Source: NORTH CAROLINA A&T STATE UNIV submitted to
A BIOREFINERY FOR THE PRODUCTION OF BIODIESEL AND ORGANIC FERTILIZERS FROM MICROALGAE GROWN ON SWINE WASTEWATER
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
OTHER GRANTS
Reporting Frequency
Annual
Accession No.
1000983
Grant No.
2013-38821-21141
Cumulative Award Amt.
$299,149.00
Proposal No.
2013-03635
Multistate No.
(N/A)
Project Start Date
Sep 1, 2013
Project End Date
Aug 31, 2017
Grant Year
2013
Program Code
[EQ]- Research Project
Recipient Organization
NORTH CAROLINA A&T STATE UNIV
1601 EAST MARKET STREET
GREENSBORO,NC 27411
Performing Department
Dept. of Chemical and Bioengineering
Non Technical Summary
This research project is to investigate a novel microalgae-based biorefinery for treating swine wastewater, and producing biodiesel and organic fertilizer from the microalgae. Swine wastewater will be used to grow microalgae under both photoautotropic and heterotropic conditions. A simultaneous saccharification and fermentation process will be tested to convert the algal carbohydrates into ethanol and enhance the release of algal oil. The ethanol under a supercritical condition will then be used for the simultaneous extraction and transesterification of the algal oil into biodiesel. A reactive screw extrusion process will be used to produce organic fertilizer from the solid protein-rich algal residue with enriched N and P. The synergy among the conversion of the carbohydrates, oil and protein in the microalgae into ethanol, biodiesel and organic fertilizer will minimize the use of energy, water and external chemicals by the biorefinery. Introduction of the algae-based biorefinery onto hog farms could improve the economies of those farms by reducing waste treatment costs and generating additional revenues from animal wastes. This would achieve waste reduction and create jobs in the field of biorefinery. The production of biofuels and organic fertilizer has the potential to reduce the dependency of the U.S. on imported petroleum for producing fuels and chemical fertilizers, as well as the potential to diversify energy sources, and displace fossil-based fuels and fertilizers to reduce greenhouse gas emissions. This project will significantly strengthen the increasing research capacity of NC A&T and provide research opportunities to underrepresented students in bioenergy, biorefinery and wastewater treatment technologies.
Animal Health Component
30%
Research Effort Categories
Basic
60%
Applied
30%
Developmental
10%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
51121502020100%
Knowledge Area
511 - New and Improved Non-Food Products and Processes;

Subject Of Investigation
2150 - Aquatic plants;

Field Of Science
2020 - Engineering;
Goals / Objectives
This research project is to investigate a novel microalgae-based biorefinery for treating swine wastewater, and producing biodiesel and organic fertilizer from the microalgae. We intend to reach our goal for the development of a microalgae-based biorefinery by addressing the following objectives: Objective 1: Screen microalgal strains and optimize the growth environment for the cultivation of selected microalgae on swine wastewater; Objective 2: Develop an efficient photoreactor for the outdoor growth of microalgae identified in Objective 1 on swine wastewater year around; Objective 3: Test a novel integrated process to produce biodiesel from wet microalgae using the ethanol produced from the carbohydrates in the microalgae; Objective 4: Investigate reactive screw extrusion technology for transforming microalgal residue into organic fertilizers; and Objective 5: Conduct life cycle assessment of the microalgae-based biorefinery.
Project Methods
The following five studies will be conducted to achieve the above five objectives. Study 1. Screen microalgal strains and optimize growth environment for culturing selected microalgae on swine wastewater. Local microagal strains that can grow fast on swine wastewater year around will be identified to supply oil for the production of biodiesels and to enrich the N and P in the algal biomass for the production of organic fertilizer. A selection protocol will be developed to isolate wild microalgal cells presented in wetland ponds and local lakes. This protocol will take into account the following factors: (1) growth rate; (2) lipid quantity and quality, (3) response to temperature, nutrient input and light, and (4) the requirement and uptake rate of nutrients, particularly organic carbon such as sugars and inorganic carbon from CO2. Several microalgal strains will be selected and cultured under photoautotropic, heterotropic or mixotrophic conditions individually and in a consortium way to determine their potential to assimilate organic and inorganic carbons in swine wastewater.High throughput screening will be performed to identify algal strains with high lipid content using flow cytometry. Identification of the isolated strain will be performed using morphological properties and genomic sequence. Experiments will be conducted to optimize the growth of the selected microalgal strains on swine wastewater for the treatment of swine wastewater and production of algal biomass.Thealgal biomass will be characterized to determine its potential as feedstock for the production of biodiesel and organic fertilizer. Study 2. Develop an efficient photoreactor for the outdoor growth of microalgae identified by Study 1 on swine wastewater year around. Photobioreactors which are more efficient and better in controlling growth environment, and minimizing contamination and water loss than open ponds are more suitable to grow microalgae on swine wastewater year around. Our existing 100 L photobioreactorwill be modified for outdoor growth of microalgae in a continuous mode. Three methods will be used to improve the efficiency and economics of the growth of microalgae on swine wastewater in a photobioreactor: (1) hybrid growth of photoautotropic and heterotropic microalgae, (2) two-stage cultivation, and (3) controlled light cycle. Experiments will be conducted to optimize the design and operating parameters of the photobioreactor that affect the rate of biomass production, the chemical composition of algae and the removal efficiency of the nutrients in the swine wastewater. Study 3. Test a novel integrated process to produce biodiesel from wet microalgae using the ethanol produced from the carbohydrates in the microalgae. A simultaneous saccharification and fermentation (SSF) process will be used to enhance the release of oil from wet microalgae and produce ethanol for the extraction and transesterification of algal oil.A fractional factorial experimental designwill be used to investigate the responses of ethanol yield, final ethanol concentration and fermentation rate toprocess factors during SSF of wet microalage. A novel simultaneous extraction and transesterification (SET) process will be investigated to convert the oil in the pretreated microalgal slurry using the ethanol produced during the SSF under subcritical/supercritical conditions.The effect of operating conditions on the decomposition of protein and residual carbohydrates and nitrogen content in the biodiesel will be analyzed.The extract will be separated into the biodiesel phase and aqueous phase. The aqueous phase which is rich in nutrients of nitrogen and other elements such as Ca, Mg and K will be recycled for microalgae cultivation. The contents of fatty acid ethyl esters, ethanol, glycerol residual oil in both biodiesel and aqueous phases will be analyzed using a GC-MS. A light microscope will be used to detect the changes to algal cells caused by SET.The solid algal residue will be used for the production of organic fertilizers. Study 4. Investigate reactive screw extrusion technology for transforming algal residue into organic fertilizers. Thermal gravimetric analysis (TGA) will be conducted to analyze the thermal degradation characteristics of proteins, organic P and residual carbohydrates in algal residue. The evolutionary gases from the TGA will be analyzed by a MS.The effect of water in the microalgae and purging gas including CO2, air and N2 on the hydrolysis of C-N peptide bonds, decarboxylation and deamination will be analyzed.A reactive screw extrusion process will be developed to (1) partially carbonize the biomass into a biochar form, (2) enrich N and P contents by torrefying the biomass and releasing volatiles, and (3) make a dry fertilizer as appropriately sized particles.Experiments will be conducted to analyze the effects of extrusion conditionsand microalgae characteristicson the physical and chemical properties of the fertilizer pellets, and air emission of the extrusion process.The release characteristics and kinetics of the organic fertilizers will be measured by mixing a given fertilizers with soil under controlled condition for six months.For comparison, chemical fertilizers will also be tested at the same condition. Samples will be taken at weekly intervals to determine the acidity, mechanical strength and N and P contents. Regression models will be developed to quantify the changes of the chemical and physical properties of the fertilizer pellets as functions of the extrusion and soil conditions. Air emission samples will be taken from the testing chamber. The emissions from the fertilizers will be analyzed on a gas chromatograph. Study 5. Economic analysis and life cycle assessment of the microalgae-based biorefinery. Life cycle assessment (LCA)is an emerging tool to quantify the environmental impacts of human activities. The impact indicators used in the LCA may include global warming potential, acidification, eutrophication, photochemical oxidation and energy use. A process model based on ASPEN Plus will be developed to generate the inventory data for emissions. The process model will be used to track the C, N and P flows through the whole biofinery system. The inputs of C, N and P in swine wastewater and the outputs of C, N and P in final biodiesel and fertilizers will be measured. The nutrient loss or emissions such as N2O from the growth and processing of algae for biofuels and fertilizer s will be measured and analyzed. LCA will then be used to identify and quantify the potential environmental impacts of the microalgae-based biorefinery. An economic model will be developed to determine the cost of the microalgae biorefinery at different scales. The capital costs will be determined by the components of the system, their basic costs and the life of the system. The operating costs will be determined by the consumption of thermal energy and electricity, the labor and the maintenance costs. The data of environmental impacts of microalgae-based biodiesel and fertilizer will be available through this research, which will be compared to those of petroleum-based fuels and fertilizers. A small-scale demonstration unit will be constructed at NC A&T farm to introduce the technology to hog farmers as a possible means for improving their operations by reducing waste treatment costs and generating additional revenues the wastes.The technology developed by this project will be patented and disseminated by our technology transfer office, which will assist us in communicating our findings to industry stakeholders. The results obtained from the experiments in this study will be disseminated to researchers at the annual meetings of relevant professional organizations. The results will also be presented at NC A&T's annual Small Farm Conference to help small farmers learn about new business opportunities in producing bioenergy and bio-based products from animal wastes.

