Bio-energy Research
At the
University of South Florida
Contact Persons
Dr. D. Yogi Goswami
John & Naida Ramil Professor and
Co-Director, Clean Energy Research Center
Tel. (813) 974-0956
Fax: (813) 974-2050
e-mail:
Dr. James Garey
Chair, Department of Biology
Tel. (813) 974-3250
Fax: (813) 974-3263
e-mail:
Dr. Robert Chang
Vice President, Office of Research
University of South Florida
4202 E. Fowler Ave., Tampa, FL 33620
Bio-energy Research
At the
University of South Florida
Bio-energy research at the University of South Florida is being conducted in the colleges of Engineering and Arts & Sciences. Below are some examples of the typical on going research in the areas of conversion of Biomass to liquid fuels and hydrogen and fundamental research in Genomics.
Hydrogen Production from Biomass
The Clean Energy Research Center (CERC) at the University of South Florida has been working in the broad areas of renewable hydrogen production, hydrogen storage and fuel cells for the last 10 years. Since 2002 we have focused on renewable hydrogen production from biomass as part of a project supported by the US Department of Energy. Thermochemical biomass gasification has been identified as a promising technology for renewable hydrogen production. Our overall objective was to improve the hydrogen yield, total gas yield and process efficiency. A detailed thermodynamic analysis of biomass gasification was conducted and the process parameters that influence the hydrogen yield in gasification were identified. A parametric modeling study gave the optimal conditions for hydrogen production in biomass gasification. The study also found that the maximum hydrogen yield is constrained by the CO2 formed in the product gas. Further investigation led to the development of a novel technique that can significantly enhance the hydrogen yield, reduce the tar impurities and CO2 formed in the product gas. The novel technology also has the potential to lower the capital cost of the conventional biomass gasification process.
It makes use of suitable materials called sorbents which absorb the CO2 formed during biomass gasification and thereby influence the water gas shift (WGS) reaction in favor of hydrogen. Theoretical simulations carried out in ASPEN Plus® process simulator showed a 19% increase in the hydrogen yield and 50% reduction in the product gas CO2. Moreover the gasifier could be operated at 200oC lower temperature than conventional, still giving the same or even more hydrogen than conventional gasification. Experimental studies were then carried out by gasifying South Eastern Pine bark (an abundant woody biomass found in Florida and Southern Georgia) in presence of calcium oxide. The hydrogen yield and overall gas yield had more than doubled at gasification temperature as low as 500oC (Figure 1). The tars in the product gas had reduced significantly. The carbon conversion efficiency (which is a measure of the effectiveness of gasification) increased drastically from 23% to almost 63% when the gasification was conducted in presence of the sorbent. The calcium oxide not only played the role of sorbent but also acted like a catalyst. The exothermic CO2 absorption reaction can be coupled with endothermic steam biomass gasification to provide in-situ heat thereby lowering the external heat supply. This will lead to reduction in the gasifier heat duty, making it more compact and reducing the capital costs. The product gas coming out of the system has less hydrocarbon and tar impurities than a conventional biomass gasification system, and this will reduce the gas cleaning and conditioning equipment and the associated costs.
The concept of using sorbents for biomass gasification has shown substantial promise at the laboratory scale. We propose to continue this work aimed at developing a pilot-scale plant that can employ the sorbent enhanced gasification concept to produce a hydrogen rich gas stream with reduced CO2 and tars. This gas can be sent to a storage unit, fuel cell or gas turbine with greatly reduced gas cleaning cost. The electricity so generated would be renewable, CO2 neutral and sourced locally, thereby increasing Florida’s energy independence. We also plan to investigate conversion of the CO2 coming from sorbent regeneration into agricultural fertilizers such as ammonium bicarbonate or urea. Hence there is potential to actually remove CO2 from the atmosphere, making sorbent enhanced biomass gasification a CO2 negative technology. This will have a significant positive influence on the environment while simultaneously boosting the economy and agriculture of Florida.
(a) (b)
Figure 1: (a) Effect of sorbent addition at 500°C (b) Tar laden condensate—without sorbent (left) and with sorbent (right) showing substantial reduction in tars in presence of sorbents.
Production of Liquid Fuels from Florida Biomass via Thermochemical Conversion
The objective of this project is to develop an economically viable thermo-chemical process for converting readily available Florida biomass to clean burning liquid fuels. This is the first phase of a two phase project leading to commercial production of synthetic gasoline from biomass in Florida. In this first phase we will establish the best technology and best processing conditions for the types of biomass produced in Florida, along with the design and cost specifications for a pilot plant project. During the second phase, Biomass Investment Group is committed to build the pilot plant and to bring the technology to full scale commercialization.
Florida has large amounts of biomass from sugar industry (Bagasse), citrus industry (citrus peels) and forest products (easily grown pine and tall grasses). Many of these biomass products are rich in lignin and hence more suited to conversion via the thermo chemical process as opposed to biochemical conversion to alcohols. In the thermo chemical process the biomass is first partially oxidized to form a mixture of carbon monoxide and hydrogen (syngas) and then converted to clean burning liquid hydrocarbon fuels such as ethanol or gasoline via the well known Fischer-Tropsch synthesis projects developed in Germany during the 1920s and 1930s. The key technology development here is the design of the gasifier which involves fine tuning of processing conditions ( contact method, temperature, pressure, biomass to oxygen ratio etc.) to achieve optimum production of syngas while minimizing pollutant formation and maximizing energy production. The technology for FTS also need to be adapted to take into account the economic conditions and fuel supply needs of the state of Florida.
Our preliminary investigations will focus on the fine tuning of this process for sugar cane bagasse and switchgrass through bench scale experiments for determining yield, kinetics and optimum processing conditions. This will be accompanied by modeling and simulation studies to establish the process design for pilot plant construction and commercial production. Using this model we can establish the best mix of products (liquid fuels, syngas or methane gas) that will lead to eventual commercialization of the process.
The potential impact on the agriculture and energy production in Florida will be significant. The long term implications point to decreasing the dependence of the state on imported oil and gasoline and the development of a strong renewable energy industry tailored specifically to take advantage of the unique biomass production capacity available in Florida.
Genomics, Computational Biology and Bioinformatics at USF
Biological systems function by generating and distributing energy in a variety of ways. Modeling these biological systems will lead to new engineering approaches to energy generation and distribution of that energy to human populations. The Division of Cell Biology, Microbiology and Molecular Biology (CMM) at the University of South Florida is undergoing an expansion focused on using proteomic and genomic approaches to studying cell signaling pathways in prokaryotes and eukaryotes, including those involved with the generation and distribution of energy in the cell. We have recently hired new faculty in the areas of genomics, proteomics and computational biology and are in the process of hiring four more this year. Common interests involve analyzing large data sets of DNA or protein sequences to understand cellular processes and the application of those findings. In addition, we have an interest in biosensors and are closely associated with the new Florida Center of Excellence in Biomolecular Identification and Targeted Therapeutics, which has a significant proteomics/genomics component. Other groups at USF with significant interests in proteomics/genomics and biosensors include the Moffit Cancer Center and the School of Marine Sciences. The Mathematics and Chemistry Departments have faculty pursuing computational approaches to biological and chemical problems. In summary, USF is in a strong position to be involved with bioenergy research involving genomics, proteomics and computational biology.