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Today, the developed countries of the world, including European ones, implement various innovative concepts of energy-saving technologies in construction, where energy, economic, environmental and social measures are one. Teachers and students of the Dnieper State College of Construction and Assembly Technologies are not indifferent to these problems. Projects created by the method of modeling on polyfoam: Ecological project of the "Green" district of Stockholm "Hammarby-Shestad", Project "ECO-FARM", and "Alternative biofuel from algae". The projects were created by the method of modeling during the work of the biology group "Nadiya" and the ecology group "Ekomaybutne". The model of the constructed ecological farm almost completely provides itself with alternative sources of energy and fuel and does not depend on traditional hydrocarbon energy sources, world prices for which are growing rapidly. The Swedish environmental model is an example for Ukraine, which has a significant agricultural potential of energy biomass, developed industry, a large amount of heat emissions for the construction of binary power plants. For students, future professionals, the creation of such ecological farms is a clear example of rational nature management, resource and energy conservation. The creation of such ecological areas as Hammarby Shestad and similar "Eco-farms" contributes to the preservation of traditional energy resources, improves the environment, stabilizes the climate on the planet. Solving problems in the field of bioenergy will contribute to solving economic, social and environmental problems, achieving national strategic goals in general.

Researchers are looking for alternative energy sources, and biofuel from algae has a significant contribution as an alternative renewable fuel. This paper aims to evaluate fundamental running param...

Algal-based biofuels offer distinct advantages over other types of biofuels currently available within the fuel industry. However, one important disadvantage is that over their entire life cycle, they consume significant amounts of energy through cultivation, pretreatment, and production. Under pretreatment, drying is an energy-intensive yet highly critical process in standardizing the production of algal biofuel products. The current study proposes the use of artificial intelligence (AI) methods in optimizing the efficiency of a vacuum drying process. Previously, vacuum drying was modeled using least-squares regression methods, which captured the general linear or non-linear trend of the samples, but secured poor accuracy for individual sample points. In addition, these methods are unsuitable for online parameter optimization. Three AI-based models were developed to model the vacuum drying process, specifically an artificial neural network (ANN), a support vector machine (SVM), and an extreme gradient boosting machine (XGB). Based on error values, the ANN (RMSE = 0.0437) and XGB (RMSE = 0.0308) outperformed polynomial regression, and all models obtained meaningful lower values than multivariate linear regression (MLR). There is a notable difference in the ability of XGB to approximate individual sample points, particularly at high and low tail-ends of the dataset. Overall, the AI methods exhibited higher accuracy in estimating the drying characteristics for the chosen strain of algae. The current study may be extended to optimization by relating the control parameters to energy consumption, and automation based on the mathematical model.

Emission of NOx in biodiesel is a major challenge in implementing the biodiesel as alternate of fossil fuel. In this study, pure petroleum diesel fuel, algae oil, mango seed biodiesel and nanoaddit...

Diesel Powered engines are predominately used in transport and power generators. Due to rapid depletion of fossils fuels like diesel, there is need to find alternate resources for as a fuel for transport and power sector. The use of third generation fuels like algae seems to be a promising solution to satisfy our energy demands in future. In these work algae is used as an alternative fuel with different blend combination with diesel and the results obtained are summarized. Algae fuel is blended with diesel on a volume basis, namely A10, A20, A30, A40 and A100 and made to run in diesel engines. The properties of the fuels were found according to American Society for Testing and Materials standards. Experimental testing was carried out in a single cylinder direct injection diesel engine. Among the various blends tested A20 shows closer estimation with diesel results in higher thermal efficiency lower HC, CO, Smoke and particulate matter emissions. However, the other emissions like Nitrous oxide and carbon dioxide were shown marginally higher. Regarding cylinder pressure and heat release rate curves, the peak value obtained is considerably lower at higher load condition while compared with diesel.

Diisocyanates used in polyurethanes are commonly prepared by phosgenation of petroleum-sourced diamines. This involves highly toxic phosgene and produces corrosive HCl, limiting synthetic applicati...

Arabian Gulf is characterized by being nutrient-rich, which contributes to the biodiversity of marine macro- and microalgae. Marine algae are a potentially prolific source of many valuable products that may represent useful leads in developing the quality of human life. The studies on the bioactivity of marine algae in the Arabian Gulf region are very recent; thus, there are not many studies on this field. This review paper is focus on the importance of algae in various fields, and the benefit of such organisms to solve many environmental and health problems to develop the economy, and healthcare of surrounding Gulf countries by taking advantage of many common algal species present in the Arabian Gulf waters. Studies focuses on potentially using local algal species to control common environmental problems in the region such as harmful algal blooms, oil spills, and in wastewater treatment. Furthermore, they were a potential source of food and feed, and can be used in medical field for the treatment of many common diseases. This review describe researches involving the most common algal species found in Arabian Gulf contributing for the bioactive compound’s isolation, for its productivity in large scale, and for its potential biotechnological applications. Key words: Biotechnology, Marine algae, seaweeds, algae processing, pharmacologically active compounds, algae as food, aquaculture feed, algae oil content.

Due to rapid rise in world population and increasing demands in energy sector, the fossils fuels reserves are drastically and continuously depleting, globally. The reckless use of fossils fuels contributes to greenhouse gases, air pollution, and global warming, which culminate in ecological imbalance and health hazards. Therefore, alternate sources of renewable energy are required to meet the future demands of global energy sector. Microalgae being photoautotrophic organisms have the attributes of rapid biomass production and carbohydrates, proteins, and lipids/oil production. They can be one of the best resources, not only for biodiesel production, but also hydrogen and methane gas, bio oil, heat, and electricity generation. Hence, biodiesel production from algal biomass is lucrative for the scientific community because it is nonpolluting, biodegradable, nontoxic, noncorrosive, and sulfur-free. The algal biofuel production shall not only revolutionize the environmental pollution regulation but also be useful in economic and social upliftment of producers.