Progress 09/01/13 to 08/31/17

Outputs
Target Audience:1. During this report period, this project was used to support three graduate students including two from interdisciplinary Ph.D. program of energy and environmental systems and one from M.S. program in agricultural and environmental systems to conduct their dissertation/thesis research. The three graduate students were educated through formal classroom instruction, and practicum experiences with the financial support provided by this project. 2. We provided training and research opportunity to one undergraduate student in biological engineering, who was hired to work on algal cultivation, characterization and wastewater analysis for this project. The project was also used to support a senior capstone design project for undergraduate students in biological engineering. 3. This project was used to support PI (Lijun Wang), Co-PI (Bo Zhang) and one Ph.D. student (Quazi Rahman) to attend three professional conferences (the USDA-NIFA 1890 Institution Teaching Research and Extension Capacity Building Grants Program Project Director Meeting, Virginia Beach, VA, Sept. 19-20, 2016; the ARD Research Symposium 2017, April 1-4, 2017 Atlanta, GA; and the 2017 ASABE annual meeting in July 16-19, 2017 Spokane, Washington). They presented the research results generated by this project at these three conferences. 4. Through this project, we established contacts with several other universities and companies for collaborations on algal cultivation and processing. 5. We demonstrated the technology of algal cultivation for wastewater treatment and biofuel production to a large number of K-12 students on the Energy Day of NC A&T State University on March 21st of 2017, and small farm owners on the 16th Farmer Field Day of NC A&T State University on June 15 of 2017. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? (1) This grant was used to support two Ph.D. and one M.S. students to conduct their dissertation /thesis research (Quazi M. Rahman, Ph.D. student in energy and environmental systems (EES), dissertation topic: A novel biorefinery for the production of biodiesel and organic fertilizers from wet microalgae, estimated duration: August 2014-May 2018; Emmanuel Ansah Ph.D. student in EES, dissertation topic: Experimental study and process modeling of pyrolysis of biomass to chemicals and biofuels, graduation: December 2017; andDominic Bekoe Dominic, M.S. student in Agricultural and Environmental Systems, thesis topic: Aerobic and anaerobic treatment of swine manure for the enhancement of algal cultivation, graduation: May 2017). (2) During this report period, this grant was used to support one undergraduate student (Karina Lei Relatado) in biological engineering program at NCAT to obtain research experience and one senior capstone design project for a group of senior undergraduate students in biological engineering program at NCAT. (3) This grant provided travel funds to PI (Lijun Wang), Co-PI (Bo Zhang) and Ph.D. student (Quazi M. Rahman) to present their research results at three professional conferences. How have the results been disseminated to communities of interest?During this report period, the PI, Co-PIs and graduate students who worked on this project developed four manuscripts including three published/accepted and one under review based on the research results from this project. We gave four presentations at three professional conferences. We demonstrated the technology of algal cultivation for wastewater treatment and biofuel production to a large number of K-12 students on the Energy Day of NC A&T State University on March 21st of 2017, and small farm owners on the 16th Farmer Field Day of NC A&T State University on June 15 of 2017. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? During this report period, we have generated scientific information for a microalgae-based refinery to produce drop-in fuels and organic fertilizers, and an enhanced outdoor microalgae cultivation system coupled with aerobic treatment and anaerobic digestion of agricultural wastes. Accomplishment 1. A novel biorefinery for producing biodiesel and organic fertilizers from wet microalgae. We investigated different pretreatment methods of wet algae to enhance ethanol yield during fermentation; evaluated simultaneous extraction and transesterification (SET) in various supercritical ethanol conditions; modified, characterized and used solid residue derived from SET process for ammonia-nitrogen capture and biochar-based catalyst; and conducted process modeling of the algae-based biorefinery for the co-production of biodiesel and organic fertilizer. The research highlights include: Microalgae was pretreated with dilute sulfuric acid under various conditions and subsequently fermented with yeast Saccharomyces cerevisiae; The highest ethanol yield was 83% of the theoretical value that was obtained at 4% (wt./vol.) microalgal biomass concentration at 32oC after 48 h fermentation; Fermented microalgae were simultaneously extracted and transesterified with a 15% ethanol solution, resulting in an 80% conversion; Application of the biochar based catalyst successfully upgraded the algal extracts to hydrocarbons, and produced ammonia fertilizer from N-containing organic compounds; and Biochar was used as an absorber to filter processing and agricultural wastewater to enrich the nutrient onto biochar, which was further pelletized to form organic fertilizers. Accomplishment 2. An enhanced outdoor microalgae cultivation process integrated with aerobic treatment and anaerobic digestion of wastes. This research was to develop an efficient process to treat swine manure for the enhancement of anaerobic digestion (AD) and microalgal cultivation in a wastes-based biorefinery context. The potential advantages of this integrated process include: The exothermic aerobic treatment process can be used to adjust the temperature of the subsequent AD process; aerobic treatment removes chemicals that are toxic to AD; and nutrient enriched gas is used for algal cultivation and agitation. The experimental results were used to establish a demonstration unit. The research highlights include: A 14-day aerobic treatment reduced the total solid content of swine manure by 15-24%, and changed the manure composition; Ammonia and carbon dioxide were stripped by the air supplied, and the off-gas was further used to aerate the culture of Chlorella vulgaris; The microalgal growth rates in Bristol medium and the wastewater with the off-gas increased from 0.08 to 0.22 g/L/d and from 0.15 to 0.24 g/L/d, respectively; The aerobically treated swine manure showed a higher methane yield than untreated manure; An integrated growth kinetic, light transfer and computational dynamic model was used to develop design and operational strategies to increase the algal productivity in open raceway ponds; and The experimental data was used to establish the outdoor demonstration unit consisting of a 100 L composter, a 200 L anaerobic digester, a 60 L tubular photobioreactor, and a 300 L micro-open raceway pond.

