Analysis of fire behaviour simulations over Spain with WRF-FIRE

Wildland fire spread and behaviour are complex phenomena owing to both the number of involved physico-chemical factors, and the non-linear relationship between variables. Spain is plagued by forest and brush fires every summer, when the extremely dry weather sets in along with high temperatures. The use of fire behaviour models requires the availability of high resolution environmental and fuel data; in the absence of real data, errors on the simulated fire spread can be compounded to affect the spatial and temporal accuracy of predicted data. The effect of input values on the accuracy of WRF-FIRE simulations was evaluated to assess the capabilities of the new system for wildland fire in accurately forecasting fire behaviour. The results confirm that the use of accurate meteorological data and a custom fuel moisture content model is crucial to obtain precise simulations of fire behaviour.

Dynamic analysis of physiological properties of Torulaspora delbrueckii in wine fermentations and its incidence on wine quality

This work examines the physiology of a new commercial strain of Torulaspora delbrueckii in the production of red wine following different combined fermentation strategies. For a detailed comparison, several yeast metabolites and the strains implantation were measured over the entire fermentation period. In all fermentations in which T. delbrueckii was involved, the ethanol concentration was reduced; some malic acid was consumed; more pyruvic acid was released, and fewer amounts of higher alcohols were produced. The sensorial properties of final wines varied widely, emphasising the structure of wine in sequential fermentations with T. delbrueckii. These wines presented the maximum overall impression and were preferred by tasters. Semi-industrial assays were carried out confirming these differences at a higher scale. No important differences were observed in volatile aroma composition between fermentations. However, differences in mouthfeel properties were observed in semi-industrial fermentations, which were correlated with an increase in the mannoprotein content of red wines fermented sequentially with T. delbrueckii.

Experimental determination of some physical properties of gasoline,ethanol and ETBE ternary blends

The addition of oxygenated renewable fuels, such as ethanol or ethyl tert-butyl ether (ETBE) to standard gasoline may be necessary to comply with some environmental directives but could also prevent compliance with some fuel regulations and could also seriously change engine performance. From this point of view, the Reid Vapour Pressure (RVP), the distillation curve, the oxygen content and the density belong to the group of the most relevant parameters. This study evaluates the influence of the simultaneous addition of ethanol and ETBE on some physical properties of engine gasoline. The main conclusion is that the simultaneous addition of ETBE and ethanol changes the RVP, the distillation curve and the density in a way that can affect engine operation and the mandatory EN 228 and ASTM D4814 standards. Some opposite properties of both oxygenates could help to increase the renewable energy content without preventing compliance with these regulations.

Clonagem molecular, expressão, purificação e caracterização estrutural da endoglucanase de Trichoderma harzianum visando o desenvolvimento de coquetéis enzimáticos para a produção de etanol lignocelulósico

O aumento na demanda mundial por energia, a perspectiva de encolhimento dos recursos energéticos e a preocupação global com a questão ambiental, despertaram o interesse por fontes alternativas de energia. A biomassa lignocelulósica é abundante e de baixo custo, com potencial para complementar a produção em larga escala de combustíveis. A degradação das moléculas constituintes da parede celular à açúcares fermentescíveis e então à etanol, ocorre através da hidrólise enzimática da biomassa. Contudo, a utilização de enzimas para esse fim encontra-se em estágio exploratório e representa um gargalo na implementação de tecnologias de etanol 2G em escala industrial, desencadeando a busca de celulases bioquimicamente mais ativas, estáveis e economicamente viáveis. O presente trabalho visou a caracterização da endoglucanase I do fungo Trichoderma harzianum, e para isso foi realizada expressão, ensaios bioquímicos e biofísicos do domínio catalítico (ThCel7B-CCD) e da proteína inteira (ThCel7B-full). A enzima exibiu um perfil acidofílico, com atividade ótima em pH 3,0 a 55°C. A proteína também se mostrou capaz de hidrolisar uma variedade de substratos, sendo a maior atividade hidrolítica em β-glucano (75 U mg-1). Ao analisar a estabilidade térmica medida a 55°C em pH 5, a atividade residual manteve-se intacta por mais de 2 meses. Outra característica relevante foi o elevado grau de sinergismo entre ThCel7B e ThCel7A. Análises de microscopia eletrônica de flocos de aveia submetidas à hidrólise com ThCel7B evidenciaram os efeitos de degradação do substrato em relação às amostras controle. O conjunto desses resultados, além de importante para a compreensão do mecanismo molecular de ThCel7B e de outras endoglucanases da família GH7, também revelou uma enzima de interesse biotecnológicos uma vez que o comportamento ácido e sua estabilidade térmica são características relevantes para aplicações industriais sob condições extremamente ácidas.

Gaseificação de vinhaça em água supercrítica.