The biodiesel as a substitute to fossil fuel is able to reduce the dependence on petroleum products as well as increase the engine performance. These biofuel produced from the different sources and also it is directly used for the engine it will not fully burn and it produces increased exhaust emission level. In this research, 20% of neochloris oleoabundans algae oil (B20) blended with neat diesel fuel along with cerium oxide (CeO2) nanoparticle was used in the dosage of 25 ppm, 50 ppm, 75 ppm and 100 ppm. The experimental outcomes obtained indicated that the brake thermal efficiency had been improved and also the exhaust engine emission was decreased. And also the brake specific fuel consumption had been decreased. This research was performed in a single cylinder air cooled engine connected with electrical dynamometer without having engine alteration and also the injection pressure and timings are maintained at the original standard suitable for the engine. The energy of cerium oxide blend with the biodiesel increased the performance of the diesel engines.

Single injection techniques and diesel/biodiesel blends study showed promising outcomes of improving the relationship between nitrogen oxides and particulates in diesel engines, and therefore their impacts are not entirely accepted. In this context, this paper dealt with the characterization of the impact of single injection strategies and biodiesel on polluting emissions, the performance, and behavior of the injection system. An engine test operation was carried out to achieve this, and an injection simulation model was developed. Low load motor testing with a pilot injection decreased NOx emissions and PM emissions compared to simple injection, as long as the precise modification of the injection parameters is made in advance. The decrease explains this simultaneous reduction in the premixed combustion process and the volume of fuel injected during the main injection by using the pilot injection.

The biodiesel as a replacement source to fossil fuel is able to minimize the dependence on petroleum products as well as control the pollution issues. These biofuel produced from the different sources and also it is directly used for the engine it will not fully burn and it produces increased exhaust emission level. In this research, 20% of neochloris oleoabundans algae oil (B20) blended with neat diesel fuel along with cerium oxide (CeO2) nanoparticle was used in the dosage of 25 ppm, 50 ppm, 75 ppm and 100 ppm. This research was performed in a single cylinder air cooled engine connected with electrical dynamometer without having engine alteration and also the injection pressure and timings are maintained at the original standard suitable for the engine. The energy of cerium oxide blend with the biodiesel increased the combustion properties in the engine, and results in decreased carbon deposits in the cylinder wall.

The current investigation of the work managed the overall performance attributes of a CI engine dealing with S. Marginatum macroalgae biodiesel diesel blends. The physical and chemical features of biodiesel diesel blends had been powered and compared to ASTM D6751. These types of mixes had been used for the testing on diesel engine at the different load that's low high and part load in a fixed rotational of 1500 rpm. It had been observed that biodiesel B20 blend perform more effective combustion at high load as well as part load in comparison of lower load condition.

One type of motor vehicle engine that is very suitable for transportation and heavy equipment vehicles is a diesel engine, because high combustion efficiency, reliability, fuel flexibility, and low fuel consumption make diesel widely used in several countries. A mixture of S. Marginatum algae biodiesel and bio solar fuel is used as an alternative fuel. This test is carried out by using variations in the percentage of the load, with variations of pure diesel fuel (D100) and a mixture of bio solar fuels, and algae biodiesel at t 1500 rpm. In this context, the purpose of this study was to obtain its performance curves from a diesel engine of the brand, using as fuel mixtures diesel oil, bio solar fuel, and S. Marginatum algae biodiesel, in the proportions B20, B20 + 10%, B20 + 15%, and B20 + 20%, the power take-off dynamometer test. The results showed that engine performance of equivalence ratio an increase with other models of the same used in the region, showing the best engine output in the region bio solar fuel mixtures with the Hot EGR (Exhaust Gas Recirculation) system.

World at giving is stood around the twin problems of fossil oil product intake and normal degradation. The purpose of this research is actually to examine the behaviour of C. racemosa algae oil biodiesel within a diesel engine. Biodiesel is an unparalleled earth-friendly source meant to extend the worth to fossil fuels, and also the durability and cleanliness of diesel-powered engines. C. racemosa algae may be used to make biodiesel, only because of high oil content. The transesterification of the oil produces biodiesel. The abundant benefits of biodiesel tend to get over by few disadvantages like the increase in the nitrogen oxide, its incompatibility at cold temperature conditions, and also the regular periods of engine parts replacement. Generally, there is additional scope for the improvement in fuel properties and also to overcome the disadvantages by the addition of nanoparticles as fuel additives. In the current study, the Bi2O3 nano additives inside algae oil-based methyl ester blend as well as its diesel blends are examined the performance and emission characteristics at various loads.

The concerns of fossil fuel depletion and environmental issues have increased general interest in studies on the development of sustainable biofuel. In the biofuel production process, the extraction technique is a key technology with respect to energy consumption and product value. In this review, recent advances related to the extraction process in biofuel production are discussed. The major extraction methods were classified as conventional solvent extraction (CSE), physical-supported solvent extraction (PSSE), supercritical fluid extraction (SFE), and novel extractions. We address each of these classified extraction methods in turn both in relation to the feedstock utilized in the different biofuel generation methods and to the targeted biofuels. Our objective is to provide a concise, timely, and comprehensive review on various extraction methods applied/studied regarding biofuel production, their principles and advantages/limitations, and recent case studies. In particular, the classified extraction methods in the production of third-generation algal biofuel were intensively evaluated. Consequently, the concept of free from drying and cell disruption (FDC) routes was advanced herein as it may possess the potential to reduce the requirement for input energy during the production of algae biofuels.

