Using macroalgae as biofuel: current opportunities and challenges

2020 ◽  
Vol 63 (4) ◽  
pp. 355-370 ◽  
Author(s):  
Guang Gao ◽  
James Grant Burgess ◽  
Min Wu ◽  
Shujun Wang ◽  
Kunshan Gao
Keyword(s):  
Cost Effectiveness ◽  
Fossil Fuels ◽  
Agricultural Land ◽  
Biomass Productivity ◽  
Dry Mass ◽  
Biofuel Production ◽  
Electricity Production ◽  
Energy Productivity ◽  
Lower Growth ◽  
Algal Biofuels

AbstractThe rising global demand for energy and the decreasing stocks of fossil fuels, combined with environmental problems associated with greenhouse gas emissions, are driving research and development for alternative and renewable sources of energy. Algae have been gaining increasing attention as a potential source of bio-renewable energy because they grow rapidly, and farming them does not, generally, compete for agricultural land use. Previous studies of algal biofuels have focused on microalgae because of their fast growth rate and high lipid content. Here we analyze the multiple merits of biofuel production using macroalgae, with particular reference to their chemical composition, biomass and biofuel productivity, and cost-effectiveness. Compared to microalgae, macroalgae have lower growth rates and energy productivity but higher cost-effectiveness. A biomass productivity of over 73.5 t dry mass ha−1 year−1 with a methane yield of 285 m3 t−1 dry mass would make electricity production from macroalgae profitable, and this might be achieved using fast-growing macroalgae, such as Ulva. Taking into account the remediation of eutrophication and CO2, exploring macroalgae for a renewable bioenergy is of importance and feasible.

Electricity production and its effects on carbon dioxide emissions in the Kingdom of Saudi Arabia: إنتاج الكهرباء وآثاره في انبعاثات ثاني أكسيد الكربون في المملكة العربية السعودية

2021 ◽  
Vol 5 (3) ◽  
pp. 134-108
Author(s):  
Zakiah Radhi Alhajji, Mohamed Elsayed Hafez Ali Zakiah Radhi Alhajji, Mohamed Elsayed Hafez Ali
Keyword(s):  
Carbon Dioxide ◽  
Saudi Arabia ◽  
Carbon Dioxide Emissions ◽  
Fossil Fuels ◽  
Electric Energy ◽  
Total Carbon ◽  
Electricity Production ◽  
Energy Productivity ◽  
Gulf Region ◽  
Kingdom Of Saudi Arabia

Because of increased demand for electrical energy in the Kingdom of Saudi Arabia, which has resulted in an increase in carbon dioxide emissions, the electricity system in the Kingdom of Saudi Arabia is the largest in the Gulf region and the Arab world, with approximately 61.7 gigatons (GW) of peak demand and 89.2 gigatons (GW) of available capacity in 2018 of electricity power. It has grown rapidly over more than 20 years and has almost doubled in size since 2000. Where we observe that the total carbon dioxide emissions in the Kingdom of Saudi Arabia from 1990 to 2020; where shows rapid growth in emissions of carbon dioxide and greenhouse gases, as it was found that CO2 emissions in 1990 amounted to 151 million metric tons compared to 2011 when it reached about 435 million metric tons, and the increase continued until 2020 when it reached about 530 million metric tons. The comprehensive study relied on time series analysis to carefully analyze the electric energy productivity rate from fossil fuels and the significant amount of carbon dioxide emissions typically resulting from promptly burning fossil fuels to naturally produce electric energy. Therefore, the Kingdom of Saudi Arabia, through Vision 2030 and the Paris Agreement on Climate Change, looks to reduce the rate of carbon dioxide emissions in the field of electric power generation by diversifying the fuels used or replacing them with clean and renewable energy such as solar and wind energy.

scholarly journals The Use of Urea and Kelp Waste Extract is A Promising Strategy for Maximizing the Biomass Productivity and Lipid Content in Chlorella sorokiniana

Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 463 ◽  
Author(s):  
Ali Nawaz Kumbhar ◽  
Meilin He ◽  
Abdul Razzaque Rajper ◽  
Khalil Ahmed Memon ◽  
Muhammad Rizwan ◽  
...  
Keyword(s):  
Lipid Content ◽  
Fossil Fuels ◽  
Fossil Fuel ◽  
Lipid Production ◽  
Total Lipid Content ◽  
Biomass Productivity ◽  
Chlorella Sorokiniana ◽  
Biofuel Production ◽  
Promising Strategy ◽  
Waste Extract