Publications

  • Type: Theses/Dissertations Status: Published Year Published: 2017 Citation: Dominic Bekoe, Aerobic and anaerobic treatment of swine manure for the enhancement of algal cultivation, M.S. thesis in Agricultural and Environmental Systems, North Carolina A&T State University, May 2017.
  • Type: Theses/Dissertations Status: Published Year Published: 2017 Citation: Emmanuel Ansah, Experimental study and process modeling of pyrolysis of biomass to chemicals and biofuels, Ph.D. dissertation in Energy and environmental systems, North Carolina A&T State University, December 2017.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Zhang, B., Wang, L., Li, R., Rahman, Q. M., and Shahbazi, A. 2017. Catalytic Conversion of Chlamydomonas to Hydrocarbons via the Ethanol-Assisted Liquefaction and Hydrotreating Processes. Energy & Fuels. 31(11):12223-12231, DOI: 10.1021/acs.energyfuels.7b02080.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Bekoe, D., Wang, L., Zhang, B., Todd, M.S., and Shahbazi, A. 2017. Aerobic treatment of swine manure to enhance anaerobic digestion and microalgal cultivation. Journal of Environmental Science and Health, Part B. http://dx.doi.org/10.1080/03601234.2017.1397454.
  • Type: Journal Articles Status: Accepted Year Published: 2017 Citation: Amini, H., Wang, L.J., Shahbazi, A., Bikdash, M., KC, D. and Yuan, W. 2017. An integrated growth kinetics and computational fluid dynamics model for the analysis of algal productivity in open raceway ponds. Computer and Electronics in Agriculture (in press).
  • Type: Journal Articles Status: Submitted Year Published: 2017 Citation: Ansah, E., Wang, L.J., Zhang, B., Eshun, J., Rahman, Q., Shahbazi, A. and Schimmel, K. 2017. Catalytic pyrolysis of raw and hydrothermally carbonized Chlamydomonas debaryana Microalgae for denitrogenation and production of aromatic hydrocarbons. Fuel (under review).
  • Type: Book Chapters Status: Awaiting Publication Year Published: 2017 Citation: Joseph, G. and Wang, L.J. 2017. Chapter 12 Production of biofuels from biomass by fungal whole-cell biocatalysts, In: Kumar, S., Dheeran, P., Taherzadeh, M. and Khanal S. (eds), Fungal Biorefineries. Cham, Switzerland: Springer International Publishing AG.
  • Type: Book Chapters Status: Awaiting Publication Year Published: 2017 Citation: Wang, L.J., Zhang, B., Joseph, G. 2017. Chapter 13 Biogas production and quality control. In Bioenergy and biofuels. CRC Press. (in press)
  • Type: Book Chapters Status: Awaiting Publication Year Published: 2017 Citation: Zhang, B., Wang, L., Li, R. 2017. Chapter 10 Bioconversion and chemical conversion of biogas for fuel production. In Handbook of Biotechnology for Renewable Fuels: Technology Assessments, Emerging Industrial Applications, and Future Outlooks, Elsevier. (in press)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Rahman, Q. and Wang, L.J. 2017. A novel biorefinery approach for producing biofuel from fermented microalgae. ASABE Annual International Meeting, Spokane, Washington, July 16-19.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Zhang, B., Wang, L.J., Bekoe, D., and Shahbazi, A. 2017. Thermophilic anaerobic co-digestion of swine manure with agricultural residues and energy crops. The 18th Research Symposium of the Association of 1890 Research Directors, Inc. (ARD), Atlanta, GA, April 1-4.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Wang, L.J., Zhang, B., and Shahbazi, A. 2016. A biorefinery for the production of biodiesel and organic fertilizer from microalgae grown on swine wastewater. The USDA-NIFA 1890 Institution Teaching Research and Extension Capacity Building Grants Program Project Director Meeting, Virginia Beach, VA, Sept. 19-20.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Zhang, B., Wang, L.J., Bekoe, D. and Li, R. 2017. Biogas production by thermophilic anaerobic co-digestion and its dry reforming. ASABE Annual International Meeting, Spokane, Washington, July 16-19.