PurposeThe purpose of this paper is to acquaint the readers with the insights regarding the interventions of microalgal technology for production of metabolites and functional ingredients from microalgae for food and nutraceutical application and exploration of microalgae biomass for food application.Design/methodology/approachVarious information databases such as journals, library catalogues and professional websites were used to collect information pertaining to application of microalgae in food and nutraceutical sector. Systematic review was made with recent studies covering the vital aspects of art of microalgae cultivation for metabolite production, functional ingredients from microalgae, market scenario and utilisation of microalgae biomass for the valorisation of the food products. Key points have been discussed after every section to highlight the practical implications to make this review more insightful for the readers.FindingsMicroalgal technology provides sustainable solution for its application in food and nutraceutical sector. The heart of metabolite production lies in the optimisation of cultivation conditions of microalgae. Wide array of functional components are obtained from microalgae. Microalgae offer an alternative source for omega-3 fatty acids. Microalgae is widely exploited for production of pigments, namely, ß-carotene, astaxanthin, lutein, phycocyanin and chlorophyll, that have important implication as natural colourants and nutraceuticals in food. Larger diversity of sterols found in microalgae confers bioactivity. Microalgae is finding its place in market shelves as nutraceuticals where its functional ingredients are in the form of powder, tablets, extract and beverages and in innovative products such as microalgae protein and fat, culinary algae oil and butter. Sprulina and Chlorella are popular choice for the supplementation of food products with microalgae biomass.Originality/valueThis is a comprehensive review that highlights the application of microalgal technology for the development of healthy food products and presents holistic intervention in food and nutraceutical sector.

Development of photo-bioreactors (PBRs) has been accelerated owing to their potential application in the production of algal biofuel. But the application of PBRs should be looked beyond fuel and towards feed items/wastewater treatment solutions it can provide. The PBRs discussed in the review are broadly divided into two major categories, that is, open and closed type. The open PBRs are simple open pond systems while closed ones include vertical, flat plate, tubular, foil and recently developed porous substrate bioreactor. The efficiency of all PBRs depends on the surface-to-volume illumination ratio apart from mixing. The recently developed porous substrate bioreactor is technologically superior to its predecessors in terms of water usage and does not require biomass separation. The authors emphasize on the development of PBRs with the hope that their success would match as that of solar energy panels for power generation which have come a long way from the laboratory to real-world applications.

Fourth generation biofuel (FGB) uses genetically modified (GM) algae to enhance biofuel production. Although GM algae biofuel is a well-known alternative to fossil fuels, the potential environmental and health-related risks are still of great concern. An evaluation of these concerns and accordingly devising appropriate mitigation strategies to deal with them are important to a successful commercialized production of FGB. While extensive research has been carried out on genetic modification and other technologies that aim to increase the productivity of algae strains, only a handful of them deal with the legislative limitations imposed on exploiting and processing GM algae. This paper examines this legislation and the mitigation strategies to meet potential risks associated with the exploitation and processing of FGB. Open-pond system is an economic solution for large-scale cultivation of microalgae; however, the concern regarding the health and environmental risk of cultivating GM algae and the associated stringent regulations is considered as the main barrier of FGB production. Disposal of the residue is another important issue that should be considered in FGB production. The byproducts obtained from energy extraction step and residual water from the harvesting process may contain plasmid or chromosomal DNA that may cause the risk of lateral gene transfer. Hence an appropriate mitigation practices should be used for replacement of the hazardous water residue and by-products with more environmentally friendly alternatives. The results obtained from several field testing projects for open-environment exploitation of GM algae show that under the various conditions used, there was no apparent proof to support possible horizontal gene transfer in release of GM algae.

Biodiesel produced from different raw materials is the most effective way to solve problems related to the fuel crisis and environmental problems. In the present study, the methodology of t...

A feeding trial was conducted to assess the effects of dietary Nannochloropsis sp. as powder or lipid on survival, growth performance and fatty acids content in Kuruma shrimp juvenile. Seven isonitrogenous, isolipidic and isocaloric diets were formulated to contain in first group graded levels of Nannochloropsis powder: 0% (CON, control diet), 4% (A), 7% (B) and 10% (C) dry matter then in second group algae oil proportionally extracted (AE, BE and CE, respectively). The feeding trial was conducted for 50 days. The results showed that the substitution of fish oil (FO) with algae powder diets A, B and C significantly (P

Algal biofuel is considered as an alternative to fossil fuels. Due to the structure simplicity and genetic tractability of many microalgae, they are also gradually recognized as an ideal factory for the production of various metabolites of high commercial values. In this mini-review, we attempt to summarize recent development on metabolic engineering of microalgae to explore their metabolic versatility for the production of hydrogen, carbohydrates, terpenes, fatty acids, alcohols, aliphatic alkanes and alkenes. In addition, we also present key challenges facing algal engineering, and propose a few strategies that could leverage the advancement in systems biology and genomics. We foresee a bright future for microalgae studies to advance both research and technology development.

Thin-layer cascades (TLCs) enable algae cultivation at high cell densities, thus increasing biomass yields and facilitating the harvest process. This makes them a promising technology for industrial-scale algal fuel production. Using Life Cycle Assessment (LCA), we calculate the greenhouse gas (GHG) emissions of aviation fuel produced using algal biomass from TLCs. We find that the impact (81 g CO2e per MJ) is lower than that of fuel from algal biomass cultivated in open race way ponds (94 g CO2e). However, neither of the two cultivation systems achieve sufficient GHG savings for compliance with the Renewable Energy Directive II. Seawater desalination in particular dominates the TLC impact, indicating a trade-off between carbon and water footprint. In both cultivation systems, the mixing power and fertilizer consumption present further significant impacts. There is uncertainty in the correlation between mixing power and algal oil yield, which should be investigated by future experimental studies.

