Catalytic Valorization of Biomass : Dehydration, Hydrogenation and Hydrodeoxygenation

Abundant and inexpensive lignocellulosic biomass combined with the wide variety of terpenes, isolable from plants, have emerged as the strongest candidates to replace raw oil as a feedstock in the production of chemicals. Through catalytic modification, biomass feedstocks can be converted to various value-added products that can be utilized in a broad selection of applications. The literature review presents catalytic dehydration, hydrogenation and hydrodeoxygenation (HDO) as defunctionalization methods to synthesize value-added chemicals from multifunctional biomass-based substrates. For example, the hydroxyl groups of monosaccharides, sugar alcohols, and terpenoids can be removed with Brønsted or Lewis acid-catalyzed dehydration, generating versatile platform chemicals for mainly biofuel and polymer applications. Hydrogenation as a valorization method is presented through noble metal-catalyzed hydrogenation of C=C and C=O bonds of diverse lignocellulose-based substrates, for example, the conversion of monosaccharides to sugar alcohols. HDO is an efficient defunctionalization method for simultaneous reduction of unsaturated bonds and lowering the oxygen content of the substrates. Depending on the employed catalyst system, the reaction produces selectively or fully defunctionalized biomass-based products. The main themes of the literature review relate to the subject of the author’s articles published in peer-reviewed journals. The results and discussion section will cover the most significant findings and discussions from the author’s publications. The first part of the section describes new one-step HDO system for the conversion of enlarged furfural derivatives to biofuel compatible alkanes employing Eu(OTf)3 and Pd/C as deoxygenation and hydrogenation catalysts, respectively. The second part will cover the development and study of the new and recyclable Ru/C-based catalysts for the synthesis of isosorbide from lignin-containing cellulose. In the final part of the section, the findings of a robust and highly efficient transition metal triflate catalyzed dehydration of alcohols and terpenoids to olefins are reported. All the publications have significance in the field of biomass valorization and catalytic synthesis of sustainable chemicals.Biomassa on tunnistettu parhaaksi raaka-aineeksi korvaamaan raakaöljy kemikaalien tuotannossa. Kasvit ja puut tuottavat runsaasti käyttökelpoisia yhdisteitä, kuten lignoselluloosaa ja terpeenejä, jotka soveltuvat toisen sukupolven uusiutuvien kemikaalien lähtöaineiksi. Näistä esimerkiksi puu- ja paperiteollisuuden sekä maanviljelyn tähteistä saatavilla olevista yhdisteistä voidaan valmistaa kemikaaleja polymeeri-, polttoaine- sekä hienokemikaalisovelluksiin rikkomalla lignoselluloosan rakennekomponenttien polymeerirakenne ja tämän jälkeisellä funktionaalisten ryhmien poistolla. Väitöskirjan kirjallisuuskatsaus käsittelee biomassapohjaisten lähtöaineiden katalyyttistä arvonlisäystä dehydraatiolla, vedytyksellä sekä hydrodeoksygenaatiolla. Kirjallisuuskatsauksessa painotetaan sakkarideja sekä terpeenialkoholeja lähtöaineina, happokatalyyttistä happipitoisten funktionaalisuuksien poistoa ja tyydyttymättömien sidosten jalometallikatalysoitua vedytystä. Tavoitteena on antaa ymmärrys biomassan muokkauksen nykytilasta ja kehitystarpeista sekä riittävät pohjatiedot väitöskirjan osajulkaisujen uutuuden ymmärtämiseen. Alallaan merkitykselliset väitöskirjan osajulkaisut mukailevat kirjallisuuskatsauksen pääteemoja. Ensimmäinen osajulkaisu käsittelee furfuraalijohdannaisten katalyyttistä hydrodeoksygenaatiota alkaaneiksi, joita voidaan hyödyntää polttoainesovelluksissa. Toisessa osajulkaisussa tutkitaan selluloosan konversiota lääkeaine- sekä polymeerisovelluksiin sopivaksi isosorbidiksi hydrolyysin, vedytyksen sekä dehydraation kautta. Tämän lisäksi artikkelissa käsitellään uuden kestävämmän vedytyskatalyytin kehitystä kyseiseen synteesiin. Kolmannessa osajulkaisussa valmistetaan olefiineja alkoholeista, eettereistä ja estereistä poistamalla lähtöaineiden funktionaalisia ryhmiä siirtymämetallikatalyytteillä. Näitä olefiinejä voidaan hyödyntää polymeerien ja hienokemikaalien valmistuksessa