A gaseificação utiliza o conteúdo intrínseco de carbonos e hidrogênios das matérias primas sólidas ou líquidas na geração de uma mistura de hidrogênio (H2), monóxido de carbono (CO), dióxido de carbono (CO2) e metano (CH4). Tal mistura pode ser utilizada como matéria prima na síntese de novos produtos ou como combustível. A gaseificação pode ser utilizada no processamento de uma gama variada de produtos, independentemente de suas características ou estado físico. A utilização de biomassa como insumo da gaseificação vem sendo cada vez mais explorada e estudada, já que apresenta benefícios não somente na esfera ambiental, mas também em âmbitos econômicos e sociais. A vinhaça é um subproduto do processo de produção de álcool, que contém grandes concentrações de nutrientes e matéria orgânica em sua composição. A sua utilização hoje está limitada a fertirrigação e a aplicações isoladas em biodigestão e outros, que não são suficientes para o consumo da produção anual crescente do resíduo. Seu uso na gaseificação permitiria o aproveitamento do conteúdo orgânico da mesma e a produção de gases de alto valor agregado. Como a umidade do insumo interfere negativamente na eficiência da gaseificação clássica, a aplicação da mesma para matérias primas com alto teor de líquidos não é recomendada. Uma alternativa viável seria a utilização do meio gaseificante supercrítico, que resulta em rendimentos constantes, independentemente da umidade da corrente de entrada do reator. O presente trabalho consiste no projeto de um módulo de gaseificação de vinhaça em água supercrítica, a ser instalado como uma unidade anexa a usinas de açúcar e álcool. Ele compreende o projeto conceitual e análise de viabilidade deste módulo, incluindo estimativas de CAPEX (Capital Expenditure) e OPEX (Operation Expenditure) e uma análise de sensibilidade dos mesmos. O estudo apresenta ainda o estado da arte do conhecimento e da tecnologia de gaseificação com água supercrítica (SCWG), relacionando os gargalos a serem resolvidos, assim como os ganhos intrínsecos da definição conceitual do projeto.

On-line microwave-based preconcentration device for inductively coupled plasma atomic emission spectrometry: Application to the elemental analysis of spirit samples

A microwave-based thermal nebulizer (MWTN) has been employed for the first time as on-line preconcentration device in inductively coupled plasma atomic emission spectrometry (ICP-AES). By the appropriate selection of the experimental conditions, the MWTN could be either operated as a conventional thermal nebulizer or as on-line analyte preconcentration and nebulization device. Thus, when operating at microwave power values above 100 W and highly concentrated alcohol solutions, the amount of energy per solvent mass liquid unit (EMR) is high enough to completely evaporate the solvent inside the system and, as a consequence, the analyte is deposited (and then preconcentrated) on the inner walls of the MWTN capillary. When reducing the EMR to the appropriate value (e.g., by reducing the microwave power at a constant sample uptake rate) the retained analyte is swept along by the liquid-gas stream and an analyte-enriched aerosol is generated and next introduced into the plasma cell. Emission signals obtained with the MWTN operating in preconcentration-nebulization mode improved when increasing preconcentration time and sample uptake rate as well as when decreasing the nozzle inner diameter. When running with pure ethanol solution at its optimum experimental conditions, the MWTN in preconcentration-nebulization mode afforded limits of detection up to one order of magnitude lowers than those obtained operating the MWTN exclusively as a nebulizer. To validate the method, the multi-element analysis (i.e. Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Pb and Zn) of different commercial spirit samples in ICP-AES has been performed. Analyte recoveries for all the elements studied ranged between 93% and 107% and the dynamic linear range covered up to 4 orders of magnitude (i.e. from 0.1 to 1000 μg L−1). In these analysis, both MWTN operating modes afforded similar results. Nevertheless, the preconcentration-nebulization mode permits to determine a higher number of analytes due to its higher detection capabilities.

Steam reforming of ethanol over bimetallic RhPt/La2O3: Long-term stability under favorable reaction conditions

Recently, the steam reforming of biofuels has been presented as a potential hydrogen source for fuel cells. Because this scenario represents an interesting opportunity for Colombia (South America), which produces large amounts of bioethanol, the steam reforming of ethanol was studied over a bimetallic RhPt/La2O3 catalyst under bulk mass transfer conditions. The effect of temperature and the initial concentrations of ethanol and water were evaluated at space velocities above 55,000 h−1 to determine the conditions that maximize the H2/CO ratio and reduce CH4 production while maintaining 100% conversion of ethanol. These requirements were accomplished when 21 mol% H2O and 3 mol% C2H5OH (steam/ethanol molar ratio = 7) were reacted at 600 °C. The catalyst stability was assessed under these reaction conditions during 120 h on stream, obtaining ethanol conversions above 99% during the entire test. The effect of both H2 and air flows as catalyst regeneration treatments were evaluated after 44 and 67 h on stream, respectively. The results showed that H2 treatment accelerated catalyst deactivation, and air regeneration increased both the catalyst stability and the H2 selectivity while decreasing CH4 generation. Fresh and spent catalyst samples were characterized by TEM/EDX, XPS, TPR, and TGA. Although the Rh and Pt in the fresh catalyst were completely reduced, the spent samples showed a partial oxidation of Rh and small amounts of carbonaceous residue. A possible Rh–Pt–Rh2O3 structure was proposed as the active site on the catalyst, which was regenerated by air treatment.

