@article{lan_cruz_li_boakye_park_tiller_mittal_johnson_park_yao_2024, title={Life-Cycle Assessment of Sustainable Aviation Fuel Derived from Paper Sludge}, volume={12}, ISSN={["2168-0485"]}, url={https://doi.org/10.1021/acssuschemeng.4c00795}, DOI={10.1021/acssuschemeng.4c00795}, abstractNote={Converting waste paper sludge to sustainable aviation fuel (SAF) offers a circular economy strategy to decarbonize the aviation sector. This study develops a life-cycle assessment (LCA) for converting high-ash paper sludge to SAF in the U.S. using a catalytic sugar upgrading system that consists of ash removal, enzymatic hydrolysis, dehydration, aldol condensation, and hydroprocessing. The LCA is coupled with a process simulation for an industrial-scale biorefinery based on experimental data. We quantified the carbon intensity as 35.7–41.8 gCO2eq MJ–1 SAF (−636 to −584 gCO2eq per dry kg paper sludge) with acetone as a solvent, renewable fuel, and biobased chemicals; this is further reduced to 5.1–11.1 gCO2eq MJ–1 (−925 to −873 gCO2eq per dry kg paper sludge) if ash is recycled and used for substituting cement. Converting 1 dry kg paper sludge to SAF with acetone, renewable fuel, and biobased chemicals (−925 to −584 gCO2eq) is more climate beneficial than landfilling without landfill gas recovery (791 gCO2eq) and with landfill gas recovery (−294 gCO2eq). More than 330 million gallons of SAF can be produced annually (>4 million dry t paper sludge/year in the U.S.), resulting in a reduction of 2–7 million tCO2eq.}, number={22}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, author={Lan, Kai and Cruz, David and Li, Jinyue and Boakye, Amma Asantewaa Agyei and Park, Hyeonji and Tiller, Phoenix and Mittal, Ashutosh and Johnson, David K. and Park, Sunkyu and Yao, Yuan}, year={2024}, month={Apr}, pages={8379–8390} }
 @article{tiller_park_cruz_carrejo_johnson_mittal_venditti_park_2024, title={Techno-economic analysis of biomass value-added processing informed by pilot scale de-ashing of paper sludge feedstock}, volume={401}, ISSN={["1873-2976"]}, url={http://dx.doi.org/10.1016/j.biortech.2024.130744}, DOI={10.1016/j.biortech.2024.130744}, abstractNote={Paper sludge biomass represents an underutilized feedstock rich in pulped and processed cellulose which is currently a waste stream with significant disposal cost to industry for landfilling services. Effective fractionation of the cellulose from paper sludge presents an opportunity to yield cellulose as feedstock for value-added processes. A novel approach to cellulose fractionation is the sidehill screening system, herein studied at the pilot-plant scale. Composition analysis determined ash removal and carbohydrate retention of both sidehill and high-performance benchtop screening systems. Sidehill screening resulted in greater carbohydrates retention relative to benchtop screening (90% vs 66%) and similar ash removal (95% vs 98%). Techno-economic analysis for production of sugar syrup yielded a minimum selling price of $331/metric ton of sugar syrup including disposal savings, significantly less than a commercial sugar syrup without fractionation. Sensitivity analysis showed that screening conditions played a significant role in economic feasibility for cellulosic yield and downstream processes.}, journal={BIORESOURCE TECHNOLOGY}, author={Tiller, Phoenix and Park, Hyeonji and Cruz, David and Carrejo, Edgar and Johnson, David K. and Mittal, Ashutosh and Venditti, Richard and Park, Sunkyu}, year={2024}, month={Jun} }
 @article{park_rahmani_treasure_lee_tiller_pasquinelli_kelley_park_2024, title={Understanding the formation of insoluble gel particles during cellulose diacetate production}, volume={2}, ISSN={["1572-882X"]}, url={http://dx.doi.org/10.1007/s10570-024-05769-0}, DOI={10.1007/s10570-024-05769-0}, journal={CELLULOSE}, author={Park, Seonghyun and Rahmani, Farzin and Treasure, Trevor and Lee, Joo and Tiller, Phoenix and Pasquinelli, Melissa A. and Kelley, Stephen S. and Park, Sunkyu}, year={2024}, month={Feb} }