Selective Aerobic Oxidation of Alcohols with NO3‐ Activated Nitroxyl Radical/Manganese Catalyst System

A homogeneous Mn(NO3)(2)/2,2,6,6-tetramethylpiperidin-1-yl)oxyl/2-picolinic acid catalyst system is highly active and versatile for the selective aerobic oxidation of alcohols (2,2,6,6-tet-ramethylpiperidin-1-yl)oxyl = TEMPO, 2-picolinic acid = PyCOOH). The catalytic method enables near quantitative conversion of various primary alcohols to the respective aldehydes using a very simple reaction setup and workup. This study presents findings on the catalyst stability and mechanisms of deactivation. The results show that NO3- plays a crucial catalytic role in the reaction as a source of oxygen activating NOx species. Yet, disproportionation of NO3- to the volatile NO2 during the reaction leads to catalyst deactivation under open air conditions. Catalyst deactivation through this route can be overcome by adding a catalytic amount of nitrate salt, for example NaNO3 into the reaction. This stabilizes the Mn(NO3)(2)/TEMPO/PyCOOH catalyst and enables oxidation of various primary alcohols to the respective aldehydes using low catalyst loadings under ambient conditions. Secondary alcohols can be oxidized with a modified catalyst utilizing sterically accessible nitroxyl radical 9-azabicyclo[3.3.1]nonane N-oxyl (ABNO) instead of TEMPO. At the end of the alcohol oxidation, pure carbonyl products and the reusable catalyst can be recovered simply by extracting with organic solvent and dilute aqueous acid, followed by evaporation of both phases.Peer reviewe

Energy, Environment and Livelihoods in the Lao PDR : Results from a 2011 Household Survey

This report presents the main results of a household survey collected in 2011. The data was originally collected for FFRC project Interlinkages between energy and livelihoods - Data, training and Scenarios for sustainable energy planning in Laos (INES), funded by the Energy and Environment Partnership (EEP) with the Mekong Region, financed by the Ministry for Foreign Affairs of Finland and the Nordic Development Fund. The demographic profile of the households was surveyed first. The actual questions were related to the following topics: (1) household assets, (2) livelihood activities, (3) income and liabilities, (4) food security and (5) survival strategies, (6) energy use; and (7) environment. This publication is also organized according to these research themes. While the section exploring residential energy use was fairly extensive and utilized throughout the project, the other themes received less attention. The main reason for compiling this e-book was to disseminate all the key results from the survey, especially those with little publicity so far. Similar, recent household level data from Laos is not currently available from any other sources, as far as we know. Thus, this e-Book report provides unique results on the Laotian society and economy based on the household survey findings

Furfuraalien kondensaatioreaktiot

Tässä opinnäytetyössä käsitellään biopohjaisten 2-furaldehydin (furfuraali) ja 5-(hydroksimetyyli)-2-furaldehydin (HMF) sekä näiden johdannaisten katalyyttisiä kondensaatioreaktioita. Kondensaatioreaktioilla näistä lähtöainemolekyyleistä voidaan valmistaa hienokemikaaleja sekä mahdollisia biopolttoaineita. Kirjallisuuskatsauksessa käydään yksityiskohtaisesti läpi neljä eri kondensaatioreakiotyyppiä, aldolikondensaatio, esteröimisreaktio, eetteröimisreaktio sekä pelkistävä aminaatio. Lisäksi katsauksessa on esitetty muutamia muita kirjallisuudessa raportoituja kondensaatioreaktioita. Opinnäytetyöhön on listattu kirjallisuudesta löytyneitä esimerkkejä reaktioiden katalyyteistä sekä reaktiotuotteista. Kokeellisessa osuudessa on tutkittu furfuraalin ja HMF:n aldolikondensaatioreaktiota metyyli-isobutyyliketonin (MIBK) kanssa. Tutkimukset painottuivat enemmän furfuraalin ja MIBK:n reaktioon. Tämän reaktion reaktio-olosuhteet optimoitiin tutkimalla katalyytin aktiivisuutta, reaktioaikaa sekä reaktiolämpötilaa. HMF:n ja MIBK:n aldolikondensaatiossa tutkittiin lähtöaineen puhtauden vaikutusta reaktion saantoon. Myös levuliinihapon ja furfuraalin välistä aldolikondensaatioreaktiota kokeiltiin