Progress 09/01/15 to 08/31/16

Outputs
Target Audience: This project has been used to support two graduate students including one from interdisciplinary Ph.D. program of energy and environmental systems and one from interdisciplinary Ph.D. program in computational science and engineering to conduct their dissertation research. The two graduate students were educated through formal classroom instruction, and practicum experiences with the financial support provided by this project. They also presented their research to a large audience of students through their department seminar. Research faculty have provided training and research opportunity to one undergraduate students in biological engineering, who were hired to work on algal cultivation, characterization and wastewater analysis for this project. The project was also used to support a senior capstone design project ofutilizing algae for the treatment of wastewater for undergraduate students in biological engineering. This project was used to support PI (Lijun Wang) and Co-PI (Bo Zhang) to attend two professional conferences (the 2016 ASABE annual meeting in Orlando, FL, July 17-20; and the 2016 USDA-NIFA 1890 Institution Teaching Research and Extension Capacity Building Grants Program Project Director Meeting, Virginia Beach, VA, Sept. 19-20). They presented the research results generated by this project to abroad group of audienceat these two conferences. Through this project, we established contacts with several other universities and companies for collaborations on algal cultivation and processing. Research faculty demonstrated the technology of algal cultivation for wastewater treatment and biofuel production to a large number of K-12 students on the Energy Day of NC A&T State University on the April 6th of 2016. Changes/Problems:Research faculty initially proprosed to use a reactive screw extrusion technology for transforming microalgal residue into organic fertilizers. However, it is very difficult to prepare a large amount of algal residue for the experiments on reactive screw extrusion using an available scrw extruderon campus.Researchersdecided toconductthe reactive thermochemical conversion of algal resiude inot organic fertilizers in a smallcontinuous stirred tank reactor instead of a screw extruder reactor. What opportunities for training and professional development has the project provided?(1) This grant was used to support two Ph.D. students (Quazi M. Rahman, Ph.D. student in energy and environmental systems, dissertation topic: A novel biorefinery for the production of biodiesel and organic fertilizers from wet microalgae, estimated duration: August 2014-July 2017; Hossein Amini, Ph.D. student in computational science and engineering, dissertation topic: Numerical and experimental investigation of a microalgae cultivation system for wastewater treatment and bioenergy production, graduation date: July 2016). (2) During this report period, this grant was used to support one undergraduate student in biological engineering program at NCAT to obtain research experience and one senior capstone design project for a group of senior undergraduate students in biological engineering program at NCAT. (4) This grant provided travel funds to PI (Lijun Wang) and Co-PI (Bo Zhang) to present their research results at two professional conferences. How have the results been disseminated to communities of interest?During this report period, the PI, Co-PIs and graduate students who worked on this project developed six manuscripts including four published and two under review based on the research results from this project. We gave two presentations at two professional conferences. Research faculty also demonstrated the technology of algal cultivation for wastewater treatment and biofuel production to a large number of K-12 students on the Energy Day of NC A&T State University on the April 6th of 2016. What do you plan to do during the next reporting period to accomplish the goals?There will be five major research activities including: Further develop the thermochemical carbonization process to convert algal biomass into activated carbon, biodiesel, and value-added chemicals Improve and optimize the fermentation of wet algae into bioethanol to enhance the oil extraction Develop novel catalysts for producing and upgrading of algae-based biofuels Conduct economic analysis and life cycle assessment of the microalgae-based biorefinery with up-to-date information The second Ph.D. student who is working on a novel microalgae-biorefinery for this project will complete her dissertations Researcherswill develop at least 3 manuscripts and give at least 2 presentations at professional conferences during the next reporting period.

Impacts
What was accomplished under these goals? During this report period,researchers have generated scientific information for microalgae cultivation on swine wastewater and microalgae refinery. 1. Numerical and experimental investigation of a microalgae cultivation system for wastewater treatment and bioenergy production.Researchers first analyzed the effects of harvesting cell density, medium depth and environmental factors on biomass and lipid productivities of Chlorella vulgaris grown in swine wastewater. The research highlights include: Optimum condition forC. vulgariswas 24oC, 230mEm-2s-1light intensity and pH 7.4 C. vulgarisyields 0.160 g/day in 1 L swine wastewater with 102 mg N and 76 mg P C. vulgarisyields 0.191 g/day in 1 L Bold's medium with 100 mg N and 53 mg P Medium depth and cell density significantly in ORPs affect the algal productivity Research faculty then conducted numerical and experimental investigation of hydrodynamics and light transfer in open raceway ponds at various algal cell concentrations and medium depths. The research highlights include: Hydrodynamics and light transfer in ORP were numerically and experimentally studied Increasing paddlewheel velocity to 0.2 m/s significantly reduces cell sedimentation Cell sedimentation likely occurs in ORPs of 0.2 m rather than 0.3 m medium depth Increasing paddlewheel velocity only increases light uniformity near medium surface Light intensity sharply drops with several cm from the medium surface Researchersfinally developed an integrated mathematical model for simulating algal growth in open raceway ponds. The research highlights include: Predicted and measured light profiles in ORP with various cell densities well agreed Predicted and measured algal productivities in ORP with various depths well agreed Harvesting algae at targeting concentration or time can increase ORP's productivity Algal productivity in ORPs decreased with the increase of harvesting cell density 2. A novel biorefinery for production of biodiesel and organic fertilizers from wet microalgae. We investigated different pretreatment methods of wet algae to enhance ethanol yield during fermentation; evaluated simultaneous extraction and transesterification (SET) in various supercritical ethanol conditions; modified, characterized and used solid residue derived from SET process for ammonia-nitrogen capture and biochar-based catalyst; and conducted process modeling of the algae-based biorefinery for production of biodiesel and organic fertilizer. The research highlights include: Algal fatty acids were extracted with a 90% ethanol-water solution. Algal fatty acids could be transesterified by heating them above 200oC with alcohol. Application of the biochar based catalyst successfully upgraded the algal extracts to hydrocarbons. At the algal growth rate of 25 g/m2/day in the swine wastewater with 22 mg/L NH3, 80 mg/L NO3 and 76 mg/L PO4, the microalgae-based biorefinery on one hectare land can treat 601 m3 wastewater, and produce 95.5 kg biodiesel, 571 m3 clean water, and 106 kg fertilizer (including 45 kg biochar, 18.8 kg NH3, 35.7 kg PO4, 6.7 kg glycerin) each day. The reduction of the energy used for the biodiesel production and the increase of the algal growth rate can reduce the amount of global warming gas emissions. One Ph.D. dissertation and three paper have been completed within this period, and two manuscripts based on the above research results are under review. Research faculty also filed one intellectual property disclosure based on the research from this project.

