Comparative Analysis of Biodiesel Production from Different Potential Feedstocks in the Philippines

Abstract

In response to the worsening crisis on energy security and climate change, the Philippine Biofuels Law (Republic Act 9367) was enacted which mandates the blending of biodiesel to petroleum diesel sold in the country. Primarily, feedstock and pricing concerns led to stagnant growth of the Philippine biodiesel industry. Hence, viability of different potential biodiesel feedstocks such as coconut, oil palm, and soybean (first generation), jatropha and used cooking oil (second generation), and microalgae (third generation) was assessed through extensive research and developments. Among these sources, oil palm is regarded as the best complementary feedstock to coconut due to its high biodiesel productivity of 376 million liters per year. Oil palm biodiesel production in the Philippines was also found to have a low carbon footprint of 1.80 kg CO2e per liter and a GHG reduction potential of 42%, which corresponds to a GHG savings of about 1.05 million metric tons CO2e per year for a 5% blending mandate in 2025. Additionally, a low biodiesel selling price of about Php 33.26 per liter can be achieved from using this feedstock for biodiesel production. Hence, use of a low cost and readily available feedstock coupled with established processing technologies and pricing mechanisms will help boost the biodiesel industry in the Philippines.

1. Introduction

The use of renewable energy sources such as biofuels is a major thrust to combat the imminent crisis on energy security and climate change. With diminishing fossil fuel supply and global warming issues, a transition to cleaner and more secure fuel production is necessary. This led to the implementation of Republic Act 9367, otherwise known as the Biofuels Act of 2006. This Act primarily aims to lessen the country’s dependence on imported fossil fuels by utilizing renewable and clean energy sources, thereby mitigating climate change while also promoting employment opportunities for the country’s economic growth [1].

Pursuant to the Biofuels Law, a mandate was implemented on blending locally sourced biofuels to all petroleum-based fuel sold in the country. After two years since the law took effect last 06 February 2007, the mandated minimum level of bioethanol blending to gasoline was 5% by volume while biodiesel blending to diesel was set to 2% by volume. The Department of Energy (DOE) is mandated to spearhead the implementation of the Act through the creation of the National Biofuel Board (NBB). To further promote the development of biofuels in the country, the Biofuels Act provides incentives to investments related to the production, distribution, and use of locally produced biofuels. These incentives include elimination of specific tax on local or imported biofuels additives, exemption of the sale of raw material used to produce biofuels such as, but not limited to, coconut, jatropha, cassava, sugarcane, corn, and sweet sorghum from the value added tax, exemption of water effluents derived from biofuels production from wastewater charges in accordance with the Republic Act No. 9275 or the Philippine Clean Water Act of 2004, and provision for financial assistance from government financial institutions for activities engaged in the production, storage, handing, and transport of biofuel and biofuel feedstock [2]. Primarily, high selling price of biofuels due to the high domestic cost of production is the main challenge facing the country’s biofuels industry. In response to this, development and implementation of various research studies were initiated by the Department of Agriculture (DA) and the Department of Science and Technology (DOST) through the Philippine Council for Industry and Energy Research and Development (PCIEERD) in support to identifying and developing sustainable and viable feedstocks as well as economically feasible conversion technologies for biofuels production and utilization.

At present, the bioethanol blending of 10% remains consistent with the mandate under the Act. From sugarcane as main biomass source for bioethanol fuel, a shift to use of molasses, a byproduct of sugar-making process, has been initiated. On the other hand, biodiesel in the country is solely sourced from coconut. Although NBB has recommended an increase in the biodiesel blend to 5% in 2015, it was indefinitely delayed owing to feedstock and pricing concerns causing the current blending scenario for biodiesel to remain stagnant at 2% [3]. With the plan of further increasing the country’s blending targets for biodiesel to 10% by 2020 and eventually to 20% by 2025 onwards, exploration of a more sustainable and economical feedstocks is necessary to meet the increasing biodiesel demand. Some of the feedstocks under study as potential sources for biodiesel production include coconut, oil palm, soybean, jatropha, used cooking oil, and microalgae. Hence, this book chapter provides an information on the suitability of different potential feedstocks in the Philippines that can be utilized for biodiesel production. Appropriate technologies for the conversion of these feedstocks to biodiesel fuel are also discussed. A brief overview of the current situation of the biodiesel industry in the Philippines is also provided in this chapter.

