Novel Nanostructured Pd/Co-Alumina Materials for the Catalytic Oxidation of Atmospheric Pollutants.

Cobalt-doped alumina catalysts were prepared using different methods, either conventional wet impregnation (WI) and/or advanced spray impregnation (SI), and they were evaluated as novel oxidation catalysts for CO and MeOH oxidation. The spray impregnation technique was used with the aim of achieving the synthesis of core-shell catalytic nanostructures to secure the chemical/thermal stability of active sites on the catalyst carrier. The catalysts were further promoted with a low Pd content (0.

Adsorption of Hydrogen Sulfide on Activated Carbon Materials Derived from the Solid Fibrous Digestate.

The goal of this work is to develop a sustainable value chain of carbonaceous adsorbents that can be produced from the solid fibrous digestate (SFD) of biogas plants and further applied in integrated desulfurization-upgrading (CO/CH separation) processes of biogas to yield high-purity biomethane. For this purpose, physical and chemical activation of the SFD-derived BC was optimized to afford micro-mesoporous activated carbons (ACs) of high BET surface area (590-2300 mg) and enhanced pore volume (0.57-1.

Understanding the Upgrading of Sewage Sludge-Derived Hydrothermal Liquefaction Biocrude via Advanced Characterization.

Hydrothermal liquefaction (HTL) can thermochemically transform sewage sludge into a biocrude with high energy content, high chemical complexity, and high O and N content. The development of an efficient upgrading process for such complex feedstocks necessitates detailed knowledge of the molecular composition and the specific heteroatom-containing compounds to understand and optimize the hydrotreating reactions. In this study, we present the upgrading of sewage sludge-derived HTL biocrude via a two-stage hydrotreatment process and perform advanced chemical characterization of the feedstock, intermediate, and final upgraded products with gas chromatography-mass spectrometry (GC-MS) and Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS).

Efficient production of nutraceuticals and lactic acid from lignocellulosic biomass by combining organosolv fractionation with enzymatic/fermentative routes.

The aim of this work was to investigate the use of isobutanol as organic solvent for the efficient delignification and fractionation of beechwood through the OxiOrganosolv process in the absence of any catalyst. The results demonstrate that cellulose-rich solid pulp produced after pretreatment is a source of fermentable sugars that can be easily hydrolyzed and serve as a carbon source in microbial fermentations for the production of omega-3 fatty acids and D-lactic acid. The C5 sugars are recovered in the aqueous liquid fractions and comprise a fraction rich in xylo-oligosaccharides with prebiotic potential.

Conversion of organosolv pretreated hardwood biomass into 5-hydroxymethylfurfural (HMF) by combining enzymatic hydrolysis and isomerization with homogeneous catalysis.

Background: Over the last few years, valorization of lignocellulosic biomass has been expanded beyond the production of second-generation biofuels to the synthesis of numerous platform chemicals to be used instead of their fossil-based counterparts. One such well-researched example is 5-hydroxymethylfurfural (HMF), which is preferably produced by the dehydration of fructose. Fructose is obtained by the isomerization of glucose, which in turn is derived by the hydrolysis of cellulose.

Novel trends in the thermo-chemical recycling of plastics from WEEE containing brominated flame retardants.

The amount of plastics from waste electric and electronic equipment (WEEE) has enormously increased nowadays, due to the rapid expansion and consumption of electronic devices and their short lifespan. This, in combination with their non-biodegradability, led to the need to explore environmentally friendly solutions for their safe disposal. One main obstacle when recycling plastics from WEEE is that they usually comprise harmful additives such as brominated flame retardants (BFRs) that need to be removed before or during their recycling.

OxiOrganosolv: A novel acid free oxidative organosolv fractionation for lignocellulose fine sugar streams.