The use of fossil fuels for energy demands is insufficient for escalating demands as they are limited in nature and are not environment friendly. Various microbial sources are under scanner for clean energy production out of which algae comes as a promising one. Production of biohydrogen from algae has brought a lot of hopes in the energy production sector. Algae are powerhouse of renewable chemicals including biofuel precursors. Biohydrogen is one of such biofuel precursors; it proves to be a clean and sustainable fuel and can be produced in industries. Currently however, it cannot stand up to the present energy demands of the world due to certain obstacles, such as cost effectiveness, storage and transportation of hydrogen. One of the main hurdles in algal biofuel technology is the rigid nature of algal cell wall. To get around this, pretreatment of algal biomass is imperative to overcome productivity issues, so as not to compromise biofuel yield. Improving the biofuel production at every step can make a huge difference in outcomes and thus comes up as a promising tool. Therefore, in the present state of art review, various methods of algal biomass pretreatment, different enzymes involved in hydrogen production, various factors influencing hydrogen production from algae and genetic engineering avenues have been discussed in brief.

Carbon dioxide gas is the key element of the carbon cycle and a major source for photosynthesis, but for the past 150 years, the atmospheric CO2 has been increased drastically from 250 to 418 ppm due to the extreme utilization of fossil fuels. This accelerated release of CO2 acts as a major source for climatic change due to the greenhouse gas effect resulting in global warming and melting of polar ice caps, alteration in biogeochemical cycles, altered rainfall, ocean acidification, eutrophication of lakes, imbalance in the ecological communities and extinction of some species, effects on soil fertility, changes in the metabolism and at the molecular level. Reduce, reuse and recycle strategy can be applied to control elevated CO2 levels by preventing deforestation, using renewable energy as an alternative for fossil fuels and reusing the atmospheric CO2. Carbon capture and storage (CCS), Carbon capture and utilization (CCU) are the two technologies adapted to capture the atmospheric CO2, utilize it, and focus on permanent storage in the geological sites. Captured CO2 is used to produce many value added products such as polymers, biofuels, reactants etc. Plants and microorganisms act as a natural CO2 filter. Several biomolecules such as carbohydrates, proteins, and lipids are produced due to the biological carbon fixation process using photosynthesis. Six different photosynthetic pathways and some non-photosynthetic pathways to fix atmospheric CO2 have been reported in diverse species of plants and microbes such as bacteria, fungi, yeast, algae etc. Algae are the most potent microbe in CO2 utilization and biological carbon fixation compared to other microbes and used widely on a large industrial scale for biofuel production. Algal biofuel production using captured CO2 is the best productive method to recycle and reduce atmospheric CO2.

The exhaustion of limited fossil fuel resources and the overwhelming emissions of toxic gases from these fuels cause extensive damage to the environment. The world is focusing at replacing fossil fuels with clean energy production. Biofuels are eco-friendly and renewable energy and hence have received the attention of researchers around the globe as an alternate source of energy. Annually, the production of biofuels increases by 5% and is estimated to reach 50 million m3 of biofuel by 2025. The downsides of the first and second generations of biofuels resulted in the creation of a third generation of biofuel from algal sources. The major advantages of using algae as feedstock include low cost and the utilization of a high level of CO2 in the atmosphere, which make algae a good choice for biofuel production. Nanomaterials support and enhance biomass growth and improve harvesting efficiency in a short time.

The rising need for energy due to the increase in the population and its desire for higher living standards has emerged as one of the major problems for scientists. In the past few years, the diversification of bioenergy sources isn’t able to come up to the commercialization step; this has emerged as an important energy issue. The researches based on third-generation bioenergy production from algal biomass have emerged as the most potential resource among all the resources that minimize the drawbacks of the first- and second-generation bioenergy. Algal biomass is considered for the economic production of bioenergy like bioethanol, biodiesel, biohydrogen, biogas, and other co-products. This potential of algae is due to its high growth rate, CO2 utilization, less greenhouse gas (GHG) emission, and ability to store a high amount of carbohydrates and lipids. In this chapter, we will study the importance of algal biomass in terms of improved bioenergy production. This chapter discusses different recent development and findings for high algae cultivation with enhanced cell content especially lipids, various harvesting techniques, oil extraction methods, and algal oil to bioenergy conversion techniques.

Fossil fuels are used for the generation of electrical power, as well as liquid fuels. There are a variety of renewable or low atmospheric pollution technologies that can generate electrical power, including solar, wind, hydroelectric, geothermal, and nuclear. However, renewable technologies to supplement or replace liquid fossil fuels are still in their early developmental stages. The International Energy Agency expects that biofuels will contribute 6% of total fuel use by 2030, but could expand significantly if undeveloped petroleum fields are not accessed or if substantial new fields are not identified. The use of liquid fossil fuel as an energy source has long been considered unsustainable and most importantly the liquid fossil fuel will be diminished by the middle of this century. In addition, the fossil fuel is directly related to environmental degradation and greenhouse emission. Biofuel produced from plants, animals, or algae products can offer an alternative to reduce our dependency on fossil fuel and assist to maintain healthy global environment. Microalgae are becoming popular candidate for biofuel production due to their high lipid contents, ease of cultivation, and rapid growth rate. Fatty acid methyl esters (FAME) are used as alternative diesel fuel originating from renewable sources. The attention is focused on the materials that do not compete with food and feed production. Algae have a significant potential as an alternative biodiesel feedstock. In comparison to other crops, they have the advantage in very fast reproduction cycles, enhanced resistance to high UV radiation doses, and higher effectiveness of energy conversion to biomass due to low demands on other metabolic functions. Moreover, they fix atmospheric CO2 very efficiently. Microalgae have benefit over other sources of biofuel as it fixes atmospheric CO2 very efficiently and also fulfill liquid fuel demand for present as well as future generation.

Massive utilization of the fossil fuels has caused the unwanted release of many harmful pollutants to the environment. The consequent increment of the environmental pollutions has raised many environmental issues to the escalating populations. The impressing issue can be minimized by adopting alternative renewable biofuel resources. However, the bioprocessing of biofuels production such as biodiesel, bioethanol, biobutanol, biohydrogen, and biogas needs to be efficient and improved.