Publications

  • Type: Theses/Dissertations Status: Published Year Published: 2016 Citation: Hossein Amini, Numerical and experimental investigation of a microalgae cultivation system for wastewater treatment and bioenergy production, North Carolina Agricultural and Technical State University, July 2016.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Amini, H., Wang, L.J., Shahbazi, A., Bikdash, M., KC, D., Yuan, W. and Hashemisohi, A. 2016. Numerical and experimental investigation of the hydrodynamics and light transfer in open raceway ponds with different algal cell concentrations and medium depths. Chemical Engineering Science 156: 11-23.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Amini, H., Wang, L.J., and Shahbazi, A. 2016. Effects of harvesting cell density, medium depth and environmental factors on biomass and lipid productivities of Chlorella vulgaris in swine wastewater. Chemical Engineering Science 152: 403-412.
  • Type: Journal Articles Status: Submitted Year Published: 2016 Citation: Amini, H., Wang, L.J., Shahbazi, A., Bikdash, M., KC, D. and Yuan, W. 2016. Mathematical Modeling and Experimental Validation of Microalgal Cultivation in Open Raceway Ponds. Chemical Engineering Science (under review)
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Zhang, B., Wang, L.J., Riddicka, B., Li, R., Able, J. and Shahbazi, A. 2016. Sustainable production of algal biomass and biofuels using swine wastewater in North Carolina, US. Sustainability 8(5):477-488.
  • Type: Journal Articles Status: Under Review Year Published: 2016 Citation: 5. Rahman, Q.M., Wang, L.J., Zhang, B., and Shahbazi, A. 2016. Effect of pretreatment and simultaneous saccharification and fermentation on conversion of wet algae to crude biodiesel under supercritical ethanol condition (under internal review).
  • Type: Journal Articles Status: Under Review Year Published: 2016 Citation: Zhang, B., Wang, LJ., Li, R., and Shahbazi, A. 2016. Conversion of microalgal biomass to green diesel via the simultaneous extraction- transesterification and hydrotreating processes (under internal review).
  • Type: Book Chapters Status: Published Year Published: 2016 Citation: Zhang, B., Wang, L.J., Li, R. 2016. Chapter 2, Production of Biogas from Aquatic Plants in Aquatic Biomass: Progress and Perspectives, in Aquatic Plants: Composition, Nutrient Concentration and Environmental Impact. Nova Science Publishers, pp. 33-46.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Wang, L.J., Zhang, B., and Shahbazi, A. 2016. A biorefinery for the production of biodiesel and organic fertilizer from microalgae grown on swine wastewater. The USDA-NIFA 1890 Institution Teaching Research and Extension Capacity Building Grants Program Project Director Meeting, Virginia Beach, VA, Sept. 19-20.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Zhang, B., Wang, L.J., Li, R. and Shahbazi, A. 2016. Conversion of microalgal biomass to green diesel via the simultaneous extraction-transesterification and hydrotreating processes. The ASABE Annual Meeting, Orlando, FL, July 17-20.


Progress 09/01/14 to 08/31/15

Outputs
Target Audience:1. This project has been used to support two graduate students including one from interdisciplinary Ph.D. program of energy and environmental systems and one from interdisciplinary Ph.D. program in computational science and engineering to conduct their dissertation research. The two graduate students were educated through formal classroom instruction, and practicum experiences with the financial support provided by this project. 2. We have provided training and research opportunities to three undergraduate students in biological engineering, who were hired to work on algal cultivation, characterization and wastewater analysis for this project. 3. This project was used to support PI (Lijun Wang), Co-PI (Bo Zhang) and one Ph.D. student to attend three professional conferences (the 5th International Conference of Algal Biomass, Biofuels and Bioproducts, San Diego, CA, June 7-10, 2015; the 2015 ASABE annual meeting in New Orleans, LA, July, 26-29; and the 2014 AIChE annual meeting in Atlanta, GA, November, 16-21). Wepresented the research results generated by this project at these three conferences. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?(1) This grant was used to support two Ph.D. students (Quazi M. Rahman, Ph.D. student in energy and environmental systems, dissertation topic: A novel biorefinery for the production of biodiesel and organic fertilizers from wet microalgae, estimated duration: August 2014-December 2016; Hossein Amini, Ph.D. student in computational science and engineering, dissertation topic: Computer-aided design and analysis of a microalgae-based biorefinery for wastewater treatment and bioenergy production, expected graduation date: July 2016). (2) This grant was used to support three undergraduate students in biological engineering program at NCAT to obtain research experience (Jacqueline Batts, microalgae processing; Justin Able, microalgal cultivation; Bilal Riddick, wastewater analysis). (3) This grant was also used to support one postdoc (Dr. Hui Wang, research topic: LCA of microalgae-based biorefinery) and one research engineer (Dr. Bo Zhang, research topic: microalgae cultivation and processing). (4) This grant provided travel funds to PI (Lijun Wang), Co-PI (Bo Zhang) and Ph.D. student (Hossein Amini) to present their research results at the 2015 ASABE annual meeting, the 5th International Coference on Algal Biomass, Biofuels and Bioproducts and the 2014 AIChE annual meeting. How have the results been disseminated to communities of interest?During this report period, the PI, Co-PIs and graduate students who worked on this project published developed five manuscripts including two published and three under review and gave three presentations based on the research results from this project at three different professional conferences. What do you plan to do during the next reporting period to accomplish the goals? Improve and optimize the fermentation of wet algae into bioethanol to enhance the oil extraction Further develop the thermochemical carbonization process to convert fermented algal biomass into activated carbon, biodiesel, and value-added chemicals Develop novel catalysts for producing and upgrading of algae-based biofuels Improve the CFD mathematical model and analyze the algal productivity in open raceway ponds with different design and operating parameters using the model Conduct economic analysis and life cycle assessment of the microalgae-based biorefinery with up-to-date information Two Ph.D. students who are working on this project will complete their dissertations We will develop at least 5 manuscripts and one intellectual property based on the research from this project. We will give at least 3 presentations at professional conferences.