The valorization of lignocellulosic biomass towards the production of value-added products requires an efficient pretreatment/fractionation step. In this work we present a novel, acid-free, mildly oxidative organosolv delignification process -OxiOrganosolv- which employs oxygen gas to depolymerize and remove lignin. The results demonstrate that the OxiOrganosolv process achieved lignin removal as high as 97% in a single stage, with a variety of solvents; it was also efficient in delignifying both beechwood (hardwood) and pine (softwood), a task in which organosolv pretreatments have failed in the past.

Utilization of lignocellulosic biomass towards the production of omega-3 fatty acids by the heterotrophic marine microalga Crypthecodinium cohnii.

Omega-3 fatty acids have become a commodity of high nutritional and commercial value; intensive fishing and its environmental and social cost has led researchers to seeking alternative more sustainable ways of producing them. Heterotrophic microalgae such as Crypthecodinium cohnii, a marine dinoflagellate, have the ability to utilize various substrates and accumulate high amounts of docosahexaenoic acid (DHA). In this work, a mild oxidative organosolv pretreatment of beechwood pulps was employed that allowed up to 95% of lignin removal in a single stage, thus yielding a cellulose-rich solid fraction.

Scaling-Up of Bio-Oil Upgrading during Biomass Pyrolysis over ZrO /ZSM-5-Attapulgite.

Ex situ catalytic biomass pyrolysis was investigated at both laboratory and bench scale by using a zeolite ZSM-5-based catalyst for selectively upgrading the bio-oil vapors. The catalyst consisted of nanocrystalline ZSM-5, modified by incorporation of ZrO and agglomerated with attapulgite (ZrO /n-ZSM-5-ATP). Characterization of this material by means of different techniques, including CO and NH temperature-programmed desorption (TPD), NMR spectroscopy, UV/Vis microspectroscopy, and fluorescence microscopy, showed that it possessed the right combination of accessibility and acid-base properties for promoting the conversion of the bulky molecules formed by lignocellulose pyrolysis and their subsequent deoxygenation to upgraded liquid organic fractions (bio-oil).

Utilisation of poultry industry wastes for liquid biofuel production via thermal and catalytic fast pyrolysis.

The objective of this study was to examine the potential of poultry wastes to be used as feedstock in non-catalytic and catalytic fast pyrolysis processes, which is a continuation of our previous research on their conversion into biofuel via slow pyrolysis and hydrothermal conversion. Both poultry meal and poultry litter were examined, initially in a fixed bed bench-scale reactor using ZSM-5 and MgO as catalysts. Pyrolysis of poultry meal yielded high amounts of bio-oil, while pyrolysis of poultry litter yielded high amounts of solid residue owing to its high ash content.

Acid Assisted Organosolv Delignification of Beechwood and Pulp Conversion towards High Concentrated Cellulosic Ethanol via High Gravity Enzymatic Hydrolysis and Fermentation.

Background: Future biorefineries will focus on converting low value waste streams to chemical products that are derived from petroleum or refined sugars. Feedstock pretreatment in a simple, cost effective, agnostic manner is a major challenge.

Methods: In this work, beechwood sawdust was delignified via an organosolv process, assisted by homogeneous inorganic acid catalysis.

Effect of Steam Deactivation Severity of ZSM-5 Additives on LPG Olefins Production in the FCC Process.

ZSM-5-containing catalytic additives are widely used in oil refineries to boost light olefin production and improve gasoline octanes in the Fluid Catalytic Cracking (FCC) process. Under the hydrothermal conditions present in the FCC regenerator (typically >700 °C and >8% steam), FCC catalysts and additives are subject to deactivation. Zeolites (e.

Impact of Macroporosity on Catalytic Upgrading of Fast Pyrolysis Bio-Oil by Esterification over Silica Sulfonic Acids.

Fast pyrolysis bio-oils possess unfavorable physicochemical properties and poor stability, in large part, owing to the presence of carboxylic acids, which hinders their use as biofuels. Catalytic esterification offers an atom- and energy-efficient route to upgrade pyrolysis bio-oils. Propyl sulfonic acid (PrSO H) silicas are active for carboxylic acid esterification but suffer mass-transport limitations for bulky substrates.