2. The Philippine biodiesel industry

2.1 Biodiesel situation in the Philippines

As the country foresees to become energy self-sufficient, the alarming energy crisis poses challenges caused mainly by heavy reliance on fossil fuels and imported energy as well as the continuously rising energy demand. With the average annual rate of 4.2% increase in energy consumption, the total final energy consumption of the country is expected to rise from 29.8 million metric tons of oil equivalent (Mtoe) in 2015 to about 54.9 Mtoe by 2030. Primarily, transport, industry, residential, commercial, and agriculture are the major energy-intensive sectors [4].

Following the implementation of the Comprehensive Automotive Resurgence Strategy (CARS) Program which aims to strengthen the Philippine automotive industry, local production and domestic sales or market for automotive vehicles are expected to significantly increase. As a result, the transport sector will continue to dominate the Philippines’ total final energy consumption with 35.7% average share annually [5]. Consequently, bulk percentage averaging to about 46% of the country’s total energy requirement is sourced from petroleum products. Particularly, gasoline and diesel account for average shares of 28.4 and 50.5% of the total oil requirement, respectively [4]. In 2018, it was reported that oil products’ consumption reached about 16.9 Mtoe [5]. A slightly lower consumption of 16 Mtoe was recorded in 2020 due to the halted activities especially the public and private transportation brought about by the COVID-19 pandemic restrictions [6]. Nonetheless, with the expected continuous increase in demand for petroleum products as transport fuel, the need for a more sustainable and cleaner alternative fuel such as biofuels is necessary.

Presently, DOE has maintained the implementation of 2% by volume biodiesel blends even though a 10% planned increase in blending must have been imposed for the year 2020 (Figure 1). Due to marginally higher pump prices, the recommended increase in blending target has been delayed. With the anticipated implementation of increased blending mandate, a total of 13 biodiesel accredited facilities operate as of December 2020, with a total production capacity of 707.90 million liters biodiesel per year (MLPY) (Table 1). With the current scenario, the total local biodiesel production as reported by DOE is 187.67 million liters in 2020 and an overall sale of about 160.42 million liters [6, 7, 8, 9, 10]. This volume of local production translates to approximately 26.5% of the total biodiesel production capacity of the country.

Figure 1.

Mandated biodiesel blending based on the Biofuels Act of 2006.

Biodiesel producers	Location	Plant Capacity (MLPY)
Chemrez Technologies, Inc.	Quezon City	90
Golden Asian Oil International, Inc.	Pasig City	60
Phil. Biochem Products, Inc.	Muntinlupa City	40
Pure Essence International, Inc.	Pasig City	72
JNJ Oleochemicals, Inc.	Lucena City, Quezon	63.3
Mt. Holly Coco Industrial, Inc.	Lucena City, Quezon	60
Tantuco Enterprises, Inc.	Tayabas, Quezon	90
Archemicals Corp.	Tagoloan, Misamis Oriental	33
Bioenergy 8 Corporation	Sasa, Davao City, Davao	30
Ecoenergy Corporation	General Santos City, Cotabato	30
Ecoenergy Corporation	Polomolok, Cotabato	100
Freyvonne Milling Services	Toril, Davao City, Davao	15.6
Phoenix Petroleum Philippines, Inc.	Villanueva, Misamis Oriental	24

Table 1.

List of accredited biodiesel producers in the Philippines as of 31 December 2020.

Clearly, the local biodiesel production capacity is sufficient to meet the biodiesel demand since 2007 (Figure 2). However, amid excess supply of coconut which is the sole feedstock for biodiesel in the country, fluctuating feedstock cost remains a challenge resulting to limitation in feedstock supply for biodiesel. Consequently, higher fuel pump prices at increased blending rate continues to be the main concern impeding the implementation of the recommended increase in biodiesel blending mandates.

Figure 2.

