastes are generated from the processing and consumption of coconut fruits. 0.747 million tonnes of shells and 0.374 million tonnes of husks were produced annually. This amount corresponds to 1.99 million boe and 1.12 million boe respectively. The copra produced was 0.35 million tonnes with an energy potential of 1.18 million boe. 3. Wastes generated during replanting. Energy extracted from the leaves and trunks is estimated at 207.6 boe per hectare. There is no detailed study being carried out on the utilization of coconut waste as fuel in Malaysia. It may be due to the location of coconut plantations, which are usually located in the rural area with poor infrastructure. Moreover, coconut plantations are not as energy intensive compared to the palm oil industries. Cocoa Cultivation In 1996, the total plantation area of cocoa was 235,000 ha. The biomass sources of cocoa plantation mainly come from the pruning process. Waste generated from cocoa fruits, leaf and wood biomass generated during replanting. It is estimated that 25.2 million tonnes per ha per year of dry organic biomass matter are produced from the pruning process. This is equivalent to 71.7 boe per ha per year of energy potential. Energy potential of the cocoa wastes per ha per year are 2.08 boe from the fruit, 0.36 boe from the dry cocoa husk and 1.72 boe from the cocoa beans. The total energy potential from cocoa cultivation is 80.33 boe per ha per year, but it has been not yet been exploited in Malaysia. Furthermore, there is no project being reported in utilization of this fuel source in Malaysia. Sugarcane Cultivation In 1997, the total land area under sugarcane cultivation was 18,000 ha, which is primarily located in the northern states of peninsular Malaysia. Sugarcane plantations derive energy from sugarcane related wastes including sugar, bagasse, dry leaves and cane top. 150,000 tonnes of dry bagasse was produced, which had an energy potential of 0.421 million boe per year. All the bagasse was used as a boiler fuel in the sugar mills. During replanting, sugar wastes such as leaves and cane tops are disposed of through burning. The total energy from these wastes is about 0.298 million boe per year (PTM, 1999). Table 7 indicates that the potential for bagasse production in Malaysia is 300,000 tones per year, with a potential to generate 218 GW hours. Duval (2001) reported a summary of biomass residues and wastes generated in each Southeast Asian country by the wood and food processing industries, and the associated power generation potential. No data on bagasse fuel in Malaysia was reported. Palm Oil In Malaysia, at present more than 2.8 million hectares of land under oil palm cultivation. The industry is the biggest biomass producer in Malaysia. Of primary interest, the



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waste from the palm oil mills is utilized on-site to provide energy for the mill as well as electricity exports to the grid. As of 1995, there are some 281 palm-oil mills in operation with an aggregate installed capacity of around 200 MWe. All this capacity is installed to meet own demand (captive power). It was estimated that a total of 42 million tons of fresh empty fruit bunches (EFB) were produced in Malaysia annually. This translates to around 17 million tons of waste. For low-pressure systems with an assumed conversion rate of 2.5 kg of palm oil waste per kWh, potentially 7,000 GWh could be generated. However, the EFB has found an alternative use, such as medium density fibreboard in furniture making. These competing alternatives may eventually result in waste shortages at palm-oil mills (Chuah and Azni, 2003). Palm oil mill processing also produces palm oil mill effluent (POME), which is treated in tanks and then released into the water table, but could be utilised as a source of biogas. From Table 7, it is clearly seen that the yearly available biomass in 2000 was 17,980,000 tonnes per annum, with the potential to generate 3,198 GW-hours, with a potential capacity of 365 MW. The mills are estimated to produce 31,500 million m3 of POME per year, with a potential to generate 1,587 GW hours, with a capacity of 177 MW. Animal Wastes Other than crop residues, animal wastes are also utilized for power generation. The utilization of biogas from animal wastes in Malaysia was considered in the early eighties. Various studies to use biogas from animal wastes have been carried out in Malaysia. Sormana (1992) studied the anaerobic digestion of chicken dung and Sow et al. (1994) studied anaerobic digestion of slaughterhouse wastes. However, it was not felt to be attractive at that time, namely because there was no large-scale livestock industry and farm animals were normally scattered so that collection of waste was difficult. The Standard Industrial Research Institute of Malaysia (SIRIM) had also carried out a 60 kVA pilot program of biogas generation in a chicken farm. The system however was later abandoned due to the difficulties of handling the scattered waste, not the technicality of the system (Othman et al., 1996). Efforts were once being made to convert pig waste into biogas through anaerobic digestion. A study on pig waste biogas was conducted in a government experimental pig farm but was abandoned when the farm was closed down. Malaysian Agricultural Research and Development Institute (MARDI) had operated an operational biogas plant with 500–600 pigs at its research station. But the research unit was shut down in 1985 due to religious reasons. However, the plant can still be operated for lighting, provide heating for the piglets and a biogas stove (Othman et al., 1996). Pig waste is considered a problematic waste because of its sensitive nature to the Muslims in Malaysia. By 1996, there were four biogas plants built in Sibu, Sarawak (Othman et al, 1996). These projects were funded by German Appropriate Technology Exchange (GATE) with technical expertise from Sri Lanka and designed from a Chinese model (Bathia and Mills, 1985). The biogas generated from these plants was mainly used for cooking, lighting and water pumping. Unfortunately these biogas pilot initiatives did not lead to further exploitation of the potential. Most farmers were not keen to install the biogas plant due to financial and technical reasons. It was cheaper to get conventional fuel and reduce farmer’s maintenance burden. Technical expertise and support was lacking which led to less interest in the biogas option from farmers.

