Introduction of Integrated Energy Plantation Model for ...

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Introduction of Integrated Energy Plantation Model for Microalgae-Using Palm Oil Mill Effluent (POME)

Nugroho Adi SASONGKO※1※ 2, Ryozo NOGUCHI ※1, Tofael AHAMED※1, and Tomohiro TAKAIGAWA ※1

(Received September 16, 2014)

Large scale utilization of microalgae to produce biodiesel will boost large amounts of fertilizer and water consumption in upstream stage and needs excessive energy in the downstream process. To overcome these issues, the integrated energy plantation has been introduced as a suitable cultivation system, including the possibility to utilize its effluent. As a free and rich nutrient source for microalgae growth, POME was carefully evaluated in order to find out more energy return in upstream stage. In the downstream stage model, a wet lipid process pathway was chosen as the current best available method. Consequently, reducing energy consumption for the biodiesel production cycle was achieved and the energy profit ratio reached up to 2.6. Energy demand was lessened by a combination of outputs from one system, and served as inputs to another, from the integration of POME treatment, biomass power plant, biogas production, microalgae cultivation, and co-products utilization. Therefore, the energy and material balances could significantly outperform those from the single system.

バイオディーゼル燃料を製造するための微細藻類利用の大規模化は，上流工程では肥料や水の大量消費をもたらし，下流工程では過剰なエネルギーを必要とする。これらの課題を克服するために，統合化されたエネルギープランテーションが，その排水の利用の可能性を含めて，適切な栽培システムとして提案された。微細藻類の成長のための無料で豊富な栄養源として，POME（パームオイル搾油排水）が，上流工程でより多くのエネルギー収支を得るために，慎重に評価された。下流工程モデルでは，水分を含む脂質処理方法が，現在利用可能な最善の方法として選択された。その結果，バイオディーゼル燃料の生産サイクルのためのエネルギー消費削減が達成され，エネルギー収支比は 2.6まで到達した。エネルギーの需要は，一つのシステムからの複数の出力の組み合わせにより減少し，POME 処理，バイオマス発電所，バイオガスの生産，微細藻類の培養，および副産物利用の統合から，別の入力エネルギーとして提供された。そのため，統合システムのエネルギー・マテリアルバランスは，単独のシステムに比べて，十分に性能が優れていることが明らかとなった。

Key WordsBiofuel production, Integrated energy plantation, Microalgae cultivation, Palm Oil Mill Effluent (POME)

※1 University of Tsukuba 1-1-1, Tennoudai, Tsukuba-shi, Ibaraki 305-8577, Japan※ 2 The Agency of Assessment and Application of Technology Jakarta, 10340 Indonesia

Journal of the Japan Institute of Energy, 94, 561-570（2015）

Special articles: Grand Renewable Energy 2014特集：再生可能エネルギー 2014

1.　Introduction　1.1　General

In 2025, the total consumption of diesel fuel in Indonesia will reach approximately 31 million kL 1). To fulfill the target of national energy policy on biofuel energy roadmap, The Ministry of Energy and Mineral Resources released a regulation on Biodiesel utilization (No. 25, August 29th, 2013) and stated the minimum biodiesel blended is 10% for all sectors beginning from January 2014 2). As a

main source of biodiesel, Palm Oil Plantation needs to be expanded additional 6 million ha of land. This amount of land can be reduced through the cultivation of microalgae-based biodiesel. Microalgae has the potential to produce 22.3 thousand L/ha/year of biodiesel (30 g/m2/day and lipid content 30%). The calculation of land required for each biodiesel crops is presented on Fig. 1. By this estimation, approximately 1.4 million ha to meet national biodiesel target by 2025. This advantage can diminish land clearing for another 4.6 million ha, furthermore reducing land use change in Indonesia. Compared to perennial crops such as

This study was partly presented in the GRE2014.

562 J. Jpn. Inst. Energy, Vol. 94, No. 6, 2015

oil palm, the ratio of microalgae biomass production rate is much higher. Microalgae lipid production can reach 10 times more than conventional biofuel crops 3).