Biodiesel plant capacity utilization in the Philippines, 2007-2021.

As shown on Figure 3, the same trend was observed for biodiesel price and the local price of feedstock CNO. An increase in feedstock price results to a rise in the biodiesel selling price since total production cost for biodiesel is largely dictated by the cost of feedstock. On the average, a huge price difference can be observed between diesel and biodiesel prices. This entails that a further increase in the biodiesel blending rate would cause a significant rise in diesel fuel pump prices. Perhaps, this remains as the drawback of implementing the increased biodiesel blending. Hence, feedstock diversification is a great advantage to substantially improve the cost savings for higher biodiesel blends.

Figure 3.

Comparative prices of diesel, biodiesel, and feedstock CNO, 2011-2020.

2.2 Biodiesel industry outlook

With the expected increase in diesel demand in the next 20 years, biodiesel requirement will hike up, more so with the implementation of the impending higher biodiesel blending mandates. At present, the production capacity of the country is about 384% of the biodiesel requirement for a 2% blending [11]. In 2022, the demand for biodiesel is projected to be 690 million liters if the 5% blending mandate will be imposed (Figure 4). At an 80% plant utilization rate, additional capacity of nearly 160 million liters is needed to meet this demand. In terms of feedstock availability, the target biodiesel supply even at the increased blending rate by 2022 only requires about 40% of the total coconut oil (CNO) available in the country. By the end of the planning period, further increasing the blending mandate to 20% will require around 6700 million liters biodiesel. This brings the target total production capacity of biodiesel to approximately 8400 million liters by 2040 and a feedstock requirement which is about four times the current local supply of CNO.

Figure 4.

Biodiesel demand projection, 2020-2040.

3. Conversion technologies for biodiesel production

Biodiesel derived from domestic renewable sources such as animal fats, vegetable oils, and algal oil has considerably similar properties and characteristics to petroleum-based diesel, making it a promising alternative fuel [12]. Edible oils are commonly produced from edible feedstocks such as coconut oil, soybean oil, palm oil, rapeseed oil, olive oil, corn oil, etc. Different non-edible oils including jatropha oil, petroleum nut oil, and castor oil can also be used for biodiesel production. In the case of waste oils, the possible feedstocks are waste cooking oil, fish oil, animal tallow oil, and pyrolysis oil while algal oil is usually sourced from Chlorella vulgaris algae [13]. Generally, the process flow for biodiesel production includes feedstock production and harvesting, oil extraction, oil refining, transesterification, and distillation (Figure 5).

Figure 5.

General process flow for biodiesel production.

Oil can be extracted from the raw material using mechanical extraction or solvent/enzyme extraction. Mechanical extraction usually uses a screw type machine to expel the oil through pressing (Figure 6). This process is relatively simple and is applicable to almost any kind of nuts and oilseeds, though, oil yield or recovery is oftentimes quite low [14]. Unlike mechanical extraction, solvent/enzyme extraction can result to significantly higher oil yields with oil reduction in meal to less than 1% by weight (Figure 7). However, this method has higher energy requirement and takes longer time. Another method that can be used for oil extraction is the enzymatic extraction method which uses suitable enzymes. As compared to other methods such as the solvent extraction method, it is more environment-friendly but disadvantageous in terms of costs and processing time [15].

Figure 6.

General process flow of oil extraction via mechanical extraction.

Figure 7.

General process flow of oil extraction via solvent extraction.

Crude oil, a product of oil extraction, is then refined to further improve the quality of the oil. Typically, oil refining process consists of several stages such as degumming, centrifugation, neutralization, oil bleaching, filtration, deaeration, and deodorization (Figure 8). Phospholipids are commonly removed by acid degumming using concentrated phosphoric acid at a temperature below 100°C. Phospholipids precipitated into gums are separated through centrifugation. Removal of free fatty acids (FFA) is done in the neutralization stage where alkaline solution such as sodium hydroxide is made to react with FFA forming soap stock which is removed again by centrifugation. Bleaching using adsorbents is employed to further improve the quality of the oil through the removal of other impurities and contaminants such as residual soap and gums, chlorophyll, oxidation products, and trace metals causing impurity reduction from 1.2 to 0.84% by mass. The recommended dosage loading of adsorbents used in the bleaching process are 17 kg bleaching earth and 5 kg activated carbon per metric ton of oil fed. These adsorbents are then removed by filtration while the bleached oil undergoes deaeration and deodorization. These last two stages of refining process aid in moisture and FFA removal to attain the desired 0.15% by mass moisture content and 0.025% by mass maximum FFA content of refined oil to be fed for biodiesel production [14, 16].