Impacts
What was accomplished under these goals? During this report period, we have generated scientific information for screening local algal strains grown on swine wastewater and improving the algal growth in swine wastewater through nutrient enrichment and optimization of growth conditions. We developed a validated mathematical model to improve the design and operation of open raceway ponds for the massive production of algae on swine wastewater. We developed a new biological process to convert wet microalgae into biofuels and organic fertilizer. The whole project provided an innovative and sustainable approach to recover the nutrient, water and energy in swine wastewater and make three major products of biofuels, organic fertilizer and clean water. This project also provided training opportunities and financial support to two Ph.D. students and three undergraduate students to conduct research on algal cultivation and processing. This project also enhance our research and educational capacity in the bioenergy and waste-to-energy fields. Screening local microalgae strains: A green microalga, C. debaryana, was isolated from a local wastewater lagoon, screened for its lipid content, and further identified with DNA sequence analysis. C. debaryana was able to utilize 1.3-1.6 g COD, 55 to 90 ppm N, and 48 to 89 ppm P/g biomass. The lipid content of the algae, in which 14 different C5-C22 fatty acids were identified, was 19.9 % of cell dry weight. C. debaryana was grown in swine wastewater under various environmental conditions, and the obtained information was used to evaluate the potential of algal biomass and biofuels production in North Carolina. Our research showed that a) Growing C. debaryana in a 10-acre pond on swine wastewater under local weather conditions would yield algal biomass of 113 ton/y; b) If all swine wastewater generated in North Carolina was treated with algae, it'll require 137-485 acres of ponds, yielding biomass of 5,048-10,468 ton/y and algal oil of 1,010-2,094 ton/y. Enhancement of algal growth through nutrient enrichment: The off-gas from the manure aerobic treatment that was rich in CO2, N and P was used to grow C. debaryana. The final algal biomass yield reached 3 g/L within 20 days, compared to 0.6-1.5 g/L for the typical biomass yield of this species in swine wastewater. We also investigated the possibility of integrating the algal cultivation with the woody biomass gasification. Our results showed that the ash from pine gasification was a valuable nutrient source with abundant minerals (15-25 wt % C, ~21% minerals and 52-63 wt % O) to enhance the growth of C. debaryana. We used another nutrient source of green juice that was a by-product the green biorefinery of fresh cattail to enhance the growth of Chlorella spp. The highest growth rate was observed in 10% juice medium, resulting in a similar OD value as the proteose medium. Optimum growth conditions: The optimum environmental condition for growing C. vulgaris was experimentally determined at light intensity of 240 μEm-2 s-1, 24°C and pH of 7.4. At the optimum environmental condition, the growth rate of C. vulgaris on swine wastewater with 102 mg N/l and 76 mg P/l was 0.160 g/l/day, compared to 0.191 g/L/day for its growth on a modified Bold's medium with 100 mg N/l and 53 mg P/l. A regression model was developed to estimate the biomass productivity of C. vulgaris grown on the swine wastewater in an open raceway pond with different medium depths and harvesting cell densities under the weather condition in North Carolina yearly around. At 20 cm medium depth, the highest growth rate was 0.162 g/l/day, which was obtained at 0.1 g/l harvesting cell density, 24oC and 1,350 μEm-2 s-1 solar irradiance in August. If the medium depth increased to 30 cm, the highest growth rate at 0.1 g/l harvesting cell density was 0.156 g/l/day, which was obtained at 23oC and 1,500 μEm-2 s-1 in June. If the harvesting cell density increased to 0.4 g/l, the highest growth rate decreased significantly to 0.033 and 0.02 g/l/day for 20 cm and 30 cm medium depths, respectively. At 0.1g/l harvesting cell density, the yearly algal productivity was 85 and 64 ton/hectare at 30 cm and 20 cm medium depths. Mathematical model: A 3-D CFD model was developed to improve the design and operation of open raceway ponds (ORP). Experiments were carried out on a lab-scale ORP with 140 L culture medium to validate the CFD model. The predicted velocity and light intensity distribution well agreed with the experimental values. At a paddlewheel rotational speed of 10 rpm and water depth of 0.2 m, the CFD simulations indicated that the minimum mixing time for the lab-scale ORP was 10 s. The maximum velocity in the ORP channels increased from the bottom to the top surface of the culture medium. The maximum velocity at the top surface was 0.81 m/s, compared to 0.47 m/s at the depth of 0.05 m. Therefore, microalgae cells in an OPR experience a large variation of resident time and light exposure for each circulation loop in the ORP channels, which will result in different specific growth rates. There was a significant decrease in light intensity with the initial several centimeters from the medium surface. With a light intensity of 100 μEm-2 s-1 on the surface of the medium, the increase of the harvesting cell density from 0.1 to 0.4 g/L resulted the bottom light intensity to decrease down from 21 to 7 μEm-2 s-1 in an ORP with a culture medium at 20 cm depth. Processing of wet algae into biofuels and organic fertilizer: Pretreatment and fermentation of wet microalgae were conducted to enhance the oil extraction. The algae biomass was collected and washed with DI water prior to pretreatment. The biomass was autoclaved at 121oC for 15, 30 and 45 min. The highest ethanol yield at 63% of theoretical value was obtained from the algal biomass autoclaved for 45 min and subsequently fermented at 37°C with 1g/L yeast loading, with 15 FPU cellulase/g glucan and with 5% (w/v) biomass concentration. Protein content of algae was increased by 10-30% after fermentation. The extracted residue will be analyzed for organic fertilizer production. A novel simultaneous extraction and transesterification (SET) process is being investigated to convert the oil in the fermented microalgal biomass under subcritical/supercritical conditions. The extracted residue will be analyzed for organic fertilizer production. A catalytic thermochemical process was further developed to simultaneously extract algal oil from fermentation residues, and convert the oil into biodiesel. An acidic catalyst (SO42-/support) was selected to compare the transesterification efficiency of the process with and without supplying catalysts. The thermochemical liquefaction process was operated at 200-290°C, and the formation of algal oil ethyl esters (algae-based biodiesel) was confirmed using GC/MS analysis. Life Cycle Assessment (LCA) of the Microalgae Biorefinery: LCA was performed to investigate the environmental impact of a microalgae-based refinery for treating swine wastewater and producing biofuels and organic fertilizers. The biorefinery can produce 95.5 kg biodiesel, 571 m3 clean water and 106 kg organic fertilizer (including 45 kg activated biochar, 18.8 kg NH3, 35.7 kg PO4, 6.7 kg glycerin) from the microalgae cultivated in 1 ha raceway pond at a growth rate of 25 g/m2/day using 601 m3 swine wastewater with 22 mg/L NH3, 80 mg/L NO3 and 76 mg/L PO4 each day. The LCA results showed that the total amount of nonrenewable energy input of the biorefinery was 19, 090 MJ/day and the total global warming potential (GWP) of the biorefinery was 841.5 kg CO2 equivalent. The production of the biodiesel using supercritical ethanol/subcritical water at 280oC and 6.4 MPa was the main energy user (31%) and contributor of GWP (47%). The sensitivity analysis indicated that microalgae growth rate and electricity usage for biodiesel production were key factors for the reduction of GHG emissions.

