Utilization of lipid-extracted biomass (LEB) to improve the economic feasibility of biodiesel production from green microalgae

2020 ◽  
Vol 28 (3) ◽  
pp. 325-338
Author(s):  
Sabrina Marie Desjardins ◽  
Corey Alfred Laamanen ◽  
Nathan Basiliko ◽  
John Ashley Scott

Photosynthetic green microalgae are eukaryotic microorganisms that can mitigate anthropogenic carbon dioxide and generate lipids as a feedstock for production of biodiesel. Biodiesel production may not, however, compete economically with fossil fuel sourced diesel, but obtaining additional value from the biomass left after lipid extraction has the potential to help make the overall process more cost-effective. This review focuses on these additional value-added options that obtain and utilize either whole lipid-extracted biomass (LEB), which typically constitutes 60%–70% of total cell mass, or specific non-biodiesel lipid components such as polyunsaturated fatty acids, carbohydrates, and proteins.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Azhar Najjar ◽  
Elhagag Ahmed Hassan ◽  
Nidal Zabermawi ◽  
Saber H. Saber ◽  
Leena H. Bajrai ◽  
...  

AbstractIn this study, two highly thermotolerant and methanol-tolerant lipase-producing bacteria were isolated from cooking oil and they exhibited a high number of catalytic lipase activities recording 18.65 ± 0.68 U/mL and 13.14 ± 0.03 U/mL, respectively. Bacterial isolates were identified according to phenotypic and genotypic 16S rRNA characterization as Kocuria flava ASU5 (MT919305) and Bacillus circulans ASU11 (MT919306). Lipases produced from Kocuria flava ASU5 showed the highest methanol tolerance, recording 98.4% relative activity as well as exhibited high thermostability and alkaline stability. Under the optimum conditions obtained from 3D plots of response surface methodology design, the Kocuria flava ASU5 biocatalyst exhibited an 83.08% yield of biodiesel at optimized reaction variables of, 60 ○C, pH value 8 and 1:2 oil/alcohol molar ratios in the reaction mixture. As well as, the obtained results showed the interactions of temperature/methanol were significant effects, whereas this was not noted in the case of temperature/pH and pH/methanol interactions. The obtained amount of biodiesel from cooking oil was 83.08%, which was analyzed by a GC/Ms profile. The produced biodiesel was confirmed by Fourier-transform infrared spectroscopy (FTIR) approaches showing an absorption band at 1743 cm−1, which is recognized for its absorption in the carbonyl group (C=O) which is characteristic of ester absorption. The energy content generated from biodiesel synthesized was estimated as 12,628.5 kJ/mol. Consequently, Kocuria flava MT919305 may provide promising thermostable, methanol-tolerant lipases, which may improve the economic feasibility and biotechnology of enzyme biocatalysis in the synthesis of value-added green chemicals.


Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 373 ◽  
Author(s):  
Mattia Bartoli ◽  
Chengyong Zhu ◽  
Michael Chae ◽  
David Bressler

Although thermal hydrolysis of digested biosolids is an extremely promising strategy for wastewater management, the process economics are prohibitive. Here, a biosolids-based material generated through thermal hydrolysis was used as a catalyst for urea glycerolysis performed under several conditions. The catalytic system showed remarkable activity, reaching conversion values of up to 70.8 ± 0.9% after six hours, at 140 °C using a catalyst/glycerol weight ratio of 9% and an air stream to remove NH3 formed during the process. Temperature played the most substantial role among reaction parameters; increasing temperature from 100 °C to 140 °C improved conversion by 35% and glycidol selectivity by 22%. Furthermore, the catalyst retained good activity even after the fourth catalytic run (conversion rate of 56.4 ± 1.3%) with only a slight decrease in glycidol selectivity. Thus, the use of a biosolids-based catalyst may facilitate conversion of various glycerol sources (i.e., byproduct streams from biodiesel production) into value-added products such as glycidol, and may also improve the economic feasibility of using thermal hydrolysis for treatment of biosolids.