Modelling atomic layer deposition overcoating formation on a porous heterogeneous catalyst

Publisher Copyright: © 2022 The Royal Society of Chemistry.Atomic layer deposition (ALD) was used to deposit a protective overcoating (Al2O3) on an industrially relevant Co-based Fischer-Tropsch catalyst. A trimethylaluminium/water (TMA/H2O) ALD process was used to prepare ∼0.7-2.2 nm overcoatings on an incipient wetness impregnated Co-Pt/TiO2 catalyst. A diffusion-reaction differential equation model was used to predict precursor transport and the resulting deposited overcoating surface coverage inside a catalyst particle. The model was validated against transmission electron (TEM) and scanning electron (SEM) microscopy studies. The prepared model utilised catalyst physical properties and ALD process parameters to estimate achieved overcoating thickness for 20 and 30 deposition cycles (1.36 and 2.04 nm respectively). The TEM analysis supported these estimates, with 1.29 ± 0.16 and 2.15 ± 0.29 nm average layer thicknesses. In addition to layer thickness estimation, the model was used to predict overcoating penetration into the porous catalyst. The model estimated a penetration depth of ∼19 μm, and cross-sectional scanning electron microscopy supported the prediction with a deepest penetration of 15-18 μm. The model successfully estimated the deepest penetration, however, the microscopy study showed penetration depth fluctuation between 0-18 μm, having an average of 9.6 μm.Peer reviewe

Low-speed pre-ignition and super-knock in boosted spark-ignition engines : A review

Funding Information: The authors want to thank the support by the Dean’s grant of Aalto University School of Engineering , Henry Ford Foundation of Finland and Technology Industries of Finland, Combustion Engines Branch Group. Publisher Copyright: © 2022 The AuthorsThe introduction of downsized, turbocharged Gasoline Direct Injection (GDI) engines in the automotive market has led to a rapid increase in research on Low-speed Pre-ignition (LSPI) and super-knock as abnormal combustion phenomena within the last decade. The former is characterized as an early ignition of the fuel–air mixture, primarily initiated by an oil–fuel droplet or detached deposit. Meanwhile, super-knock is an occasional development from pre-ignition to high intensity knocking through detonation, which is either initiated by a shock wave interacting with a propagating reaction and cylinder surfaces or inside a hotspot with a suitable heat release and reactivity gradient. The phenomenon can be divided into four stages, including LSPI precursor initiation, establishment and propagation of a pre-ignited flame, autoignition of end-gases and development to a detonation. LSPI and super-knock are rare phenomena, difficult to observe optically in engines, and differences in methodologies and setups between steady-state experiments can lead to discrepancies in results. Experimental research has included more detailed approaches using glow plug-equipped engines, constant volume combustion chambers and rapid compression machines. In addition, the improved availability of mechanisms for fuel and lubricant surrogates has allowed researchers to model the oil–fuel interaction at the cylinder walls, evaporation and autoignition of oil–fuel droplets and regimes for different propagation modes of an autoignition reaction wave. This paper presents a comprehensive review of the underlying phenomena behind LSPI and its development to super-knock. Furthermore, it presents the methodology in experimental research and draws conclusions for mitigating strategies based on studies involving fuel, oil and engine parameters. Finally, it discusses the prerequisites for LSPI from oil–fuel droplets and the future needs of research as original equipment manufacturers (OEM) and lubricant industry have already adopted some proven solutionsto their products.Peer reviewe