　1.2　ObjectiveThis research work intended to explore the

possibility of utilizing of POME for microalgae cultivation. In this regard, the material and energy balances of the integrated energy plantation were selected as the objective for achieving technical feasibility.

2.　Material and Methods　2.1　POME treatment

The total land for palm plantation in Indonesia was 9 million ha and there are 695 palm mills had the average capacity of 37.2 tons of Fresh Fruit Bunches (FFB/h) 4). In each mill, POME has a unique characteristic. The effluent depends on the natural properties of the FFB, extraction and efficiency of the Crude Palm Oil (CPO) processes. The effluent treatment system is a multiple conventional anaerobic and aerobic lagoons. The typical land size was required 5 - 10 ha for POME treatment with a depth of 3 m, and often up to 6 m. Wastewater was generated from the steam extraction process, was about 0.5 m3 POME/t FFB

or 2.5 m3 POME/t CPO 5). In Indonesia, there were few investigations of wastewater generated from POME. For examples, 3.5 m3 POME/t CPO or 0.7 m3 POME/t FFB and 1.5 m3 POME/t FFB of volume estimation, respectively 6) 7).

POME cou ld release 18 m3/ha/year, then approximately 162 million m3/year of nutrients rich effluent from 9 million ha palm plantations. Where water scarcity is an issue, this large volume of POME is prospective to be used as a medium source for microalgae growth. A large fraction of the nutrients is recycled from the secondary treatment pond, thus resulting significant savings in makeup nutrient costs. It is a valuable resource to establish a large-scale cultivation and it can be considered in developing low cost microalgae production system. Further, commercial production of microalgae-based biofuels could be feasible.

POME was considered as a polluting agro-industrial effluent due to its high values of Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD) concentrations ranging from 50,000 to 90,000 mg/L. However, CPO which was extracted using steam and no additional of chemicals, released a homogeneous effluent and nutrient-rich (relatively clean and easy to control for further processing compared to municipal or industrial wastewater). In order to use

Fig. 1　Estimated land required for different biofuel crops to fulfill the target of national biofuel roadmap in 2025

563J. Jpn. Inst. Energy, Vol. 94, No. 6, 2015

POME for microalgae growth, it was necessary to treat effluent especially pH, COD, BOD, total nitrogen, total phosphorous, and ammonia composition. In addition, pH was needed to be neutralized and it was required to shift other effluent composition meets the tolerable limit for microalgae growth.

Table 1 shows POME characteristics which to be considered for microalgae cultivation. From field measurement, other minerals such as Ca, Mg, Fe, K, Na, B and Mn have composition 860, 800, 126, 2,470, 130, 5.18 and 9.22 mg/L respectively.

Field investigation and measurement showed that a palm mill with a capacity of 45 tons FFB/h, and located in 20,000 ha plantation, had average POME of 360,000 m3/year. Processing water in two particular sites (PTPN V Riau province, and PTPN VII Lampung province, Indonesia) had average 21,454 m3/month. An effluent rate of 66,666 L/d or 20,000 m3/month or 240,000 m3/year was used in this analysis, which sufficient to run 10 ha of microalgae cultivation ponds (Fig. 2). In a study, COD approximately 1,000 mg/L was affected the high consumption rate and growth of microalgae biomass 8). It was investigated for Chlorella pyrenoidosa, cultivated in POME with different concentrations (0, 250, 500 and 1,000 mg COD/L).

Meanwhile, a 5 year continuous field measurement from a particular POME treatment facility showed that COD had an average amount of 1,471.9 mg/L in the stabilization pond (Fig. 3). Certain COD concentration in the effluent can be controlled by utilizing aquatic plants. Aquatic plants grow in the stabilization pond found to be effectively balanced the nutrient ratio. If the nutrients are higher

than ideal ratio, aquatic plants can be left to grow rapidly. While on the contrary, aquatic plants should be reduced, if the condition does not meet the minimum nutrient ratio. Nowadays, utilization of aquatic plants is a common practice in the palm oil industry before releasing the effluents into water bodies such as rivers, comply the requirements of environmental regulations.