2021 ◽  
Vol 9 ◽  
Author(s):  
Nazifa Rafa ◽  
Shams Forruque Ahmed ◽  
Irfan Anjum Badruddin ◽  
M. Mofijur ◽  
Sarfaraz Kamangar

Third-generation biofuel produced from microalgae is a viable solution to global energy insecurity and climate change. Despite an annual current global algal biomass production of 38 million litres, commercialization confronts significant economic challenges. However, cost minimization strategies, particularly for microalgae cultivation, have largely been excluded from recent studies. Therefore, this review provides essential insights into the technologies and economics of cost minimization strategies for large-scale applications. Cultivation of microalgae through aquafarming, in wastewater, or for biogas upgrading, and co-production of value-added products (VAPs) such as photo-bioreactors, protein, astaxanthin, and exopolysaccharides can drastically reduce biodiesel production costs. For instance, the co-production of photo-bioreactors and astaxanthin can reduce the cost of biodiesel production from $3.90 to $0.54 per litre. Though many technical challenges need to be addressed, the economic analysis reveals that incorporating such cost-effective strategies can make the biorefinery concept feasible and profitable. The cost of producing microalgal biodiesel can be lowered to $0.73kg−1 dry weight when cultivated in wastewater or $0.54L−1 when co-produced with VAPs. Most importantly, access to co-product markets with higher VAPs needs to be encouraged as the global market for microalgae-based VAPs is estimated to rise to $53.43 billion in 2026. Therefore, policies that incentivize research and development, as well as the production and consumption of microalgae-based biodiesel, are important to reduce the large gap in production cost that persists between biodiesel and petroleum diesel.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Peter Adeniyi Alaba ◽  
Ching Shya Lee ◽  
Faisal Abnisa ◽  
Mohamed Kheireddine Aroua ◽  
Patrick Cognet ◽  
...  

AbstractGlycerol electrooxidation has attracted immense attention due to the economic advantage it could add to biodiesel production. One of the significant challenges for the industrial development of glycerol electrooxidation process is the search for a suitable electrocatalyst that is sustainable, cost effective, and tolerant to carbonaceous species, results in high performance, and is capable of replacing the conventional Pt/C catalyst. We review suitable, sustainable, and inexpensive alternative electrocatalysts with enhanced activity, selectivity, and durability, ensuring the economic viability of the glycerol electrooxidation process. The alternatives discussed here include Pd-based, Au-based, Ni-based, and Ag-based catalysts, as well as the combination of two or three of these metals. Also discussed here are the prospective materials that are yet to be explored for glycerol oxidation but are reported to be bifunctional (being capable of both anodic and cathodic reaction). These include heteroatom-doped metal-free electrocatalysts, which are carbon materials doped with one or two heteroatoms (N, B, S, P, F, I, Br, Cl), and heteroatom-doped nonprecious transition metals. Rational design of these materials can produce electrocatalysts with activity comparable to that of Pt/C catalysts. The takeaway from this review is that it provides an insight into further study and engineering applications on the efficient and cost-effective conversion of glycerol to value-added chemicals.


Author(s):  
Aarthy A ◽  
Smita Kumari ◽  
Prachi Turkar ◽  
Sangeetha Subramanian

 Objective: This review article deals with the effect that various cell disruption techniques have on the efficiency of lipid extraction. We have reviewed existing algal cell disruption techniques that aid the biodiesel production process.Methods: Current rise in demand for energy has led the researcher to focus on the production of sustainable fuels, among which biodiesel has received greater attention. This is due to its larger lipid content, higher growth rate, larger biomass production, and lower land use. Extraction of lipid from algae (micro and macro) for the production of biodiesel involves numerous downstream processing steps, of which cell wall disruption is a crucial step. Bead milling, high-pressure homogenization, ultra-sonication, freeze-drying, acid treatment, and enzymatic lysis are some methods of cell disruption. The cell disruption technique needs to be optimized based on the structure and biochemical composition of algae.Result: The lipid extraction efficiency varies depending on the algal species and the cell disruption technique used.Conclusion: In-depth research and development of new techniques are required to further enhance the cell disruption of the algal cell wall for the enhanced recovery of lipids. In addition, the operating costs and energy consumption should also be optimized for the cost-effective recovery.


Author(s):  
Shwe Sin Win ◽  
Swati Hegde ◽  
Thomas A. Trabold

Crude (i.e., unrefined) glycerol is the major by-product of biodiesel production, based on the homogeneous alkaline catalytic transesterification reaction. Currently, global biodiesel production capacity has been rising rapidly due to the overall growth of renewable energy demand. The amount of glycerol is increasing in parallel, and there is presently little market value for crude glycerol. In addition, disposing of this material via conventional methods becomes one of the major environmental issues and a burden for biodiesel manufacturers. Thus, utilization of purified glycerol in value-added applications such as food processing, cosmetics, soap and pharmaceuticals is critical to achieve economic scale of biodiesel production. In this paper, various pathways available to community-based biodiesel producers have been modeled to inform the decision-making process. A case study at Rochester Institute of Technology (RIT) was selected to evaluate the proposed system. Different pathways of utilizing crude glycerol were investigated, and economic feasibility of each pathway was analyzed. Purification of crude glycerol from waste cooking oil-based-biodiesel production was performed at small bench scale. Various recipes with different raw materials and purified glycerol as an ingredient were created for different kinds of saponification processes and applications. The resulting data from this preliminary assessment showed that producing biodiesel and high-quality soap is the most profitable option for RIT.


Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1978 ◽  
Author(s):  
Sanna Uski ◽  
Erkka Rinne ◽  
Janne Sarsama

Microgrids can be used for securing the supply of power during network outages. Underground cabling of distribution networks is another effective but conventional and expensive alternative to enhance the reliability of the power supply. This paper first presents an analysis method for the determination of microgrid power supply adequacy during islanded operation and, second, presents a comparison method for the overall cost calculation of microgrids versus underground cabling. The microgrid power adequacy during a rather long network outage is required in order to indicate high level of reliability of the supply. The overall cost calculation considers the economic benefits and costs incurred, combined for both the distribution network company and the consumer. Whereas the microgrid setup determines the islanded-operation power adequacy and thus the reliability of the supply, the economic feasibility results from the normal operations and services. The methods are illustrated by two typical, and even critical, case studies in rural distribution networks: an electric-heated detached house and a dairy farm. These case studies show that even in the case of a single consumer, a microgrid option could be more economical than network renovation by underground cabling of a branch in order to increase the reliability.


Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 899
Author(s):  
Djordje Mitrovic ◽  
Miguel Crespo Chacón ◽  
Aida Mérida García ◽  
Jorge García Morillo ◽  
Juan Antonio Rodríguez Diaz ◽  
...  

Studies have shown micro-hydropower (MHP) opportunities for energy recovery and CO2 reductions in the water sector. This paper conducts a large-scale assessment of this potential using a dataset amassed across six EU countries (Ireland, Northern Ireland, Scotland, Wales, Spain, and Portugal) for the drinking water, irrigation, and wastewater sectors. Extrapolating the collected data, the total annual MHP potential was estimated between 482.3 and 821.6 GWh, depending on the assumptions, divided among Ireland (15.5–32.2 GWh), Scotland (17.8–139.7 GWh), Northern Ireland (5.9–8.2 GWh), Wales (10.2–8.1 GWh), Spain (375.3–539.9 GWh), and Portugal (57.6–93.5 GWh) and distributed across the drinking water (43–67%), irrigation (51–30%), and wastewater (6–3%) sectors. The findings demonstrated reductions in energy consumption in water networks between 1.7 and 13.0%. Forty-five percent of the energy estimated from the analysed sites was associated with just 3% of their number, having a power output capacity >15 kW. This demonstrated that a significant proportion of energy could be exploited at a small number of sites, with a valuable contribution to net energy efficiency gains and CO2 emission reductions. This also demonstrates cost-effective, value-added, multi-country benefits to policy makers, establishing the case to incentivise MHP in water networks to help achieve the desired CO2 emissions reductions targets.


2020 ◽  
Vol 18 (1) ◽  
pp. 874-881
Author(s):  
Laras Prasakti ◽  
Sangga Hadi Pratama ◽  
Ardian Fauzi ◽  
Yano Surya Pradana ◽  
Arief Budiman ◽  
...  

AbstractAs fossil fuels were depleting at an alarming rate, the development of renewable energy has become necessary. One of the promising renewable energy to be used is biodiesel. The interest in using third-generation feedstock, which is microalgae, is rapidly growing. The use of third-generation biodiesel feedstock will be more beneficial as it does not compete with food crop use and land utilization. The advantageous characteristic which sets microalgae apart from other biomass sources is that microalgae have high biomass yield. Conventionally, microalgae biodiesel is produced by lipid extraction followed by transesterification. In this study, combination process between hydrothermal liquefaction (HTL) and esterification is explored. The HTL process is one of the biomass thermochemical conversion methods to produce liquid fuel. In this study, the HTL process will be coupled with esterification, which takes fatty acid from HTL as raw material for producing biodiesel. Both the processes will be studied by simulating with Aspen Plus and thermodynamic analysis in terms of energy and exergy. Based on the simulation process, it was reported that both processes demand similar energy consumption. However, exergy analysis shows that total exergy loss of conventional exergy loss is greater than the HTL-esterification process.


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