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[EN] Efficient processing of vegetal biomass is a great challenge to current research studies. This work is focused on improving the yield of enzymatic hydrolysis of wood residues by removal of lignin using a alkaline wash assisted by microwave heating. The treatments were carried out for one hour in a pressurized microwave reactor (Synthwave-Milestone). The performance of the treatments was assessed by monitoring the concentration of lignin (determined by UV absorbance at 320 nm against a calibration curve). Each experiment was carried out in duplicate. The treatment conditions were established according to an experimental matrix constructed (in Design Expert 11) after the careful selection of the most important factors that affect the lignin removal from wood residue: concentration of NaOH solution, liquid to solid ratio and temperature. A central composite design was constructed with the independent factors mentioned above. ANOVA indicated adequate fitting of the model (correlation coefficient R2=0.95). The exploration of the experimental space (figure 1) with the fitted model indicates the dominant effect of temperature as independent factor. Optimization of experimental conditions within the experimental space was carried according to the following criteria: minimization of temperature, liquid to solid ratio and NaOH concentration and maximization of the response variable, the lignin concentration. The optimal solution (141 mg lignin / g dry wood residue) proposed by the model for these optimization criteria indicates a point in the region determined by the following coordinates: 0.4M NaOH, 1070C and a ratio of liquid to solid equal to 50.

[EN] Efficient processing of vegetal biomass is a great challenge to current research studies. This work is focused on improving the yield of enzymatic hydrolysis of wood residues by removal of lignin using a alkaline wash assisted by microwave heating. The treatments were carried out for one hour in a pressurized microwave reactor (Synthwave-Milestone). The performance of the treatments was assessed by monitoring the concentration of lignin (determined by UV absorbance at 320 nm against a calibration curve). Each experiment was carried out in duplicate. The treatment conditions were established according to an experimental matrix constructed (in Design Expert 11) after the careful selection of the most important factors that affect the lignin removal from wood residue: concentration of NaOH solution, liquid to solid ratio and temperature. A central composite design was constructed with the independent factors mentioned above. ANOVA indicated adequate fitting of the model (correlation coefficient R2=0.95). The exploration of the experimental space (figure 1) with the fitted model indicates the dominant effect of temperature as independent factor. Optimization of experimental conditions within the experimental space was carried according to the following criteria: minimization of temperature, liquid to solid ratio and NaOH concentration and maximization of the response variable, the lignin concentration. The optimal solution (141 mg lignin / g dry wood residue) proposed by the model for these optimization criteria indicates a point in the region determined by the following coordinates: 0.4M NaOH, 1070C and a ratio of liquid to solid equal to 50.

[EN] Algae are very effective in capturing the sun's energy, carbon dioxide from the atmosphere, and nutrients to turn them into useful substances (carbohydrates, oils, proteins, etc.). Besides the main metabolites, there are also secondary metabolites, such as carotenoids (astaxanthin, β-carotene, lutein, lycopene, and canthaxanthin [1]). Both major and compounds existing in small amounts in algae are useful. Oils and carbohydrates could provide biofuels, proteins can get products with nutritional value and from carotenoids can be prepared food supplements. Obtaining biofuel from algae has not yet proved to be economically viable [2, 3]. A much higher interest might be getting food supplements from algae. To increase their value as ingredients for food supplements, algal oils should have a higher degree of unsaturation (rich in omega 3) and an increased carotenoid content to be an important additional benefit in over all processing of algae. There are studies that refer to the influence of environmental factors on algae composition [2], but the microwave influence on algae growth, especially algal metabolites composition change is very poor studied. In this paper, besides the experiments for the activation of algal growth in discontinuous reactors [4] additional work was conducted in a continuous photobioreactor. The goal was checking not only the growth of microalgae but also their content in polyunsaturated oil and in carotenoids. By microwave-controlled irradiation of the nutrient and algae flux, which is recirculated through the photobioreactor and through a glass reactor located in a TE-type monomod cavity, the lipid content of the algae increased, but only, the modification of the lipid fraction content was significantly increased in the concentration of polyunsaturated acids with 16 and 18 carbon atoms. As far as carotenoids are concerned, the algae nannochloris has a higher carotenoid content over many known vegetables holding carotene or lycopene (carrots

[EN] Efficient processing of vegetal biomass is a great challenge to current research studies. This work is focused on improving the yield of enzymatic hydrolysis of wood residues by removal of lignin using a alkaline wash assisted by microwave heating. The treatments were carried out for one hour in a pressurized microwave reactor (Synthwave-Milestone). The performance of the treatments was assessed by monitoring the concentration of lignin (determined by UV absorbance at 320 nm against a calibration curve). Each experiment was carried out in duplicate. The treatment conditions were established according to an experimental matrix constructed (in Design Expert 11) after the careful selection of the most important factors that affect the lignin removal from wood residue: concentration of NaOH solution, liquid to solid ratio and temperature. A central composite design was constructed with the independent factors mentioned above. ANOVA indicated adequate fitting of the model (correlation coefficient R2=0.95). The exploration of the experimental space (figure 1) with the fitted model indicates the dominant effect of temperature as independent factor. Optimization of experimental conditions within the experimental space was carried according to the following criteria: minimization of temperature, liquid to solid ratio and NaOH concentration and maximization of the response variable, the lignin concentration. The optimal solution (141 mg lignin / g dry wood residue) proposed by the model for these optimization criteria indicates a point in the region determined by the following coordinates: 0.4M NaOH, 1070C and a ratio of liquid to solid equal to 50.