Fig. 4 shows, from a particular site, pH had an average of 7.7 for 5 years, where NH3-N had an average 125.1 mg/L. The microalgae biomass and lipid productivities were highest at pH between 7.0 - 8.0 for Chlorella sp. 9).

Table 1 POME characteristics to be considered for microalgae cultivation

ParametersPOME [mg/L]

Cooling pond (Inlet) Aerobic pond (Outlet)Temperature 70 - 80 30 - 40pH 4.0 - 5.0 7.0Total COD 40,000 - 90,000 350 - 1,300*Total BOD 15,000 - 30,000 100 - 700*TSS 20,000 - 40,000 700*TDS 15,000 - 30,000VSS 15,000 - 35,000Total Carbohydrate 29,000 - 45,000Total Proteins 17,500 - 32,500Total lipids 15,000 - 23,000Total N 1494.66* 456 - 750*NH3

+N 50.42* 34.2*Total P (PO4-P) 315.36* 68.40 - 180*K 1,000 - 2,500 110 - 924Mg 250 - 1,000 17 - 152*Sample of field measurement from PTPN V, Riau 2013

Fig. 4 Monthly average of pH and Ammonia concentration in a particular stabilization pond (2009 - June 2014)

Fig. 2 Monthly average of total processing water in a particular palm oil mill (2009 - June 2014)

Fig. 3 Monthly average of COD concentration in a particular stabilization pond (2009 - June 2014)


Meanwhile, under different NH3-N concentration, biomass concentration of Chlorella vulgaris reached optimum growth between 40 - 250 mg/L 10).

　2.2　Microalgae cultivation in POMEThe limitation in this phase is the selection of strains,

which can grow and produce high quantities of lipids. Fig. 5 shows a summary from previous research of microalgae cultivation. In a study, Chlorella vulgaris was investigated for lipid production in a wastewater treatment and found that culture achieved the highest lipid content about 42% of dry weight and average productivity was 147 mg/L/d 11). Microalgae biomass production cultivated in POME has the possibility to use up to 75% concentration of POME to grow Chlorella sorokiniana C212 and biomass productivity reached up to 97.14 ± 2.14 mg/L/d with lipid content approximately 20% 12).

Meanwhile a previous study estimated that 30% of lipid content from Chlorella vulgaris in dry weight can be reached 13). Chlorella pyrenoidosa has achieved the highest lipid content of 38.6% of dry biomass 9). In other research, the influence of different concentrations of filtered and centrifuged POME has studied in sea water (1, 5, 10, 15 and 20%) as an alternative medium for microalgae cell growth and lipid yield 14). Both Isochrysis galbana and Pavlova lutheri had enhanced cell growth and lipid accumulation at 15 % level with maximum specific growth rate (0.16/d and 0.14/d) and lipid content (26.3 ± 0.31 % and 34.5 ± 0.82 %),

respectively, after 16 days of cultivation. From field investigation, Scenedesmus sp. was found

as a native wild microalgae in the existing POME treatment with vast biomass production but detailed studies have not been done. Furthermore, other researchers found Chlorella sp. in sewage can reach 30.0 - 40.0 g/m2/d of biomass productivity 15). POME and serum latex from rubber effluent had used as a base medium for cultivating four strains of oleaginous yeast, Yarrowia lipolytica TISTR 5054, 5151, 5212 and 5621 16). These yeasts grew well in POME and produced relatively high amount of lipid (1.6 - 1.7 g/L) corresponding to a high lipid content 48 - 61% based on their dry cell mass. Hence, in our proposed microalgae cultivation, it was assumed that mixothropic microalgae (Chlorella sp. and Scenedesmus sp., with lipid content about 30% of dry weight) were cultivated in nearby POME treatment location of 10 ha integrated open pond and protected from direct rain. Mixothropic microalgae was chosen because of its excellent ability to live in the wastewater, rapid growth and vast biomass production.