Publications

  • Type: Journal Articles Status: Submitted Year Published: 2015 Citation: Amini, H., Wang, L.J., Shahbazi, A. and Hashemisohi, A. 2015. Effects of harvesting cell density, medium depth and environmental factors on biomass and lipid productivities of Chlorella vulgaris in swine wastewater. Journal of Applied Phycology (Submitted to the journal)
  • Type: Journal Articles Status: Submitted Year Published: 2015 Citation: Amini, H., Wang, L.J. and Shahbazi, A. 2015. Computational fluid dynamics modeling of hydrodynamics and light intensity distribution in an open raceway pond for microalgae cultivation. Chemical Engineering Journal (Submitted to the journal).
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Wang, L.J., Agyemang, S.A., Amini, H., and Shahbazi, A. 2015. Mathematical modeling of production and biorefinery of energy crops. Renewable & Sustainable Energy Reviews, 43: 530544.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Rahman, Q.M., Wang, L.J., Zhang, B., Xiu, S., and Shahbazi, A. 2015. Green Biorefinery of Fresh Cattail for Microalgal Culture and Ethanol Production, Bioresource Technology, 185: 436440.
  • Type: Journal Articles Status: Submitted Year Published: 2015 Citation: Zhang, B., Wang, L.J., Riddick,B.A., Li, R., Able, J.R., and Shahbazi, A. 2015. Prospects of using local microalga Chlamydomonas debaryana for biomass production and swine wastewater treatment in North Carolina, Renewable Energy, (Submitted to the journalunder review).
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Wang, L.J., Zhang, B., Dominic, B. and Shahbazi, A. 2015. Aerobic and Anaerobic Treatment of Animal Manures for the Enhancement of Algal Cultivation, ASABE 2015, July 26-29, 2015  New Orleans, LA
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Zhang, B., and Wang, L.J. 2015. Utilization of Off-Gas from Manure Treatment for the Improvement of Algal Biomass Yield, ASABE 2015, July 26-29, 2015  New Orleans, LA
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Wang, L.J., Zhang, B., and Shahbazi, A. 2015. Life Cycle Assessment of a Microalgae Biorefinery for the Treatment of Swine Wastewater and Production of Biodiesel and Organic Fertilizers. Algal Biomass, Biofuels and Bioproducts, San Diego, CA, June 7-10.


Progress 09/01/13 to 08/31/14

Outputs
Target Audience: 1. This project has been used to support two graduate students including one from interdisciplinary Ph.D. program of energy and environmental systems and one from interdisciplinary Ph.D. program in computational science and engineering. The two graduate students were educated through formal classroom instruction, and practicum experiences with the financial support provided by this project. 2. We have provided training and research opportunities to three undergraduate students in biological engineering, who were hired to work on algal cultivation, characterization and wastewater analysis for this project. 3. This project was sued to support PI (Lijun Wang), Co-PI (Bo Zhang) and one Ph.D. student to attend two professional conferences (2014 ASABE annual meeting in Montreal, Canada in the July of 2014 and 2014 AIChE annual meeting in Atlanta, GA in the November of 2014). They presented the research results generated by this project at these two conferences. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? (1) This grant was used to support two Ph.D. students (Quazi M. Rahman, Ph.D. student in energy and environmental systems, dissertation topic: A novel biorefinery for the production of biodiesel and organic fertilizers from wet microalgae, estimated duration: August 2014-December 2016; Hossein Amini, Ph.D. student in computational science and engineering, dissertation topic: Computer-aided design and analysis of a microalgae-based biorefinery for wastewater treatment and bioenergy production, expected graduation date: December 2015). (2) This grant was used to support three undergraduate students in biological engineering program at NCA&T to obtain research experience (Jacqueline Batts, microalgae processing; Justin Able, microalgal cultivation; Bilal Riddick, wastewater analysis). (3) This grant was also used to support one postdoc (Dr. Hui Wang, research topic: LCA of microalgae-based biorefinery) and one research engineer (Dr. Bo Zhang, research topic: microalgae cultivation and processing). (4) This grant provided travel funds to Co-PI (Bo Zhang) and Ph.D. student (Hossein Amini) to present their research results at the 2014 ASABE annual meeting in Montreal, Canada in the July of 2014 and 2014 AIChE annual meeting in Atlanta, GA in the November of 2014, respectively. How have the results been disseminated to communities of interest? During this reporting period, the PI, Co-PIs and graduate students who worked on this project published three book chapters, prepared six manuscripts including two published and four under review and gave two presentations based on the research results from this project at two different professional conferences. The PI gave one seminar based on the research project in the Center for Energy Research and Technology at NCA&T. The communication office in the School of Agriculture and Environmental Science at NCA&T has published a video about algal cultivation in our raceway ponds at youtube (https://www.youtube.com/watch?v=2NJasw3fMTE). What do you plan to do during the next reporting period to accomplish the goals? There will be five major research activities during the next reporting period including: 1. Investigate thermochemical carbonization of microalgae to convert biomass into activated carbon, biodiesel, and value added chemicals 2. Investigate reactive screw extrusion technology for transforming microalgal residue into organic fertilizers 3. Develop novel catalysts for microalgae pyrolysis to minimize the nitrogen content in the bio-oil 4. Raceway ponds and photobioreactors will be used to grow algae for biomass production, wastewater treatment, syngas and biogas cleaning, and validation of CFD model 5. Economic analysis and life cycle assessment of the microalgae-based biorefinery

