ALGAE MODELING

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1003460
• Project Start Date: Oct 1, 2014
• Project End Date: Sep 30, 2019
• Program Code: [(N/A)]- (N/A)

Recipient Organization
UNIVERSITY OF ARIZONA
888 N EUCLID AVE
TUCSON,AZ 85719-4824

Performing Department
Agri & Biosystems Engineering

Non Technical Summary
The ARID (Algae Raceway Integrated Design) raceway was invented and patented (Ryan et al., 2012) at the University of Arizona (UA) by Randy Ryan, Peter Waller, Murat Kacira, and Peiwen Li. The ARID raceway had improved temperature characteristics (Crowe et al., 2012; Waller et al., 2012). The hydraulics of the raceway was improved (Xu et al., 2012), and the new version was called the ARID-HV (Algae Raceway Integrated Design - High Velocity) raceway. Dr. Waller developed a temperature model of the ARID and ARID-HV raceways and then worked with Michael Huesemann at the Pacific Northwest National Laboratory (PNNL) to develop an algae growth and light model for the ARID and ARID-HV raceways. The current growth model research is a collaborative effort between Dr. Waller at UA and Dr. Huesemann, Dr. Wigmosta, and Dr. Skaggs at PNNL. The model currently calculates algae growth rate as a function of water temperature and light intensity in 100 layers in the algae culture. The model calculates water temperature as a function of atmospheric weather parameters from AZMET (Arizona Meteorological Network). Light is calculated based on solar radiation, solar angle, water albedo, and light absorption by algae. The algae culture is divided into 100 layers, and algae growth in each layer is calculated during each time step and then the culture is mixed. In this proposed Hatch project, we hope to improve the heat and light algorithms and improve the modeling of algae response to heat and light. We also plan to increase the number of algae species that are modeled with this approach. Finally we plan to add algae response to pH and nutrients to the model.

Animal Health Component

50%

Research Effort Categories

Basic

50%

Applied

50%

Developmental

0%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
402	4099	2010	100%

Knowledge Area
402 - Engineering Systems and Equipment;

Subject Of Investigation
4099 - Microorganisms, general/other;

Field Of Science
2010 - Physics;

Keywords

algae

growth

model

temperature

raceway

ph

carbon dioxide

fertilizer

nutrients

arid

light

Goals / Objectives
Goals:1. Develop the temperature and algae growth model for the conventional and ARID raceways.2. Add a CO2-pH component to the ARID raceway model3. Add a fertilizer component to the ARID raceway model4. Package the model in a user-friendly Excel/VBA environmentObjectives:1a. Calibrate the temperature models with temperature data from the ARID and conventional raceway testbeds that are operated under the DOE Regional Algal Feedstock Testbed project. At the conclusion of the project, the model should be able to predict raceway temperatures year round within +/- 2 C.1b. Calibrate the algae growth models with algae growth data from the ARID and conventional raceway testbeds that are operated under the DOE Regional Algal Feedstock Testbed project. At the conclusion of the project, the model should be able to predict algae concentration within +/- 0.2 OD over a 3 day period in the outdoor testbeds, assuming no die off due to microorganisms and optimal CO2 and fertilizer concentration.1c. Calibrate the algae growth models with algae growth data from Huesemann's experiments at Pacific Northwest National Lab.At the conclusion of the project, the model should be able to predict algae concentration within +/- 0.1 OD over a 3 day period in the indoor prototype raceways, assuming no die off due to microorganisms and optimal CO2 and fertilizer concentration.2a. Develop a model of CO2 sparging (introduction of gaseous CO2 into the raceway)2b. Develop a model of CO2 uptake and loss in the raceway2c. Calibrate the CO2 model with data from the outdoor testbed raceways and from Michael Huesemann's experiments at Pacific Northwest National Lab. The model should be able to design an efficient sparging unit and predict the instantaneous CO2 input rate (averaged over an hour) as a function of algal growth,water temperature, and mixing in the raceway at a given pH setpoint within +/- 10%.3a. Calibrate the fertilizer model with testbed data. Be able to predict fertilizer requirements and use within +/-10% over a 1 week period.4a. Allow testbed managers to use the model for 2 months4b. Respond to criticisms of testbed managers with model improvements.