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Another study on the possibility of developing biogas power generating system from layer’s farming is carried out by Othman et al (1996). This study was conducted in a 48 acres farm about 50 km South of Kuala Lumpur. The farm consists of 300,000 heads of layer producing 9000 kg/day dry weight of the chicken dung. The gas has been used in a combined heat and power system to meet the energy requirements of the farm.


Urban Wastes: Landfills and Incineration With the increase in the population of the urban area the problem of disposing of solid wastes has become more serious. In Malaysia, the national average of the amount of waste generated is at 0.5–0.8 kg/person/day. However, in the cities these figures have escalated to 1.7 kg/person/day (Kathirvale et al., 2003). Currently, an average of 2500 ton of municipal solid waste (MSW) is collected every day for the city of Kuala Lumpur, capital city of Malaysia. Table 10 shows an average composition weight percentage of components in MSW generated by various sources in Kuala Lumpur. Generally there are two methods of MSW disposal in Malaysia—landfill and incineration. Initiatives have been taken by the government and the private sectors to tap the landfill gas (LFG) for the generation of electricity. Currently, there are only a handful of properly designed and operated landfills in the country and most of them are located in the capital, Kuala Lumpur area. One of these projects is the Ayer Itam Landfill located at Puchong, Selangor which had been commissioned on April 2004, using LFG for power Table 10 Average composition weight percentage of components in municipal solid waste (MSW) generated by various sources in Kuala Lumpur. Sources

Food/organic Mix paper News print High grade paper Corrugated paper Plastic (rigid) Plastic (film) Plastic (foam) pampers Textile Rubber/leather Wood Yard Glass (clear) Glass (colored) Ferrous Non-ferrous Aluminium Batteries/hazards Fine Other organic Other inorganic Others Total

Residential high income (%)

Residential medium income (%)

Residential low income (%)

Commercial (%)

Institutional (%)

30.84 9.75 6.05 – 1.37 3.85 21.62 0.74 6.49 1.43 0.48 5.83 6.12 1.58 1.17 1.93 0.17 0.34 0.22 – 0.02 – – 100.00

38.42 7.22 7.76 1.02 1.75 3.57 14.75 1.72 7.58 3.55 1.78 1.39 1.12 2.07 2.02 3.05 0.00 0.08 0.18 0.71 0.00 0.27 – 100.00

54.04 6.37 3.72 – 1.53 1.90 8.91 0.85 5.83 5.47 1.46 0.86 2.03 1.21 0.09 2.25 0.18 0.39 – 2.66 – 0.25 – 100.00

41.48 8.92 7.13 0.35 2.19 3.56 12.79 0.83 3.80 1.91 0.80 0.96 5.75 2.90 1.82 2.47 0.55 0.25 0.29 0.00 1.26 – – 100.00

22.36 11.27 4.31 – 1.12 3.56 11.82 4.12 1.69 4.65 2.07 9.84 0.87 0.28 0.24 3.75 1.55 0.04 0.06 0.39 1.00 8.05 6.97 100.00


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Table 11 Amount of energy recoverable from municipal solid waste (MSW) by incineration. Material

Total energy Energy Calorific Treatment Waste to recovered Recoverable/ value of technology energy (WTE) conversion fuel (kJ/kg) ton of fuel (kW) (based on 1500 ton/ day) (MW) efficiency (%)

