Progress 09/15/24 to 09/14/25
Outputs
Target Audience:Target audiences: Postdoc, graduates, undergraduates and researchers.The postdoc and graduates participated in this project by developing biomass fractionation platforms. The obtained preliminary results were shared with undergraduate students via formal classroom instruction (PKG 322-Packaging with Paper and Paperboard at Michigan State University) and with researchers via an oral presentation in 2024 AIChE annual conference. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Michigan State University: One postdoc and one graduate student were involved in the research activities of this project. They have learned about prototyping and developing solution-based and solution-free fractionation platforms through biomass and acetalization chemistry. They were trained to analyze fractionated biomass products using combined analysis techniques (e.g., 2 D HSQC NMR, HPLC, FTIR, XRD, SEM-EDS) and explain the analysis results. They were also trained in literature research, preparing conference abstracts, and preparing manuscripts. Texas A&M University: One graduate student was involved in this project. The graduate student studied the mass balance and energy consumption of the developed solution-based and solution-free fractionation platforms. How have the results been disseminated to communities of interest?The findings of this project were shared with 156 undergraduates through a core undergraduate course (PKG 322-Packaging with Paper and Paperboard at Michigan State University). The undergraduates have learned about the economic and environmental advantages of the developed energy-efficient, atmospheric-pressure and solution-free fractionation platforms compared to conventional energy-intensive, high-pressure and solution-based fractionation processes. The results were also disseminated to researchers via an oral presentation at the 2024 AIChE annual conference. What do you plan to do during the next reporting period to accomplish the goals?We will continue to develop fractionation platforms via solution-based and solution-free processes using different acids, aldehydes and alcohols. We will conduct their TEA, LCA, and corrosion analyses. We will also elucidate their working mechanisms via model studies. We will continue training the postdoc and graduate students through this project. We will continue disseminating the results of this project to undergraduates, researchers and public via teaching PKG 322, attending AIChE conferences, publishing peer-reviewed journal articles, and attending Michigan State University extension annual events.
Impacts
What was accomplished under these goals?
One hydroxyl-containing acid and one aldehyde were used to develop fractionation platform II via solution-based and solution-free processes under different experimental conditions for aspen chips. The absorption experiments were conducted to estimate the amounts of acid and aldehyde absorbed by aspen. The results showed that one gram of aspen (oven-dry) absorbed about 2.29 grams of acid (oven-dry). This indicated that about 27.8% acid was absorbed by aspen and 72.2% acid accordingly remained in solution. In the presence of aldehyde, one gram of aspen (oven-dry) absorbed about 2.24 grams of acid and aldehyde (oven-dry). Compared to the solution-based process, the solution-free process used about 72.2% less acid by recycling free acid in solution for reuse. After the aspen fractionation, the obtained products (cellulose, xylose and its derivative, and lignin) were separated from chemicals (acid, aldehyde) and solvents (ethanol, water). The obtained lignin samples were characterized in terms of chemical structure (composition, S/G ratio, condensed/uncondensed, beta-O-4 linkage) and molecular weight/PDI using 2D HSQC NMR, GPC, and SEM-EDS techniques. The obtained cellulose samples were analyzed in terms of crystallinity and composition using XRD and SEM-EDS techniques. The aspen fractionation results indicated that this platform was highly effective at a wide range of mild temperatures (e.g., 55-95 degree C) via both solution-based and solution-free processes. At 55-65 degree C for 90 min, the solution-based process isolated about 55-80% lignin from aspen chips. At 75-95 degree C for 90 min, the solution-based process isolated about 90-95% lignin. By comparison, the solution-free process was more efficient in isolating lignin than the solution-based process under the same experimental conditions. More importantly, the solution-free process condensed lignin less than the solution-based process did. The solution-free process could condense lignin less and preserve some (e.g., about 9%) beta-O-4 linkages at a milder temperature (e.g., 55 degree C for 90 min). The addition of aldehyde enhanced the performance of the solution-free process in preserving lignin structure. The XRD results showed that the cellulose crystallinity index ranged from 40 to 60. By comparison, the cellulose samples obtained from solution-free process showed higher crystallinity indexes than those from solution-based process. The SEM-EDS and FTIR results collectively indicated that aldehyde slightly modified cellulose via reacting with its surface hydroxyls during aspen fractionation. Model studies were conducted to understand the reaction between xylose and aldehyde in the presence of acid. The results showed that xylose reacted with aldehyde to form xylose dioxolo. The reusability of recycled acid without aldehyde was preliminarily evaluated. The results showed that the recycled acid could be reused several times without greatly reducing the performance of fractionating aspen. One aldehyde-containing acid was also used to develop fractionation platform II via solution-based and solution-free processes under different experimental conditions for poplar chips. The results showed that this platform effectively fractionated poplar chips at mild conditions (e.g., 50-80 degree C for 0.25-3 h) and isolated about 50-72% lignin. Both processes produced water-soluble lignin samples with uncondensed structure and many beta-O-4 linkages (e.g., 10-40%). By comparison, the solution-free process produced more stable water-soluble lignin.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2024
Citation:
Minsheng Lin and Qiang Yang. Fractionation of lignocellulosic through a solution-free process. 2024 AIChE Annual Meeting, October 28, San Diego, CA.
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