Figure 8.

General process flow of oil refining.

Transesterification is the main conversion technique for biodiesel production. This process involves the reversible reaction of oil or triglyceride to alcohol in the presence of a base catalyst forming fatty acid methyl esters (FAME) or biodiesel and glycerol. The process is usually carried out in a series of two batch transesterification reaction at 60°C (Figure 9). The initial reaction takes place for two hours causing a 96% conversion of triglycerides to biodiesel. Glycerol, a by-product of the reaction, is immiscible with biodiesel and eventually settles forming a layer below the biodiesel. The glycerol layer along with 60% of the unreacted methanol is allowed to settle for an hour before being withdrawn out of the reactor and processed for purification. The biodiesel layer is then subjected to the second reaction to convert the remaining triglyceride to biodiesel with about 99.95% conversion [14, 16].

Figure 9.

General process flow of biodiesel production.

Conversion technologies have a significant impact on the competitiveness of biodiesel as alternative fuel since it relates to quality and productivity. Hence, development of advanced processing technologies for biodiesel has been the focus of many researches. More so, selection of a good complementary feedstock is important to bridge the gaps in the Philippine biodiesel industry.

4. Feedstock development

Looking into feedstock development, three generations of biodiesel have been classified. The first-generation biodiesel is generally related to edible biomass sources such as food crops. However, with concerning issues and risks on food security, its implementation appears to have certain restrictions. Drawbacks of first-generation feedstocks led to growing interest on fuels produced from non-edible lignocellulosic biomass sources which are classified as second-generation biodiesel. These include fuels derived from forest and agricultural residues, animal wastes, and municipal solid wastes. Third generation biodiesel, on the other hand, include fuels that are produced from algal biomass or feedstocks which do not compete with food and arable lands [15].

4.1 First-generation biodiesel

4.1.1 Coconut as biodiesel feedstock

The Philippines is known as the world’s second largest coconut producer and the top exporter of coconut products such as coconut oil. According to the Philippine Statistics Authority (PSA), 348 million coconut trees can be found in around 70 out of more than 80 provinces in the country in 2019, covering approximately a quarter of the total agricultural lands in the Philippines [17].

Biodiesel from coconut is derived specifically from the extracted oil from copra. Copra is the dried kernel part of the fruit which can be scooped out of the shell after drying up to a moisture content of about 6%. Copra is heated to 104–110°C in a conditioning unit to further improve oil extraction [14]. Crude coconut oil then undergoes oil refining process to increase the efficiency of the transesterification reaction for biodiesel production.

In the Philippines, a hectare of coconut plantation can yield 100 trees with an average nut yield per tree using the tall variety of 70 nuts annually. Equivalently, 1305 kg of copra is produced per hectare of coconut plantation per year. For an average yield of 605 liters of coco biodiesel per metric ton of copra, about 38,000 ha coconut plantation is needed to supply the nuts requirement of about 266 million per year for a commercial scale 30 million liter per year biodiesel capacity [16].

4.1.2 Soybean as biodiesel feedstock

In the Philippines, soybean is used primarily as a main ingredient in livestock feed because of its high protein content. However, due to insufficient domestic production, the country has been importing huge amounts of soybeans to meet the local demand. In 2019, the country’s soybean gross supply was 178,772 metric tons in which only 659 metric tons or about 0.36% of the total supply was produced locally, and the remaining 178,113 metric tons (99.64%) was imported by the country. Domestic production of soybeans was reported to decrease at an average rate of −0.57% growth per year from 2017 to 2019 [18].

