A FUNDAMENTAL STUDY OF TORREFIED-BIOMASS CATALYTIC PYROLYSIS

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1001721
• Project Start Date: Nov 29, 2013
• Project End Date: Sep 30, 2015
• Program Code: [(N/A)]- (N/A)

Recipient Organization
AUBURN UNIVERSITY
108 M. WHITE SMITH HALL
AUBURN,AL 36849

Performing Department
Biosystems Engineering

Non Technical Summary
The conversion of biomass to pyrolysis oil (i.e., bio-oil) and subsequent conversion to gasoline and diesel range compounds have a significant potential in reducing the United States' dependence on imported petroleum products. Using fast pyrolysis technology, a high yield of bio-oil can be achieved from various biomass feedstocks. However, bio-oil is unstable and acidic, contains char particles, and has about half the heating value of petroleum liquid fuels. Acidity, high viscosity, high oxygen content, difficulties in removing char particles, and immiscibility with petroleum liquids have restricted the use of bio-oil. A catalytic pyrolysis process has been found to be effective in alleviating some of the negative properties of the bio-oil. The catalytic process-- that uses some shape selective zeolites-- involves the cleavage of C-C bonds associated with dehydration, decarboxylation, and decarbonylation, and produces aromatic compounds. The impacts of this project include understanding the effect of biomass structure and zeolite's properties on catalytic pyrolysis of thermally pretreated biomass for hydrocarbons production. Biomass-derived liquid fuels have a potential to provide a cost-effective and sustainable supply of energy, while meeting greenhouse gas reduction targets and the goals of the Energy Independent and Security Act (EISA) of 2007, which calls for a reduction in the country's reliance on fossil fuels. The successful completion of this project will have a major impact on the profitability of farming, forest products, and pulp industries in the state of Alabama and in the U.S. in general. The project will train a new generation of graduate with its multidisciplinary focus on bio-energy research, while providing a solid fundamental background in her core area. The training of the graduate and undergraduate students will help transfer technology to U.S. industry, thereby enhancing its competitiveness in the field of energy technologies.

Animal Health Component

25%

Research Effort Categories

Basic

75%

Applied

25%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
511	0650	2020	50%
511	0650	2000	50%

Knowledge Area
511 - New and Improved Non-Food Products and Processes;

Subject Of Investigation
0650 - Wood and wood products;

Field Of Science
2020 - Engineering; 2000 - Chemistry;

Keywords

biomass

catalytic pyrolysis

torrefaction

zsm-5

Goals / Objectives
The objective of this study is to discover biomass torrefaction chemistry, and its impact on catalytic pyrolysis for hydrocarbons (compounds present in gasoline and diesel) production. The PI plans to accomplish the overall objective of this study by pursuing the following three aims: (i) investigate the effect of thermal treatment on biomass structure, and (ii) understand the effect of biomass structure on hydrocarbons yield using catalytic pyrolysis, and (iii) investigate the role of alkali and alkaline earth metals on biomass structural change during thermal treatment and catalytic pyrolysis.

Project Methods
Investigate the Effect of Thermal Treatment on Biomass Structure. Lignocellulosic biomass is composed of a complex structure of cellulose, hemicellulose and lignin. During torrefaction, several β-aryl-ether linkages cleave and condensed aromatic units are formed by condensation reactions of lignin. Also, a number of cellulose decomposition products are formed as a result of glycosidic bond breakages. In this task, torrefied biomass samples will be prepared at different temperatures and residence time, and the chemistry of biomass torrefaction will be investigated using solid-state 13C NMR, single-quantum correlation-nuclear magnetic resonance (HSQC-NMR), Fourier transform infrared spectroscopy (FTIR)/near-infrared spectroscopy (NIR), Py-GC/MS and other analytical tools to determine properties such as change in methoxyl functional groups, carbon functionality, aromaticity, spectroscopic fingerprints, carbohydrate profiles, molecular weight of lignin, DP (degree of polymerization), cellulose crystallinity, lignin structure (S/G ratio). Understand the Effect of Biomass Structure on Hydrocarbons Yield Using Catalytic Pyrolysis. Past studies on thermal treatment of biomass and pyrolysis were mainly focused on heating value and elemental constituent rather than understanding the effect of biomass structure on liquid fuels. The H+ZSM-5 catalyst with different SiO2/Al2O3 ratios will be tested using torrefied biomass. The spectrum of hydrocarbon products and coke formation under each experimental condition will be quantified. The relation between biomass structure and a slate of products will be developed using chemometric techniques. Investigate the Role of Alkali and Alkaline Earth Metals on Biomass Structural Change During Thermal Treatment and Catalytic Pyrolysis. Different concentrations of sodium (Na) and potassium (K) will be added to pine biomass to analyze the effect of these metals on products formation--many of the biomass contain alkali and alkaline earth metals in the form of ash. It is expected that these metals will have an impact on biomass structural change during torrefaction and we will investigate their influence. In a separate investigation, torrefied and untorrefied feedstocks will be converted over a zeolite having different loadings of Na and K initially present in the zeolite. It is anticipated that the mechanism for catalytic conversion will change from a globally, acid-mediated one to a globally, basic-mediated mechanism as the ratio of alkali metal/framework Al(III) in the zeolite increases from a fraction less than unity to a multiple greater than unity. The study will be done to understand how this change in the reaction mechanism can be exploited to maximize the yields of liquid hydrocarbons.