Microalgae can grow optimally in POME using an ideal nutrients ratio of C:N:P equal to 56:8:1 15). Meanwhile, based on field measurement, the characteristic of C:N:P ratio in a particular site of POME treatment in Indonesia has average values of 36:6:1. Thus, additional nutrients are necessary to balance the existing nutrient in POME. Therefore, additional nutrients such as synthetic fertilizers and flue gases (CO2 & NOX) could reach the nutrient

Fig. 5　Biomass and Lipid production from several microalgae cultivation in POME


balance. In this analysis, the ideal nutrient ratio would be adjusted by additional CO2 and NOX from the flue gases of biogas and biomass power plant.

In addition, the possibilities of adding synthetic nutrients were not taken into account in this simulation. It was assumed that the balance nutrient composition can be reached by considering flue gases from the methane gas engine and biomass boiler or power plant inside the mill.

　2.3　System boundary and model constructionThe integrated plantation model was constructed

in a simulation with three main systems that couple each other’s: The first part is the existing POME treatment, the second part is the anaerobic digester which produced methane biogas and Empty Fruit Bunch (EFB) biomass for power plant to generate electricity, and the third part is a microalgae production pathway (Fig. 6). Moreover, the microalgae-based biofuel production cycle was divided into three main phases: cultivation, harvesting and cell

lysing, and lipid conversion process (Tables 2 and 3). There are many combinations of unit operation that can form a biofuel production system. Cost-effective methods of cultivation, harvesting and dewatering microalgae biomass and lipid extraction, conversion and purification to fuel are critical issues to the effective commercial scale of biodiesel production.

The pond was designed to meet the common practices of available large scale cultivation system 20). High Rate Production Pond (HRPP) was used as a medium for the growth of microalgae with the optimum size approximately between 1,500 - 2,000 m2 of each raceways and 0.3 m depth and optimum mixing in microalgae pond occurs between 0.2 to 0.3 m/s 23) (Fig. 7).

Furthermore, the present of tannic acid negatively affected to the microalgae chlorophyll formation as a consequence of the darkening of POME led to shading by limited light penetration in the medium 12). Biotic inhibitor could be added to the cultivated ponds to avoid the strong

Fig. 6　Concept of integrated energy plantation


Table 2 Cultivation stage of proposed integrated energy plantation system

Cultivation stagePond dimension 20 m x 100 m x 0.3 m, baffled to

regulate water stream, protected from direct rain.

Cultivation size 50 raceway ponds in 10 ha flat land.

Strain selection Mixotrophic microalgae strains (Chlorella sp., Scenedesmus sp.). 30% lipids, 31% carbohydrates, 37.5% proteins, and 1.5% nucleic acids.

Lethal factor 0.1Production cycle 7 daysAnnual operating 341 d/yearCleaning and maintenance 24 d/yearSun radiation 13 - 23 MJ/m2/d, average 17 MJ/

m2/dT ambient 23.0 - 34.5 °C, average 27.0 °CRainfall 1,700 - 4,000 mm/year Evapotranspiration 3.5 - 5.8 mm/d, average 4.0 mm/dPOME pump in Motor rating, 5.9 kW

Running time, 12 hr/dUtilization, 80%

HRPP paddlewheel mixing Motor rating, 3.725 kWRunning time, 24 hr/dBlade length, 0.2 mUtilization, 80%Mixing speed, 0.2-0.3 m/s,

Biotic inhibitor 0.09 mg/L POMEEmbedded energy 50 J/mg 21)

Average flue gases flow rateFlue gases blower & Spurger Motor rating 5.5 kW

Running time 12 hr/dSingle stage/channel , stat ic pressure < 0.6 bar. Gas flow rate up to 300 m3/hrUtilization 80%

φCO2 carbonation 20% 22)

Biomass productivity ~118 mg/L/d (~26.5 - 30 g/m2/d)gCO2/g microalgae 1.8 22)