Fuel atomization in diesel compression ignition engines is significantly affected on the performance, evaporation, self-ignition, and emissions of the engine. Therefore, the quality of the spray atomization has to study at first. Algae-Derived renewable diesel fuel in a single hole nozzle atomizer has been chosen as an alternative fuel for diesel. The differences in physical properties of algae-derived renewable diesel, biodiesels (from palm and cooked oil) and pure diesel are effected on both spray characteristics and the internal nozzle flow. Numerical simulations are presented in this study using Eulerian-Eulerian technique to model the spray- gas interaction. The spray moments model has been used to characterize the spray parameters. First, the model is validated against the spray tip penetration of diesel spray characteristics obtained from the experimental data conducted in house-code using constant volume spray chamber and the results show a good agreement. Then, comparisons were made among the selected fuels. The numerical simulations show that the algae-derived renewable diesel is very similar to pure diesel and can be used as an alternative fuel. http://dx.doi.org/10.30572/2018/kje/100110

It has been proposed that future efforts should focus on basic studies, biotechnology studies and synthetic biology studies related to algal biofuels and various high-value bioproducts for the economically viable production of algal biof uels. In recognition of diminishing fossil fuel reserves and the worsening environment, microalgal biofuel has been proposed as a renewable energy source with great potential. Algal biofuel thus became one of the hottest topics in renewable energy research in the new century, especially over the past decade. Between 2007 and 2017, research related to microalgal biofuels experienced a dramatic, three-stage development, rising, growing exponentially, and then declining rapidly due to overheating of the subject. However, biofuel-driven algal biotechnology and bioproducts research has been thriving since 2010. To clarify the gains (and pains) of the past decade and detail prospects for the future, this review summarizes the extensive scientific progress and substantial technical advances in algal biofuel over the past decade, covering basic biology, applied research, as well as the production of value-added natural products. Even after 10 years of hard work and billions of dollars in investments, its unacceptably high cost remains the ultimate bottleneck for the industrialization of algal biofuel. To maximize the total research benefits, both economically and socially, it has been proposed that future efforts should focus on basic studies to characterize oilgae, on biotechnology studies into various high-value bioproducts. Moreover, the development of synthetic biology provides new possibilities for the economically viable production of biofuels via the directional manufacture of microalgal bioproducts in algal cell factories.

Among different biofuel feedstocks, algal biodiesel is seen as a promising feedstock. Different research papers have assessed the sustainability of algal biofuel production, but it is always difficult to have a better sense of the results since comparing them with all the differences in data sources, life cycle assumptions, functional units and environmental metrics measured is difficult. The present study develops a comparative life cycle assessment of algal biofuel production under autotrophic and heterotrophic conditions with different inputs. SimaPro 8 was used considering five different scenarios for microalgae cultivation to compare environmental impacts, energy demand and damage analysis associated with water scarcity methodology. Open ponds with three different assumptions of using fresh water, recycled water and waste water, and photobioreactor and heterotrophic technologies are considered. Results were analyzed per energy basis—the functional unit of 1 MJ of energy produced. Results of total GHG emissions show that algae cultivated in pond with wastewater and heterotrophic culture are competitive with tradition fossil fuels. Also the use of algae as the source of energy might increase the energy demand, whereas it does not have adverse impact on the environment, health and climate. The results of the water scarcity indicator show the competiveness of algae oil. This study presents an overview of environmental impacts throughout the full life cycle of a product through different pathways in cultivation stage which demonstrates the importance of decision-making process for further investment.

The conclusions from life cycle assessment of algal biofuels (e.g., biodiesel, renewable diesel) vary significantly due to both modeling and inherent technological uncertainties. The inherent uncertainties of US-based algal biofuels production were investigated by eliminating modeling uncertainty via comprehensive harmonization through a meta-analysis. Following harmonization, the cumulative fossil energy consumption (MJ/MJ), global warming potential (g CO2-eq/MJ) and water consumption (m3/MJ) of different algal biofuel process trains were investigated through a stochastic life cycle model. By focusing on the inherent differences of current technologies, this study identified (1) the differences in impact results between different process trains (i.e., different combinations of technology choices along the fuel production life cycle), (2) high impact hotspots, and (3) possible low impact process trains, all of which are crucial to further improve the sustainability of algal biofuels. The median (range) values of the three indicators for the most common algal biodiesel process train are 3.5 (2.9–4.2) MJ/MJ, 99 (55–151) g CO2-eq/MJ and 0.08 (0.07–0.09) m3/MJ, with corresponding inter-quartile ranges being 63%, 46% and 43% less than the literature values, respectively. The median (range) values of the three indicators for the most common algae renewable diesel process train are 1.7 (1.4–2.2) MJ/MJ, 84 (60–112) g CO2-eq/MJ and 0.04 (0.03–0.05) m3/MJ, with the corresponding reductions in inter-quartile range by 83%, 83% and 84%, respectively. Although neither of the median global warming potential results for algal biofuels met the mandatory thresholds in the Renewable Fuel Standard (45 g CO2-eq/MJ), it is possible to meet the requirement by integrating low impact technology options into the process trains.

The process technologies for conversion of bio-feedstocks such as vegetable oils, animal fats, and algal oil into renewable diesel have been developed and commercialized during the last decade. The global annual production capacity of renewable diesel is approaching to 5.5 million tons per year. The refining process generally includes pretreatment of the renewable feedstock to remove impurities, hydroprocessing and isomerization to produce hydrocarbons, and distillation to produce a fuel suitable for use as diesel or jet fuel. This article reviews recent development in the commercial production of renewable diesel, pretreatment technologies, chemistry of deoxygenation and cracking of triglycerides, the effect of reaction parameters on the relative activities of different reaction pathways, catalyst development, and the technical details of commercial processes for refining bio-feedstocks.