Aside from soybean meal, soybean processing also produces soybean oil as secondary product, making it one of the potential alternative feedstocks for biodiesel production. Solvent extraction is usually employed for an integrated soybean meal and biodiesel production system for a higher oil recovery and a more preferred soybean meal grade for animal feeds.

On the average, threshed soybean yield in the Philippines can reach 2.5 metric tons per hectare per cropping with a biodiesel potential of 100–129 liters per metric ton depending on the oil extraction method used. A total of 93,000–121,000 ha of soybean plantation, yielding about 233,000–302,000 metric tons threshed soybean per year is needed to supply the feedstock requirement for a commercial scale 30 million liter per year biodiesel plant [19].

4.1.3 Oil palm as biodiesel feedstock

Oil palm is a tropical tree crop typically grown in areas where rain is abundant. Normally, wild palms have a life span of up to 200 years while commercial palms only have 20–30 years economic life span [20]. Oil palm as a plantation crop is a high-yielding source of two distinct oils such as palm oil and palm kernel oil (lauric oil) which can be obtained from the fibrous mesocarp or flesh of the fruit and kernel of the nut, respectively.

Similar to coconut oil, oil palm is identified as one of the alternative feedstocks for biodiesel production because it contains highly saturated vegetable fats [21]. Processing of oil palm includes bunch reception followed by sterilization and threshing to remove the fruit from the bunch. The fruitlets are then digested and pressed to extract the crude palm oil which undergoes clarification before the oil refining process.

The average yield of oil palm is 135 trees per hectare. About 20 metric tons of fresh fruit bunches (FFB) per hectare is harvested annually with a biodiesel potential of 188 liters per metric ton. For a 30 million liters per year biodiesel capacity, about 8000 ha of oil palm plantation is required to produce 160,000 metric tons of FFB per year [20, 21].

4.2 Second-generation biodiesel

4.2.1 Jatropha curcas as biodiesel feedstock

Jatropha is locally known as tubang-bakod and is considered as a potential source for biodiesel production due to its suitability in tropical and subtropical regions as well as its higher seed productivity and rapid growth [22]. On the average, it has a productive life span ranging from 35 to 50 years. Unlike other crops such as palm and coconut which takes about eight and four years, respectively before the first harvest, jatropha can be harvested in just 14 months [23]. Since this crop is not used for food applications, its potential as a biodiesel feedstock in the Philippines has grown interest. With an oil content of about 20–60%, jatropha is found to have a higher oil content than that of other oilseed crops such as palm oil. However, the high content of free fatty acids (FFA) in jatropha is seen as a disadvantage for biodiesel production since this requires an additional transesterification reaction to improve the biodiesel quality [24].

On the average, the yield of jatropha is 2500 plants per hectare, producing about six to eight metric tons of seeds. With its biodiesel potential yield of 185 liters per metric ton, about 23,000 ha of jatropha plantation to produce approximately 160,000 metric tons of seeds is needed to supply the feedstock requirement for a commercial scale 30 million liter per year biodiesel plant [25, 26].

4.2.2 Used cooking oil as biodiesel feedstock

Used cooking oil has drawn considerable interest as a potential alternative source for biodiesel production due to its low cost and its availability at a huge quantity as waste. Though waste cooking oil has been used in soap production, most of its volume is discarded into the environment. Since feedstock cost is one of the primary concerns in biodiesel production, utilization of used cooking oil as feedstock can significantly contribute to cost savings.

At the optimum conditions of 6.51 mol/mol methanol-to-oil molar ratio, 0.171 mol/mol sodium hydroxide-to-oil molar ratio, 47.0°C, and 30-minute reaction time for the sodium hydroxide-catalyzed transesterification of used cooking oil, the percent mass yield of biodiesel is around 80. This means that approximately 8 kg of biodiesel can be produced from 10 kg of used cooking oil [27]. This results to a biodiesel potential yield of approximately 905 liters per metric ton. Hence, for a commercial scale 30 million liter per year biodiesel plant, about 34,000 metric tons of used cooking oil is required as feedstock annually.