The decline in fossil fuel reserves has forced researchers to seek out alternatives to fossil fuels. Microalgae are considered to be a promising feedstock for sustainable biofuel production. Previous studies have shown that urea is an important nitrogen source for cell growth and the lipid production of microalgae. The present study investigated the effect of different concentrations of urea combined with kelp waste extract on the biomass and lipid content of Chlorella sorokiniana. The results revealed that the highest cell density, 20.36 × 107 cells−1, and maximal dry biomass, 1.70 g/L, were achieved in the presence of 0.5 g/L of urea combined with 8% kelp waste extract. Similarly, the maximum chlorophyll a, b and beta carotenoid were 10.36 mg/L, 7.05, and 3.01 mg/L, respectively. The highest quantity of carbohydrate content, 290.51 µg/mL, was achieved in the presence of 0.2 g/L of urea and 8% kelp waste extract. The highest fluorescence intensity, 40.05 × 107 cells−1, and maximum total lipid content (30%) were achieved in the presence of 0.1 g/L of urea and 8% kelp waste extract. The current study suggests that the combination of urea and kelp waste extract is the best strategy to enhance the biomass and lipid content in Chlorella sorokiniana.

Microalgae as a renewable source of energy –processing and biofuel production a short review

2021 ◽  
Vol 5 (S1) ◽  
pp. 1295-1301
Author(s):  
K. Ashok ◽  
M. Babu ◽  
S. Anandhi ◽  
G. Padmapriya ◽  
V. Jula
Keyword(s):  
Rural Communities ◽  
Fossil Fuels ◽  
Food Additives ◽  
Clean Energy ◽  
Short Review ◽  
Biofuel Production ◽  
Pharmaceutical Drugs ◽  
Commercial Development ◽  
Algal Biofuels ◽  
The Government

The large application potential of micro-algae in the clean energy, biopharmaceutical and nutraceutical industries have recently drawn a substantial world interest. Biofuels, bioactive pharmaceutical drugs and food additives are organic, natural and economical sources. As biofuels, they have a good cost, renewability or environmental replacement for liquid fossil fuels. Microalges provide productive biomass feedstock for biofuel as demand for biofuels rises worldwide. These resources may be processed into biodiesel with ample supplies of biomass in rural communities. The cultivation of genetically modified algae in recent years has been pursued to promote the marketing of algae. In particular, this would benefit society if linked with a successful policy on algal biofuels and other by-products in the government. In terms of survival of the world's current problems, Algal technologies are a transformative but complementary tool. Algal fuel marketing remains a bottleneck and a threat. It is technically possible to have a big output but it is not economic. This study therefore focuses principally on problems in commercial development of biological microalgae and potential strategies for overcoming this challenge.

scholarly journals Rapid Aggregation of Biofuel-Producing Algae by the Bacterium Bacillus sp. Strain RP1137

2013 ◽  
Vol 79 (19) ◽  
pp. 6093-6101 ◽  
Author(s):  
Ryan J. Powell ◽  
Russell T. Hill
Keyword(s):  
Fossil Fuels ◽  
Low Energy ◽  
Biofuel Production ◽  
Liquid Fuels ◽  
Magnesium Ions ◽  
Nannochloropsis Oceanica ◽  
Algal Biofuels ◽  
Content Type ◽  
Ph Dependent ◽  
Bacterium Bacillus

ABSTRACTAlgal biofuels represent one of the most promising means of sustainably replacing liquid fuels. However, significant challenges remain before alga-based fuels become competitive with fossil fuels. One of the largest challenges is the ability to harvest the algae in an economical and low-energy manner. In this article, we describe the isolation of a bacterial strain,Bacillussp. strain RP1137, which can rapidly aggregate several algae that are candidates for biofuel production, including aNannochloropsissp. This bacterium aggregates algae in a pH-dependent and reversible manner and retains its aggregation ability after paraformaldehyde fixation, opening the possibility for reuse of the cells. The optimal ratio of bacteria to algae is described, as is the robustness of aggregation at different salinities and temperatures. Aggregation is dependent on the presence of calcium or magnesium ions. The efficiency of aggregation ofNannochloropsis oceanicaIMET1 is between 70 and 95% and is comparable to that obtained by other means of harvest; however, the rate of harvest is fast, with aggregates forming in 30 s.

scholarly journals A Review of Energy Consumption in the Acquisition of Bio-Feedstock for Microalgae Biofuel Production

2021 ◽  
Vol 13 (16) ◽  
pp. 8873
Author(s):  
Minghao Chen ◽  
Yixuan Chen ◽  
Qingtao Zhang
Keyword(s):  
Energy Consumption ◽  
Large Scale ◽  
Fossil Fuels ◽  
Biomass Concentration ◽  
Biomass Productivity ◽  
Biofuel Production ◽  
Scale Production ◽  
Culture Methods ◽  
Cultivation System ◽  
Cultivation Systems

