Biofuel Archives - Everflow Global

Algae-Based Biofuels an Alternative option for Fuel Security

February 14, 2023February 17, 2023
by everflow

Algae-based biofuel has recently become a popular renewable energy source due to its potential to produce vegetable oil and petroleum-derived fuels, like gasoline, diesel, and jet fuel. Through a process of distillation, natural oils found in certain types of algae can be isolated and used as a direct replacement for traditional petroleum-based fuels. This promising energy source could revolutionize the way we power our world.

Bio-fuel derived from algae is considered carbon-neutral as the carbon emitted from burning it is the same as the amount of carbon that was recently absorbed by the algae as food. While industry claims suggest that the GHG footprint of algae-based bio-diesel. It is 93 percent lower than conventional diesel, this does not factor in the CO₂ used in its production.

Algae-based fuel yields more energy per unit area than other bio-fuels and can be produced on land that is not suitable for other agricultural activities. Many companies have already started large-scale production of algae-based fuel and trials with airlines such as United and Qantas. These have been conducted using fuel blends of up to 40 percent algae-derived fuel. To maximize efficiency, vertical photo bio-reactors (PBRs) are now in use and can recycle up to 85 percent of the water along with excess nutrients and CO₂ (Rony, Z. I., et al. 2023).

Importance and challenges of Algal Biofuels

Algal Biofuels are gaining attention as a potential renewable alternative to traditional fuels. Algal biofuels are produced from oils extracted from microalgae, which are a form of microscopic life found in water. Algae can be grown in ponds, tanks, or bioreactors, and the oils they produce can be refined into biofuels. The use of fossil fuels is essential for the functioning of the global economy, and the energy needed for domestic as well as industrial growth. Consequently, there is a growing concentration of atmospheric CO_2,which is likely to have a significant impact on the climate of all parts of the world.

Moreover, since petroleum is a finite resource derived from ancient algae deposits, it will eventually become scarce or too expensive to recover. A variety of technologies have been explored as alternatives, and it appears that a combination of these strategies. These could potentially decrease our reliance on fossil fuels.

From 1978 to 1996, the U.S. Department of Energy funded a research project to develop renewable transportation fuels from high lipid-producing algae. Early research focused on identifying high lipid-yielding strains or detecting culture conditions, such as nutritional stress, to enhance lipid production. However, they found that high lipid production was always associated with lower biomass productivity, resulting in a lower overall lipid yield.

Subsequently, attention has shifted to cultivating conditions that promote both high biomass productivity and lipid content in the range of 20-30% (John S. et. al., 1998). Additionally, the algal feedstock is an optimal choice for bioethanol and biogas production due to its low lignin content. Thus, the current focus is on generating large amounts of algal biomass and utilizing it for cost-effective energy production, such as bioethanol, bio CNG (methane or biogas), and syngas. (Magar C. & Deodhar M. 2019)

Different fuel forms from Biofuels

Algal biofuel offers a potential alternative to conventional fossil fuels, due to its production process. By utilizing specific algae species, carbon dioxide can be converted into high carbohydrate, lipid, and hydrocarbon compositions. These compositions can then be used to produce ethanol, biodiesel, and renewable distillates. All of which are viable replacements for fossil fuels. Therefore, algal biofuel is an environmentally-friendly resource that can help reduce our dependence on non-renewable fuels.

Biodiesel – The lipid (oily) part of the algae biomass can be extracted and converted into biodiesel through a transesterification process akin to that used for other vegetable oils.
Biogas – It is produced as per the conventional ruminant dung-based method of biogas production in anaerobic digesters (AD). The steps involved are acid hydrolysis of algal biomass and then methanogenesis to produce methane with a low-cost biorefinery approach.
Bioethanol – Microalgae are rich in lipids, proteins, carbohydrates, and other valuable compounds, making them ideal for bioethanol production. The carbohydrates in microalgal cells can be transformed into bioethanol through fermentation, which overcomes many of the limitations associated with conventional sources of starch. Additionally, since microalgal cells do not contain structural biopolymers such as hemicelluloses and lignin, bioethanol production is easier than with terrestrial plants.

