Laiza Canielas Krause

Dry washing in biodiesel purification: a comparative study of adsorbents

The purpose of this work is to compare the efficiency of different adsorbents in the purification of biodiesel produced by alkaline transesterification of soybean oil (Methanol/KOH). The proposed methodologies were based on the use of Magnesol®, silica, Amberlite BD10 DRY® and Purolite PD 206® as adsorbents and were developed by adsorption at 65 oC. The response of each adsorbent was measured through the residual potassium, alcohol, water and soaps dissolved in the purified biodiesel. As a result, we observe that Magnesol® and silica showed better adsorption properties than Amberlite BD10 DRY® and Purolite PD 206®, especially for removing soap, free and bonded glycerol and potassium. In comparison to the conventional acid water washing, these matrices were found to be equally appropriate for the removal of inorganic and organic contaminant species from biodiesel. The main results found for these two adsorbents (Magnesol® 1% and silica 2%) were values below 0.17 mg KOH g-1 for acid number, 1 mg kg-1 of K, 61 ppm of soap, 500 mg kg-1 of water, 0.22% of methanol and 0.03% of free glycerol

Preliminary studies of bio-oil from fast pyrolysis of coconut fibers.

This work studied fast pyrolysis as a way to use the residual fiber obtained from the shells of coconut ( Cocos nucifera L. var. Dwarf, from Aracaju, northeastern Brazil). The bio-oil produced by fast pyrolysis and the aqueous phase (formed during the pyrolysis) were characterized by GC/qMS and GC×GC/TOF-MS. Many oxygenated compounds such as phenols, aldehydes, and ketones were identified in the extracts obtained in both phases, with a high predominance of phenolic compounds, mainly alkylphenols. Eighty-one compounds were identified in the bio-oil and 42 in the aqueous phase using GC/qMS, and 95 and 68 in the same samples were identified by GC×GC/TOF-MS. The better performance of GC×GC/TOF-MS was due to the possibility of resolving some coeluted peaks in the one-dimension gas chromatography. Semiquantitative analysis of the samples verified that 59% of the area on the chromatogram of bio-oil is composed by phenols and 12% by aldehydes, mainly furfural. Using the same criterion, 77% of the organic compounds in the aqueous phase are phenols. Therefore, this preliminary assessment indicates that coconut fibers have the potential to be a cost-effective and promising alternative to obtain new products and minimize environmental impact.

Pyrolysis of Agroindustrial Residues of Coffee, Sugarcane Straw and Coconut-Fibers in a Semi-pilot Plant for Production of Bio-oils: Gas Chromatographic Characterization

Microbial, vegetal or animal organic matter, which has potential to be transformed into energy, is considered biomass. Among the various alternative energy sources, biomass is the only one with the possibility of generating a class of substances of interest for fine chemistry (ketones, aldehydes, alcohols, phenols, etc.). From biomass, it is possible to produce bio-oil using pyrolysis, a thermodegradation process. The quality of the bio-oil depends on the process conditions (pyrolysis temperature, heating temperature, etc.) and biomass used. In this paper, the pyrolysis (using a fixed bed reactor) of three biomasses (coconut fiber, coffee grounds and sugar cane straw) is studied. The results indicated that the bio-oil yields for all biomass were similar, approximately 37%. The chemical profile obtained by gas chromatography coupled with mass spectrometry (GC/qMS) showed high amounts of fatty acids in the coffee grounds bio-oil and aliphatic and aromatic hydrocarbons in coconut fiber bio-oil, whereas guaiacols were the predominant components of the sugar cane straw bio-oil.