Project Methods
The modeling calibrations are conducted with benchtop experiments, prototype indoor raceways, and outdoor testbeds. Models are written in VBA/Excel and Fluent computational fluid dynamics platforms.The Pacific Northwest National Laboratory (PNNL) model of temperature and algae growth (Wigmosta and Skaggs) and the University of Arizona model of algae growth are developed independently and cross-checked against each other and against experiments. This allows the team to find errors in the models. In addition, strengths in each modeling group can be passed to the other group. The PNNL group has many calibration sites for conventional algae raceway temperature prediction.Another strength of PNNL is Dr. Huesemann's extensive research on algae response to heat and light. Benchtop experiments are used to parameterize the growth coefficients over a range of heat and light. Then, indoor prototype raceways with temperature and light control are used to evaluate model predictions for different climates.The CO2-pH model is being developed in collaboration with Dr. Roberto Saez in chemical engineering. Then, the pH model will be transferred to the raceway. Parameters that must be considered are algae response to pH, algae response to carbon dioxide, sparging rate, Henry's Law and volatilization of carbon dioxide to the atmosphere, effect of turbulence on loss rate, other possible sources of carbon dioxide, cost of carbon dioxide in comparison to growth benefit, interactions with other nutrients, interaction with temperature, and several other parameters. Many of the models have already been developed for the wastewater treatment industry, and we will attempt to integrate those models. We will also add additional species to the growth model as growth data becomes available from PNNL.The ARID research team, which is currently led by Dr. Ogden, obtained an $8 million grant from DOE, which began in 2013. As part of this research effort, algae test beds in New Mexico (Las Cruces), West Texas (Pecos), and Arizona (Tucson) will grow several species of algae in the different locations. Research recording methods have been carefully established so that modelers, such as Dr. Waller, will have sufficient data to calibrate their models. ARID-HV and conventional raceways will be included as test beds. This will hopefully complete the circle and enable us to produce field ready models that can be used for management and evaluation.

Progress 10/01/14 to 09/30/19

Outputs
Target Audience:Our target audience is algae biofuel researchers and companies. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Three graduate students obtained PhD's under this project. How have the results been disseminated to communities of interest?We published the results in Algal Research Journal What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? We developed and refined the temperature and algae growth models for conventional and ARID raceways. We applied fundamental heat transfer equations and obtained a high level of correlation between the model results and the observed temperatures in raceways. An important factor was the development of a shading model of the raceway. This model was published. We did not add a CO2-pH model to the ARID raceway model because other collaborators were working on it. We added a nitrogen component to the algae growth model and published this model. It is based on the concept that algae takes up and stores nutrients from the water until they are needed. The algae growth models were compared to algae growth in several experiments and had a high correlation with algae biomass concentration during several harvesting cycles.

Publications

• Type: Journal Articles Status: Published Year Published: 2019 Citation: Attalah, S., Waller, P., Steichen, S., Gao, S., Brown, C. C., Ogden, K., & Brown, J. K. (2019). Application of deoxygenation-aeration cycling to control the predatory bacterium Vampirovibrio chlorellavorus in Chlorella sorokiniana cultures. ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS, 39.
• Type: Journal Articles Status: Published Year Published: 2019 Citation: Khawam, G., Waller, P., Gao, S., Edmundson, S., Wigmosta, M. S., & Ogden, K. (2019). Model of temperature, evaporation, and productivity in elevated experimental algae raceways and comparison with commercial raceways. ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS, 39.
• Type: Journal Articles Status: Published Year Published: 2019 Citation: Attalah, S., Waller, P., Steichen, S., Brown, C. C., Mehdipour, Y., Ogden, K., & Brown, J. K. (2019). Cost minimization of deoxygenation for control of Vampirovibrio chlorellavorus in Chlorella sorokiniana cultures. ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS, 42.
• Type: Journal Articles Status: Published Year Published: 2019 Citation: Khawam, G., Waller, P., Gao, S., Edmundson, S., Huesemann, M., Attalah, S., & Ogden, K. L. (2019). Simulation of shading and algal growth in experimental raceways. ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS, 41.

Progress 10/01/17 to 09/30/18

Outputs
Target Audience:The target audience of our research is the algae biofuel production research community Changes/Problems:Our project is no longer funded, but we are actively writing research papers. What opportunities for training and professional development has the project provided?Two PhD students were trained as algae modelers. How have the results been disseminated to communities of interest?We have submitted 6 publications to peer reviewed journals. One has been accepted, one is in press, one is being revised. What do you plan to do during the next reporting period to accomplish the goals?We plan to finish submitting and revising publications.

Impacts
What was accomplished under these goals? We added a fertilizer component to algae growth models. We developed an Excel/VBA program and Python program and organized data in Excel sheets for all of the Regional Algal Feedstock Testbed experiments. We evaluated algae growth models with data from the RAFT project.

Publications

• Type: Journal Articles Status: Published Year Published: 2018 Citation: Gao, Song, Peter Waller, George Khawam, Said Attalah, Michael Huesemann, and Kimberly Ogden. "Incorporation of salinity, nitrogen, and shading stress factors into the Huesemann Algae Biomass Growth model." Algal research 35 (2018): 462-470.

Progress 10/01/16 to 09/30/17

Outputs
Target Audience:Our target audience is the Department of Energy and other researchers in the algae/biofuels discipline Changes/Problems:We made a major shift to using python code in our models so that we could make the models accessible on the web. What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?We have submitted three papers to Algal Research. What do you plan to do during the next reporting period to accomplish the goals?We plan to continue to submit papers. We plan to continue to improve the algae website.

