Seaweeds are the kind of macroalgae or microalgae, which grow in every ocean. Being located in the tropical area in Indian Ocean, where more than 732 verities of seaweed species are found (Ganesan et al., 2019). Bangladesh is surrounded by the Bay of Bengal in the south, which is a part of the Indian Ocean, has a coastline of 710 km along his southern portion. It is rich in various forms of seaweeds (around 200 variety of species) having huge nutriatious elements (i.e., lipid, protein and carbohydrate) (Ahmed, 2019; Sarkar et al., 2016; Nehal, 2014).

Seaweeds can also be used as food, production of fertilizers, cosmetics, medicine, chemical or bio-fuel (Balina et al., 2017). Ironically, bioenergy or a form of green energy can be produced with the effective utilization of macroalgae (Michalak, 2018). Productions of bio-energy from seaweeds are becoming popular day by day in the Asian countries. Seaweeds of this region can be used as a new and alternative source of energy that can enhance solar energy conservation and environment friendly fuel production for various vehicles in near future (Hamouda, 2015).

Biofuels can be defined in different ways based on the types of processing, use of technology, types of feed stocks or their level of development (Fig 1) (Dragone, 2010). This paper mainly investigates present availability and status for commercial production of biofuels in the Bay of Bengal. 

Problem Statement 

Bangladesh has a coastline of 710 kms and oceanic territory of 1,07,000 sq.kms., which is almost 1.4 times greater than the terrestrial area of the country (Ahmed, 2019; The Territorial Waters and Maritime Zones Act, 1974).

Fig.  1: Classification of biofuels (Adopted from Dragone et al., 2010).

The tropical climate and habitable marine environment make the oceanic area so resourceful. There are also verities of seaweeds found along with other oceanic resources in the region. However, there is lack of research as well as development to make productive use of the seaweeds found in the bay areas of Bangladesh. So, it is urgently needed to identify the types of seaweeds found through research. On the other hand, because of increasing trend of interest in alternative sources of cleaner energy their research on bio-fuel production has been increased. So, research on available seaweeds in Bangladesh along with potentials of bio-fuel production from seaweeds is very much needed. 

Bio-fuel production and utilization on commercial basis is a comparatively new concept. Most of the countries are yet to find the viability and commercial production capacity of bio-fuel as an alternative source of energy. Human rely on fossil fuel for energy consumption that is not finite. So, scientists and experts have been looking for other sources of energy such as hydroelectricity, renewable energy, petroleum through hydraulic fracturing, or nuclear energy etc. We try to explore whether marine resources available in the Bay of Bengal have potential as an alternative source of energy of our own. So, to conduct this research a qualitative research approach has been applied. Data and information had been collected from secondary sources. Data was collected from sources from web of science, Scopus, Academia, etc. (using keywords). A total of 36 available articles were reviewed by using keywords to find out core information related to this paper. More-over, interview of five experts and scientists from various levels had been conducted. Then sustainable SWOT analysis has been conducted after reviewing literatures and taking interviews of the experts SWOT analysis has been utilized as a very effective tool to get findings from SWOT matrix for sustainable production and consumption of any natural resource (Metzer et al., 2012). Finally, findings and representation was data has been based on available papers and expert review.

Relationship of Seaweeds with Biofuel

At the time of global dependency of petroleum and concern on adverse impact of burning fossils fuels such as coal or petroleum on environment, biofuel can be great sources of environment friendly biofuel of second or third generation of bio-energy. It can be generated from different types of seaweeds. Furthermore, biofuel needs almost no modification and non-toxic bio-refinery process. Biofuel has potential demand in the emerging market because of its environment friendly nature (Rocca et al., 2015). Other reasons for the use of biofuel can be (Rajkumar et al., 2014):

• It is a non-terrestrial marine source of green energy.
• It emits less CO2, which is good for environment.
• It could be a cultivable green energy. 
• Increasing level of sea/oceanic water, additional type of seaweed could be found.
• Over whelming CO2 from the environment could be suctioned by biofuel.Furthermore, three major nutrients from seaweeds are responsible to convert seaweeds into biofuel. Nutrients are Lipid (such as triglycerides, hydrocarbons), Carbohydrates and Proteins (Ruiz et al., 2013). Types of fuel production from nutrients in seaweeds are (Darzains et al., 2010):

a) Biodiesel and Green diesel can be produced from Lipid/Oil.

b) Bioethanol can be produced from Carbohydrates.

c) Biomethane and Biohydrogen can be produced from Proteins.