Quantification of nitrogen compounds in diesel fuel samples by comprehensive two‐dimensional gas chromatography coupled with quadrupole mass spectrometry

Although several methods for the analysis of nitrogen compounds in diesel fuel have been described in the literature, the demand for rapid, sensitive, and robust analyses has increased in recent years. In this study, a comprehensive two-dimensional gas chromatographic method was developed for the identification and quantification of nitrogen compounds in diesel fuel samples. The quantification was performed using the standard addition method and the analysis was conducted using comprehensive two-dimensional gas chromatography coupled with fast quadrupole mass spectrometry. This study is the first to report quantification of nitrogen compounds in diesel fuel samples using the standard addition method without fractionation. This type of analysis was previously performed using many laborious separation steps, which can lead to errors and losses. The proposed method shows good linearity for target nitrogen compounds evaluated (m-toluidine, 4-ethylaniline, indole, 7-methylindole, 7-ethylindole, carbazole, isoquinoline, 4-methylquinoline, benzo[h]quinolone, and acridine) over a range from 0.05 to 2.0 mg/L, and limits of detection and quantification of <0.06 and 0.16 mg/L, respectively, for all nitrogen compounds studied.

Chromatographic Methods Applied to the Characterization of Bio-Oil from the Pyrolysis of Agro-Industrial Biomasses

Biomass conversion into solid, liquid and gaseous products by pyrolytic technology is one of the most promising alternative to convert the biomass into useful products and energy. The total characterization of the products from the pyrolysis of biomass is one of the great challenges in this field, mainly due to their molecular complexity. Pyrolysis is a process that causes degradation of biomass in a non‐oxidative atmosphere, at rela‐ tively high temperatures, producing a solid residue rich in carbon and mineral matter, gases and bio‐oil. The yield and properties of the products depend on the nature of the biomass and the type of the pyrolysis process (type of reactor, temperature, gas flow, catalyst). Due to the high molecular complexity of bio‐oil, many different technical had been developed to their complete characterization. This chapter describes the principles of the techniques and main application of chromatographic methods (GC, LC, GC × GC, LC × LC, Nano‐LC) in the analysis of bio‐oils derived from thermo‐degradation of bio‐ masses. Especial attention is carried out to two‐dimensional techniques that represent the state of the art in terms of separation, sensibility, selectivity and velocity of data acquisi‐ tion for characterization of complex organic mixtures. For proper use of bio‐oil in the chemical industry, it is essential the identification and unambiguous determination of its major constituents. Only then, it is possible to propose a recovery route of some of these components for the development of an industry dedicated to a bio‐refinery. For this, chromatographic methods, especially GC × GC/MS, are fundamental because they allow analysis with high sensitivity and accuracy in identifying each constituent of the bio‐oil.

Production of xanthan gum from soybean biodiesel: a preliminary study

Background Xanthan gum, a commercial microbial polysaccharide, has many industrial applications, including the tertiary recovery of oil, due to its unique rheological behavior (e. g. high viscosity at low concentrations, pseudoplasticity, solubility, stability over a wide range of pH values and temperatures, compatibility with many salts) [1]. Its production employs glucose or sucrose, which raises the price of xanthan production. One way to reduce the cost is to use cheaper alternative substrates, like residues [2]. Biodiesel is included in this context because its chemical composition is susceptible to oxidation, which decreases its capacity as a fuel, resulting in the possibility of organic residue accumulation [3]. Thus, biodiesel conversion into xanthan gum by a fermentation process is one alternative for reducing costs, since the substrate is a critical aspect in its commercial production, and also for minimizing possible environmental impacts. Accordingly, the goal this study was to evaluate the effect of soybean biodiesel as an alternative substrate for non-food grade xanthan gum biosynthesis.