Microalgae biofuel is expected to be an ideal alternative to fossil fuels to mitigate the effects of climate change and the energy crisis. However, the production process of microalgae biofuel is sometimes considered to be energy intensive and uneconomical, which limits its large-scale production. Several cultivation systems are used to acquire feedstock for microalgal biofuels production. The energy consumption of different cultivation systems is different, and the concentration of culture medium (microalgae cells contained in the unit volume of medium) and other properties of microalgae vary with the culture methods, which affects the energy consumption of subsequent processes. This review compared the energy consumption of different cultivation systems, including the open pond system, four types of closed photobioreactor (PBR) systems, and the hybrid cultivation system, and the energy consumption of the subsequent harvesting process. The biomass concentration and areal biomass production of every cultivation system were also analyzed. The results show that the flat-panel PBRs and the column PBRs are both preferred for large-scale biofuel production for high biomass productivity.

scholarly journals The significance of nitrous oxide emission due to cropping of grain for biofuel production: a Swedish perspective

2011 ◽  
Vol 8 (12) ◽  
pp. 3581-3591 ◽  
Author(s):  
Å. Kasimir Klemedtsson ◽  
K. A. Smith
Keyword(s):  
Nitrous Oxide ◽  
Crop Production ◽  
Fossil Fuels ◽  
Agricultural Land ◽  
N2o Emission ◽  
Biofuel Production ◽  
Organic Soils ◽  
N2o Emissions ◽  
Agricultural Crop ◽  
The Eu

Abstract. The current regulations governing production of biofuels in the European Union require that they have to mitigate climate change, by producing >35% less greenhouse gases (GHG) than fossil fuels. There is a risk that this may not be achievable, since land use for crop production inevitably emits the potent GHG nitrous oxide (N2O), due to nitrogen fertilisation and cycling in the environment. We analyse first-generation biofuel production on agricultural land and conclude that efficient agricultural crop production resulting in a good harvest and low N2O emission can fulfil the EU standard, and is possible under certain conditions for the Swedish agricultural and bioethanol production systems. However, in years having low crop yields, and where cropping is on organic soils, total GHG emissions per unit of fuel produced can be even higher than those released by burning of fossil fuels. In general, the N2O emission size in Sweden and elsewhere in northern Europe is such that there is a >50% chance that the 35% saving requirement will not be met. Thus ecosystem N2O emissions have to be convincingly assessed. Here we compare Swedish emission data with values estimated by means of statistical models and by a global, top-down, approach; the measurements and the predictions often show higher values that would fail to meet the EU standard and thus prevent biofuel production development.

scholarly journals Perception and Attitude of Community towards the Development of Nyamplung in Patutrejo Village, Purworejo District

2020 ◽  
Vol 3 (1) ◽  
pp. 55-66
Author(s):  
Sanudin Sanudin
Keyword(s):  
Alternative Energy ◽  
Fossil Fuels ◽  
Agricultural Land ◽  
Biofuel Production ◽  
Global Awareness ◽  
Alternative Energy Sources ◽  
Central Java ◽  
Perceptions And Attitudes ◽  
Modern Machine ◽  
Environmental Functions

Global awareness of the energy crisis and the environmental impacts related to fossil fuels have driven the use of alternative energy sources such as biofuels. Nyamplung is one type of plant suitable for biofuel production. This study aims to determine perception and attitude community towards the development of nyamplung. The study was conducted in April - July 2018 in Patutrejo Village, Purworejo District, Central Java. Data collection was carried out by interviewing the community involved in the Self-Sufficient Village program in 2009, namely farmers, extension workers, officials in the Forestry Service Branch and officials in Perum Perhutani. The data obtained were tabulated and analyzed using a Likert Scale. The results showed that perceptions and attitudes of the community towards the development of nyamplung are as follows: First, nyamplung is suitable to be developed for environmental functions, namely as a windbreak, which protects agricultural land near the sea to remain productive; Second, nyamplung is not profitable to be developed for biofuel business because the price of nyamplung seeds is low and the processing of nyamplung seeds requires a modern machine; and Third, the development of nyamplung for biofuels does not have the support of the community. They are not willing to plant nyamplung on their own land, are not interested in processing nyamplung seeds for biofuel and are not interested in collecting and selling nyamplung seeds.