CO2 in flue gases 15% (biomass power plant) 22)

Flue gases volume at standard pressure

5 m3/kg 22)

Average flue gases stream flow rate

900 Nm3/h (for fresh water)320 Nm3/h (in POME)

Daily flue gases need in POME

26,730-38,400 m3/12 h/10 ha or 5,346 - 7,680 kg/10 ha/d

Table 3 Harvesting, lipid conversion and other stages of proposed integrated energy plantation system

Harvesting stageη Harvesting 80%Cell lysing / disruption

Pulsed electric field (30.38 J/L microalgae slurry) 24)

Flocculants 33,110 mg/L POMEEmbedded energy 0.005 J/mg 24)

De-flocculants 82,780 mg/L POME0.00733 J/mg 24)

Mechanical belt filter press

Motor rating 7.46 kWRunning time 12 hr/dUtilization 80%

Return flow pump to the POME treatment

Motor rating 5.9 kWRunning time 12 hr/dUtilization 70%

Transfer pump 0.746 kW/ha (5 raceways)Running time 12 hr/dUtilization 80%

Settlement tank pump

Motor rating 1.49 kW, Running time 12 hr/dUtilization 80%

Lipid conversion stageBio-oil refining pump 70% capacity of transfer pumpSupercritical Methanol

Water content ~10%T = 250 °C, P = 35 MPaReaction ～ 30 minutes/L BiodieselEnergy requirement 0.7 kWh/L Biodiesel 25)26)

Methanol 30.30 MJ energy required to produce 1 kg MeOH (GREET, 2006) 25)

6.5 : 1 of MeOH : lipid molar ratio for trans-esterification process, with 50% MeOH recycled3.15 MJ/kg biodiesel of MeOH input

Energy content (LHV) 37.8 MJ/kg (Microalgae biodiesel) 24)

Other circulation pumpsMain POME circulation pump 30.94 MJ/ha/dInlet Anaerobic digester pump 25.78 MJ/ha/dOutlet Anaerobic digester pump 22.69 MJ/ha/dAdditional fresh water pump 10.31 MJ/ha/d

Biogas system (Fixed bed anaerobic digestion system) 5) - Annual operation for 317 daysConversion factor kg CH4/kg COD degraded 0.25Retention time Days 14Biogas yield m3-Biogas/m3-POME 16.8CH4 fraction m3-CH4/m3-Biogas 0.60CH4 density kg/m3 0.668Biogas production ton/year 2,880CH4 production ton/year 1,728CH4 average calorific value (standard)

MJ/m3 36.30MJ/kg 50.10

Potential Heat MJ/m3 of POME treated 135 - 151Combine heat and power (CHP)

% 50

Potential Power generated

kW 1,200MWh/year 9,129


and energy balances of some points from the boundary system, such as: Inoculum facility, Daily workers̀ activities, Construction of facilities, Cleaning and maintenance period and Products transportation.

3.　Results and DiscussionThe outdoor cultivation pond model for microalgae

production was proposed in this research. The analysis discussed scale up from laboratory to field size with total area of 10 ha and consisted 50 raceways (Fig. 6, Table 2). The wet extraction route included POME for cultivation, f locculation, dewatering and controlled shock for cell disruption in harvesting, supercritical methanol process for lipid conversion, had the potential to increase net EPR 2.67 to 3.05. Fig. 8 shows the total energy required during cultivation is 297.41 MJ/ha/d. HRPP paddlewheel took a significant portion, around 86.5% from total energy required.

In order to achieve nutrient balance, volume of

growth of bacteria and wild organisms. In another study, 0.09 mg/L waste water of antibiotics was added or about 4.5 J/L POME equivalent 21). The integrated system was simulated based on one crop cycle and one year operation. The fresh water flow was proposed in the cultivation stage to compensate evaporation rate, to control salt accumulation and to maintain the nutrient balance in a certain level.