Micro-algae are photosynthetic organisms, which represent a promissory renewable raw material for biofuels production, since they can be cultivated in non-fertile lands, avoiding the competition with food crops for land use. From micro-algae, oil can be obtained oil that can be converted to biodiesel, green diesel and biojet fuel. In particular, the renewable aviation fuel is one of the less explored biofuels; nevertheless, for the aviation sector, this is the best alternative to reduce CO2 emissions, allowing its sustainable development. In order to produce hydrocarbons in the boiling point range of jet fuel, we need to transform the micro-algae oil. A number of research projects report the use of micro-algae oil for the production of biojet fuel through the hydrotreating process. However, the application of process intensification strategies for the hydroprocessing of micro-algae oil has not been reported. Therefore, in this work we propose the modeling, simulation and intensification of the hydrotreating process to produce biojet fuel, considering micro-algae oil as raw material. The hydroprocessing of micro-algae oil is modeled in Aspen Plus processes simulator, based on data from an experimental study recently reported. The produced renewable hydrocarbons are purified through conventional and intensified distillation sequences; thereby, conventional and intensified hydrotreating processes are defined and evaluated in terms of total annual costs, CO2 emissions and biojet fuel price. Simulation results show that the implementation of intensification strategies leads to the production of biojet fuel with reduced carbon dioxide emissions, 34% less, and a competitive price per liter, 78% cheaper than fossil jet fuel price.

This paper presents a novel method for effective, economical, energy-efficient algae harvesting from large (1-4 acre) outdoor circulating raceway pond systems: a portable 4-cable-suspended robot. Algae, used as an alternative energy crop to produce biofuels (and other consumer products), still remains too expensive. One of the greatest expenses in processing algae is the harvesting process. To replace the typical energy-intensive pumping of the entire pond water through algae filters, we propose using a cable-suspended robot to collect algae, which largely then drains of water while the robot translates the product to a collection point. An additional benefit of our concept, in additional to lower harvesting cost, is that the algae still growing in the pond is not shocked as in the current pumping process, leading to better, healthier yields. Further, the proposed robot system is portable, capable of harvesting multiple ponds while algae continues to grow.

Chemical Looping Combustion (CLC) and Chemical Looping with Oxygen Uncoupling (CLOU) are low-pollution energy generation techniques conventionally utilizing natural gas or synthetic gas as fuel. Using a redox reaction of metal oxides in dual fluidised beds, CO2 can be captured and prevented from entering the atmosphere at efficiencies up to 80% [4,8]. Algae is a sustainable source of biofuel with the additional benefit of carbon capture through photosynthesis [7]. This Meta-Study attempts to determine the viability of algae as CLC/CLOU reactor fuel for long term sustainable energy generation by identifying trends in different fuels and reactants to see if algae fuel can produce an acceptable output and identify areas of weakness. Energy balance calculations were performed as well as thermal energy output, processing energy and enthalpy values. Graciliara sp. and Chlorella Vulgaris made the most effective fuels for CLC and CLOU respectively due to the low amount of algae required to produce fuel. For CLC, 3.57kg Graciliara sp. produced 1kg fuel. For CLOU, 1.7kg Chlorella Vulgaris produced 1kg fuel. CLOU was the most mass efficient with an energy/mass efficiency ratio of 11600kJ/kg compared to CLC’s 15.7kJ/kg. The energy balance ratio analysis of the production of algal fuel also identified Chlorella Vulgaris as the best fuel, with an EBR of -0.4 in CLOU. In terms of evaluating output, CLOU's energy/mass efficiency ratio surpassed a modern coal plant [45], whose value was 2840 kJ/kg. The defining factor was the enthalpy of reaction.

The aim of this work is to decrease emissions in diesel engines fueled with diesel and algae biodiesel blends and also addition of BiO nanoparticles. Azolla algae can be used to produce biodiesel, ...

Aim of this paper is to present an engineering tool for the design and modeling of the upgrading of three biomass derived liquids (bio-oil, vegetable oil and algal oil) through hydrotreating process for the production of advanced biofuels. For each case, the appropriate approach was followed regarding the model compound selection for each bio-feedstock, the main reactor modeling, the products separation and purification and the make-up hydrogen production. Simulation runs were performed in ASPEN Plus™ and revealed the importance for make-up H2 production from recovered light gases and external fuel such as natural gas (the heat content on LHV basis if the inlet natural gas is 7.4% of the produced fuel in the jatropha oil case), showing also the beneficial impact of a good catalyst. The energy balance calculations showed that the most energy demanding components are the air compressor before reformer and make-up H2 compressor at the hydrogen production plant. The assumption of a chemical equilibrium can be regarded as a well-fitting and valid approach for the process design. The representation of bio-liquid by a model compound (i.e. palmitic acid in case of algal oil) may result in good estimations in terms of mass (0.845 kgG-Diesel/kgalgal-oil product yield) and heat balance of the total process (94.9% thermal efficiency) but all the detected fatty acid is suggested be taken into account for a more detailed analysis.

A sustainable micro-algal biofuel process plant was hypothetically and detailed-designed for the production of value products from algae. The process plant cultures algae through controlled growth and processes: production of biomass, extraction of lipids and biofuels and refinement into finished products. The start-off feedstock was Nannochloropsis spp. and the four end products produced were bio-kerosene, methane, biomass slurry and CO₂. The algae were grown to maturity within the least allowable possible time under controlled conditions. From an in-depth analysis of the customer specifications, concept development and selection, the study defines an overall depiction of the end products from the concepts evaluated by using the Pugh matrix and Six sigma methodologies. DMADV approach was implemented.The process finally generated an economically viable algae biomass for conversion to biofuels and other viable products. This paper focuses on the process planning, criteria/concept selection, design optimization with necessary characterizations which were filtered into measurable characteristics for the design of an operable, sustainable functioning plant.