Pioneer Countries in Biofuel Production Using Marine Algae

USA has become the market leader successfully through the utilization of their land, technology, skills and proper management (Fig. 2) (Statistics, 2017; Lundquist et al., 2010). The country has been the worlds largest producer of biodiesel since 2015, bioethanol since 2016 and the 3rd largest producer of biogas (Uddin et al., 2017; Bilan et al., 2017). In addition, they have the most skilled scientists, man-power to conduct research, development and maximum utilization of available seaweeds in the USA for biofuel production. Few decades ago, operation and maintenance costs were significant for the cultivation of seaweeds in the USA (Burg et al., 2016). It is found that profitability can be ensured if selling price of seaweed had increased. Selling price from the bio-fuel would be higher because of higher costs (i.e., installation cost, raw material cost, production cost, harvesting cost, labor cost, transportation cost, maintenance cost, insurance and other costs) related to location of the production site, availability of essential elements for seaweed production. For the case of USA, selling price of sea weeds has to be increased by 300% when the average production cost was $1747/metric ton equivalent to $1.747/liter in 2016 (ibid). It was mentioned that estimated break even fuel ethanol selling price (BFESP) using sea-weeds was $0.58/liter which was three times higher than 2010, however, the production cost of ethanol was calculated as $0.93/liter after the minimal reduction in transportation and labor costs and maximize productivity by increasing production scale in 2017 in USA (Soleymani & Rosentrater, 2017). After calculating the percentage of the bioethanol production cost using the average production cost of 2016 and estimated cost of 2017 shown above, 40-43% (approx.) cost of bioethanol production from seaweeds would be reduced in the USA. However, factors related to production cost of biofuel using seaweeds can be varied from country to country. Again, bio-diesel price was equivalent to diesel when vegetable oil price declined and the production costs of biodiesel reduced in 2018 (US bio-fuel market update, 2018). 

Fig. 2: Leading countries in biofuel production in 2017 (Statistics, 2017).

Another pioneer country for biofuel production from marine algae is Brazil, who established the worlds first industrial biofuel plant for producing biofuel from seaweeds in the Northeastern State of Pernam-buco since 2013. Brazil and the United States produce 62% of worlds demand of bioethanol with the advanced technology and different plants (Ozcimen & Inan, 2015). In last decade, commercial cultivation had been implanted in coastal areas on the southern and south eastern coasts of Brazil, which was ranked the 2nd largest producer of both biodiesel and bioethanol in 2015 (Bilan, 2017; Trivedi et al., 2015). Furthermore, Germany did research on off-shore cultivation of brown seaweed for food and fuel production (Buschmann et al., 2017). Germany was the 3rdlargest producer of biodiesel in 2015 and 2nd largest producer of biogas in the same year (Bilan et al., 2017). Argentina ranked 5th largest producer of bio-diesel in 2015 (ibid). In addition, France ranked as 4th largest producer of biodiesel in 2015 and Canada ranked 5th largest producer of bioethanol in 2016. Japan, China, Korea, Taiwan, Philippines, Malaysia, Indonesia and Thailand are cultivating seaweeds at present. Around 221 species of sea-weeds are found in the South-East Asia, which is commercially important not only for biofuel pro-duction but also for food and other consumptive purposes (Ahmed, & Taparhudee, 2010). China ranked as 4th largest producer of bioethanol in 2016 and held the largest shares of biogas (Bilan, 2017).

Pioneer Countries of Biofuel Production

A number of projects were successfully implemented biofuel production. Table 1 shows some of the projects related to biofuel production around the world. Different types of projects were taken as a part of innovation of green energy for future generation. However, most of them are now slowed down due to the excessive cost, potential scope of commercialization, insufficient investment for global market and potential negative impact on environment. As projects were under considerations or in pipeline, financial data related to raw materials, machineries, cons-truction and others are not available. Moreover, most of the statistical data are not available due to the privacy policy of the companies and competition in global market. In addition, other countries are in the process of research and experiments to innovate new methods for cost-effective biofuel production for future generation to save environment. Some of the available projects summary run by pioneered countries is shown in Table 1.

Table 1: Project summary of biofuel production from algae.  

A total of 200 species of seaweeds (red, brown, green) are used in food and pharmaceutical industry in Tamil Nadu Coast line but some wasted are used as the raw material for biodiesel production because they have hydrocarbon as an essential ingredient to produce biodiesel (Sharmila et al., 2012). In AUF-WIND Project, Germany, they are highly optimist about the manipulation of microalgae named Chlorophyta (green algae) and Cyanobacteria (blue green algae) for the production of biodiesel and kerosene because they contain lipid more than 40% (Grob-belaar, 2016). AquaFUELs under EU Project identified 72 algae where 34 algae are for biomass production, 32 algae are for biodiesel production, 10 algae are for bioethanol and 9 algae are for biohydrogen. Australia had some selected plant for the production of biodiesel where they were used to export biodiesel. On the other hand, some of them were closed due to the imposition of excise. Some selected production plant of Australia is shown in Table 2 till 2017 (Farrell, 2017).

