University of Michigan-Flint

Faculty Name:  Jie Song

Department:  Chemistry and Biochemistry

Campus Address:  566B MSB

Email:  jiesong@umflint.edu

Phone:  810-762-3275

Project Description:  Renewable biomass has attracted a lot of attentions during the last two decades due to the shortage of fossil oil. How to efficiently and effectively convert the biomass to the energy is a big challenge.  Processing of biomass usually involves two steps, pyrolysis and gasification. Pyrolysis is the pretreatment step to eliminate unstable components and for biomass, the pyrolysis burned the cellulose, semi-cellulose, and lignin from the biomass and generates char, which will be used to generate the fuel gas during the gasification step. High Temperature Agent Gasification (HTAG), which was developed about a decade ago, uses highly preheated (over 1273K) oxidizing agents, compared to low temperature in the conventional method.  The experimental studies have shown that the generated fuel has high calorific value. Due to the extreme experimental conditions, our understanding about the gasification process is very limited.

Computational tool can supply the chemical insight about what happens. It is believed that, either oxidizing agent as air, oxygen, steam, or their decomposed intermediates are adsorbed on edges of the char surface, followed by the chemical desorption accompanied by the release of fuel gas (H2 or CO). There are two theoretical models of char edge used: armchair and zigzag. Systematical studies have been done on the adsorption of these oxidizing agents on one of edges, due to the exponentially increasing requirements of computer resources. However, the adsorption between two edges can't be overlooked. For example, when only one edge model is considered, H atom in water molecule points to the armchair edge but O atom orients to the zigzag edge. It is very likely that oxidizing agents may be adsorbed tightly between two edges and therefore, change the chemical desorption mechanism.

In this study, a hybrid ONIOM method is applied to reduce the requirements of computer resources and maintain the chemical accuracy. In addition, the adsorption occurring between two edges may supply the guidance to examine the desorption process.

Semesters Desired:  Fall 2011 AND Winter 2012

GSRA Position Description:  1. GSRA should be able to work independently after a short training;

2. GSRA will conduct the research, analyze the data, summarize the result for the weekly meeting;

3. GSRA will learn how to present the data;

4. GSRA will try to submit the abstract to the national meeting;

5. GSRA will help/train the new undergraduate researcher as well.

Specific Day/Time Requirements:  None identified

Special Requirements:  None identified

Graduate Students in These Programs May Apply:  Candidate in mind