Biodiesel has been identified to be a suitable biodegradable substitute to petro-diesel. The Egyptian consumption rate of fossil diesel is approximately 37 kt per day from which 50–60% are imported. Using algal biofuels has led to a potential techno-economic assessment of 1.0 million ton (MT) biodiesel to be produced from microalgae grown on domestic wastewater via heterogeneous transesterification catalysis using sodium orthosilicate (Na4SiO4) as catalyst in order to minimize the diesel shortage in Egypt and mandating B5 by 2020. Process equipment and units required have been sized with an accuracy of ±20%. Mass balance, total capital investment (TCI), total production cost (TPC) and economic potential (EP) have all been assessed based on the marketed biodiesel price of US$1000 per ton and an evaluated Nannochloropsis sp. algal biomass cost of US$400 per ton. An algal biodiesel project of 1.0MT has been proven to be feasible with return on investment (ROI) and pay-back period of 41% and 2 years, respectively. A break-even analysis has disclosed that the cost of algal biodiesel that renders the project feasible is should be above US$843 per ton while the cost of algal biomass should not exceed US$461 per ton. Furthermore, sensitivity analysis was evaluated on variations in microalgae lipids content using ROI and payback time. The results obtained using Tornado Chart recommended that the minimum oil content should be 35% for profitable algal biodiesel business. Finally, a comparison between the investigations of algal biofuel versus Jatropha curcas biodiesel was performed, and positive prospects were detected for industrializing algal biodiesel whenever Brent Crude Oil Spot exceeds US$100 per barrel.

Carbon dioxide (CO2) supply is an important consideration for algae production systems, and using high-purity CO2 eliminates the need for purification processes. This study assessed the challenges and opportunities inherent in using waste high-purity CO2 to produce algae in the United States. The United States’ upper Midwest region is rich in high-purity CO2 from corn ethanol production. However, its climate is not as favorable for algae production as that on the Gulf Coast. This study assessed the tradeoffs between these factors by comparing algae biofuel production with and without high-purity CO2 across these two regions. Monthly algae cultivation was modeled in open ponds co-located with high-purity CO2 sources in the Midwest and along the Gulf Coast, where many steam methane reforming and ammonia production facilities are located. This revealed that, by avoiding the energy-intensive carbon-capture process, an algae site that sources carbon from a high-purity CO2 source would achieve a 9–39% reduction in life-cycle greenhouse gas (GHG) emissions and a 9–37% reduction in life-cycle fossil energy use compared to a similar site using dilute CO2 for algae cultivation. The results also suggest that during warm months an algae pond in the Midwest would achieve results that are comparable to GHG emissions from a pond on the Gulf Coast. Furthermore, several Midwest algae ponds investigated in this study create less local water stress than those located along the Gulf Coast. The abundant high-purity CO2 from corn ethanol plants thus creates a potential opportunity for algae cultivation in the Midwest. This study illustrated the interplay between algae productivity, CO2 delivery, GHG emissions, and water stress in siting algae ponds.

The ambitious targets of the aviation industry to reduce greenhouse gas emissions require the use of biofuels in this transport sector in the short and medium term. While five biogenic aviation turbine fuels have already been certified by the American Society for Testing and Materials (ASTM D7566), the search for suitable alternatives continues, seeking higher possible blending ratios or better fuel qualities. Fluidized-bed catalytic cracking (FCC) of algae oil, followed by hydrotreatment of intermediates, could be such a potential option. This conversion concept has several potential advantages, such as aromatic compounds in the biokerosene and the use of a non-food biogenic oil as feedstock. Material and energy balances are obtained from flowsheet simulation using ASPEN Plus®, with the aim to assess the efficiency of the process. The simulation model contains all relevant conversion and separation steps, and auxiliary components such as a steam reformer and a furnace. Simulation parameters for all unit operations were based on current literature to represent the state-of-the-art of the involved technologies. Additionally, the process was optimized by heat integration and waste heat utilization. The established simulation model is proposed to serve as a concept study and basis for the implementation of future experimental results and perceptions. With an energy efficiency of 95% and a biokerosene yield of 41%, the results emphasize the potential of this conversion process.

The aviation sector relies on petroleum jet fuel because it is the most efficient energy carrier. Due to environmental and economic concerns a strong demand for alternative fuels is emerging. There is a need for diversification of energy sources from natural resources. These resources must be environmentally friendly and costs effective. Environmental impacts of fossil fuels on global warming and climate change are being a major concern today. Furthermore, the fluctuations of oil prices and need for sustainable fuel supply are the strong drivers for the economies of fuel users. In the aviation sector, Jet fuel from microalgae is one of the alternatives receiving considerable attention; it offers the potential to diversify energy sources. Microalgae species can produce lipids; they do not require high use of land, do not need freshwater, can grow in marine water or wastewater, grow faster in very short period of time, the produced oil is not a threat to food security. Similarly, the effect of climate change and global warming due to the generation of greenhouse gases (GHG) from petroleum jet fuel can be considerably reduced due to low carbon footprint generated by algae based fuels. Therefore, algae based aviation fuels can be considered as an alternative to produce an efficient fuel compared to conventional fuels. Conversely, the key challenge is: many algae species have lower lipid content. Harvesting and drying processes are costly as well as upstream processes to convert microalgae oil into Jet fuel. Although algae biofuels are still small players in the aviation industry, there is a potential for the future. This review analyses some routes to be explored or already explored, their strengths and weaknesses, the current trends and possible conceptual approaches to get aviation fuel from microalgae oil.

To fulfill the need of renewable, sustainable, and cleaner form of fuel, scientists are attracted toward biodiesel and hydrotreated vegetable oil or green (renewable) diesel. Biodiesel is generally...