Other Biofuel from Algae

Butanol can be produced from whole or processed algal biomass with the help of a solar-powered biorefinery. This fuel has an energy density that is 10% lower than that of gasoline, and higher than both methanol and ethanol. Further, Clostridia fermentation of macroalgae can produce butanol and other solvents. Additionally, it can be blended with gasoline to create a renewable fuel blend.
De-oiled biomass pyrolysis for crude oil production- The production of bio-oil and biochar through the pyrolysis of de-oiled cakes and seed cakes has been gaining attention. The study is a comprehensive analysis of investigations into the characterization of these materials. Also, the reactors and operating parameters employed were conducted. The kinetic and thermodynamic analysis of pyrolysis, the characterization of the resulting biochar, and its potential applications were also evaluated. Results showed that the average activation energy for pyrolysis of de-oiled cakes was between 98 and 162 kJ/mol. The findings suggest that biochar from de-oiled cakes has the potential for a range of emerging applications due to its high specific surface area and abundance of surface functional groups. Moreover, it was found that plasma and microwave-based reactors could be excellent options for further exploration.
Hydrogen – Biohydrogen is the hydrogen produced by living organisms such as algae, bacteria, and archaea. It can be extracted from both cultivated sources and waste organic materials and is primarily released during microbial fermentation processes. During this process, organic matter is broken down into carbon dioxide and hydrogen. Microalgae such as cyanobacteria and green algae can not only derive biohydrogen from their photosynthetic metabolism. But can also be used as feedstock for microbial dark fermentation to produce biohydrogen.

Benefits of Algal Biofuel

Bio-based fuel offers combustion that is carbon-neutral, meaning the amount of carbon dioxide released during combustion. The amount of CO₂ absorbed by plants used to create fuel results in net-zero CO₂ emissions.
Biofuel could be used alongside our existing fuel sources, providing an additional option to the fuels we currently use.
Biofuel can produce a variety of different by-products, which are similar to the hydrocarbons created from petroleum.
Biofuel is a crop that can be grown with a high level of efficiency, providing us with an alternative energy source. That can be used to power transportation and other machinery.

crop and oil content — **Yield of various plant oils (Demirbas et al., 2010)**

The project conducted by the US DOE (Department of Energy) for screening algal species lead to turn the research towards Biomass from algal oil

In 2010, biomass-derived fuels were identified as a potential solution to reduce the US nation’s dependence. The dependence was on imported oil and the associated economic and security risks. The Energy Independence and Security Act of 2007 (EISA) set a Renewable Fuel Standard (RFS) requiring 36 billion gallons of renewable fuels. Such as advanced cellulosic biofuels and biomass-based diesel, to be sold in the U.S. by 2022. During that time along with many other biofuel options renewable Algae-based biofuels also emerged as a promising alternative. It could help the U.S. meet the EISA goals and move closer to energy independence (U.S. DOE 2010).

Since the termination of the DOE-supported Aquatic Species Program in 1996, the necessity for reducing U.S. reliance on foreign oil. And promoting environmental protection has generated a resurgence of interest in employing algae as a biofuel feedstock. The rising cost of petroleum has also contributed to this renewed enthusiasm for the development of algal feedstocks for biofuel production (U.S. DOE 2010, loc. cit.).

Well-known microalgal species for oil content and biofuel production

Microalgae include many microscopic, photosynthetic organisms that are capable of producing biomass much faster than terrestrial plants. Microalgae boast a lipid content of up to 50% in the form of triglyceride – the essential starting material for biodiesel production. With over 800,000 species, ranging from 1 to 50 µm in diameter, they offer a more efficient alternative to macroalgae. Microalgae such as brown algae, green seaweed, and red algae. Harvesting microalgae is an expensive step in process of biofuel production – accounting for up to 30% of the total cost. Transesterification is the reaction used to convert triglycerides into biodiesel. While thermochemical and biochemical processes are necessary to convert the entire biomass into biofuel. Microalgae can also be used to create multiple forms of biofuel, making them a versatile source of renewable energy.

