PUBLICATIONS

Report with Catalist evaluation results (2012) pdf

In the report catalysts screening studies were carried targeting to the selection of the best catalyst for the catalytic pyrolysis process of acid hydrolysis residues (AHR). This process focuses on the production of an upgraded biooil that could be used as diesel or diesel miscible biofuel and it is an upgrading process of AHR.
Development of near infrared spectroscopy models for the quantitative prediction of the lignocellulosic components of wet Miscanthus samples, Hayes, DJ Bioresource Technology, 119 (2012) 393-405.

Abstract:
Miscanthus samples were scanned over the visible and near infrared wavelengths at several stages of processing (wet-chopped, air-dried, dried and ground, and dried and sieved). Models were developed to predict lignocellulosic and elemental constituents based on these spectra. The dry and sieved scans gave the most accurate models; however the wet-chopped models for glucose, xylose, and Klason lignin provided excellent accuracies with root mean square error of predictions of 1.27%, 0.54%, and 0.93%, respectively. These models can be suitable for most applications. The wet models for arabinose, Klason lignin, acid soluble lignin, ash, extractives, rhamnose, acid insoluble residue, and nitrogen tended to have lower R2 values (0.80+) for the validation sets and the wet models for galactose, mannose, and acid insoluble ash were less accurate, only having value for rough sample screening. This research shows the potential for online analysis at bioreﬁneries for the major lignocellulosic constituents of interest.
Autothermal, single-stage, performic acid pretreatment of Miscanthus x giganteus for the rapid fractionation of its biomass components into a lignin/hemicellulose-rich liquor and a cellulase-digestible pulp, Haverty, D; Dussan, K; Piterina, AV; Leahy, JJ; Hayes, MHB; Bioresource Technology 109 (2012) 173–177.

Abstract:
A novel approach to the performic acid pulping of biomass enables effective deligniﬁcation and fractionation in a time frame not achieved heretofore. An autothermal decomposition reaction was triggered when 100 mg/L Fe2(SO4)3 in 4.0 M NaOH was added to 5% or 7.5% H2O2 in aqueous formic acid containing chipped Miscanthus x giganteus. Peroxy-decomposition resulted in pressures of 19 and 35 bar in the 5% and 7.5% peroxide liquors and reduced the lignin content in the resulting pulps to <6% within 140 and 30 min, respectively. Solubilised lignin was available for recovery from the liquor by subsequent dilution with water. Hemicellulose removal to the liquor was 68% and 89% for the 5% and 7.5% peroxide solutions. Crystalline cellulose yields were >99% and >95% and the rate of glucose release from cellulase digestion of the pulps in 24 h was more than 20-fold that for the raw Miscanthus.

The authors acknowledge ﬁnancial support via a research grant from EU-FP7-DIBANET project and via the a Postdoctoral Fellowship (A.V.P.) from the Enterprise Partnership Scheme co-funded by the Irish Research Council for Sc.
Pressurised Pyrolysis of Miscanthus using a Fixed Bed Reactor. Melligan, F; Auccaise, R; Novotny, EH; Leahy, JJ; Hayes, MHB; Kwapinski, W; Bioresource Technology 102 (2011) 3466-3470.

Abstract:
Miscanthus x giganteus was pyrolysed, in a fixed bed reactor in a constant flow of dinitrogen gas, at a rate of 13 °C/min from ambient to 550 °C, then held for 25 min at this temperature. The pressures employed ranged from atmospheric to 26 bar. The major compounds identified in the bio-oil were water, phenol, and phenol derivatives. The water contents impact on the usefulness of the bio-oil as a fuel. However, the phenols could provide useful platform chemicals and products. The properties of the char were determined using elemental analyses, surface area measurements using the Brunauer–Emmett–Teller equation, a calorimetric bomb, Scanning Electron Microscopy, and solid state 13C NMR spectroscopy. The chars were highly carbonised, especially at the higher pressures, and provided thermally stable materials. Pressure impacted greatly on the surface area. Char formed at atmospheric pressure had a surface area of 162 m2/g, whereas that from the highest pressure applied was only 0.137 m2/g.
Characterisation of the products from pyrolysis of residues after acid hydrolysis of Miscanthus. Melligan, F; Dussan, K; Auccaise, R; Novotny, EH; Leahy, JJ; Hayes, MHB; Kwapinski, W. Bioresource Technology, 108 (2012) 258–263.

Abstract:
Platform chemicals such as furfural and hydroxymethylfurfural are major products formed during the acid hydrolysis of lignocellulosic biomass in second generation biorefining processes. Solid hydrolysis residues (HR) can amount to 50 wt.% of the starting biomass materials. Pyrolysis of the HRs gives rise to biochar, bio-liquids, and gases. Time and temperature were variables during the pyrolysis of HRs in a fixed bed tubular reactor, and both parameters have major influences on the amounts and properties of the products. Biochar, with potential for carbon sequestration and soil conditioning, composed about half of the HR pyrolysis product. The amounts (11–20 wt.%) and compositions (up to 77% of phenols in organic fraction) of the bio-liquids formed suggest that these have little value as fuels, but could be sources of phenols, and the gas can have application as a fuel.
Biochar and soil nitrous oxide emissions, Alho, CFBV; Cardoso, AS; Alves, Bruno JR; Novotny, EH. Pesquisa Agropecuária Brasileira, 47 (2012) 722-725.

