acidic hydrolysis, and the production of (bio)ethanol by hydrolysis with cellulases.,,, According to the literature grapefruit peels contains about 27 % of pectin. Based on the results described in Chapters 3 and 4, optimized conditions were used for the extraction of mesoporous cellulose from virgin citrus peels: grapefruit; lemon, and ;lime without any pre-treatment or addition of any mineral acid in order to further understand the variation in textural properties and degree of crystallinity with respect to processing conditions. Within the context of biorefinery it is important that it can operate with different feedstocks depending regardless of security of supply, if orange peel becomes limited i.e., then biorefinery can switch to different citrus waste without compromising productivity. 5.2 Results and Discussion The yields of cellulosic matter post microwave treatment at 180 oC were: grapefruit peel, 5.1% (dark-grey brown); lemon peel, 5.1% (dark grey), and; lime peel, 4.9% (grey). 5.2.1 ATR-IR Spectroscopic analysis Figure 42 shows the ATR-IR spectra of the cellulosic matter derived from microwave hydrothermal treatment at 180 oC of lime-, lemon-, and grapefruit-peel compared with that of cellulosic matter from orange peel under the same extraction conditions to draw a parallel amongst the different fruits belonging to the same family. From the IR spectra shown in Figure 42 no significant difference in the spectra was observed thus the process was feedstock independent and based on Table 2 (Chapter 3, section 3.2.2), the absorption bands of the samples were in complete accordance with the reference absorption bands found for micro-crystalline cellulose. Figure 42. ATR-IR spectra of cellulosic matter derived from different citrus peels at 180 oC compared with the commercial cellulose For further clarity and to show that pectin has been removed very efficiently (significant decrease in absorption bands between 1700 1630 cm-1), the ATR-IR spectra of grapefruit –
acidic hydrolysis, and the production of (bio)ethanol by hydrolysis with cellulases.,,, According to the literature grapefruit peels contains about 27 % of pectin. Based on the results described in Chapters 3 and 4, optimized conditions were used for the extraction of mesoporous cellulose from virgin citrus peels: grapefruit; lemon, and ;lime without any pre-treatment or addition of any mineral acid in order to further understand the variation in textural properties and degree of crystallinity with respect to processing conditions. Within the context of biorefinery it is important that it can operate with different feedstocks depending regardless of security of supply, i.e., if orange peel becomes limited then biorefinery can switch to different citrus waste without compromising productivity. 5.2 Results and Discussion The yields of cellulosic matter post microwave treatment at 180 oC were: grapefruit peel, 5.1% (dark-grey brown); lemon peel, 5.1% (dark grey), and; lime peel, 4.9% (grey). 5.2.1 ATR-IR Spectroscopic analysis Figure 42 shows the ATR-IR spectra of the cellulosic matter derived from microwave hydrothermal treatment at 180 oC of lime-, lemon-, and grapefruit-peel compared with that of cellulosic matter from orange peel under the same extraction conditions to draw a parallel amongst the different fruits belonging to the same family. From the IR spectra shown in Figure 42 no significant difference in the spectra was observed thus the process was feedstock independent and based on Table 2 (Chapter 3, section 3.2.2), the absorption bands of the samples were in complete accordance with the reference absorption bands found for micro-crystalline cellulose. Figure 42. ATR-IR spectra of cellulosic matter derived from different citrus peels at 180 oC compared with the commercial cellulose For further clarity and to show that pectin has been removed very efficiently (significant decrease in absorption bands between 1700 – 1630 cm-1), the ATR-IR spectra of grapefruit
Final%20Mres%20thesis%2010-06-2014.docx