Overall, the balance of material and energy flows have been analyzed. A ratio of the energy output compared to the amount of energy input in a production cycle referred to as Energy Profit Ratio (EPR). This modest ratio can be useful in assessing the viability of fuels production. A ratio of less than 1 indicates that more energy is used than produced, and value 3 of the EPR has been suggested as the minimum that is sustainable 20). This was assumed that the POME treatment plant works at the same efficiency level all the time. The embodied energy within process equipment was not considered in the energy balances of this work. Nevertheless, this analysis excluded material

Fig. 7　Boundary condition for microalgae cultivation

Biomass power plant from solid waste of fiber, shells and EFB - Annual operation for 317 daysBiomass production (38% of FFB)

ton/year 133,900

EFB, Fiber and shells as fuel for steam turbine power plant (24% of FFB)

ton/year 73,333

Steam power plant efficiency

% 30

Potential power generated

kW 8,000MWh/year 60,864


Fig. 8　Energy balance at cultivation stage

Fig. 9　Energy balance at harvesting stage

Fig. 10　Energy required at dewatering process

required flue gases (CO2 and NOX) was calculated. The result shows approximately 320 Nm3/h or 26,730 - 38,400 m3

/12 h/10 ha or 5,346 - 7,680 kg/10 ha/d of flue gases stream was required. Flue gases utilization for microalgae growth was one of potential method of CO2 sequestration.

On harvesting stage, material and energy balance for a daily production is shown (Fig. 9). The analysis showed that everyday, approximately 184.8 kg/ha of microalgae biomass could be harvested. Before continuing to the lipid conversion stage, water content of the biomass should be lowered. Dewatering process required a huge amount of heat supply. At fresh harvesting by using flocculation, the concentration of microalgae biomass could be 10% of biomass and 90% of water. Approximately 1,110 MJ/d heat supply was required to reduce water content to 10% or lower. The level of 10% was chosen as a target where the wet lipid process had an optimum or higher performance.

In terms of the exergy application, waste heat utilization from biogas and biomass power plant is very promising for dewatering process during the harvesting phase. Calculation shows that removing up to 90% of moisture content from microalgae slurry was practically viable to meet the requirement on lipid conversion process. Waste heat from flue gases, boiler, power plant and lipid conversion process was possible to use up to 50% from total potential (Fig. 10).

Wet lipid conversion of supercritical methanol required energy input approximately 2.52 MJ/L biodiesel or

about 22.82 GJ/production cycle for the proposed 10 ha of land (Fig. 11).

The total fossil energy required (equivalent) in daily microalgae cultivation could be reached up to 853.80 MJ


Fig. 11　Energy balance at lipid conversion process

Fig. 12 Share of fossil energy input in daily microalgae-based biodiesel production system

production was 100 GJ/production cycle. This net-energy production is equal to emission reduction of 336.33 tons CO2

equivalent/year from avoided diesel fossil fuel. In overall, by implementing this microalgae based biodiesel production, about 780.52 tons CO2 equivalent/year can be sequestrated. Based on current best available methods or technologies, microalgae cultivation by POME utilization, provide a positive energy return and might be economically viable.

In total, 674.5 tons of microalgae biomass or 223 kL/year of biodiesel can be produced. The biomass production even can be more or double by recycling the water from cultivation pond after harvesting and passed through some pre-treatment. This recycled nutrient rich water can be used to another cultivation pond.

Approximately 3.28 kWh will be required to produce 1 liter of biodiesel. However, the electricity need can be lowered to 2.87 kWh/L biodiesel production when the electric heater is replaced by using biogas dryer in the harvesting stage. From a reference, electricity need of 2.34 kWh/L microalgae-based biodiesel has been achieved 27). If 2.5 kWh electric heater is utilized, EPR will approximately 2.67.Meanwhile, 3.05 of EPR could be reached by replacing electric heater to biogas dryer. By integrated system, the positive balance of electricity could be achieved.