Progress 11/29/13 to 09/30/15

Outputs
Target Audience:The target audiences reached in this project were mainly researchers that are working in the field of bioenergy especially those who are working in the field of thermochemical conversion process for the production of biofuels. Research results were disseminated through presentations at conferences and peer-reviewed articles. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Students involved in this project were provided with fundamental knowledge of biomass chemistry and engineering process for producing biofuels from fast pyrolysis of biomass. How have the results been disseminated to communities of interest?Yes, the results from research have been disseminated through standard procedure (peer-reviewed articles and conferences), which were discussed in products section. What do you plan to do during the next reporting period to accomplish the goals?This project was for two years and we have completed the project goals that were laid out during the proposal submission. There is no future plan for this aspect of the project until we were able to secure funding to exapnd the scope of the project.

Impacts
What was accomplished under these goals? The first part of this study was focused on aromatics production through catalytic pyrolysis of major biomass constituent i.e., cellulose. Furthermore, cellulose was torrefied to understand torrefaction's effect on pyrolysis products. The influence of SiO2/Al2O3 ratios of zeolite (ZSM-5) catalyst on aromatics production during pyrolysis of raw and torrefied cellulose was investigated. Results showed that the catalyst acidity played a pivotal role in eliminating anhydro-sugars and other oxygenated compounds while producing more aromatics. The maximum aromatics yield (~25 wt.%) was obtained when ZSM5 with the highest acidity (SiO2/Al2O3 =30) was used while the lowest yield (7.99 wt.%) was obtained when the least acidic catalyst was used (SiO2/Al2O3 =280) for raw cellulose pyrolysis. Torrefaction process showed to have positive effect on the aromatic production from pyrolysis. There were no aromatics produced from pyrolysis of raw cellulose in the absence of catalyst whereas significant amount of aromatic compounds were produced from both catalytic and non-catalytic pyrolysis of torrefied cellulose. The aromatic hydrocarbons produced from catalytic pyrolysis of torrefied cellulose were 5% more than that produced from raw cellulose at the highest temperature and catalyst acidity (SiO2/Al2O3 =30). The second part of the objcetive was focused on another major component of biomass. i.e., lignin. The objective of this study was to investigate the effect of temperature (500, 550 and 600°C) and shape selective zeolite catalyst of different acidity on aromatic hydrocarbons yield from raw and torrefied lignin pyrolysis. An FTIR analysis showed that torrefaction resulted in more C-C, C-O and C=O stretch units. Catalyst acidity was found to be highly favorable for aromatic hydrocarbon production in the case of both raw and torrefied lignin pyrolysis. High amount of aromatic hydrocarbons (~35 wt.% C) was produced from torrefied lignin pyrolysis using zeolite catalyst of SiO2/Al2O3 ratio of 30 at 600°C. Under the same conditions, total carbon yield from catalytic pyrolysis of torrefied lignin was about 46 wt.%. The study showed that torrefaction favors high aromatic hydrocarbons production from catalytic pyrolysis of lignin. The third part of the study was focused to evaluate the catalytic effect of CaO, MgO and ZSM-5 as in-situ upgrading catalysts during biomass pyrolysis in a fluidized bed reactor. Southern pine sawdust were subjected to pyrolysis with inert bed material (quartz sand) and subsequently with the catalysts. The quality of bio-oil obtained was compared to the baseline values (i.e.,with the use of sand as bed material without any catalyst) in terms of its chemical composition, heating value, viscosity, pH,total acid number (TAN), oxygen and water contents. The use of CaO resulted in an improvement in pH (2.39 to 3.98) and TAN (88.9 to 46.6) of the bio-oil when compared to the results when using only sand. In comparison, MgO was a mild catalyst as it altered the bio-oil quality slightly while ZSM-5 had no effect on the acid content in bio-oil although it produced bio-oil with the least oxygen content at a significantly lower yield and higher water content (38.5%). In terms of chemical composition, the catalysts exhibited different behaviors to various groups of compounds. Anhydrosugars were reduced by all the catalysts tested to different extents, but CaO significantly altered the quality of bio-oil by reducing organic acids, while CaO and ZSM-5 reduced the abundance of phenolic compounds with higher oxygen content. Accelerated aging test was performed to compare the efficacy of these in-situ catalysts on improving the stability of bio-oil, and it was observed that the bio-oil produced using CaO was the most stable when compared to the baseline and other catalytic bio-oils tested in this study. The final and fourth part of this study was focused on understanding the effect of torrefaction on biomass structure. During torrefaction, structural transformations in biomass constitutive polymers: hemicellulose, cellulose and lignin took place, which were evaluated using component analysis, solid state CP/MAS 13C NMR and XRD techniques. Torrefaction caused deacetylation and decomposition of hemicellulose, cleavage of aryl ether linkages and demethoxylation of lignin, degradation of cellulose and overall increase in aromaticity of biomass, all of which affected the product yield from pyrolysis of torrefied biomass.

