Grantee Research Project Results
Final Report: Algae Biofuel Osmosis Dewatering (ABODE): A novel process for biofuel feedstock generation and advances in microalgae separation using forward osmosis
EPA Grant Number: SU836132Title: Algae Biofuel Osmosis Dewatering (ABODE): A novel process for biofuel feedstock generation and advances in microalgae separation using forward osmosis
Investigators: Lee, Woo Hyoung
Institution: University of Central Florida
EPA Project Officer: Page, Angela
Phase: I
Project Period: September 1, 2015 through August 31, 2016
Project Amount: $15,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2015) RFA Text | Recipients Lists
Research Category: P3 Awards , Pollution Prevention/Sustainable Development , Sustainable and Healthy Communities , P3 Challenge Area - Air Quality
Objective:
The research project established and advanced fundamentals associated with a ‘waste–products’ vision centered on recycling organic waste to a biofuel. There are almost seven billion people on earth today that are dependent on fossil energy as a major energy source. Over the coming decades, it will be increasingly prudent to develop and implement strategies for obtaining sustainable energy. This is to not only reduce the quantity of carbon and greenhouse gases entering the atmosphere, but to also achieve a reliable domestic energy source. There is clear motivation to use algae as a biofuel feedstock due to its rapid growth rate and high lipid to biomass ratio compared to other crops traditionally used for biofuels. Algae production capitalizes on sensible land and water use as well as algae's natural ability to uptake nutrients, such as nitrogen and phosphorus, which would otherwise further derogate waterways through eutrophication. Despite the lengthy list of benefits offered by algae-based biofuel, full-scale implementation of algae as a bioenergy source has been prohibitively expensive. To overcome some of the economic barriers for implementing algae-biostock production, this research aims to
integrate previously studied methods for increasing efficiency and lowering production costs in algae cultivation. Our process, termed ABODE (Algae Biofuel Osmosis Dewatering), involves a photobioreactor for the growth of algae using secondary waste water with an attached forward osmosis (FO) extraction process to dewater the algae for bioenergy production using sustainable, low-cost draw solutions. The objectives of the Phase I award were to 1) integrate a novel forward osmosis (FO) system into algae-biofuel production processes using sustainable draw solution optimization and 2) to enable undergraduates and graduate students to design scientific and technical solutions to the current sustainability challenges (i.e., Energy and Water). Specifically, through this award, we achieved the following objectives: 1) designed, built, and operated an algae biofuel osmosis dewatering (ABODE) process for algae separation for sustainable biofuel production; 2) evaluated algae separation using a FO system and optimized draw solution conditions; 3) enhanced algae biomass and lipid productivity; 4) initiated a partnership between Orlando Utility Commission (OUC), University of Central Florida (UCF), and City of Orlando to develop
various R&D projects using algae and explore potential collaborations and synergies to maximize efforts; 5) worked with Air and Waste management Association (A&WMA) to arrange the upcoming webinar highlighting research conclusions from the project efforts; 6) incorporated the outcomes in the undergraduates/graduates courses offering at UCF (ENV 6030: Environmental Biotechnology and EES 4111C: Biological Process Control); and 7) created
outreach activities that includes: UCF News, an interview with UCF’s Sustainability Initiatives, and presentations at a national conference (Annual Water Environmental Federation Technical Exhibition and Conference (WEFTEC) and UCF’s Annual Showcase of Undergraduate Research Excellence (SURE).
Summary/Accomplishments (Outputs/Outcomes):
Results from this project displayed significant improvements in lipid production, algal growth, settling velocities, water flux, and membrane fouling. In high salinity and low nitrogen conditions, we found that the lipid content was increased up to 45% from a salinity effect. This is a significant improvement given that typical lipid contents in algae biomass range from only 15-25%. Forward osmosis (FO) required a relatively small energy input and was resistant to biofouling with SEM data supporting the hypothesis that low pressure membranes are resistant to biofouling. It was not the fastest method for dewatering, but the low energy and resource costs means that forward osmosis could have potential as a primary dewatering or pretreatment method. The goal of achieving 80 to 90% dewater of algae can be achieved by the proposed FO system. For simulated sea water (35.5 g/L NaCl), it was estimated that 0.5 L of algae water would require for 54.2 and 61 hrs for obtaining 80% and 90% dewatering efficiency, respectively, under the assumption of a cross flow velocity of 1.5–10.7 cm/sec, an active FO membrane surface area of 0.00125 m2, and the predetermined average water flux of the PES FO membrane (5.9 L/m2h). The sustainable aspects of this project stem from its careful consideration of people, prosperity, and the planet. For the People, algae-based biofuel will create a reliable domestic energy source which has national security benefits. Algae also can improve water (by removing N & P) and air quality (by capturing CO2), thus positively impacting human health. We will also develop an innovative process with low costs and energy consumption in operation, making
algae biofuel economically feasible for Prosperity. In addition, farming algae for biofuel would create and maintain domestic jobs. Algae’s rapid growth and reproductive rates will make algae an exceptional source of sustainable energy by utilizing and treating wastewater for Planet.