MSW MSW MSW

Incineration Incineration incineration

25 25 25

9210 6280 3349

639 436 233

960 655 350

Energy Recoverable (normalized to per ton of MSW input) (kW) 639 436 233

generation. This project was being developed by a TNB subsidiary, Jana Landfill Sdn. Bhd. (JLSB), and is under the small renewable energy power (SREP) program. The plant has a capacity of 2.0–5.0 MW. SIRIM-Projass is another engineering group interested in developing LFG power facilities and is in the early stages of developing a municipal waste site (PTM, 2004). A few landfill gas potential studies undertaken to date have also suggested that many of the existing landfills are not currently suited to exploitation for energy production, mainly due to their small scale. As for incineration, the normal practice is that the solid waste is burnt without recovering the energy. Kathirvale et al. (2003) carried out a study to evaluate the energy recovery potential from MSW. They found that incineration gives the best returns in terms of the amount of energy recovered. The amount of energy can be recovered are shown in Table 11. Recently, the government has planned for a gasification unit with ash melting incineration system for the city of Kuala Lumpur with a capacity to incinerate 1500 ton of MSW/day and is expected to be operational by the year 2006. BIOMASS ENERGY CONVERSION TECHNOLOGIES Energy from biomass can be converted via three general categories: thermochemical, physical or chemical processes and biological conversion. Thermochemical conversion processes include combustion, gasification and pyrolysis processes. The later two characterized by processing with a very limited amount of air. Its main advantages are production of a fuel which does not need to be used “in-situ“ (Andries and Buhre, 2000; Storm et al., 2000; Yin et al., 2000). Physical processes basically include pressing processes and extraction of vegetable oils, which can be used directly or indirectly as biofuels. Chemical processes generally involve chemical transformations of oil and other products extracted from plants in order to convert them into biofuels. For biological processes, two processes, namely alcoholic fermentation and biomethanization from the biodegradable organic matter to produce biogas, are commonly considered (Sarayama, 1999). Figure 2 shows the main ways of energetic exploitation of biomass. PALM OIL BASED BIOMASS COGENERATION PROJECTS IN MALAYSIA Many palm oil mill owners do have the potential to generate electricity and might sell it to the big energy supplier like Tenaga Nasional Berhad (TNB). All the palm oil mills in Malaysia use palm fibre and shell (by product of oil palm milling) as the boiler fuel to produce steam and electricity for palm oil production processes. This biomass can supply enough electricity to meet the energy demand of a palm oil mill. It is estimated that

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T.G. CHUAH ET AL. Conversion Technology

pyrolysis

Primary product

Processing technology

charcoal

mixing

upgrading

liquid

Secondary product

Product usage

Slurry fuel

Process heating/drying

Gasoline, diesel

Mech. System IC engine, steam turbine

Fuel gas

gasification

Steam generation purification


Gas

Fuel alcohol

Electrical generation

synthesis incineration heat

Chemical products

Heat exchanger

Figure 2 Possible products from thermal conversion of solid wastes.

in the year 2004 about 1400 million kWh of electricity was generated and consumed by the palm oil mills (Ma and Yusof, 2005). However, the palm oil mills generally have excess fibre and shell, which are not used and have to be disposed off separately. In other words, the palm oil mills still have excess capacity to produce more renewable energy. Apart from palm fibre and shell, empty fruit bunches (EFB) are another source of biomass which can be readily converted into energy. The energy data analyzed for various palm biomass is shown in Table 12. The data provides useful information for the utilization of palm biomass as boiler fuels. Historically, the little incentive provided by the Malaysian government to the local palm oil mills led to the minimization of process steam demands. This in turn would Table 12 Energy Database for Palm Biomass. Sample

Empty Fruit Bunches (EFB) Fibre Shell Palm kernel Cake Nut Crude Palm Oil Kernel Oil Liquor from (EFB) Palm Oil Mill Effluent (POME) Trunk Petiole Root

Heat Value (kJ/kg)

Ash (%)

Volatile Matter (%)

Moisture (%)

Hexane Extraction (%)

