Process intensified lauric acid self-ketonization and its economic and environmental impact on biolubricant base oil production
Intensified lauric acid self-ketonization and its impact on biolubricant base oil production.
09 BIOMASS FUELS↗
Engineering topics
Saha, Basudeb
Publications and source records attributed to Saha, Basudeb.
Chemical Recycling Processes of Waste Polyethylene Terephthalate Using Solid Catalysts
Polyethylene terephthalate (PET) is a non-degradable single-use plastic and a major component of plastic waste in landfills. Chemical recycling is one of the most widely adopted methods to transform post-consumer PET into PET's building block chemicals. Non-catalytic depolymerization of PET is very slow and requires high temperatures and/or pressures. Recent advancements in the field of material science and catalysis have delivered several innovative strategies to promote PET depolymerization under mild reaction conditions. Particularly, heterogeneous catalysts assisted depolymerization of post-consumer PET to monomers and other value-added chemicals is the most industrially compatible method. Here, this review includes current progresses on the heterogeneously catalyzed chemical recycling of PET. It describes four key pathways for PET depolymerization including, glycolysis, pyrolysis, alcoholysis, and reductive depolymerization. The catalyst function, active sites and structure-activity correlations are briefly outlined in each section. An outlook for future development is also presented.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Bio-based polymers from raw lignocellulosic biomass
Disclosed herein is a method of making polymerizable bio-based monomers containing one phenolic hydroxyl group which has been derivatized to provide at least one polymerizable functional group which is an ethylenically unsaturated functional group (such as a [meth]acrylate group), where the precursors of the polymerizable bio-based monomers are derived from raw lignin-containing biomass. Also disclosed herein are bio-based copolymers prepared from such bio-based monomers and a co-monomer, and methods of making and using such bio-based copolymers. In particular, the bio-based copolymers can be used as pressure sensitive adhesives, binders, and polymer electrolytes.
Epps, III, Thomas H.↗
Production of Environmentally-Acceptable BioLubricants for Hydropower Applications
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09 BIOMASS FUELS↗
Synthesis of (hemi)cellulosic lubricant base oils via catalytic coupling and deoxygenation pathways
The past decade has witnessed a significant growth in bioproduct development due to the strong interest in creating a more diverse energy supply, environmental sustainability, and a carbon neutral bioeconomy. The initial biorefinery strategy, which focused mainly on the production of low carbon number drop-in bioproducts, has recently shifted its focus on the production of high carbon number and high performance bioproducts with unique properties and value propositions. One such product is lubricant base oil (LBO), which represents over $150 billion global lubricant market and is used for various industrial, automotive, marine, metal-working, consumer, and specialized applications. The application landscape of lubricants has changed significantly over the past decade because of environmental regulations and the growing demand for sustainable lubricants to mitigate regulatory challenges and improve carbon footprint. Currently, only 3% LBOs are produced from bio-based triglycerides/fatty acids. Because of low oxidation stability and high hydrolytic susceptibility, these bio-based LBOs have limited applications. Thus, research and development and commercialization efforts for (hemi)cellulosic LBOs to meet the market demand have received momentum over the past few years. This review describes strategies to produce (hemi)cellulosic LBOs via carbon–carbon coupling and hydrodeoxygenation chemistries. We emphasize the coupling strategies to create LBOs with a branched architecture to surrogate petroleum-based poly-α-olefins. Here, a structure–property relationship for tuning the key specifications of LBOs as a function of molecular architecture is illustrated. Mechanistic understanding and molecular interactions of multi-furan substrates with the active sites of complex multifunctional catalysts are described. Furthermore, techno-economic and life-cycle analysis is summarized along with standing challenges and future opportunities.