Microalgae are divided into two main types- filamentous (Multicellular) and phytoplankton (unicellular). Three prominent families of microalgae have been identified, Chlorophyceae (green algae), Bacillariophyceae (diatoms), and Chrysophyceae (golden algae), Cyanophyceae (Blue-Green Algae). To cultivate microalgae, open ponds, and photobioreactors are used. Open ponds are often less expensive and the most used method in developing countries, but it is vulnerable to contamination. To harvest microalgae, methods such as flocculation, flotation, gravity sedimentation, filtration, electrophoresis, and filtration are used.

Oil extraction from microalgae is a key step for biodiesel production- mechanical crushing, solvent extraction, pyrolysis, sonication, autoclaving, and microwaving are some of the methods used. The fatty acids produced from microalgae oil are mainly polyunsaturated and can be prone to oxidation. Chlorella vulgaris, Chlorella protothecoides, Nannochloropsis sp., Nitzchia sp., Chlamydomonas reinhardtii, Schizochytrium sp., Scenedesmus obliques, and Neochloris oleabundans. These have been identified as good sources for biodiesel production based on quality composition and oil yield (Adewuyi, A. et al 2022).

Challenges in Algal Biomass and Biofuel Production

Algal biomass production requires a significant amount of water and land in order to be successful and yield a productive output.
Designing and constructing of algae cultivation system is a very complex and cost-intensive process.
Maintenance of some stringent environmental condition for high lipid-producing microalgae strain is very essential which make the production further expensive.
Contamination by other fastidious microorganisms and invaders, and algae grazers make mass-scale cultivation unrealistic.
Algal biofuel technology faces major challenges associated with efficient biomass harvesting and pre-treatment at low cost. And microalgae with reduced emissions of gases and high yields with scalable co-products.
Different products require different methods of pre-treatment; mechanical methods yield biodiesel while enzymatic and chemical methods (such as acidic hydrolysis). These are used for bioethanol production due to the need for the degradation of cellulose, hemicellulose, and starch.

(Khan, M.I., Shin, J.H. & Kim, J.D. et al 2018).

Biorefinery concept to cope with existing issues for sustainable development in the field

The news from Bloomberg about Exxon’s retreat on algal biofuel funding to the Viridos facility in Calipatria. California is an example of multiple industrial failures that happened in the last century in the field of algae-based biofuels. Though the lab scale results and initial pilot trials always seem promising when it comes to the actual continuous production of high lipid-containing algal biomass the whole system fails. This required furthermore comprehensive research to understand the reasons behind the failures and financial crunches makes it impossible.

The way to deal with this issue has already been proposed by many experts in the field of algal biotechnology. The concept of biorefinery is the perfect way for sustainable development in this field. The Biorefinery concept aims to provide an alternative solution to current economic, environmental, and social issues. The biorefinery is to integrate analysis of the three pillars of sustainability through a life cycle sustainability assessment (LCSA). In order to ensure a “good” or “appropriated” conceptual design (Solarte-Toro, J. C., & Alzate, C. A. C. 2021).

This integrated analysis evaluates economic, environmental, and social impacts and benefits through the entire life cycle of the product. It considers the effects of one dimension on the other and covers the whole life cycle of products analyzed from different perspectives. The main users of the results of the LCSA are potential and future decision-makers, stakeholders, enterprises, and consumers. This process is intended to provide a comprehensive understanding of the product and its life cycle. Also, can be used as a tool for decision-making to create more sustainable products (Solarte-Toro, J. C., & Alzate, C. A. C. 2021 loc. cit.).

Conclusion:

Along with many other alternative conventional and non-conventional energy resources, the generation of algae-based biofuel is the need of the growing population and industrialization. Making fuel from algae is a tedious task particularly facing issues where the crucial step of technology transfer from lab to land is ceased and failed due to various obstacles. Making the whole technology self-sustainable is very important and the best way to do it is by biorefinery concept along with the generation of bio commodity options. This is especially done to generate the funding to support algae biofuel research and development.

Algae-based Biofuel is High Volume Low-Value product that will not survive until permanent and stable financial support is grown through High-Value Low Volume products of algae. Nutraceuticals, pharmaceuticals, cosmetics, health care, food, and feed from algae are revenue-generation options. Also, it will potentially support biofuel development from algae. Algae biofuel is definitely a potential option for energy in the future considering the potential of algal biomass and its growth rate but making it really is challenging. The ongoing research in the algae-based Biofuel field and large-scale trials will help to understand the future of this technology.