4.3 Third-generation biodiesel

4.3.1 Microalgae as biodiesel feedstock

Microalgae have emerged as a suitable feedstock for biodiesel production due to its high lipid content, rapid biomass growth, and cultivation which does not compete with food crops for arable land [28]. As compared to other crop-based biodiesel feedstocks, microalgae appear to have the highest oil productivity [29].

Parametric studies on microalgae (C. vulgaris) as feedstock for biodiesel production revealed that maximum oil extraction efficiency of around 15% can be obtained using a biomass-to-solvent ratio of 1:14 at a 24-hr duration and a 1:2 (v/v) ratio of methanol-to-chloroform as solvent via Soxhlet method. Moreover, the optimum conditions for base-catalyzed transesterification for biodiesel production are 1:6:0.2 oil-to-methanol-sodium hydroxide molar ratio at 55°C reaction temperature and five minutes reaction time [30]. Meanwhile, the biodiesel potential yield of microalgae is 896 liters per metric ton. Hence, a total of 263 ha of cultivation area, yielding an annual biomass production of 34,000 metric tons is needed to supply the feedstock requirement for a commercial scale 30 million liter per year biodiesel plant.

5. Suitability assessment of biodiesel production from different feedstocks

5.1 Feedstock availability and biodiesel potential yield

As shown in Table 2, in terms of biodiesel productivity which assumes maximum biomass conversion to biodiesel for the given possible available land area, coconut has the highest potential among the potential feedstocks considering the huge plantation area for this crop of about a quarter of the total agricultural lands in the country. Even at a 5% blending mandate by 2025, the existing cropping area for coconut is almost four times greater than the area requirement to produce enough feedstock.

Feedstock		Maximum biodiesel potential yield (L/ton)	Biomass production yield (ton/ha)	Potential available area (ha)	Biodiesel productivity (L)	^*Land area needed (ha)	Percent of existing cropping area	Source
First generation
Coconut (copra)		605	1.30	3.65 M	2.87B	1.02 M	360	[16]
Soybean (grains)	Solvent Extraction	129	2.5	300	0.097 M	2.49 M	0.012	[19]
	Mechanical Extraction	100			0.075 M	3.22 M	0.009
Oil Palm (fresh fruit bunch)		188	20	0.1 M	376 M	0.21 M	47	[20]
Second generation
Jatropha (seed)		185	7.5	0.1 M (idle lands suitable for jatropha cultivation)	139 M	0.58 M	17	[26]
Used Cooking Oil		905	0.04 million tons (MT)	—	36.2 M	0.89 MT	4.50	[27]
Third generation
Microalgae (Chlorella vulgaris)		896	128	—	—	6150	—	[30]

Table 2.

Biodiesel potential yield of different biodiesel feedstocks in the Philippines.

Moreover, oil palm is the second crop-based feedstock with the highest biodiesel productivity. Its utilization for biodiesel production in the Philippines has already been proposed as alternative to coconut oil, however, a more comprehensive study for its viability still needs to be conducted before its implementation as required by the Department of Energy (DOE) [31]. Once allowed as alternative feedstock, the potential available area for this crop can sustain almost half of the biodiesel requirement for a 5% blending rate in 2025.

Looking into the biodiesel potential, used cooking oil and microalgae have the highest maximum yield among the possible feedstocks. However, oil extraction from microalgae is still performed in lab-scale and no technology has been confirmed yet as to its practical application in large scale lipid extraction [15, 32]. Nonetheless, only around 6150 ha will be required as biomass cultivation area to achieve the biodiesel requirement in 2025 if microalgae will be used as feedstock. Similarly, utilization of used cooking oil for biodiesel production still requires further studies specifically on process optimization and raw material quality control [11]. Meanwhile, with the available quantity of used cooking oil, this feedstock can contribute about 4.50% of the total biodiesel requirement in 2025.