We report a direct comparison of microwave heating and conventional heating in solvent extraction by using exactly the same reaction conditions (including heating rate) in the extraction of polyphenols from dried sea buckthorn leaves. We have for the first time decoupled the effects of bulk heating rate and mixing regime from the fundamental microwave heating mechanism. We show that although microwave selective heating can increase the yield and quality of the polyphenols extracted, if the same bulk heating rate is applied there is no difference in treatment time and therefore theoretical energy requirements of the process. The first implication of these results for process intensification is that if microwave selective heating can be enhanced in scaled up processes through electromagnetic design, the extract yield and quality may be increased further. The second implication is that conventional extraction processes could be designed to provide the same heating rate and hence treatment time as microwave extraction, but any potential energy and space savings would have to be balanced against the increase in capital cost and complexity of the equipment. That said, the very small penetration depth of microwaves into ethanol/water solvent also poses design challenges in the scale up of microwave equipment.

We report a direct comparison of microwave heating and conventional heating in solvent extraction by using exactly the same reaction conditions (including heating rate) in the extraction of polyphenols from dried sea buckthorn leaves. We have for the first time decoupled the effects of bulk heating rate and mixing regime from the fundamental microwave heating mechanism. We show that although microwave selective heating can increase the yield and quality of the polyphenols extracted, if the same bulk heating rate is applied there is no difference in treatment time and therefore theoretical energy requirements of the process. The first implication of these results for process intensification is that if microwave selective heating can be enhanced in scaled up processes through electromagnetic design, the extract yield and quality may be increased further. The second implication is that conventional extraction processes could be designed to provide the same heating rate and hence treatment time as microwave extraction, but any potential energy and space savings would have to be balanced against the increase in capital cost and complexity of the equipment. That said, the very small penetration depth of microwaves into ethanol/water solvent also poses design challenges in the scale up of microwave equipment.

We report a direct comparison of microwave heating and conventional heating in solvent extraction by using exactly the same reaction conditions (including heating rate) in the extraction of polyphenols from dried sea buckthorn leaves. We have for the first time decoupled the effects of bulk heating rate and mixing regime from the fundamental microwave heating mechanism. We show that although microwave selective heating can increase the yield and quality of the polyphenols extracted, if the same bulk heating rate is applied there is no difference in treatment time and therefore theoretical energy requirements of the process. The first implication of these results for process intensification is that if microwave selective heating can be enhanced in scaled up processes through electromagnetic design, the extract yield and quality may be increased further. The second implication is that conventional extraction processes could be designed to provide the same heating rate and hence treatment time as microwave extraction, but any potential energy and space savings would have to be balanced against the increase in capital cost and complexity of the equipment. That said, the very small penetration depth of microwaves into ethanol/water solvent also poses design challenges in the scale up of microwave equipment.

We report a direct comparison of microwave heating and conventional heating in solvent extraction by using exactly the same reaction conditions (including heating rate) in the extraction of polyphenols from dried sea buckthorn leaves. We have for the first time decoupled the effects of bulk heating rate and mixing regime from the fundamental microwave heating mechanism. We show that although microwave selective heating can increase the yield and quality of the polyphenols extracted, if the same bulk heating rate is applied there is no difference in treatment time and therefore theoretical energy requirements of the process. The first implication of these results for process intensification is that if microwave selective heating can be enhanced in scaled up processes through electromagnetic design, the extract yield and quality may be increased further. The second implication is that conventional extraction processes could be designed to provide the same heating rate and hence treatment time as microwave extraction, but any potential energy and space savings would have to be balanced against the increase in capital cost and complexity of the equipment. That said, the very small penetration depth of microwaves into ethanol/water solvent also poses design challenges in the scale up of microwave equipment.

We report a direct comparison of microwave heating and conventional heating in solvent extraction by using exactly the same reaction conditions (including heating rate) in the extraction of polyphenols from dried sea buckthorn leaves. We have for the first time decoupled the effects of bulk heating rate and mixing regime from the fundamental microwave heating mechanism. We show that although microwave selective heating can increase the yield and quality of the polyphenols extracted, if the same bulk heating rate is applied there is no difference in treatment time and therefore theoretical energy requirements of the process. The first implication of these results for process intensification is that if microwave selective heating can be enhanced in scaled up processes through electromagnetic design, the extract yield and quality may be increased further. The second implication is that conventional extraction processes could be designed to provide the same heating rate and hence treatment time as microwave extraction, but any potential energy and space savings would have to be balanced against the increase in capital cost and complexity of the equipment. That said, the very small penetration depth of microwaves into ethanol/water solvent also poses design challenges in the scale up of microwave equipment.