18,795 19,055 20,093 18,884 24,545 39,360 38,025 20,748 16,992

4.60 6.10 3.00 3.94 4.05 0.91 0.79 11.63 15.20

87.04 84.91 83.45 88.54 84.03 1.07 0.02 78.50 77.09

67.00 37.00 12.00 0.28 15.46 1.07 0.02 88.75 93.00

11.25 7.60 3.26 9.35 4.43 95.84 95.06 3.85 12.55

17,471 15,719 15,548

3.39 3.37 5.92

86.73 85.10 86.30

76.00 71.00 36.00

0.80 0.62 0.2



335

enable a cogeneration system to generate large amounts of electrical energy to earn additional revenue providing an incentive for adopting new process steam reductions at palm oil mills facilities (Yusuf et al, 1993). The return on investment for additional electrical power sales would typically be attractive. The launch of the Small Renewable Energy Power Programme (SREP) in May 2001, an initiative of the special Committee on Renewable Energy (SCORE) under the Ministry of Energy, Communication and Multimedia (MECM), “ kick started” the Government’s policy implementation to encourage and intensify the utilization of RE in power generation. SREP’s primary objective is to facilitate the expeditious implementation of grid—connected renewable energy resources-based small power plants (Husain and Alimat, 1999). Under this scheme, license is issued to generate and sell energy for 21 years and maximum power allowable for export is 10 MW and with added tax benefits. The status of SREP projects approved by score as of September 2004 by Malaysia Government is shown in Table 13. One of these projects is a 5.2 MW power plant at Pantai Remis Palm Oil Mill, Perak, using the empty fruit bunch (EFB) as fuel. It has connected to grid to supply power to a small town located few kilometers from the station and export to TNB at the rate of US$ 0.043 per kWh (Husain et al., 2003; Jamari, 2002; Nicholas, 2002; Zakaria, 2002). Pusat Tenaga Malaysia (PTM) or Malaysia Energy Centre has been given the mandate to spearhead the implementation of the Biomass Power Generation and Cogeneration in the Malaysian Palm Oil Industry (BIOGEN) project under the helm of the Ministry of Energy, Communication and Multimedia (MECM) in year 2003. The project is jointly funded by the Government of Malaysia (GoM), United Nations Development Programme (UNDP), Global Environment Facility (GEF) and the Malaysian private sector. The main objectives are to reduce the growth rate of green house gases (GHG) emissions from fossil fuel fired combustion processes. It is envisioned that at the end of the project implementation, GHG emission from power generation in Malaysia are reduced by 3.8%. The reduction in GHG could be made possible through fuel substitution as a result of the expected increase in installed capacity from RE power generation. The project also aims to remove some impending barriers that have been hampering RE power project development through strengthening of technical, financial and policy frameworks (PTM, 2003). The Federal Land Development Authority (FELDA) is another Malaysian government agency that actively conducting researches to use oil palm waste to produce a substitute fuel for diesel. The agency has completed building a biomass power plant in Lahad Datu, Sabah, East Malaysia and plans to build 10 more in Peninsular Malaysia. It will Table 13 Status Of SREP Projects Approved by Score as of September 2004 (Ludin et al., 2004). No.

Type

1.

Biomass

2. 3. 4.

Landfill Gas Mini-hydro Wind and Solar Total

Energy Resources

Approved Application

Grid Connected Capacity (MW)

%

Empty fruit Bunches Wood Residue Rice Husk Municipal Solid Waste Mix Fuel

25 1 2 1 3 5 25 0 62

165.9 6.6 12 5 19.2 10 95.4 0 314.1

52.8 2.1 3.8 1.6 6.1 3.2 30.4 0 100

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T.G. CHUAH ET AL.

spend about USD$1 million for each plant once it receives an approval from the Energy Commission, Malaysia (Abas, 2005). Until now, according to the report by the Ministry of Energy, Water and Communications (MECW, formerly known as MECM), 60 RE projects are approved. Among the 60 projects approved, mini-hydro (49%) and biomass (43%) (especially palm oil waste) account for more than 90% of total numbers of projects. In terms of capacity, palm oil waste accounts for 66%, mini-hydro for 31% (Othman and Sopian, 2005).


