Pyrolysis of spirulina and zeolite cracking over HZSM-5. An analytical investigation on the chemical route of bio-oil from cultivation to combustion

Spirulina (Arthrospira platensis) was cultivated in a 70\uc2\ua0L indoor vertical photobioreactor and harvested at concentrations of 1.0\uc2\ua0g\uc2\ua0L\ue2\u88\u921dry biomass. Lyophilised algal biomass was pyrolysed at 500\uc2\ua0\uc2\ub0C under nitrogen and vapours were passed over pelletised HZSM5- zeolite (SiO2/Al2O338). An organic fraction (bio-oil) overlaying an aqueous phase was obtained by cold trapping, while non-condensed bio-oil components (XAD fraction) were adsorbed onto a poly(styrene\ue2\u80\u94co-divinylbenzene) resin. About 20% of the original algal carbon was converted into inorganic carbon in the aqueous (HCO3\ue2\u88\u92/CO32\ue2\u88\u92) and gas phase (composed of 70%\uc2\ua0CO2, 20%\uc2\ua0CO). Most of spirulina carbon ended up in char (30%) and coke (30%). Bio-oil and XAD fraction represented approximately 10% mass, 20% carbon and 20% energy of algal biomass. Bio-oil composition was dominated by alkylated monoaromatic hydrocarbons, with benzene concentrations below 10\uc2\ua0g\uc2\ua0kg\ue2\u88\u921. Large part of original nitrogen was dissolved in the aqueous phase (40%) and incorporated into char/coke (37%). A minor fraction (6%) of nitrogen ended up in bio-oil in the form of indoles, pyrroles, carbazoles, anilines. While deoxygenation was effective, denitrogenation was incomplete and probably counteracted by zeolite ammonisation. Microcombustion experiments showed that the bio-oil burnt efficiently, but with a sooting flame, and a tendency to form small solid carbonaceous residues probably associated with the presence of heavy compounds

Structural Characterization of Maple Deposited Lipase Biofilm

Lipases (triacylglycerol ester hydrolases) are enzymes used in several industrial applications. Enzymes immobilization can be used to address key issues limiting widespread application at industrial level. Immobilization efficiency is related to the ability to preserve the native conformation of the enzyme. MAPLE (Matrix Assisted Pulsed Laser Evaporation) technique, a laser deposition procedure for treating organic/polymeric/biomaterials, was applied for the deposition of lipase enzyme in an ice matrix, using near infrared laser radiation. Microscopy analysis showed that the deposition occurred in micrometric and submicrometric clusters with a wide size distribution. AFM imaging showed that inter-cluster regions are uniformly covered with smaller aggregates of nanometric size. Fourier transform infrared spectroscopy was used for both recognizing the deposited material and analyzing its secondary structure. Results showed that the protein underwent reversible self-association during the deposition process. Actually, preliminary tests of MAPLE deposited lipase used for soybean oil transesterification with isopropyl alcohol followed by gas chromatography–mass spectrometry gave results consistent with undamaged deposition of lipase

Lipase biofilm deposited by Matrix Assisted Pulsed Laser Evaporation technique

Lipase is an enzyme that finds application in biodiesel production and for detection of esters and tri- glycerides in biosensors. Matrix Assisted Pulsed Laser Evaporation (MAPLE), a technique derived from Pulsed Laser Deposition (PLD) for deposition of undamaged biomolecules or polymers, is characterized by the use of a frozen target obtained from a solution/suspension of the guest material (to be deposited) in a volatile matrix (solvent). The presence of the solvent avoids or at least reduces the potential damage of guest molecules by laser radiation but only the guest material reaches the substrate in an essentially solvent-free deposition. MAPLE can be used for enzymes immobilization, essential for industrial applica- tion, allowing the development of continuous processes, an easier separation of products, the reuse of the catalyst and, in some cases, enhancing enzyme properties (pH, temperature stability, etc.) and catalytic activity in non-aqueous media. Here we show that MAPLE technique can be used to deposit undamaged lipase and that the complex structure (due to droplets generated during extraction from target) of the deposited material can be controlled by changing the laser beam fluence

Matrix Assisted Pulsed Laser Evaporation of Biological Thin Films: Lipase

Lipase is an enzyme catalyzing reactions borne by triglycerides such as transesterification for biodiesel production and has been used in biosensors for detection of β-hydroxyacid esters [1] and triglycerides in blood serum [2]. Immobilization of the enzymes is essential for their industrial application, since it allows the development of continuous processes, easier separation of products, the reuse of the catalyst and, in some cases, it enhances enzyme properties such as pH and temperature stability and their catalytic activity in non-aqueous media [3]. MAPLE is a thin film deposition technique derived from Pulsed Laser Deposition (PLD) for deposition of delicate materials (biomolecules, polymers, etc.) in undamaged form. The main difference in comparison to classical PLD is the use of a frozen (usually by means of a liquid nitrogen flux) target obtained from a solution or a suspension of the guest material (to be deposited) in a matrix (a volatile solvent). In this way, the laser beam energy is mainly absorbed by the matrix while only the guest material reaches the substrate, since the solvent is pumped away by the vacuum system. By MAPLE technique it can be possible to “freeze” the conformation of the lipase as it is in solution, in such a way to tailor lipase properties in solution. In this way the lipase conformation, essential for its catalytic activity, would be independent on the support properties. Here we show that Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique can be used to deposit lipase. 1. T. Kullick, R. Ulber, H.H. Meyer, T. Scheper, K. Schlügerl. Anal. Chim. Acta. 239 (1994) 271 2. Mohanasundaram Sulur Veeramani, Karuppiah Prakash Shyam, Noel Prashant Ratchagar, Anju Chadhabc and Enakshi Bhattacharya, Miniaturised silicon biosensors for the detection of triglyceride in blood serum, Anal. Methods, 2014, Advance Article; DOI: 10.1039/C3AY42274G. 3. P.M. Nielsen, J. Brask, L. Fjerbaek. Eur. J. Lipid Sci. Technol. 110 (2008) 692-700