Conversion of low density polyethylene into fuel through co-processing with vacuum gas oil in a fluid catalytic cracking riser reactor

In this work, mixtures of vacuum gas oil and low density polyethylene, a major component of common industrial and consumer household plastics, were pyrolytically co-processed in a fluid catalytic cracking (FCC) riser reactor as a viable alternative for the energy and petrochemical revalorisation of plastic wastes into valuable petrochemical feedstocks and fuel within an existing industrial technology. Using equilibrium FCC catalyst, the oil–polymer blends were catalytically cracked at different processing conditions of temperatures between 773 K and 973 K and catalyst feed ratios of 5:1, 7:1 and 10:1. The influence of each of these processing parameters on the cracking gas and liquid yield patterns were studied and presented. Further analysed and presented are the different compositional distributions of the obtained liquids and gaseous products. The analysis of the results obtained revealed that with very little modifications to existing process superstructure, yields and compositional distributions of products from the fluid catalytic cracking of the oil–polymer blend in many cases were very similar to those of the processed oil feedstock, bringing to manifest the viability of the feedstock co-processing without significant detriments to FCC product yields and quality.

Microwave-Assisted Extraction of Phenolic Compounds from Almond Skin Byproducts (Prunus amygdalus): A Multivariate Analysis Approach

A microwave-assisted extraction (MAE) procedure to isolate phenolic compounds from almond skin byproducts was optimized. A three-level, three-factor Box–Behnken design was used to evaluate the effect of almond skin weight, microwave power, and irradiation time on total phenolic content (TPC) and antioxidant activity (DPPH). Almond skin weight was the most important parameter in the studied responses. The best extraction was achieved using 4 g, 60 s, 100 W, and 60 mL of 70% (v/v) ethanol. TPC, antioxidant activity (DPPH, FRAP), and chemical composition (HPLC-DAD-ESI-MS/MS) were determined by using the optimized method from seven different almond cultivars. Successful discrimination was obtained for all cultivars by using multivariate linear discriminant analysis (LDA), suggesting the influence of cultivar type on polyphenol content and antioxidant activity. The results show the potential of almond skin as a natural source of phenolics and the effectiveness of MAE for the reutilization of these byproducts.

Evidence of Local pH Changes during Ethanol Oxidation at Pt Electrodes in Alkaline Media

Local changes of the interfacial pH can significantly affect the rate and mechanism during the course of an electrodic reaction. For instance, different pH values will have a significant effect on the equilibrium properties of both solution and surface species, altering the reactions kinetics. Ethanol oxidation at platinum electrodes in alkaline media involves the fast consumption of OH− species that will change the local pH at the electrode surface, decreasing the reaction rate. In this study, the local pH change during ethanol oxidation in alkaline media is accomplished by using rotating ring-disc electrode (RRDE) experiments. The current at the ring when polarized at the onset of hydrogen evolution serves as a measure of the local pH in the vicinity of the electrode. The results show that the current at the ring at 0.1 V (vs. RHE) becomes more negative during ethanol oxidation, owing to a change in the equilibrium potential of the hydrogen evolution reaction caused by a change in the local pH.

Ethanol dehydration via azeotropic distillation with gasoline fraction mixtures as entrainers: A pilot-scale study with industrially produced bioethanol and naphta

Various hydrocarbons (n-hexane, cyclohexane, toluene, isooctane) and mixtures of them (binary, ternary or quaternary), as well as two different types of industrially produced naphtha (one obtained by direct distillation and the other from a catalytic cracking process), have been tested as candidate entrainers to dehydrate ethanol. The tests were carried out in an azeotropic distillation column on a semi pilot plant. The results show that it is possible to dehydrate bioethanol using naphtha as entrainer, obtaining as a result a fuel blend with negligible water content and ready for immediate use in motor vehicles.

The combined effect of plastics and food waste accelerates the thermal decomposition of refuse-derived fuels and fuel blends

Mechanical treatments such as shredding or extrusion are applied to municipal solid wastes (MSW) to produce refuse-derived fuels (RDF). In this way, a waste fraction (mainly composed by food waste) is removed and the quality of the fuel is improved. In this research, simultaneous thermal analysis (STA) was used to investigate how different mechanical treatments applied to MSW influence the composition and combustion behaviour of fuel blends produced by combining MSW or RDF with wood in different ratios. Shredding and screening resulted in a more efficient mechanical treatment than extrusion to reduce the chlorine content in a fuel, which would improve its quality. This study revealed that when plastics and food waste are combined in the fuel matrix, the thermal decomposition of the fuels are accelerated. The combination of MSW or RDF and woody materials in a fuel blend has a positive impact on its decomposition.

A statistical evaluation of the effectiveness of FMVSS 301: Fuel System Integrity. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

A computer program (VEHSIM) for vehicle fuel economy and performance simulation (automobiles and light trucks). Volume II: users guide. Final report.

National Highway Traffic Safety Administration, Office of Research and Development, Washington, D.C.

A computer program (VEHSIM) for vehicle fuel economy and performance simulation (automobiles and light trucks). Volume IV: enhancements. Final report.

National Highway Traffic Safety Administration, Office of Research and Development, Washington D.C.