WOOD BASED BIOMASS COGENERATION PROJECTS IN MALAYSIA There are several cogeneration projects on wood-based biomass in Malaysia. Most of these cogeneration plants are in small scale and only supply to local industries. These include a 1.65 MW wood-fueled cogeneration plant in Sibu, Sarawak, commissioned in January 1994; a 1.5 MW wood-fueled cogeneration plant for the Sim Hoe Wook Industry Sdn. Bhd. complex in Bentong; and a 10 MW plywood-fired cogeneration plant was commissioned on 1995 in Keningau, Sabah, Malaysia to provide power to one of the wood complexes of Aokam Industries (Duval, 2001). PYROLYSIS OF BIOMASS Pyrolysis is thermal decomposition occurring in the absence of oxygen. It is always also the first step in combustion and gasification processes where it is followed by total or partial oxidation of the primary products. There are only a few studies reported on the pyrolysis of biomass in Malaysia. Ani et al. (1993) had carried out a study to identify the potential to convert biomass like rice husks and oil palm solid wastes into pyrolytic oil. They found that rice husk produced only a negligible amount of pyrolysis oil at a low heating rate. However, palm oil waste had produced 34.2% yield of pyrolysis oil. Several works that focus on fluidised bed pyrolysis of palm oil shells were reported (Ani and Islam, 1997; Islam et al., 1997; Islam and Ani, 1998). However, these studies are limited to the pilot scale studies. BIOGAS PRODUCTION FROM POME Besides the solid residues, palm oil mills also generate large quantities of liquid waste in the form of palm oil mill effluent (POME), which, due to its high biochemical oxygen demand (BOD), is required by law to be treated to acceptable levels before it can be discharged into watercourses or onto land. In a conventional palm oil mill, about 0.7 m3 of POME is generated for every tonne of FFB processed. An anaerobic process is adopted by the palm oil mills to treat their POME; the biogas produced during the decomposition is a valuable energy source. It contains about 60–70% methane, 30–40% carbon dioxide and trace amount of hydrogen sulphide (Ma et al., 1999; Quah and Gillies, 1981). Its fuel properties are shown in Table 14 together with other gaseous fuels. About 28 m3 of biogas is generated for every tonne of POME treated. In a gas engine it has been reported that about 1.8 Kwh of electricity could be generated from one m3 of biogas (Quah et al., 1982). It was estimated that one cubic meter of biogas is equivalent to 0.65 litre of diesel for electricity generation. Hence the total biogas energy can substitute 582 million litres of diesel in 1997. This amounted to RM378 million. Again the amount of biogas generated by an individual palm oil mill is not significant for


337

Table 14 Some properties of gaseous fuels.

Gross calorific value (MJ/Nm3) Specific gravity Ignition Temperature (oC) Inflammable limits (%) Combustion air required (m3/m3)

Biogas

Natural Gas

LPG

19.85 – 25.75 0.847 – 1.002 650 – 750 7.5 – 21 9.6

3.79 0.584 650 – 750 5 – 15 9.6

100.48 1.5 450 – 500 2 – 10 13.8


All gases evaluated at 15.5oC, atmosphere pressure and saturated with water vapour. LPG-Liquefied petroleum gas. Source: Quah and Gillies (1981).

commercial exploitation. However, the economic viability may be attractive if the palm oil mills can utilise all the fibre, shell EFB, and biogas for steam and electricity generation. So far, only a few palm oil mills harness the biogas for heat and electricity generation (Quah and Gillies, 1981; Quah et al., 1982; Gillies and Quah, 1984; Chua and Gian, 1986). The potential energy from biogas generated by POME is shown in Table 15. Again, as all the palm oil mills have enough energy from fibre and shell, there is no outlet for this surplus energy. Considering the costs of storage and transportation of the biogas, perhaps the most viable proposition is to encourage the setting up of industries in the vicinity of the palm oil mills where the biogas energy can be directly utilised. This can result in a substantial saving in energy bills. Recently, a few improved high rate bioreactors have also been tested in the treatment of POME such as the modified anaerobic baffled bioreactor (Faisal and Unno, 2001); anaerobic filter and anaerobic fluidized bed reactor (Borja and Banks, 1995); thermophilic upflow anaerobic filter (Mustapha et al., 2003); and rotating biological contactors (Najafpour et al., 2005). These were successful in increasing the efficiency of pollution reduction and methane production. Experimental results indicated better treatment of POME compared to conventional practices. However, large scale implementation of any of the improved system is still lacking. A successful example of closed tank anaerobic digester system for POME biogas capture and utilization is Keck Seng (Malaysia) Berhad. The system has been in continuous operation for over 19 years practically without any interruptions. The company has been awarded the ASEAN Energy Award 2003 for the Off-Grid category in New Renewable Source of Energy Project Competition. Keck Seng has also recently entered into a licensing agreement to allow Novaviro Technology Sdn Bhd to promote and commercialise the anaerobic digester technology in Malaysia (Tong and Jaafar, 2004).