Table 2: Selected production facilities of biodiesel in Australia (ML)-2017. 

From the Table 2 shown, it is clear that most projects were shut down. Reasons for that were for higher production cost even though sufficient investment was implemented for operation and maintenance. However, research and development of bio-fuel production projects also need to run by skilled scientists in future for the innovative production of green energies. Some competitive projects are still in global market with the utilization of technology and some are successful enough. Cost effective methodologies and distinguished area requirements can gear up for mass production of macro algae.

Potential Seaweeds for Biofuel in Bangladesh

Around 200 species seaweeds are found in St. Martin, Coxs Bazar, Sundarbans and northeast part of the Bay of Bengal, while some are found near Coxs Bazar and the Sundarbans (Benglapedia, 2021; NIB, 2018; Billah et al.,2018). Seaweeds cultivation can be easy in Bangladesh because of having accessible and tropical coastal area. In 2010, 133 species of sea-weeds were found and among them 8 were comercially important (Ahmed & Taparhudee, 2010). In 2016, 193 seaweed species of 94 genera were found belonging three divisions (such as Chlorophyta-Green Algae, Phaeophyta-Brown Algae, Rhodo-phyta-Red Algae). Among them 19 species of 14 genera was economically important (Billah et al., 2018). Again in 2016, 95 red, 47 green and 60 brown algae respectively were found from St. Martin Island. Coastal communities can be benefitted from the aquaculture in different ways. However, usefulness of the available seaweeds in the coastal areas of Bangladesh had been found in various scholarly words, which are given below (Table 3) (Sarkar et al., 2016).

Table 3: Use of available seaweeds of Bangladesh (Source: Adopted from Islam &Haroon, 2016).  

Available seaweeds can be used as medicine, agriculture, in industry and for green energy production other than only consuming as food. Thirty-seven types of seaweeds along with species are found in Bangladesh mentioned in Table 3. Ramification of nutrients based on elements (ex. water, chemical) helping to breeding them. In 2018, it is found that 37 seaweed taxa were present in northern and southern portion of St. Martin, among them 11 were under Chlorophyceae, 14 were under Phaeophyceae; 12 were under Rhodophyceae (Billah et al., 2018). In 2018, around sixty verities of seaweeds had been found in the Sundarbans, hence, about one hundred fifty-five verities of seaweed species among them were found in the Coxs Bazar (Razia, 2018). 

Mr. Shykh Seraj, renowned Agricultural Development Activist in Bangladesh, has recently mentioned about potentialities of available seaweeds in an article ‘The ample opportunities of Blue Economy in Bangladesh” on a Bangla Newspaper named “Bangladesh Pratidin” on 12 May, 2018 (Siraj, 2018):

“Around 25000 sq. kilometer from 147 Upazillas of 19 Districts, can create a new way of production of algae for agriculture or blue economy. These algae can be used as food, raw material of medicine and other industries. He also mentioned about the research of seaweeds in Coxs Bazar. He is optimist about employment generation as well as revenue generation by exporting the seaweed in different ways.”

During face-to-face conversation on 7 November 2018, Prof. Dr. Mohammad Almujaddade Alfasane, Department of Botany, University of Dhaka, mentioned about the 100 % possibility of production of biofuel from seaweed in Bangladesh. Biofuel can be produced from the algae such as Enteromorpha, Laminaira digitata, Hypnea and Sargassium (Brown and Green). Additionally, Caulerpa and Ulva Sp. could be used to produce biofuel if Lipid/Oil, Carbohydrates or Proteins is found in them. If Macro Algae are produced in seawater, production cost will be higher. On the contrary, if microalgae are pro-duced in fresh water, production cost will be cheaper. He mentioned that cost effectiveness must be ensured. Higher production cost for purchasing machineries and hiring efficient workers from overseas has to be kept under consideration. He mentioned that the production of biofuel in Bangladesh could be possible within next decade from available seaweeds or algae if coastline of Bangladesh is used for the production.

Comparison of Available Seaweeds for the Commercial Production with Different Biofuels in Bangladesh

Based on the availability of nutrients in seaweeds, different verities of biofuel can be created. Nutrients rich in the following macroalgae can be used to produce biofuel through available lipid, carbohydrate and proteins. Types of macroalgae are shown in Table 4 to differentiate the species abundant in necessary nutrients (Rajkumar et al., 2014).