5.2 Carbon footprint and GHG reduction potential

Along with issues on energy security considering the continuously increasing energy demand and diminishing fossil reserves, the alarming impacts of climate change also call for the adoption of sustainable development options. In response to this, the country committed for a 75% greenhouse gas (GHG) emissions reduction by 2030, in which 2.71% is unconditional and 72.29% is conditional based on the 2021 Nationally Determined Contribution (NDC). This is established against the forecasted business-as-usual cumulative emission of 3340.3 metric tons CO₂e for the period 2020–2030 [33]. Hence, use of technologies that can substantially curb emissions, such as biofuels, is targeted. Compared to fossil fuel, biofuels can significantly lower carbon dioxide and carbon monoxide emissions by 78 and 50%, respectively [33].

In the Philippine setting, the biodiesel industry carbon footprint results to 1.4634 kg CO₂e per liter. This was obtained by conducting Life Cycle Assessment (LCA) and taking into account a cradle-to-grave system boundary starting from feedstock cultivation up to biodiesel end-use. In Ref. to the GHG emission of petroleum diesel equal to 3.12 kg CO₂e per liter, a GHG reduction potential of about 53.05% can be achieved upon full displacement of petroleum diesel by pure coconut methyl ester or coco biodiesel [14]. Correspondingly, at varying blending rates of 2, 5, 10, and 20%, the GHG reduction potential that can be attained are 1.06, 2.65, 5.31, and 10.61%, respectively. In 2021, 2% biodiesel blending has a potential GHG savings of 289,380 metric tons CO₂e per year considering the total diesel demand of 8750 million liters. Implementing the 5% blending rate in 2025 will result to a significant hike in the potential avoided GHG emissions to nearly 1.32 million metric tons CO₂e per year from the diesel demand projection of 16,000 million liters.

Table 3 shows the carbon footprint and GHG reduction potential at varying blending percentages of different potential biodiesel feedstocks. Comparing the different feedstocks, biodiesel production from coconut has the lowest carbon footprint and highest GHG reduction potential, followed by oil palm. Oil palm biodiesel has a carbon footprint of 1.80 kg CO₂e per liter and GHG reduction potential of 42% [20, 21]. This corresponds to a GHG savings of about 1.047 million metric tons CO₂e per year for a 5% blending mandate in 2025 (Table 4). On the other hand, jatropha biodiesel and biodiesel derived from soybeans using solvent extraction results to a carbon footprint of 2.34 kg CO₂e per liter and 1.93 kg CO₂e per liter, which contributes about 25% and 38% reduction in GHG emissions, respectively [19, 34]. Potential GHG savings of the other feedstocks at varying biodiesel blending rates are also shown in Table 4.

	Coconut		Oil Palm		Soybean		Jatropha
Blending rat (%)e	Carbon Footprint (kg CO2e/L)	GHG Reduction Potential (%)	Carbon Footprint (kg CO2e/L)	GHG Reduction Potential (%)	Carbon Footprint (kg CO2e/L)	GHG Reduction Potential (%)	Carbon Footprint (kg CO2e/L)	GHG Reduction Potential (%)
2	3.0839	1.06	3.0908	0.84	3.0933	0.76	3.1014	0.50
5	3.0343	2.65	3.0515	2.10	3.0578	1.90	3.0780	1.25
10	2.9516	5.31	2.9861	4.20	2.9986	3.80	3.0391	2.50
20	2.7863	10.61	2.8552	8.40	2.8801	7.60	2.9612	5.00
100	1.4634	53.05	1.8079	42.00	1.9325	38.00	2.3378	25.00

Table 3.

Carbon footprint and GHG reduction potential of different biodiesel feedstocks at varying blending rates.

Blending rate	GHG Savings (thousand metric tons CO2e/year)
	Coconut	Oil Palm	Soybean	Jatropha
2%	529.15	418.92	379.03	249.36
5%	1322.88	1047.31	947.57	623.40
10%	2645.76	2094.62	1895.14	1246.80
20%	5291.52	4189.25	3790.27	2493.60
100%	26,457.60	20,946.24	18,951.36	12,468.00

Table 4.

GHG savings of different biodiesel feedstocks at varying blending rates.

5.3 Economic viability

The cost of biodiesel production is highly affected by the feedstock which typically accounts for 70–80% of the total production cost [28, 32]. This led to a usually higher cost of biodiesel than petroleum-based diesel which is a major drawback for biodiesel commercialization in the country. Hence, selection of a more economically viable feedstock is a great advantage to boost the biodiesel industry in the Philippines.