Impacts
What was accomplished under these goals? (1) Microalgal screening: A green microalga, Chlamydomonas debaryana, was isolated from a local wastewater lagoon, screened for its lipid content using flow cytometry, and further identified with DNA sequence analysis. The growth of C. debaryana reduced most nutritional contents of the wastewater except iron. C. debaryana was able to utilize 1.3-1.6 g COD, 55 to 90 ppm ammonia, and 48 to 89 ppm phosphorous/g biomass. The lipid content of this strain was 19.9 % of cell dry weight. The microalgal oil mostly consisted of fourteen kinds of fatty acids, ranging from C5 to C22, which can be refined into renewable jet fuel or used as sources of omega-3 and omega-6 fatty acids. (2) Microwalgae cultivation: Six 300-gallon raceway ponds (Commercial Algae Management, Inc., Franklin, NC) were purchased and installed at the NCA&T. In addition, one 60-gallon tubular photobioreactor was designed and constructed at the NCA&T farm. Photobioreactors are being operated year around. We have accumulated knowledge in cultivating microalgae in the large scale algal photobioreactors. A CFD model was used to describe the fluid flow, mass transfer and heat transfer in the cultivation system, which are affected by the design and operating parameters of the system. A light transmission and absorption model was developed to determine the local light intensity inside the cultivation system under various concentrations of algae and nutrients. The micro-environment for the microalgae growth inside the cultivation system was quantified by the CFD and lighting models. The integration of microalgae growth kinetic model, CFD model and light transmission and absorption model provided a tool to quantify the relationship between microalgae growth rate, and system design and operating parameters. (3) Microalgae processing: A Simultaneous Saccharification and Fermentation (SSF) process for fresh algae to produce biofuel ethanol by E. coli was developed. Effect of change in process parameters (Enzyme concentration, temperature, E. coli concentration) on ethanol yield and protein content was investigated for microalgae. The highest ethanol yield of 77.7% theoretical value was obtained at 37oC with 0.5 g/L E. coli concentration, with 15 FPU cellulase/g glucan and with 0.5% (w/v) biomass concentration. Protein content of fresh algae was increased by 10% after SSF experiment. A thermochemical process was further developed to simultaneously extract algal oil from fermentation residues, and convert the oil into biodiesel without supplying additional chemicals or catalyst. The thermochemical liquefaction process was operated at 240°C, and the formation of algal oil ethyl esters was confirmed using GC/MS analysis. The results proofed the concept of converting wet algal biomass into biodiesel by combining fermentation and thermochemical processes. (4) The possibility of integrating the algal technology with the woody biomass gasification was explored. It was found that the ash obtained from a pine wood gasification process was mainly composed of carbon (15-25 wt %), mineral (~21%), and oxygen (52-63 wt %), and exhibited low surface areas (8.4-11.2 m2/g). Ca, K and Na were the 3 most dominant mineral elements. The ash alone neither possessed a value as the fertilizer for C. debaryana due to poorly absorbed oxide form of elements, nor showed significant toxicity due to the absence of heavy metals such as Pb, Cd, Cr, and Cu. Our results indicated that the algal culture may be combined with the syngas production process, and provides positive effects in aquatic ecosystems. (5) Growth of microalgae Chlorella spp. using a byproduct from the biorefinery process of cattail (cattail juice) was investigated. The growth rate of microalgae increased with increasing juice concentration. Higher cattail juice concentration resulted in a higher microalgal growth rate. The highest growth rate was observed in 10% juice medium, resulting in a similar OD value as the proteose medium. The results indicated that the byproducts from biorefinery of aquatic plants could be a good source of nutrients for microalgae. (6) Life cycle assessment of the microalgae-based biorefinery was investigated with GaBi 6.0 software. Swine wastewater was used to grow microalgae for the recovery of N, P and organic matters in the wastewater. A simultaneous saccharification and fermentation (SSF) process was developed to produce ethanol from the algal carbohydrates. The ethanol under a supercritical condition was used for the simultaneous extraction and transesterification (SET) of the algal lipid into biodiesel. Meanwhile, a reactive screw extrusion (RSE) process was used to produce organic fertilizer from the solid microalgae residue in which the N and P have been enriched after the removal of carbohydrates and lipids. Three manuscripts based on the above research results are under review.

Publications

  • Type: Book Chapters Status: Published Year Published: 2014 Citation: Wang, L.J., Agyemang, S.A. and Shahbazi, A. 2014 (April). Chapter 3 Mathematical modeling in biomass and bioenergy systems in: Wang, L.J. (editor), Sustainable Bioenergy Production, Boca Raton, FL: CRC Press, Taylor & Francis, pp.67-97.
  • Type: Book Chapters Status: Published Year Published: 2014 Citation: Zhang, B. and Wang, L.J. 2014 (April). Chapter 20 Anaerobic Digestion of Organic Wastes in: Wang, L.J. (editor), Sustainable Bioenergy Production, Boca Raton, FL: CRC Press, Taylor & Francis, pp.407-421.
  • Type: Book Chapters Status: Published Year Published: 2013 Citation: Hasan, R., Wang, L.J. and Zhang, B. 2013 (Oct.). Chapter 16 Microalgae for biodiesel production and wastewater treatment, In: Zhang, B. and Wang, Y. (editors), Biomass Processing, Conversion and Biorefinery, New York: Nova Publishers, pp. 277-289.
  • Type: Journal Articles Status: Submitted Year Published: 2014 Citation: Wang, L.J., Zhang, B., Amini, H., Shahbazi, A. 2014. Microalgae cultivation on swine wastewater for the recovery of energy, nutrients and water. The Journal of Negro Education (invited submission and under review).
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Zhang, B., Wang, LJ. , Hasan, R. and Shahbazi, A. 2014. Characterization of a native algae species Chlamydomonas debaryana: strain selection, bioremediation ability and lipid characterization. BioResources, 9(4): 6130-6140, doi: 10.15376/biores.9.4.6130-6140.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Hasan, R., Zhang, B., Wang, L.J., and Shahbazi, A. 2014. Bioremediation of swine wastewater and biofule potential by using Chlorella vulgaris, Chlamydomonas reinhardtii, and Chlamydomonas debaryana. Journal of Petroleum & Environmental Biotechnology, 5(3): 175, doi: 10.13140/2.1.3348.4168.
  • Type: Journal Articles Status: Under Review Year Published: 2014 Citation: Li, R., Zhang, B., Xiu, S., Wang, H., Wang, L.J., Shahbazi, A., and Holmes, B. 2014. Investigation of biomass gasification ash characteristics and the ecotoxicity to Chlamydomonas debaryana, Applied Energy (under review).
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Zhang, B. and Wang, L.J. 2014. An integrated microalgal process for bioremediation of swine wastewater and biodiesel production. ASABE Annual Meeting, Montreal, Quebec Canada, July 13-16.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Amin, H., Wang, L.J., Shahbazi, A. 2014. Numerical analysis of the water depth of open raceway ponds on energy consumption and algal productivity using a computational fluid dynamics model. AIChE Annual Meeting, Atlanta, GA, November 16-21.
  • Type: Journal Articles Status: Under Review Year Published: 2014 Citation: Rahman, Q.M., Zhang, B., Wang, L.J., Xiu, S., and Shahbazi, A. 2014. Green biorefinery of fresh cattail biomass for microalgae culture and ethanol production, BioResources, (under review).
  • Type: Journal Articles Status: Under Review Year Published: 2014 Citation: Wang, H., and Wang, L.J. 2014. Life cycle Assessment of microalgae-based biorefinery by the improved design,Journal of Industrial Ecology (under review)