09 BIOMASS FUELS↗
Liquid–Liquid Microfluidic Flows for Ultrafast 5-Hydroxymethyl Furfural Extraction
We study the effects of liquid–liquid flow patterns on the extraction of 5-hydroxymethyl furfural from the aqueous phase into an organic phase (methyl isobutyl ketone, ethyl acetate, and 2-pentanol) at ultrashort residence times of 0.2–20 s in a coiled capillary microchannel. Slug, droplet, slug-droplet, dispersed, parallel, annular, and irregular two-phase flow patterns are generated. We evaluate the extraction efficiency and the volumetric mass transfer coefficient via experiments and computational fluid dynamics (CFD). The CFD predictions are in quantitative agreement with the experimental data. The convective and diffusive contributions to the mass transfer of different flow patterns are analyzed. For all solvent pairs, the extraction efficiency varies irregularly with increasing flow rate due to changes in the mass transfer mechanism caused by a transition between flow regimes. Overall, we demonstrate >90% extraction efficiencies with high volumetric mass transfer coefficients ranging from 0.006 to 2.17 s–1. Furthermore, a merit index is defined to assess the trade-off between the fast mass transfer and the pressure drop in biphasic microchannels. In general, the mass transfer rate increases significantly at high flow rates at the expense of a high-pressure drop. Furthermore, the ethyl acetate/water irregular flow pattern is optimal due to a large throughput, extraction efficiency, and mass transfer coefficient, with a minimal pressure drop.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
One-step lignocellulose depolymerization and saccharification to high sugar yield and less condensed isolated lignin
The cost of sugar production remains a key challenge in future lignocellulosic biorefineries. We demonstrate that ZnBr 2 , an inexpensive inorganic salt, provides nearly theoretical yields of glucose and xylose in one-step from poplar wood at 85 °C and short reaction times at molten salt hydrate (MSH) conditions without an acid. Catalytic depolymerization of the isolated MSH lignin, using a CoS 2 catalyst, yields 17% phenol-like monomers compared to only 1% produced from the acidified MSH lignin. Reductive catalytic fractionation of MSH lignin over Ru/C resulted in two times higher total monomer yield compared to the AMSH lignin. Both the lignin samples were characterized using 2D HSQC NMR and the thioacidolysis method. Thioacidolysis studies reveal 8.4% and 1.8% of β-O-4 linkages in MSH and acidified MSH lignin, respectively. Thermodynamic modeling and 13 C NMR spectroscopy indicate that the effectiveness of this catalyst arises from the strong interaction of the Lewis acidic zinc cation (Zn 2+ ) with the coordinated water molecules resulting in hydrolysis of the metal aquo complex and to the salt-driven increase in the H + activity coefficient. Techno-economic analysis demonstrates that despite being slower, the ZnBr 2 MSH media has cost advantages, compared to conventional hydrolysis and even to the LiBr and ZnBr 2 AMSH, due to the higher quality of lignin.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Fast microflow kinetics and acid catalyst deactivation in glucose conversion to 5-hydroxymethylfurfural
5-Hydroxymethyl furfural (HMF) is an important platform chemical because it can be upgraded to various drop-in and performance-advantaged products. The cascade reaction of HMF production from glucose over a Lewis acid (CrCl 3 ) and a Brønsted acid (HCl) catalyst in aqueous media is investigated in a microreactor at short residence times and high temperatures. We study the formation of various chromium species using UV-visible spectrophotometry and elucidate the Cr(III) speciation. The catalyst reactivity increases sharply at short residence times, and then drops at long times. This indicates that the catalyst treatment plays a vital role in getting optimal reactivity, and recording the catalyst history is necessary. We develop a kinetic model to describe the catalyst speciation as well as the Lewis and Brønsted acid-catalyzed reaction kinetics using a hierarchical approach. Here, the model is in good agreement with experiments. We demonstrate the benefits of tandem Lewis-external added Brønsted acid catalysis in processing time, productivity, and catalyst stability. We apply this model to optimize the HMF yield and obtain ~36% yield at 200 °C in 7 min and report the highest productivity of ~15% yield per min, demonstrating the opportunity of reaching high productivity at short residence times.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
Thiol-promoted catalytic synthesis of high-performance furan-containing lubricant base oils from biomass derived 2-alkylfurans and ketones
About 97% of lubricant base oils are currently sourced from petroleum and the majority of the rest is produced from vegetable oils. We demonstrate a promising catalytic route to produce base oils from lignocellulosic biomass-derived 2-alkylfurans and ketones via carbon–carbon coupling in neat conditions. Among several homogeneous and heterogeneous acid catalysts tested, a perfluorinated sulfonic acid (Aquivion PW79S) exhibits the best catalytic performance and yields up to 90% renewable furan-containing base oils with the use of a thiol promotor. The effects of the acid strength of the catalysts, molecular size and structure of thiols and ketones, and fraction of thiols are studied. Electronic structure calculations elucidate the reaction pathway and indicate that the thiol reduces the barrier of the rate-determining dehydration step. The structure and properties of base oils can be tuned by using different synthons. Here, these base oils have excellent properties and can be competitive with or surpass the commercial synthetic alkylnaphthalene and furan-containing bio-ester base oils.
09 BIOMASS FUELS↗
Integrated process for direct saccharification and dehydration of intact biomass to furfurals
A method of converting a lignocellulosic biomass to monosaccharides, and optionally further converting the monosaccharides to one or both of furfural and HMF, includes contacting the biomass with a reactive liquid phase comprising LiBr, H 2 SO 4 , and water, wherein H 2 SO 4 preferably constitutes at most 1.0 wt %, more preferably at most 0.5 wt %, and most preferably at most 0.1 wt % of the reactive liquid phase, and water preferably constitutes at most at most 60 wt %, more preferably at most 50 wt %, and most preferably at most 30 wt % of the reactive liquid phase.
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