Renewable Energy Research

Microalgae – Biodiesel from Algal Biomass Coupled with Waste Water Treatment and Carbon Dioxide Capture

1. Introduction

     Although considerable information, experiment results pertinent to the technology of biodiesel derived from algal biomass using of CO₂, this technology “of microalgae for bio-fuels in general and oil production in particular is not yet a commercial reality …”, as stated in a position paper in line with Algae World in 2008 by Dr. John R. Benemann.   Successful development of a CO₂ capture process with desirable by-products of algal biofuels requires proper combination of technical innovations in systems and process coupled with economic feasibility in the practical implementation, integration and scale-up for commercial production. Before such development can really take off, confidence that the entire system can operate economically and sustainably in order to merit investment and engagement is vital.  Toward this end, the modeling, simulation, and analyses of systems and processes, and particularly development of a feasible pilot-scale system that can guide the wise investment of resources is critical. 

    Despite advances and over 50 years of pilot-scale algal research, relevant information is fairly limited; even a recent review of nine alternative energy options fails to mention algal biomass.  To address the uncertainties of various parameters, lack of data for system modeling and analysis , the PIs here propose to develop a laboratory-scale or pilot-scale testing system.  In specific, a closed photo-bioreactor with means to control and observe various parameters and harvesting and dewatering system will be developed by the PIs with Engineering backgrounds. This system will be the central piece of facility to provide information for modeling studies and serve as a major stepstone for future commercial scale-up.

2. Examples of Microalgae

3. Lipid productivity of microalgae

4. Microalgal Biomass Production

5. Microalgae Species Screening

6. Cultivation – open pond and close photobioreactor

Microbial Fuel Cell (MFC) – Electricity Generation Coupled with Waste Water Treatment

Project Description

    We, a research team made of faculty members from UNLV and DRI, propose to develop practical microbioal fuel cell (MFC) technologies that can generate continuous electricity from organic waste (e.g., sewage from the waste water treatment plant in a city). We plan to develop a state-of-the-art MFC research and development laboratory and facility to support sustained research in this promising technology. Both laboratory- and engineering-scale devices will be developed to help us model and quantify the electrons released from organics as they are oxidized by microorganisms. These developed apparatuses can be used for studying various materials that may impact the long term stability and efficiency of power generation. They shall also be up-scaled and integrated into sewage treatment plants and landfills. Furthermore, we will explore the potential of photosynthetic microorganisms in MFCs that can be sustained by sunlight, which is more tangible for the State of Nevada. Based on our existing data, and data from other research groups, we recognize that many new types of bacteria need to be discovered that are capable of anodophilic electron transfer (electron transfer to an anode) or even interspecies electron transfer (electrons transferred between bacteria in any form), and this front shall be pursued in this research as well.

An MFC generates electricity directly from electron donors through the microbial activity.  Although electricity generation in MFC has been known for decades, it is until very recently that the research has been geared toward studying the economical feasibility of microbiological production of electricity. In addition, an MFC has been considered as a promising technique for waste water treatment since this process converts the major part of the chemical energy of the contaminants to electricity thereby reducing the generation of excess sludge.

    A recent census indicates that Clark County has a population of 1.6 million and more than 37 million people visit Las Vegas city on an annual basis (based on 2004 numbers). A direct consequence of this level of human activities is that more than 1,176 Million Gallon of waste water is produced and has to be treated on every single day (Water Use Data from Las Vegas Public Works for Y2006). The proposed biotechnology, which converts waste to clean energy, thus shall have profound impacts on the sustainable development in Nevada, especially in Las Vegas Metropolitan area

Specific Use for Requested Funds

1. A large portion of the requested funds will be used to develop a state-of-the-art MFC research and development laboratory and facility to support sustained research in this promising technology. This laboratory is located either at UNLV or DRI South, and it is accessible to researchers in Nevada working in a similar field. In specific,

   1. Funds are needed to help acquire the most needed equipment (list) for the lab.

   2. Funds will be used to develop much larger and accurate test apparatuses (much more advanced than the system currently operational in the PIs’ lab), including (i) a two-chamber H-shape MFC system for basic parameter research, such as examining power production using various materials, or types of microbial communities that arise during the degradation of specific compounds; (ii) an upflow, tubular type MFC with inner graphite bed anode and outer cathode; (iii) single chamber MFC system; and (iv) stacked MFC, in which multiple separate MFCs are joined in one reactor block.

   3. Funds are requested to develop or acquire new materials to build anodes and cathodes. These materials must be conductive, biocompatible, and chemically stable in the reactor environment. The majority of MFC designs require the separation of the anode and cathode compartments by a membrane that allows protons to pass between the chambers, but optimally not the electron acceptor in the cathode chamber (typically oxygen). The market for ion exchange membranes is constantly growing, and more systematic studies are necessary to evaluate the effect of the membrane on performance and long-term stability

2. The proposed research work involves faculty and students from widely different disciplines, spanning microbiology, electrochemistry, material science/engineering, electrical engineering, and instrumentation. Funds are thus requested to support 5-6 graduate students as well as a number of undergraduate students. Funds shall also be allocated to compensate for the faculty time.

3. Funds shall be used to develop a community outreach program. The developed research facility shall be open to the general public, especially people from local communities. As a good demonstration tool for science education, the program shall be able to excite K-12 students to pursue a rewarding science/engineering career.

Current Status of Project Described in this Application

    The PIs have developed a prototype MFC system (see the picture below) to demonstrate its electricity production process. This system uses sediment collected from the Clark County Wetland Park, and it has been fully functional since January 2007. At its current configuration, the system can provide a voltage as high as 3.4Volts (we expect the value can be much higher if a larger system can be constructed), and its power is high enough to illuminate an LED. In addition, this setup has suggested the possibility to co-generate electricity during a wastewater treatment process, and it serves as a step stone for the PIs to continue their research in this critical field.

   This research team is made of 5 faculty members, and it currently involves 1 graduate student and 1 visiting scholar. Dr. Jian Ma (Assistant Research Professor in Mechanical Engineering, UNLV) is an expert in system modeling, instrumentation.  Dr. Hui Zhao (Assistant Professor in Mechanical Engineering, UNLV) has a track record in biotechnology and material engineering. Dr. Henry Sun (Assistant Research Professor, DRI) is a microbiologist, and he has extensive experiences in conducting research on sewage and landfills. Dr. Yingtao Jiang (Associate Professor in Electrical/Computer Engineering, UNLV) has extensive experiences in biomedical and electrical engineering as well as instrument development. And Dr. Biswajit Das (Professor in Electrical/Computer Engineering, UNLV) is an expert in Nano Science/technology.

Phototype of MFC