Abstract:
The objective of this work was to evaluate the effect of biochar application on soil nitrous oxide emissions. The experiment was carried out in pots under greenhouse conditions. Four levels of ground commercial charcoal of 2 mm (biochar) were evaluated in a sandy Albaqualf (90% of sand): 0, 3, 6, and 9 Mg ha-1. All treatments received 100 kg ha-1 of N as urea. A cubic effect of biochar levels was observed on the N2O emissions. Biochar doses above 5 Mg ha-1 started to mitigate the emissions in the evaluated soil. However, lower doses promote the emissions.
Reproducing the organic matter model of anthropogenic dark earth of Amazonia and testing the ecotoxicity of functionalized charcoal compounds, Linhares, CR; Lemke, J; Auccaise, R; Duó, DA; Ziolli, RL; Kwapinski, W; Novotny, EH. Pesquisa Agropecuária Brasileira. 47 (2012) 693-698.

Abstract:
The objective of this work was to obtain organic compounds similar to the ones found in the organic matter of anthropogenic dark earth of Amazonia (ADE) using a chemical functionalization procedure on activated charcoal, as well as to determine their ecotoxicity. Based on the study of the rganic matter from ADE, an organic model was proposed and an attempt to reproduce it was described. Activated charcoal was oxidized with the use of sodium hypochlorite at different concentrations. Nuclear magnetic resonance was performed to verify if the spectra of the obtained products were similar to the ones of humic acids from ADE. The similarity between spectra indicated that the obtained products were polycondensed aromatic structures with carboxyl groups: a soil amendment that can contribute to soil fertility and to its sustainable use. An ecotoxicological test with aphnia similis was performed on the more soluble fraction (fulvic acids) of the produced soil amendment. Aryl chloride was formed during the synthesis of the organic compounds from activated charcoal functionalization and partially removed through a purification process. However, it is probable that some aryl chloride remained in the final product, since the ecotoxicological test indicated that the chemical functionalized soil amendment is moderately toxic.
Context and importance of biochar research, Madari, BE; Maia, CMBF; Novotny, EH. Pesquisa Agropecuária Brasileira. 47 (2012) i-ii.

In the context of global warming, major changes are expected in the worldwide energy matrix in the near future. Biomass, a renewable source, as a raw material for energy production, is fundamental in this process.
Catalytic upgrading of levulinicacid to ethyl levulinate using reusable silica-included Wells-Dawson heteropolyacid as catalyst, Pasquale, G; Vazquez, P; Romanelli, G; Baronetti, G, Catalysis Communications 18 (2012) 115–120.

Abstract
In this paper we report, for the first time, the direct incorporation of a heteropolyacid (HPA) withWells-Dawson structure during the synthesis of silica by the sol–gel technique, in acidic media, using tetraethyl orthosilicate. The catalyst characterization was carried out by 31PMAS-NMR, FT-IR, XRD,N2 adsorption–desorption measurements, and the acidic properties were determined through potentiometric titration with n-butylamine. The synthesized catalysts were used in the esterification of levulinic acid with ethanol, at 78 °C, to obtain ethyl levulinate. The synthesis of silica-included HPAs was satisfactory, and the samples kept their HPA structure intact after synthesis. The catalytic tests for the esterification reaction between levulinic acid and ethanol to produce ethyl levulinate have shown that the silica-included Wells-Dawson HPA is an active and selective catalyst for this reaction. It must be noted that silica-included HPAs also kept their structure and catalytic activity after three consecutive reaction cycles. These results indicated that these solid acids are promissory catalysts for the esterification reaction of levulinic acid and ethanol to ethyl levulinate.
Levulinicacid esterification with ethanol to ethyl levulinate production over solidacid catalysts, Fernandesa, DR; Rochaa, AS; Maia, EF; Motab, CJA; da Silva, VT, Applied Catalysis A: General 425– 426 (2012) 199– 204.

Abstract:
Levulinic acid is considered as a versatile building block because it can be used for the synthesis of several organic chemicals. In particular, its esterification with ethanol produces ethyl levulinate that can be used as diesel miscible biofuel (DMB), preventing global warming by decreasing atmospheric CO2 generated from the consumption of fossil fuels. This article explores the use of two groups of solid acid catalysts (sulfated oxides and zeolites with different pore structures) in the esterification of levulinc acid with ethanol aiming for ethyl levulinate production. It was found that while there is a correlation between the number of acidic sites and activity for the sulfated oxides, the same is not true for the studied zeolites where the pore channels play a more important role. Among the catalysts tested, Amberlyst-15 and sulfated SnO2 showed a remarkable high yield of ethyl levulinate that was probably due to the strong acidity provided by SO3H functional groups and SO4 species, respectively.
Advances in Biochar Research in Brazil, Maia, CMBF; Madari, BE; Novotny, EH. (2011) Dynamic Soil, Dynamic Plant, 5 (Special Issue 1). 53-58.

Absract:
To mitigate global warming, major changes in the global carbon balance are expected as the world’s larger economies migrate to energy matrices that emit less greenhouse gases (GHG). Alternatives of carbon-neutral technologies have led to significant alterations in the global balance of carbon. One example is the biochar, which is any source of biomass previously heated under low or no oxygen supply with the purpose of application on soil. This review aims to give an overview about the research carried out in Brazil on biochar-to-soil technology, from its structural characterization to field trials all over the country.