Impacts
What was accomplished under these goals? We refined the temperature and algae growth models this year. We calibrated them to outdoor experimental raceways. We added nutrient and shading algorithms.

Publications

• Type: Journal Articles Status: Published Year Published: 2017 Citation: Lammers, Peter J., Michael Huesemann, Wiebke Boeing, Daniel B. Anderson, Robert G. Arnold, Xuemei Bai, Manish Bhole et al. (Waller) "Review of the cultivation program within the National Alliance for Advanced Biofuels and Bioproducts." Algal research 22 (2017): 166-186.

Progress 10/01/15 to 09/30/16

Outputs
Target Audience:Our target audience is the Department of Energy and other researchers in the algal/biofuels discipline. Changes/Problems:There have been no major problems with our research. What opportunities for training and professional development has the project provided?We have trained three graduate students. One focused on translating bench scale laboratory experimental data into models of nutrient depletion and stress for outdoor raceways. One focused on temperature, evaporation, and shading models. One focused on developing control methods for algae predators. How have the results been disseminated to communities of interest?We made a presentationat the 2016 Algal Biomass, Biofuels, and BioproductsConference in San Diego in June 2016. S. Gao, P. Waller, K. Ogden, S. Attalah, M. Husesmann. Addition of salinity and shading to an algae growth model and evaluation in the ARID raceway What do you plan to do during the next reporting period to accomplish the goals?All of the graduate students are nearing completion, and we are writing several papers that summarize our work.

Impacts
What was accomplished under these goals? We have continued our refinement of the model temperature and evaporation algorithms. We have calibrated it against observed data in our paddlewheel raceways. We conducted extensive laboratory experiments on nitrogen and phosphorous requirements of three algae species: Chlorella sorokiniana, Monoraphidium, and Scenedesmus obliquus. Based on these laboratory experiments, we are developing nutrient availability models in order to adjust our growth model for nutrient limited conditions. We have been calibrating and evaluating our growth models with many of the Regional Algal Feedstock Testbed (RAFT) experiments. These include calculating fertilizer dosage rate requirements for outdoor raceways.

Publications

• Type: Book Chapters Status: Published Year Published: 2016 Citation: Huesemann, Michael, Mark Wigmosta, Braden Crowe, Peter Waller, Aaron Chavis, Samuel Hobbs, Scott Edmundson, Boris Chubukov, Vincent J. Tocco, and Andr� Coleman. "Estimating the maximum achievable productivity in outdoor ponds: Microalgae biomass growth modeling and climate-simulated culturing." In Microalgal Production for Biomass and High-Value Products, pp. 113-137. CRC Press, 2016.

Progress 10/01/14 to 09/30/15

Outputs
Target Audience:We published journal papers so the target audience was scientists and professionals in the algae to biofuels field. Changes/Problems:One of the problems was that the CO2/pH modeling project was abandoned by one student in order to concentrate on temperature and evaporation models; however, we are trying to incorporate that research into the other graduate student's work with other nutrients. What opportunities for training and professional development has the project provided?Graduate students have been trained in research and the development of algae computer models. How have the results been disseminated to communities of interest?We published 3 papers in peer-reviewed journals. What do you plan to do during the next reporting period to accomplish the goals?Graduate students are continuing to do research and work on papers in the areas of nutrient modeling, growth model, and algae culture temperature modeling.

Impacts
What was accomplished under these goals? We are working on papers concerning the algae growth model; however, these have not yet been submitted. We are also working on calibrating and adjusting the temperature models of the raceway. We are continuing to work within the DOE RAFT project to calibrate models of algae growth. We have not made progress on the CO2 models. We are doing nutrient experiments in order to calibrate the fertilizer models.

Publications

• Type: Journal Articles Status: Published Year Published: 2015 Citation: Attalah, S., Waller, P. M., Khawam, G., Ryan, R. D., & Huesemann, M. H. (2015). Energy Productivity of the High Velocity Algae Raceway Integrated Design (ARID-HV). Applied Engineering in Agriculture, 31(3), 365.
• Type: Journal Articles Status: Published Year Published: 2015 Citation: Xu, B., Li, P., Waller, P., & Huesemann, M. (2015). Evaluation of flow mixing in an ARID-HV algal raceway using statistics of temporal and spatial distribution of fluid particles. Algal Research, 9, 27-39.
• Type: Journal Articles Status: Published Year Published: 2015 Citation: Huesemann, M., Crowe, B., Waller, P., Chavis, A., Hobbs, S., Edmundson, S., & Wigmosta, M. (2016). A validated model to predict microalgae growth in outdoor pond cultures subjected to fluctuating light intensities and water temperatures. Algal Research, 13, 195-206.