A key reason inhibiting commercialization of algal oil as biodiesel feedstock, is cultivation cost. For this reason, the usability of 19 readily available industrial effluents (autoclaved and non-autoclaved) to support heterotrophic growth and lipid accumulation was evaluated using six mixed algal cultures. Autoclaved whey effluent was the best with 14.32 g biomass L−1, 13.23% lipids, resulting in a lipid production of 1.91 g lipids L−1. Biomass production and lipid accumulation were in many cases inverse, e.g. mixed algal culture termed TUT4 accumulating 84.25% lipids on autoclaved acid mine drainage, with very little biomass produced. Biomass production was dependent on the effluent type, whereas the lipid accumulation was influenced mostly by the specific mixed algal cultures. The fatty acid composition of the algal oil (fish cannery and whey effluents) showed high saturation, leading to acceptable cetane numbers, kinematic viscosity, good oxidative stability, but poor cold flow properties.

Biodiesel production from different feedstocks is one of the effective ways to anticipate the problems related with fuel crisis and environmental issues. In this study, the response surface...

Feedstock for biodiesel production has changed over time and it varies depending on regions. Reports and journal articles on biodiesel feedstock resources over the last decade from 2006 to 2016 were reviewed in this article. The regional trends still maintain as the USA and the EU still predominantly use soybean oil and rapeseed oil, respectively, and palm oil is the major source of biodiesel in Asia. It is expected that the food-crop based biodiesel will continue to be dominant for the next decade. However, it was found that uses of animal fats and used cooking oil are increasing both in the USA and the EU. Because of the increasing diversity in feedstock inputs to biodiesel, it is necessary to better understand the effects of feedstock characteristics on engine performance and emissions. In this review, we limit the reports on biodiesel emissions to those who used 100% biodiesel combusted in a one-cylinder, four-stroke, direct injection engine set up in a laboratory. All the emission results were obtained from the same or similar engine conditions to fairly compare them. CO, CO2, NOx, and PM emissions are compared between the biodiesels derived from soybean oil, rapeseed oil, palm oil, jatropha oil, used cooking oil, animal fats, and algal oil. It was found that more emission studies are needed for algal biodiesel. More in-depth studies are necessary for PM characteristics including the compositions of trace metals, elemental and organic carbon. © 2017 American Institute of Chemical Engineers Environ Prog, 2017

The unprecedented use of fossil fuels necessitates the research community to find clean, safe, renewable and sustainable energy source. One such promising source is microalgal biofuel, which can mitigate the environmental concerns and energy crisis due to its closed carbon cycle. Selection of proper strain and optimization of the culture conditions to maximize the lipid productivity is very important for successful economical biodiesel conversion process. One such robust halophilic species identified was Aphanothece halophytica with rich lipid productivity. They were cultivated in different media and optimized on lab scale as well as in large scale using raceway ponds to produce sufficient biomass for algal oil extraction. The biodiesel conversion process parameters were then optimized by multi-variant response surface methodology (RSM). The free fatty acid (FFA) content of the raw algal oil was only 0.51% which enables direct conversion by transesterification. Eco-friendly, natural white clam shell was calcinated to obtain CaO, which was recovered and reused for three times effectively. The maximum biodiesel yield of around 99 vol% was obtained for the oil/methanol ratio of 0.32(v/v) using calcinated CaO for 6 wt% of raw feed while stirring at 400 rpm at a temperature of 70 °C for 85 min. The GC–MS analysis of the algal biodiesel confirmed the presence of saturated and unsaturated fatty acids in balanced proportion to provide better oxidation stability and good combustion characteristics. Other biodiesel properties were analyzed and found to be within the standards specified by EN and ASTM for automotive application without any engine modification.

Eukaryotic microalgae and prokaryotic cyanobacteria are globally the most important primary producers, forming the base of food web in aquatic ecosystems. As such, they are eaten by a huge diversity of protistan taxa (e.g., amoeba, flagellates and ciliates), as well as zooplanktonic and larger metazoan grazers. As in terrestrial agriculture, grazing has the potential to devastate the microalgal “crop” and this has obvious implications to the commercial success of the developing microalgal industry. Whilst in conventional agriculture thousands of years of exploitation of a relatively small number of crop plants, has resulted in tools, knowledge and strategies that can manage this issue, in the case of microalgal mass culture this is relatively undeveloped. This review explores our current understanding of the issue and where further research is needed, focusing on the diversity of grazers and how microalgae under various environmental regimes and culture conditions avoid being annihilated. In addition, the implications of algal mass culture, where the objective is to maintain a virtual monoculture, are discussed in the context of how infection could be prevented/minimised and if infection occurs, how this may be managed to prevent excessive losses in productivity or quality of the algal crop. The ultimate objective would be the development of robust methodologies for the early detection of “infection” of microalgal mass-cultures. This would allow the timely implementation of best management practices to prevent/reduce, damage caused by grazing. In reality, whilst there will be areas of commonality, as in terrestrial agricultural crops, methods will be need to be specifically tailored for each algal taxon, cultivation system and location.

Mixing in traditional algae culture system consumes intensive electricity. This should be replaced by nature force to reduce energy cost and, more importantly, to realize positive energy balance of algal biofuel production. This study aims to develop a horizontal photobioreactor, in which mixing can be provided with rocking movement driven by nature force. Simple boxes were used as small-scale horizontal photobioreactors on a rocking platform for culture of alkalihalophilic Euhalothece sp. ZM001. There was no CO2 gas bubbling since 1.0 M NaHCO3 supplied sufficient inorganic carbon in it. Effect of culture depth, rocking cycle, and light intensity to algal biomass production, pH change, and DO accumulation were investigated in this system. Biomass concentration of 2.73 g/L was achieved in culture with 2.5 cm depth, and maximum productivity of 17.06 g/m2/day was obtained in culture with 10 cm depth. k L a in PBR with different culture depths and rocking cycles was measured, and it was from 0.57 to 33.49 h−1, showing great variation. To test this system at large scale, a plastic bag with a surface area of 1 m2 was placed on a rocking platform driven by water power, and it resulted in a biomass concentration of 1.88 g/L. These results proved feasibility of a novel photobioreactor system driven by nature force, as well as low cost of manufacturing, and easy scaling-up.