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Methods and Industrial Applications
Series: De Gruyter STEM
Series: De Gruyter STEM
Series: De Gruyter STEM
Stereoselective Reactions and Applications in Organic Synthesis

Abstract

Bangladesh produces a large amount of corn, pumpkin and carrots every year. To meet its huge energy demand and to lessen dependence on traditional fossil fuel these products are cost effective, renewable and abundant source for bioethanol production. The research was aimed to evaluate Bangladeshi corn, rotten carrot and pumpkin for bioethanol production. About 100 g of substrates was mixed with 300 ml distilled water and blended and sterilized. All the experiment was conducted with a temperature of 35oC, pH 6.0 and 20% sugar concentration. For fermentation, 200 ml yeast (Saccharomyces cerevisiae CCD) was added to make the total volume 500 ml. Addition of small amount of 1750 unit α-amylase enzyme to the substrate solution was found to enhance the fermentation process quicker. After 6- days of incubation, corn produced 63.00 ml of ethanol with 13.33 % (v/v) purity. Bioethanol production capacity of two different local varieties of pumpkin (red and black color) was assessed. Red pumpkin (Cucurbita maxima L.) produces 53 ml of ethanol with purity 6 %v/v and black color pumpkin produces 40 ml of yield with a low purity 4 %v/v. Carrot (Daucus carota L.) produces 73.67 ml of ethanol with 12.66 % (v/v) purity.

Abstract

World health organization (WHO) data shows that air pollution kills an estimated seven million people worldwide every year. A nanofiber based biodegradable facemask can keep breath from smoke and other particles suspended in the air. In this study, we propose branched polymeric nanofibers as a biodegradable material for air filters and facemasks. Fibers have been elecrospun using double bubble electrospinning technique. Biodegradable polymers, PVA and PVP were used in our experiment. Two tubes, each filled with one of the polymers, were supplied with air from the bottom to form bubbles of polymer solutions. DC 35-40 kV was used to deposit the fibers on an aluminum foil. Results show that the combination of polymers under specific conditions produced branched fibers with average nanofibers diameter of 495nm. FT-IR results indicate the new trends in the graph of composite nanofibers.

Abstract

Several techniques, in which different homogenous catalysts and procedures, that are in use for transesterification of a vegetable oil or an animal fat have been successful in synthesizing biodiesel, although with some certain limitations. For such a purpose, among the catalysts employed are acidic as well as basic catalysts. It has been found that acidic catalysts can be tolerant with a high content of free fatty acids found in those low value feedstock oils/fats to be transesterified, although some sort of pretreatment by means of esterification might be required in order to synthesize biodiesel. Moreover, with employing homogenous acidic catalysts, it seems that biodiesel purification procedures are simplified; thus, reducing synthesis cost. In fact, these features of homogenous acidic catalysts render them advantageous over basic ones. With basic homogenous catalysts this; however, has not been possible due to the development of saponification reaction. To effectively perform, such catalysts require that the content of free fatty acids in the feedstock oil/fat is minimal. This requirement is also applicable to the moisture level in the feedstock. In terms of corrosive effects; nevertheless, acidic catalysts are disadvantageous compared to basic ones.