Comparison of Cellulose Pyrolysis in Molten NaOH, Ca (OH)2 and Composite Alkali

2014 ◽  
Vol 852 ◽  
pp. 40-43
Author(s):  
Wu Long Yang ◽  
Hong Tao Jiang ◽  
Wei Hua ◽  
Ye Ru Wu ◽  
Feng Wen Yu ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Energy Production ◽  
Fossil Fuels ◽  
Renewable Resource ◽  
Biofuel Production ◽  
Electricity Production ◽  
Human Society ◽  
The European Union ◽  
The Past ◽  
Future Challenges

With the rapid increase of social requirements on energy, as well as the increasing deterioration of the global environment, energy production becomes one of the most important future challenges for human society. In this context, biomass has become a renewable resource with high potential for energy production [1]. In recent years, the demand for and use of renewable energy has increased globally [. Bio-energy is regarded as one of the key options to mitigate greenhouse gas emissions and substitute fossil fuels, especially obvious in Europe. Over the past 10-15 years, heat and electricity production from biomass increased with some 2% and 9% per year, respectively, biofuel production increased about eight-fold in the same period between 1990 and 2000. Biomass contributed some two-thirds of the total renewable energy production in the European Union (EU) (2000 PJ) or 4% of the total energy supply in 1999 [.

scholarly journals Production of Methane, Hydrogen and Ethanol from Secale cereale L. Straw Pretreated with Sulfuric Acid

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 1013 ◽  
Author(s):  
Jarosław Domański ◽  
Olga Marchut-Mikołajczyk ◽  
Weronika Cieciura-Włoch ◽  
Piotr Patelski ◽  
Urszula Dziekońska-Kubczak ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Secale Cereale ◽  
Treatment Time ◽  
Ethanol Yield ◽  
Biofuel Production ◽  
Enzyme Treatment ◽  
Electricity Production ◽  
The European Union ◽  
Rye Straw ◽  
Secale Cereale L

The study describes sulfuric acid pretreatment of straw from Secale cereale L. (rye straw) to evaluate the effect of acid concentration and treatment time on the efficiency of biofuel production. The highest ethanol yield occurred after the enzyme treatment at a dose of 15 filter paper unit (FPU) per gram of rye straw (subjected to chemical hydrolysis with 2% sulfuric acid (SA) at 121 °C for 1 h) during 120 h. Anaerobic digestion of rye straw treated with 10% SA at 121 °C during 1 h allowed to obtain 347.42 L methane/kg volatile solids (VS). Most hydrogen was released during dark fermentation of rye straw after pretreatment of 2% SA, 121 °C, 1 h and 1% SA, 121 °C, 2 h—131.99 and 134.71 L hydrogen/kg VS, respectively. If the rye straw produced in the European Union were processed into methane, hydrogen, ethanol, the annual electricity production in 2018 could reach 9.87 TWh (terawatt-hours), 1.16 TWh, and 0.60 TWh, respectively.

scholarly journals Conversion of biomass to biofuels and life cycle assessment: a review

2021 ◽  
Author(s):  
Ahmed I. Osman ◽  
Neha Mehta ◽  
Ahmed M. Elgarahy ◽  
Amer Al-Hinai ◽  
Ala’a H. Al-Muhtaseb ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Energy Demand ◽  
Fossil Fuels ◽  
Biomass Conversion ◽  
Biofuel Production ◽  
Process Efficiency ◽  
Liquid Fuels ◽  
Thermochemical Processes ◽  
Lower Temperature

AbstractThe global energy demand is projected to rise by almost 28% by 2040 compared to current levels. Biomass is a promising energy source for producing either solid or liquid fuels. Biofuels are alternatives to fossil fuels to reduce anthropogenic greenhouse gas emissions. Nonetheless, policy decisions for biofuels should be based on evidence that biofuels are produced in a sustainable manner. To this end, life cycle assessment (LCA) provides information on environmental impacts associated with biofuel production chains. Here, we review advances in biomass conversion to biofuels and their environmental impact by life cycle assessment. Processes are gasification, combustion, pyrolysis, enzymatic hydrolysis routes and fermentation. Thermochemical processes are classified into low temperature, below 300 °C, and high temperature, higher than 300 °C, i.e. gasification, combustion and pyrolysis. Pyrolysis is promising because it operates at a relatively lower temperature of up to 500 °C, compared to gasification, which operates at 800–1300 °C. We focus on 1) the drawbacks and advantages of the thermochemical and biochemical conversion routes of biomass into various fuels and the possibility of integrating these routes for better process efficiency; 2) methodological approaches and key findings from 40 LCA studies on biomass to biofuel conversion pathways published from 2019 to 2021; and 3) bibliometric trends and knowledge gaps in biomass conversion into biofuels using thermochemical and biochemical routes. The integration of hydrothermal and biochemical routes is promising for the circular economy.

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