A single microalgae production system might consume 0.64 GWh/year of electricity. Meanwhile electricity required for office, housing and lighting could be shared within the existing facility in the palm mill. The net-power export could be possible, from biogas and biomass power plants, co-produced by microalgae-based biodiesel. From 1,200 kW biogas and 8,000 kW biomass power plants, it might possible to generate 69.99 GWh/year of electricity (Table 3). Electricity generated from this integrated energy plantation system can be exported to the grid and could contribute of 38.69 GWh/year (Fig. 13).

4.　ConclusionsThe research suggested that integrated energy

plantation provided a positive energy balance for sustainable energy production. By combination of POME treatment with microalgae cultivation and utilization of by-product biomass, energy loads can be considerably reduced as a result of outputs from one system might serve as the inputs for the other. In addition, land optimizing of microalgae cultivation, located inside or nearby the oil palm plantation is geographically attractive and feasible. However, in this analysis, all the parameters were considered in constant condition. In further research, a design of the pilot plant will be proposed, including dynamic environmental condition and comprehensive economic analysis.

/ha/d, which include cultivation, harvesting and lipid conversion stages by 35%, 27% and 38%, respectively from this study (Fig. 12).

Meanwhile, the analysis confirmed the total energy output for 7 days cultivation (1 production cycle) of 10 ha microalgae pond was approximately 160 GJ. Total required energy was around 60 GJ. Meanwhile, net-energy


References 1） BPPT, Indonesia Energy Outlook, (2012) 2） The Ministry of Energy and Mineral Resources,

Regulation No. 25, August 29th, 2013 about Biofuel Utilization

3） Chisti, Y., Biotechnology Advances, 25(3), 294-306 (2007) 4） The Ministry of Agriculture, Annual Report, (2013) 5） Harsono et al., Journal of Cleaner Production, 64, 619-627

(2014) 6） Yaakob Z. et al., World Applied Sciences Journal, 31(10),

1744-1758 (2014) 7） Kamarudin, K. F. et al., Int. J. Adv. Sci. Lett., 19, 2914-

2918 (2013) 8） Kamyab, H. et al., Journal of Environmental Treatment

Fig. 13　Electricity balance from integrated system

Techniques, 1(2), 76-80 (2013) 9） Moheimani, N. R., Journal of Applied Phycology, 25(2),

167-176 (2013) 10） Wang T. et al., Bioresource Technology, 128, 688-696

(2013) 11） Feng Y. et al., Bioresource Technology, 102(1), 101-105

(2011) 12） Nwuche, C. O. et al., British Biotechnology Journal, 4(3),

(2014) 13） Hadiyanto, Nur M. M. A., World Applied Sciences

Journal, 31(5), 959-967 (2014) 14） Shah, S. et al., Chemical Engineering Transactions, 37,

733-738 (2014) 15） Phang, S. M., Ong, K. C., Biological Wastes, 25, 177-191

(1988)16） Cheirsilp, B., Louhasakul, Y., Bioresource Technology, 142,

329-337 (2013) 17） Vairappan, C. S., Yen, A. M., Journal o f Applied

Phycology, 20(5), 153-158 (2007) 18） Hadiyanto et al., Journal of Environmental Science and

Technology, 6(2), 79-90 (2013) 19） Ponraj, M., Din, Md., Journal of Scientific & Industrial

Research, 72, 703-706 (2013) 20） Milledge, J. J., Doctoral Thesis, The University of

Southampton, UK. (2013) 21） Beal C. M. et al., Water Environment Research, 84(9), (2012) 22） Tredici, M. R. et al., Biofuels, 1, 143-162 (2010) 23） Lundquist, T. J. et al., University of California, Berkeley:

Energy Bioscience Institute, (2010) 24） Beal, C. M. et al., Bioenergy Resources, (2011), DOI

10.1007/s12155-011-9128-4 25） Johnson, M., Doctoral Thesis, Massachusetts Institute

of Technology, (2012) 26） Sathish, Ashik, All Graduate Theses and Dissertations,

Paper 1372, Utah State University, USA. (2012) 27） Gutiěrrez-Arriaga et al., ACS Sustainable Chemistry and

Engineering (in press, 2014)

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