Production of high concentrated cellulosic ethanol by acetone/water oxidized pretreated beech wood.

Background: Lignocellulosic biomass is an abundant and inexpensive resource for biofuel production. Alongside its biotechnological conversion, pretreatment is essential to enable efficient enzymatic hydrolysis by making cellulose susceptible to cellulases. Wet oxidation of biomass, such as acetone/water oxidation, that employs hot acetone, water, and oxygen, has been found to be an attractive pretreatment method for removing lignin while producing less degradation products.

Catalysis Meets Nonthermal Separation for the Production of (Alkyl)phenols and Hydrocarbons from Pyrolysis Oil.

A simple and efficient hydrodeoxygenation strategy is described to selectively generate and separate high-value alkylphenols from pyrolysis bio-oil, produced directly from lignocellulosic biomass. The overall process is efficient and only requires low pressures of hydrogen gas (5 bar). Initially, an investigation using model compounds indicates that MoC /C is a promising catalyst for targeted hydrodeoxygenation, enabling selective retention of the desired Ar-OH substituents.

Quantitative and qualitative analysis of hemicellulose, cellulose and lignin bio-oils by comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry.

Thermal and catalytic pyrolysis are efficient processes for the transformation of biomass to bio-oil, a liquid energy carrier and a general source of chemicals. The elucidation of the bio-oil's composition is essential for a rational design of both its production and utilization process. However, the complex composition of bio-oils hinders their complete qualitative and quantitative analysis, and conventional chromatographic techniques lack the necessary separation power.

Effect of temperature on lignin-derived inhibition studied with three structurally different cellobiohydrolases.

Non-productive enzyme adsorption onto lignin inhibits enzymatic hydrolysis of lignocellulosic biomass. Three cellobiohydrolases, Trichoderma reesei Cel7A (TrCel7A) and two engineered fusion enzymes, with distinctive modular structures and temperature stabilities were employed to study the effect of temperature on inhibition arising from non-productive cellulase adsorption. The fusion enzymes, TeCel7A-CBM1 and TeCel7A-CBM3, were composed of a thermostable Talaromyces emersonii Cel7A (TeCel7A) catalytic domain fused to a carbohydrate-binding module (CBM) either from family 1 or from family 3.

An integrated process for the production of platform chemicals and diesel miscible fuels by acid-catalyzed hydrolysis and downstream upgrading of the acid hydrolysis residues with thermal and catalytic pyrolysis.

This study evaluates an integrated process for the production of platform chemicals and diesel miscible biofuels. An energy crop (Miscanthus) was treated hydrothermally to produce levulinic acid (LA). Temperatures ranging between 150 and 200 °C, sulfuric acid concentrations 1-5 wt.

Inhibition of enzymatic hydrolysis by residual lignins from softwood--study of enzyme binding and inactivation on lignin-rich surface.

Lignin-derived inhibition is a major obstacle restricting the enzymatic hydrolysis of cell wall polysaccharides especially with softwood lignocellulosics. Enzyme adsorption on lignin is suggested to contribute to the inhibitory effect of lignin. The interaction of cellulases with softwood lignin was studied in the present work with commercial Trichoderma reesei cellulases (Celluclast) and lignin-rich residues isolated from steam pretreated softwood (SPS) by enzymatic and acid hydrolysis.

Qualitative and quantitative analysis of pyrolysis oil by gas chromatography with flame ionization detection and comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry.

Pyrolysis oils have attracted a lot of interest, as they are liquid energy carriers and general sources of chemicals. In this work, gas chromatography with flame ionization detector (GC-FID) and two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS) techniques were used to provide both qualitative and quantitative results of the analysis of three different pyrolysis oils. The chromatographic methods and parameters were optimized and solvent choice and separation restrictions are discussed.