Chemical characterisation of Piper amalago (Piperaceae) essential oil by comprehensive two-dimensional gas chromatography coupled with rapid-scanning quadrupole mass spectrometry (GC×GC/qMS) and their antilithiasic activity and acute toxicity

INTRODUCTION Piper amalago has a distribution from Mexico to Brazil; their aerial parts have been used in folk medicine to treat diuretic and kidney diseases. OBJECTIVE The purpose of this study was to obtain a deeper understanding of the chemical composition of essential oils (EOs) extracted from both the leaves and stems of P. amalago, compare them, and evaluate their antilithiasic activity and acute toxicity. METHODOLOGY Extraction was performed by hydrodistillation, whereas chemical characterisation by two-dimensional gas chromatography coupled with rapid-scanning quadrupole mass spectrometry (GC×GC/qMS). The antilithiasic activity was evaluated by the effect of the EOs on calcium oxalate crystallisation in vitro. The turbidity index and the number of crystals formed were determined and used as an estimative of the activity. In the acute toxicity assay, the effects of a single oral dose of the EOs in Wistar rats were determined. General behaviour, adverse effects, and mortality were determined. RESULTS A total of 322 compounds were identified in the EOs. The sesquiterpenes displayed the highest contribution in leaves EOs among which included bicyclogermacrene and δ-cadinene. Sesquiterpenes and oxygenated sesquiterpenes displayed the highest contribution in EOs from stems, among which included bicyclogermacrene and α-cadinol. The EOs demonstrated an excellent action on the crystals growth inhibition, and the oral dose tested did not induce significant changes in the parameters for acute toxicity. CONCLUSION The oils have a high chemical complexity, and there are differences between their compositions, which could explain the observed differences in antilithiasic activity. The findings support the use of this plant in folk medicine to treat kidney diseases.

Ultrasonic Extracts of Morinda citrifolia L.: Characterization of Volatile Compounds by Gas Chromatography-Mass Spectrometry

Morinda citrifolia (noni) is found in the Atlantic and Amazonian Forest in Brazil and with recognized uses in folk medicine. However, few studies exist in its chemical characterization. The present work aims to investigate the efficiency of the sonication for extracting bioactive compounds from fruits and leaves of noni, using an experimental design of 2, whose variables were time, temperature and mass of the plant. Parallel extractions were performed using two extraction solvents (hexane and ethanol) and the same experimental design. The compounds were identified by gas chromatography coupled to mass spectrometry. The independent variable was the mass yield and all the variables studied in the sonication process were significant (p < 0.05%) for the process. Ethanol was more effective than hexane and the leaves produced higher yield and diversity of compounds than fruits. Vitamin E (tocopherol), octanoic acid, hydroxymethylfurfural, phytol and squalene were the main compounds identified.

Comprehensive Two-Dimensional Gas Chromatography and Its Application to the Investigation of Pyrolytic Liquids

The chapter presents basic principles of one-dimensional gas chromatography (1D-GC) and comprehensive two-dimensional gas chromatography (GC × GC) related to the main advantages of the two-dimensional technique, as well as its application to the study of organic compounds in liquids derived from coal, mainly through pyrolysis and extraction. It also shows the investigation of compounds contained in bio-oils obtained from biomass through pyrolysis, using GC × GC. Advances in scientific knowledge related to the composition of these complex matrices are shown through different examples of GC × GC analyses, such as the identification of trace compounds that would not be perceived by 1D-GC, organized patterns of elution of structurally related compounds that help their identification, etc. Examples shown make it clear that GC × GC is the technique of choice to elucidate composition of these complex matrices.

Biotechnological route for obtaining methyl esters from crambe oil (Crambe abyssinica)

The fatty acid esters synthesis by transesterification of oils to produce biodiesel commonly involves methanol or ethanol as acyl acceptor. The transesterification of vegetable oils catalyzed by lipases is an alternative process for obtaining biodiesel. These biocatalysts working under mild conditions of temperature, allow for easy recovery of glycerol, synthesis of specific alkyl esters and transesterification of triglycerides with high concentrations of free fatty acids. The seeds of crambe (Crambe abyssinica) have a high oil content and great potential for biodiesel production [1]. In this way, the present work aims at crambe oil transesterification with methanol catalyzed by immobilized lipase Novozyme 435 (Candida antarctica).