These aspects of sustainability focusing on people, prosperity, and the planet (P3) will establish and advance the sustainable management strategies of wastes while producing bioenergy with low carbon foot prints, representing a paradigm shift in wastewater treatment from being an economic and environmental burden on communities to a profitable commodity to be sold by municipalities to a growing biofuel industry in developing and/or developed world.
Conclusions:
By nature, microalgae are difficult to remove from solution. Cost effective harvesting of microalgae is considered to be the most problematic area of algal biofuel production and limits the commercial use of algae. Experts estimate up 20–30% of the total cost for algal biomass production in open systems come from harvesting and dewatering and 90% of the equipment costs are associated with dewatering). Given that the cost of continuous harvesting of dilute
suspensions of algae is a major ‘bottleneck’ hindering the development of a microalgal industry, we expect that the ABODE process will significantly reduce the cost for algae harvesting in a sustainable way. Though the objectives outlined in phase I, we have demonstrated that FO operation may be more sustainable than previously thought. We found that cross flow velocity may not affect membrane flux (or the rate of dewatering) which means less energy is needed for algae harvesting. Filtration is a highly efficient method for harvesting algae and has been widely studied. However, pressure driven membrane processes for the separation of algae will easily foul and increase energy costs. FO in this project demonstrated excellent dewatering efficiencies (e.g., over 85% with a reduced energy) and was less prone to fouling. This makes FO a suitable complement to algae biofuel production, as it reduces the energy required for dewatering, one of the primary obstacles facing algae biofuels as a sustainable energy source. The NASA OMEGA project and other studies have also suggested FO to be a cost saving step in dewatering freshwater microalgae (Buckwalter et al., 2013), but have not evaluated the effect of FO on algae growth and lipid production. We have found that increased salinity, caused by reverse salt flux, can actually increase lipid content while maintaining high biomass growth.
The ABODE system is a comprehensive method that strived to maximize lipid productivity using properties of draw solutions followed by sustainable and low energy techniques to easily collect the algae so their lipids can be extracted. This project is ambitious in the sense that it encompasses multiple phases of algal-biofuel processing. It is expected that our system has contributed in turning algae biofuel into an economically achievable energy source by exceeding the benchmark energy return on investment (EROI) of 3:1.
Journal Articles on this Report : 4 Displayed | Download in RIS Format
Other project views: | All 4 publications | 4 publications in selected types | All 4 journal articles |
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Church J, Hwang J, Kim K, McLean R, Oh Y, Nam B, Joo S, Lee W. Effect of salt type and concentration on the growth and lipid content of Chlorella vulgaris in synthetic saline wastewater for biofuel production. BIORESOURCE TECHNOLGY 2017;243:147-153. |
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Munshi F, Church J, McLean R, Mair N, Sadmani A, Duranceau S, Lee W. Dewatering algae using an aquaporin-based polyethersulfone forward osmosis membrane. SEPARATION AND PURIFICATION TECHNOLGY 2018;204:154-161. |
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Munshi F, Hwang J, Park J, Sadamani A, Khan M, Jeon B, Lee W. Electric field forward osmosis (EFFO) fouling mitigation in algae harvesting. SEPARATION AND PURIFICATION TECHNOLOGY 2023;327(124868) |
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Munshi F, Hwant J, Stoll S, Lee W. Reverse Salt Flux Effect on Dewatering Chlorella vulgaris in a Forward Osmosis System. WATER 2023;15(8):1462. |
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Supplemental Keywords:
Algae, biodiesel, bioenergy, carbon capture, carbon dioxide, dewatering, energy recovery, forward osmosis, global climate, greenhouse gas, green technology, harvesting, K-12, Orlando, salinity, STEM, sustainability, water, wastewaterRelevant Websites:
1. UCF EPA P3, http://cee.ucf.edu/people/Lee/EPA_P3.html
2. IDEAS presents THIS IS THE HIVE, https://www.youtube.com/watch?v=UfyrAQIbC_Y&list=PLMSO4pMQscvjoByXzjo_vtKPQ
ZleFuZgK&index=2
3. The City of Orlando's Green initiatives, http://www.cityoforlando.net/greenworks/energy-and-green-buildings/
5. UCF monthly Faculty Spotlight under UCF Sustainability Initiatives (http://sustainable.ucf.edu/facultyqa/lee), by Hannah Hollinger, Sustainability Initiatives, Feb. 2, 2016.
6. UCF Students Make School History -- Win EPA Grant for Sustainability Project (https://today.ucf.edu/ucf-students-make-school-history-win-epa-grant-for-sustainability-project/) by Aileen Perilla, UCF Today, Dec. 23, 2015.
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.