References:

Rony, Z. I., Mofijur, M., Hasan, M. M., Ahmed, S. F., Almomani, F., Rasul, M. G., … & Mahlia, T. M. I. (2023). Unanswered issues on decarbonizing the aviation industry through the development of sustainable aviation fuel from microalgae. Fuel, 334, 126553.

John, S., Terri, D., John, B., Paul, R. (1998). A Look Back at the U.S. Department of Energy’s Aquatic Species Program—Biodiesel from Algae, A national laboratory of the U.S. Department of Energy Operated by Midwest Research Institute Under Contract No. DE-AC36-83CH10093.

Magar, Chaitanya & Deodhar, Manjushri, 2019, Construction of laboratory scale photobioreactor for sequestration of CO₂ from industrial flue gases and utilizing biomass for biofuel production, Ph. D. Thesis, Dept. of Biotechnology, K.E.T.’s V. G. Vaze College of Arts, Science and Commerce, University of Mumbai.

U.S. DOE 2010. National Algal Biofuels Technology Roadmap. U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Biomass Program.

Adewuyi, A. Production of Biodiesel from Underutilized Algae Oil: Prospects and Current Challenges Encountered in Developing Countries. Biology 2022, 11, 1418.

Khan, M.I., Shin, J.H. & Kim, J.D. The promising future of microalgae: current status, challenges, and optimization of a sustainable and renewable industry for biofuels, feed, and other products. Microb Cell Fact 17, 36 (2018).

Solarte-Toro, J. C., & Alzate, C. A. C. (2021). Biorefineries as the base for accomplishing the sustainable development goals (SDGs) and the transition to bioeconomy: Technical aspects, challenges, and perspectives. Bioresource Technology, 340, 125626.

Demirbas, A., and Demirbas, M.F. “Importance of algae oil as a source of biodiesel.” “Energy Conversion and Management.” 2011. 52:163-170.

Sivaramakrishnan R, Suresh S, Kanwal S, Ramadoss G, Ramprakash B, Incharoensakdi A. Microalgal Biorefinery Concepts’ Developments for Biofuel and Bioproducts: Current Perspective and Bottlenecks. International Journal of Molecular Sciences. 2022; 23(5):2623.

Another Biofuel Blog Article

Biofuel

Biofuel: Fuel of the Future

January 28, 2023January 28, 2023
by everflow

Biofuel is a renewable energy source that is made from organic materials such as agricultural waste, wood, or biogas. And, is often used as a replacement for fossil fuels such as gasoline and diesel, due to its low environmental impact. Biofuel is also known as second-generation biofuel, as it is derived from processed bio-based products such as bio-diesel or bio-ethanol. Biofuel is currently used in a variety of ways, including transportation, heating, and industrial processes. In this post, we will discuss the different types of biofuel; the extent of production and use, and the environmental impact of biofuel. Biofuel production is growing rapidly as a way to reduce environmental impact and improve energy security. Biofuel can help reduce greenhouse gas emissions, and it can play a role in addressing global climate change.

Generations of Biofuel

Depending upon the type of biomass feedstock utilized for biofuel production generation of biofuels changes.

First generation: Biofuel was made from food crops, which have always been debated as crops for food or fuel. This generation of biofuel was never found to be sustainable and was not very practical. Today, we have more affordable and practical biofuels made from different types of plants.

Second generation: Biofuel is made from plant materials that are not food crops. This type of biofuel is called cellulosic biofuel or second generation of biofuels. The biomass feedstock utilized here is mostly agricultural residues, grasses, or other plants. Using chemical and enzymatic biomass degradation technologies, this agricultural residue is digested to produce mono-sugars. In subsequent stages of fermentation technology, these mono sugars are utilized by fungal and yeast species to produce bioethanol. Apart from this, all fresh biodegradable biomass is also utilized to produce biomethane called biogas by anaerobic fermentation technology. Further, this gas is purified to generate pure grade (>95) methane called Compressed Natural Gas (CNG), which has practical applications as automobile fuels and is also used in domestic applications and also to produce electricity.