In 2020, the average local price of crude CNO is Php 48.83 per liter. The price of biodiesel in the same year ranges from Php 35.00 to Php 71.00 per liter, whereas the diesel price is only around Php 35.16 per liter [11]. If sourced directly from copra based on farmgate price, a relatively lower biodiesel price can be achieved, ranging from Php 27.67 to Php 52.62 per liter [35]. In the case of oil palm as feedstock, a price equivalent to Php 22.72 per liter of commercially available crude palm oil results to a lower minimum selling price for biodiesel of Php 33.26 per liter, a return on investment of 14.44%, and a payback period of 5.75 years. Assuming the case of an integrated oil palm plantation and biodiesel plant, where the plantation is established from oil palm seeds, the biodiesel selling price is Php 33.53 per liter while the return on investment and payback period are 22.04% and 9.33 years, respectively [20, 21].

For jatropha biodiesel, sensitivity analysis revealed that at a seed price of Php 5.00 per kg, the selling price of biodiesel is Php 35.00 per liter to have a return on investment of 17.26% and a payback period of 3.85 years. However, use of crude jatropha oil as a bunker fuel is found more economically feasible than trans esterified crude Jatropha oil [36]. Similarly, biodiesel production from soybean appears to be economically unattractive as biodiesel price can go as high as Php 87.34 per liter depending on the crop yield and the prices of commodities. Soybean biodiesel production via solvent extraction results to a biodiesel price range of Php 48.49 to Php 84.52 per liter for manual farming and Php 33.36 to Php 67.71 per liter for mechanized farming. Using mechanical extraction, a price range of Php 38.93 to Php 87.34 per liter and Php 19.35 to Php 65.59 per liter can be obtained for manual and mechanized farming, respectively [19].

6. Conclusion

The use of biofuels in the Philippines, in pursuant to Republic Act 9367 (also known as the Biofuels Act of 2006), is a valuable initiative as the country envisions action plans towards energy security and climate change mitigation. However, feedstock availability and pricing concerns remains the primary challenges hampering the growth of the biofuels industry. At present, biodiesel in the country is solely sourced from coconut. The mandated biodiesel blending to petroleum diesel remains stagnant at 2% due to marginally higher pump prices at increased blending of coco biodiesel. Hence, research and development studies on the viability of different potential feedstocks for biodiesel has been initiated.

In this chapter, potential feedstocks for biodiesel such as coconut, oil palm, soybean, jatropha, used cooking oil, and microalgae were assessed in terms of feedstock availability and biodiesel potential yield, carbon footprint and GHG reduction potential, and economic viability. Among the feedstocks, oil palm (first generation), used cooking oil (second generation), and microalgae (third generation) have the highest biodiesel potential yield. Considering the potential available area, oil palm is the most recommended feedstock having the second highest biodiesel productivity of 376 million liters per year, next to coconut. It also has a relatively lower carbon footprint of 1.80 kg CO₂e per liter and a GHG reduction potential of 42% which is higher than the other sources. Moreover, its economic viability makes it a good complementary feedstock to coconut for biodiesel production since it results to a potentially lower biodiesel selling price of Php 33.26 per liter. Although other sources such as used cooking oil and microalgae have emerged as suitable alternative feedstocks, more comprehensive validation studies still need to be conducted for its practical application in biodiesel production.

Hence, ensuring economic and environmental sustainability is the challenge facing the biodiesel industry in the Philippines. It is therefore crucial to develop and establish appropriate and efficient processing technologies and pricing mechanisms, as well as to utilize low cost and readily available feedstocks to sustain the industry’s growth.

Acknowledgments

Data presented in this book chapter are from research projects supported by the Philippine Department of Agriculture – Bureau of Agricultural Research (DA-BAR), Department of Energy (DOE), United States Agency for International Development (USAID), and the University of the Philippines. Authors would also like to acknowledge the researchers, collaborators, and stakeholders that contribute to the success of the research projects.