 @misc{hubbe_trovagunta_zambrano_tiller_jardim_2023, title={Self-assembly Fundamentals in the Reconstruction of Lignocellulosic Materials: A Review}, volume={18}, ISSN={["1930-2126"]}, url={http://dx.doi.org/10.15376/biores.18.2.hubbe}, DOI={10.15376/biores.18.2.Hubbe}, abstractNote={This review article considers processes by which the main components of wood have been reported to arrange themselves into various kinds of organized structures, at least to a partial extent.  The biosynthesis of wood provides the clearest examples of such self-organization.  For example, even before a cellulose macromolecule has been completely synthesized in a plant organism, the leading parts of the polymer chains already will have assembled themselves into organized crystals, i.e., nano-fibrils.  This review then considers a challenge that faces industrial engineers:  how to emulate the great success of natural systems when attempting to achieve favorable materials properties, process efficiency, and environmental friendliness when developing new engineered wood structures, barrier films, and other desired products composed of lignocellulosic materials.  Based on the reviewed literature, it appears that the main chemical components of wood, even after they have been isolated from each other, still have a remnant of their initial tendencies to come back together in a somewhat non-random fashion, following mechanisms that can be favorable for the production of engineered materials having potentially useful functions.}, number={2}, journal={BIORESOURCES}, publisher={BioResources}, author={Hubbe, Martin A. and Trovagunta, Ramakrishna and Zambrano, Franklin and Tiller, Phoenix and Jardim, Juliana}, year={2023}, month={May}, pages={4262–4331} }
 @article{park_cruz_tiller_johnson_mittal_jameel_venditti_park_2022, title={Effect of ash in paper sludge on enzymatic hydrolysis}, volume={165}, ISSN={0961-9534}, url={http://dx.doi.org/10.1016/j.biombioe.2022.106567}, DOI={10.1016/j.biombioe.2022.106567}, abstractNote={The valorization of paper sludge is a high-potential process to develop renewable fuels and chemicals, which can be integrated with pulp and paper mills. Calcium carbonate is the main ash component in sludge, which plays a role in buffering pH and potentially lowering the conversion during enzymatic hydrolysis. Therefore, it is important to investigate the effect of ash on sugar yields and examine pH change to introduce efficient and economical enzymatic hydrolysis of sludge. Carbohydrate conversion was enhanced when the ash was removed by fractionation. On the other hand, the highest sugar recovery was obtained when the sludge contained 20% ash content. The pH change during enzymatic hydrolysis was influenced by ash and explained why sludge-derived hydrolysate showed lower carbohydrate conversion. Therefore, a high shear process with the increased acid amount is suggested to prohibit the negative effect of ash and enhance the accessibility of cellulase to fibers. This study highlights the feasibility of using wet waste streams generated by the paper industry.}, journal={Biomass and Bioenergy}, publisher={Elsevier BV}, author={Park, Hyeonji and Cruz, David and Tiller, Phoenix and Johnson, David K. and Mittal, Ashutosh and Jameel, Hasan and Venditti, Richard and Park, Sunkyu}, year={2022}, month={Oct}, pages={106567} }
 @misc{gaynor_szlek_kwon_tiller_byington_argyropoulos_2022, title={Lignin Use in Nonwovens: A Review}, volume={17}, ISSN={["1930-2126"]}, DOI={10.15376/biores.17.2.Gaynor}, abstractNote={While lignin has been gaining wide research interest for a variety of applications across many industries, relatively little work has been published on its applications in nonwovens. Consequently, this article offers an overview of the underlying principles and both the present and future applications of lignin within the nonwoven industry. Due to the distinct structure of lignin, processing, fiber production, composites with polymers, dye dispersant, and fire-retardant applications are all unique opportunities for lignin application in nonwovens discussed in this review. Conventional nonwoven processing techniques, such as electrospinning, have been reported to successfully produce lignin-based nonwovens, specifically lignin/polymer composite nonwovens. This account points to pivotal polymer matrix/lignin composite compatibility issues that define various processing technologies. However, lignin use is not limited to incorporation within nonwoven fibers mats and is currently used in dye dispersion with the potential of phase out petroleum-based dye dispersants. Finally, the high phenolic content of lignin endows it with fire-retardant and antimicrobial properties, among others, that present additional opportunities for lignin in the nonwoven industry. Throughout this review, an effort is made to outline the advantages and challenges of using lignin as a green and sustainable ingredient for the production of nonwoven materials.}, number={2}, journal={BIORESOURCES}, author={Gaynor, J. Gavin and Szlek, Dorota B. and Kwon, Soojin and Tiller, Phoenix S. and Byington, Matthew S. and Argyropoulos, Dimitris S.}, year={2022}, month={May}, pages={3445–3488} }