Publications

• Type: Journal Articles Status: Published Year Published: 2013 Citation: Chad L. Carter, Nourredine Abdoulmoumine, Avanti Kulkarni and Sushil Adhikari, and Oladiran Fasina. Physicochemical properties of thermally treated biomass and energy requirement for torrefaction. Trans of ASABE. Vol. 56(3). pp. 1093-1100.
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Vaishnavi Srinivasan, Sushil Adhikari, Shyamsundar Ayalur Chattanathan, Maobing Tu, Sunkyu Park. Catalytic pyrolysis of raw and thermally treated cellulose using different acidic zeolites. BioEnergy Research. DOI 10.1007/s12155-014-9426- 8.
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Sushil Adhikari, Vaishnavi Srinivasan, Oladiran Fasina. Catalytic pyrolysis of raw and thermally treated lignin using different acidic zeolites. Energy & Fuels. 2014, 28 (7), pp 45324538.
• Type: Journal Articles Status: Published Year Published: 2015 Citation: Ravishankar Mahadevan, Rajdeep Shakya, Sneha Neupane and Sushil Adhikari. Physical and chemical properties and accelerated aging test of bio-oil produced from in-situ catalytic pyrolysis in a bench-scale fluidized bed reactor. Energy & Fuels. 2015, 29 (2), pp 841848.
• Type: Journal Articles Status: Published Year Published: 2015 Citation: Sneha Neupane*, Sushil Adhikari, Zhouhong Wang, Art J. Ragauskas and Yunqiao Pu. Effect of torrefaction on biomass structure and hydrocarbons production from fast pyrolysis. Green Chemistry. 2015, 17(4), pp 2406-417.

Progress 11/29/13 to 09/30/14

Outputs
Target Audience: The target audiences reached duirng this project period were mainly undergraduate, graduate students and the scietific community that is interested in biofuels production from fast pyrolysis process. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? The student got opportunity to enhnace her expertise in biomass and biofuels. Without the support of this project, it would not have been possible. How have the results been disseminated to communities of interest? Yes. The paper below just got accepted for publication. Sushil Adhikari, Vaishnavi Srinivasan, Oladiran Fasina. 2014. Catalytic pyrolysis of raw and thermally treated lignin using different acidic zeolites. Energy & Fuels. 2014, 28 (7), pp 4532-4538. Nourredine Abdoulmoumine, Avanti Kulkarni, and Sushil Adhikari. 2014. Effect of temperature and equivalence ratio on primary gases and contaminants in a bench-scale fluidized bed gasifier from pine. Ind. Eng. Chem. Res. 2014, 53 (14), pp 5767-5777. Vaishnavi Srinivasan, Sushil Adhikari, Shyamsundar Ayalur Chattanathan, Maobing Tu, Sunkyu Park. 2014. Catalytic pyrolysis of raw and thermally treated cellulose using different acidic zeolites. BioEnergy Research. DOI 10.1007/s12155-014-9426-8. Published online 13 February 2014. Shyamsundar Ayalur Chattanathan, Sushil Adhikari, Matthew McVey and Oladiran Fasina. Hydrogen production from biogas reforming and the effect of H2S on CH4 conversion. 2014 International Journal of Hydrogen Energy. 2014 (39), pp. 19905-19911. What do you plan to do during the next reporting period to accomplish the goals? The overall objective of this study is to discover biomass torrefaction chemistry and its impact on catalytic pyrolysis for hydrocarbons production. The specific objectives are listed below, and we will continue working in acheiving those goals: -Investigate the effect on biomass structure due to thermal treatment of biomass -Understand the effect of biomass structure on hydrocarbon yield using catalytic pyrolysis

Impacts
What was accomplished under these goals? The project is almost complete and we are analyzing data right now and will decide soon whether or not we need to perform more experiments.

Publications

• Type: Journal Articles Status: Accepted Year Published: 2014 Citation: Vaishnavi Srinivasan, Sushil Adhikari, Shyamsundar Ayalur Chattanathan, Maobing Tu, Sunkyu Park. 2014. Catalytic pyrolysis of raw and thermally treated cellulose using different acidic zeolites. BioEnergy Research.
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Sushil Adhikari, Vaishnavi Srinivasan, Oladiran Fasina. 2014. Catalytic pyrolysis of raw and thermally treated lignin using different acidic zeolites. Energy & Fuels. 2014, 28 (7), pp 45324538
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Nourredine Abdoulmoumine, Avanti Kulkarni, and Sushil Adhikari. 2014. Effect of temperature and equivalence ratio on primary gases and contaminants in a bench-scale fluidized bed gasifier from pine. Ind. Eng. Chem. Res. 2014, 53 (14), pp 57675777
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Shyamsundar Ayalur Chattanathan, Sushil Adhikari, Matthew McVey and Oladiran Fasina. Hydrogen production from biogas reforming and the effect of H2S on CH4 conversion. 2014 International Journal of Hydrogen Energy. 2014 (39), pp. 19905-19911.