Third generation: The third generation of biofuels is a futuristic avenue of biofuel industries. This includes the use of advanced fermentation technologies where microbial cells that are genetically modified will produce biofuels in the fermentation broth. This broth can be easily processed to recover produced biofuel and will be ready to use for its final utility. Examples of such technology include the use of photosynthetic microalgae and dinoflagellate species that have the potential to produce fatty acids that can be easily transesterified to produce biodiesel.

Examples of Basic Biofuel

Types of biofuel: bioethanol, biodiesel, and biogas.

Bioethanol is made from biological sources, such as corn, sugar cane, or wheat. The processes used to produce ethanol are enzymatic digestion (to release sugars from stored starch), fermentation of sugars, distillation, and drying. The distillation process inputs a large amount of energy for heat.

Biodiesel is made from vegetable oils and animal fats. Biodiesel, when mixed with mineral diesel, can be used in all diesel engines and modified equipment. It can also be used in diesel engines in its pure form (B100), but this can lead to winter maintenance and performance problems as the fuel is slightly viscous at low temperatures, depending on the raw materials used.

Biogas is made from organic waste, such as food scraps, manure, and sewage. Biogas is primarily composed of methane (CH4) and carbon dioxide (CO2) and may contain small amounts of hydrogen sulfide (H2S), water, and siloxanes. The gases methane, hydrogen, and carbon monoxide (CO) can be burned or oxidized with oxygen. This release of energy allows biogas to be used as fuel. It can be used for any heating application such as fuel cell or cooking. It can also be used in gas engines to convert gas energy into electricity and heat.

Examples of extended categories of Biofuel from basic ingredients:

This category of biofuels involves the use of basic biofuel/biochemical produced from biological origin to convert into modified fuels as suitable blending formulations with conventional fossil fuels. These products can be used even as an individual fuel with necessary modifications in the existing automobile engine technology. Following some examples of extended categories of biofuels will give an idea about biofuels in conventional fuels.

Syngas

Syngas is a mixture of carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2), and sometimes other trace gases. This is produced through the gasification of biomass, and can also be produced from hydrogen and carbon dioxide through electrolysis. It is used as a substitute for natural gas and petroleum and is often used in the production of industrial chemicals, and synthetic fuels. Syngas can also be used to generate electricity via a gas turbine or fuel cell. Syngas has several advantages over other fuel sources. It is very efficient and produces fewer emissions than traditional fossil fuels, and produces fewer pollutants than natural gas.

Pyrolysis of biomass produces oil:

Pyrolysis of biomass is a fast and efficient way of producing oil. In this process, biomass such as wood, grass, and agricultural wastes are heated in the absence of oxygen under very high pressure, breaking them down into smaller molecules. This process results in the production of volatile gas and two liquid fuels, namely, light oil and heavier, more viscous oil. The oil produced is similar to diesel fuel and can be used in engines, furnaces, and boilers. It is also an important source of renewable energy and can be used to produce biofuels, such as biodiesel. Pyrolysis of biomass is an important process that can help reduce the production of greenhouse gases, as it does not involve burning fossil fuels, and the by-products can be used to produce renewable energy.

Hydrogen:

Hydrogen biofuel is a clean-burning fuel that produces no harmful emissions when burned. It is considered to be the ultimate renewable energy source since it can be produced from water with the use of renewable energy sources such as solar, wind, and hydroelectric.

The process utilized and researched in hydrogen production is: Hydrogen production using solar cells is the process of using solar energy to generate hydrogen from water. This process is known as water splitting, and it involves separating hydrogen from oxygen in water molecules.

The alternative approach also utilizes methane gas for hydrogen production which is typically achieved through a process known as steam methane reforming (SMR). This process involves the reaction of methane (CH4) with high-temperature steam (H2O) over a catalyst, usually, nickel, to produce hydrogen (H₂) and carbon dioxide (CO₂). The chemical reaction can be expressed as follows:

CH₄ + H₂O → CO₂ + 3H₂

Hydrogen can be used to power a variety of vehicles, from passenger cars to buses, trains, and boats. Also, be used to produce electricity in a variety of ways, such as through fuel cells, thermochemical processes, and electrolysis. Hydrogen biofuel has a higher energy density than other biofuels, making it a very efficient source of energy. It can be used in existing internal combustion engines without any modifications, making it a great option for transportation. It is also a great option for powering stationary applications such as generators and stationary power plants. Hydrogen biofuel has the potential to revolutionize the way we power our vehicles and reduce our dependence on fossil fuels.