Table 15 Potential energy from biogas. Year

Palm oil production (million tonnes)

POME (million m3)

Biogas (million m3)

Electricity (million KWh)

1997 2004

9.07 13.98

32 49

896 1372

1613 2470

Source: Ma and Yusof (2005).

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T.G. CHUAH ET AL.


The feasibility of anaerobic fermentation process for the production of biological hydrogen by natural anaerobic microflora from POME was studied by Morimoto et al. (2004). POME sludge containing anaerobic microorganism and microflora was collected from the anaerobic pond of POME treatment plant in a palm oil mill at Negeri Sembilan, Malaysia. From the laboratory testing, the microflora was found to produce significant amounts of hydrogen with the maximum production yield of hydrogen of 2.1 mol H2/molglucose. However, this study is still yet to investigate at the pilot plant study. Besides the palm oil milling industries, beverage and food industries in Malaysia also play their role in biogas utilization. Carlsberg (Malaysia) Sdn. Bhd. and Guiness Anchor Berhad in Petaling Jaya, Selangor have installed high rate anaerobic treatment system and generate biogas as a product. The gas is combusted to supply energy for daily utilities (Rahman, 2004). BIODIESEL AS RE IN MALAYSIA Biodiesel is the ester formed by reacting vegetable oils or animal fats with methanol or ethanol. The product in its raw from is unsuitable for many applications due to high viscosity and other deleterious properties so the methyl or ethyl ester is formed by esterification. Palm oil based methyl ester has been studied thoroughly as a diesel substitute in Malaysia (Mukti et al., 1984; Ong et al., 1985; Azhar et al., 1989; Masjuki and Sohif, 1991; Masjuki et al., 1993; Choo et al., 1995; Choo and Ma, 2000; Ali and Tan, 2005). Crude palm oil, crude palm stearin and crude palm kernel oil can be readily converted to their methyl esters. Ho et al (2005) proposed the application of immobilized lipase as an enzymatic catalytic to optimize the transestrification process. They claimed that this process could lower the production cost of biodiesel. The production by PORIM/PETRONAS patented technology (Choo et al., 1998; Ong et al., 1989) has been adequately described recently (Ma et al., 1993). Methyl esters from crude palm oil and crude palm stearin produced by PORIM/PETRONAS technology have very similar fuel properties as the petroleum diesel (Table 16). It also has a higher cetane number than diesel (Table 17). It can be used directly as fuel in unmodified diesel engines. Obviously it can be used as diesel improver. Compared to crude palm oil, the methyl esters have very much improved viscosity and volatility properties. It has a pour point of 16°C. It does not contain gummy substances. However, the high pour point of the methyl esters allows it to be used only in the tropical countries. In recent years, palm diesel with low pour point (without additives) has been developed to meet seasonal pour point requirements, for example spring (−10°C), summer (0°C), autumn (−10°C) and winter (−20°C). The MPOB patented technology (Choo et al, 2002) has overcome the pour point problem of palm diesel. With the improved pour point, palm diesel can be utilised in temperate countries (Ma and Yusof, 2005). Fuel from palm oil was first used on vehicles in Malaysia under a field trial program in 1983, with promising result leading to more experimental works, especially on a laboratory scale (Ong et al., 1985). Researches on the use of palm oil as diesel fuel alternatives had also been conducted in local universities, such as University Technology Malaysia (Azhar et al., 1989; Mukti et al., 1984) and University Malaya (Masjuki and Sohif, 1991; Masjuki et al., 1993). In March 1987, the Palm Oil Research Institute of Malaysia (PORIM), Cycle & Carriage Bintang Berghad and Diamler-Benz AG, Stuttgart, Germany, reached an agreement in which PORIM will produce the ester and to provide fuels and lubricating oils; Diamler-Benz will conduct bench tests, whilst Cycle and Carriage will install the engines into the buses and to support field tests. The tests showed that the buses with the engine designed for the


339

Table 16 Fuel characteristics of Malaysian diesel, methyl esters from crude palm oil (CPO), methyl esters from crude palm stearin (CPS) and palm diesel with low pour point. Property


Specific gravity ASTM D 1298 Sulphur content (% wt) IP 242 Viscosity at 40oC (cSt) ASTM D 445 Pour Point (oC) ASTM D 97

Malaysian diesel

Methyl esters from CPO

Methyl esters from CPS

Palm diesel with low pour point

0.8330 at 15.5oC

0.8700 at 23.6oC

0.871 at 25.5oC

0.8803 at 15.5oC

0.10

0.04

0.02