Table 4: Types of Macro Algae to produce specific type of biofuel (Source: Rajkumar et al., 2014). 

Macro Algae from Table 4 are used and have been used to produce specific types of biofuels. But bio-fuel production varies from countries to countries for the availability of raw materials, land, investment, machineries and skilled manpower. To produce potential biofuel with available seaweeds in Bangladesh are (Sarkar et al., 2106; Rakjumar et al., 2014; Darzains et al., 2010; Ahmed & Taparhudee, 2010):

a) Green Algae- Enteromorpha, Ulva, Bryopsis, Caulerpa, Codium, Halimeda and Acetabularia

b) Red Algae- Derbesia, Liagora, Galaxaura, Eut-hora, Gelidiella, Gelidium, Jania, Amphiroa, Melobesia, Kylinia, Hypnea, Gracilaria, Cate-nella, Champia, Chrysymenia, Halymenia and Caloglossa.

c) Brown Alage- Ectocarpus, Giffordia, Dictyota, Dictyopteris, Padina, Colpomenia, Hydrocla-thrus, Rosenvingea and Sargassum

Comparing Macro Algae in Table 4 and available seaweeds in Bangladesh, it is found that Biodiesel (Ulva, Enteromorpha, Sargassum, Padina, Gracilaria), Biomethane (Laminaria sp., Gracilaria sp., Sargassam sp., Ulva sp), Bioethanol (Gelidium sp., Ulva sp.) and Biohydrogen (Gelidium amansii, Laminaria japonica) can be produced using these algae in Bangladesh. There is a global trend of alternative energy production and utilization because of reducing dirty fossil fuel or coal production. So, alternative sources of energy such as wind, bio-fuel, solar or hydropower are becoming popular. However, the exact number of seaweeds from the ocean is still unknown in many regions. On the other hand, this resource is not exempt from natural disaster as well. So, commercial production needs huge investment in the oceanic or terrestrial brackish water territory. In the Table 5 SWOT matrixes identifies four major strengths, weaknesses, threats and oppor-tunities of bio-fuel production from seaweeds of the Bay of Bengal region. 

Table 5: SWOT Matrix. 

Bangladesh can be one of the beneficiaries to re-venue generation of biofuel production through available seaweeds. Eight available seaweeds are found in Bangladesh, which can be used to produce Biodiesel, Bioethanol, Biomethane and Biohydrogen. According to the experts, higher production costs have to be minimized through strategic plan for operation and maintenance. For instance, USA has been the market leader using strategic planning even though having higher transportation cost than Brazil (Bilan, 2017). It is found that production cost of biofuel can be minimized using by the processing and maintenance cost of microalgae than macroalgae (Jhing et al., 2016). However, production cost of biofuel will vary from country to country according to the conversion methods. China, India and Australia are con-tributing for the preservation of environment by pro-ducing biofuel through the low carbon development movement since 2016. However, various steps can be initiated for the biofuel production in Bangladesh (Kibria et al., 2018). Saudi Arabia is also using algae for the production of biofuel and bio-fertilizer in Al Ahsa oasis by trying to contribute to low carbon emission movement (Semary et al., 2018). In addition, researchers and scientists from developed and developing countries need to come forward to undergoing multiple long-term experiments for the technical and economic feasibility for the production of biofuel from seaweeds (Jacob et al., 2016). Moreover, mass production of biofuel can be ensured if advanced technology or substitute of it can be introduced to balance higher production cost (Soleymani, & Rosentrater, 2017). Table 5 depicts sustainable SWOT analysis framework for producing bio-fuels from seaweeds (Metzer et al., 2012). Therefore, from Table 6 it could be found that skilled manpower and investing more on this industry could create experts. 

Table 6: Sustainability SWOT Findings. 

Present concern on climate change and adverse impact of fossil fuel burning could be remedied by utilizing renewable energy or bio-fuel energy. Furthermore, foreign assistance and investments could be utilized in Bangladesh because the coastal resources of the Bay of Bengal are well recognized worldwide as a resourceful zone. Though there are lacks of research and development in the field, inclusive and potential importance of biofuel production could help local improvement and fulfill international market demand by supplying biofuel produced in the Bay of Bengal or in the coastal areas of the bay.

Our gratitude goes to Professor Dr. Mohammad Almujaddade Alfasane at the Department of Botany, University of Dhaka, for giving us his valuable time. We are also thankful to the authority of National Institute of Biotechnology of Bangladesh for supporting us by providing with various materials of available seaweeds of the country.  

The authors of this article declare that no potential conflict of interest lies to publish this research paper.