Bioether:

Bioethers are an efficient and environmentally friendly alternative to traditional petroleum-based ethers. They provide octane-enhancing properties while reducing engine wear and emissions of air pollutants. Bioethers are produced from renewable sources like wheat or sugar beets and are becoming increasingly popular in Europe, while the U.S. is phasing out the use of MTBE and ETBE as fuel oxygenates. Bioethers are not likely to become a fuel in and of themselves due to their low energy density, but their contributions to the reduction of ground-level ozone emissions make them an essential part of the transportation fuel landscape.

Biogasolin:

Biogasoline, also known as green gasoline, is a renewable biofuel made from plant sugars and other non-food materials. Biogasoline is produced using biotechnology processes that allow the conversion of glucose from plants or other non-food sources into hydrocarbons that are chemically and structurally identical to those found in commercial gasoline. Professor Lee Sang-yup and his team made use of modified Escherichia coli bacteria to produce the biogasoline, demonstrating the potential for bio gasoline to reduce our reliance on fossil fuels and make use of renewable sources of energy. The biogasoline produced in this study has the same energy density as commercial gasoline and can be used as a direct fuel substitute. Biogasoline is a promising renewable fuel that could help to combat climate change (Jang, Y. S. et al. 2012).

Methyl tert-butyl ether (MTBE):

MTBE is manufactured by the chemical reaction of methanol and isobutylene. Methanol is primarily derived from natural gas, where steam reforming converts the various light hydrocarbons in natural gas (primarily methane) into carbon monoxide and hydrogen. The resulting gases then further react in the presence of a catalyst to form methanol. Isobutylene can be produced through a variety of methods. One process involves the isomerization of n-butane into isobutane, which then undergoes dehydrogenation to form isobutylene. In the Halcon process, t-Butylhydroperoxide derived from isobutane oxygenation is reacted with propylene to produce propylene oxide and t-butanol. The t-butanol can be dehydrated to isobutylene.

On blending with petroleum, MTBE increases octane and oxygen levels in gasoline and reduces pollution emissions. Because of concerns about groundwater contamination and water quality, MTBE has now been banned or restricted in several countries. MTBE is also used in small amounts as a laboratory solvent and for some medical applications.

Positive Impact of Biofuel on the Environment, Society, and Economy

Environmental: Biofuels are carbon-free fuels derived from organic and renewable resources. They do not create pollution on combustion, which will help to reduce the climate change effect if implemented on a larger scale. Even with existing fossil fuels appropriate blending of biofuels has proved to be exerting positive environmental impacts.

Social: Biofuel technology will help to develop indigenous business models for the production of its own renewable fuel depending upon the resources available in each country. This will also help to reduce the reliance on the foreign supplier for the fuels. This will help to boost the economy of the individual countries by promoting export, business development, employment, and good transportation systems with novel biofuel resources.

Economic: Worldwide production of fossil fuels is reducing due to their limited resources. This is increasing the cost of fuel day by day. Biofuel substitution in fossil fuels will help to curtail a large number of economic losses. Biofuels will help to develop alternative energy sources along with sustainable development.

Conclusion:

The exhausting conventional energy resources have also developed environmental concerns. In the last few decades, the need for clean energy resources has received the necessary importance to tackle the issue of climate change. Non-conventional energy resources like tidal, wind power, solar, hydro, and geothermal are some of the best sources for renewable energy generation but lacking technological interventions make this task difficult. Biofuels would prove to be the best alternative sources of energy for the future. They are absolutely renewable, non-polluting, and possibly cheaper than fossil fuels and they have many benefits in long run. Therefore, biofuels are now considered a fuel of the future. The next few decades will decide the fate of these energy sources depending upon their development and implementation.

References:

Jang, Y. S., Park, J. M., Choi, S., Choi, Y. J., Cho, J. H., & Lee, S. Y. (2012). Engineering of microorganisms for the production of biofuels and perspectives based on systems metabolic engineering approaches. Biotechnology advances, 30(5), 989-1000.