Evaluation of second generation biofuels production from native halophytes by chemical-characterization of Salicornia sinus-persica

Transcription

1 Evaluation of second generation biofuels production from native halophytes by chemical-characterization of Salicornia sinus-persica Ayah Alassali, Iwona Cybulska, Mette H. Thomsen phone: Version 1 1

2 Contents Introduction Masdar Institute and SBRC The importance of halophytes for desert areas Study objectives Methodology Sugar content Extent glucan to glucose convertibility Results Wet fractionation results Sugar content analysis for juice Juice fermentability Sugar content analysis for pulp Fibers fermentability Conclusions 2

3 Introduction Masdar Institute The Masdar Institute of Science and Technology (Masdar Institute) is a graduate level, research-oriented university which is focused on alternative energy, sustainability, and the environment. 3

4 Introduction SBRC The Sustainable Bioenergy Research Consortium was established by the Masdar Institute of Science and Technology. The SBRC is focused on research in sustainable biofuels and biomaterials derived from the conversion of plant oils and biomass. 4

5 Introduction ISEA 5

6 Introduction Abu Dhabi exemplifies a coastal desert, where seawater could be used for salt-tolerant crops (halophytes) cultivation. The produced halophyte biomass could be utilized in feed, food and/or energy production, depending on its chemical composition. In this study the UAE native halophyte Salicornia sinus-persica was studied for its potential to be used as a feedstock for green biorefinery. 6

7 Study Objective: Wet fractionation of Fresh Halophyte Biomass 7

8 Methodology Sugar analysis Washed Salicornia Unwashed Salicornia Juicing Fibers Dry matter and ash content analysis Dry matter and ash content analysis Juice Strong acid hydrolysis Weak acid hydrolysis Fresh untreated juice Sugar monomer composition analysis by HPLC 8

9 Methodology Extent glucan to glucose convertibility Juice Autoclaved at 121 C, 20 min. Fresh/ no-pretreatment SSF Fibers Fresh/ no-pretreatment Mildly pretreated at 121 C, 30 and 60 min. Hydrothermal pretreatment SSF SSF conditions: cellulases (Novozymes) was used, with a pre-hydrolysis time of 2 hours at 50 C with intensive shaking (120 rpm) prior to addition of S. cerevisiae at 32 C for 7 days. 9

10 Results Wet fractionation/ DM and ash content Fresh biomass 18.19% Fibers DM (%) Ash (%) of the DM % Juice DM (%) Ash (%) of the DM DM (%) Ash (%) of the DM

11 Concentration (g/l) Results Fresh juice vs. acid hydrolyzed juice cellulose and inhibitors content Glucose Xylose Arabinose Acetic acid Ethanol 1 0 Unwashed-fresh juice Unwashed-WAH Washed-freshjuice Washed-WAH Washing had no effect on sugar composition Acid hydrolysis increases pentose content Total sugar content of the juice is approx % (comparable to other green biomasses such as grass and clover) 11

12 Concentration (g/l) Results Juice fermentation Fermentation of fresh juice of Salicornia sinus-persica with S. cerevisiae Time (hours) Glucose Xylose Arabinose Ethanol Lactic acid Acetic acid Formic acid 12

13 Ethanol yield (%) Results Juice fermentation Time (h) 13

14 Concentration (g/l) Results Autoclaved (121 C for 20 minutes) vs. fresh Juice fermentation Lactic acid Formic acid Acetic acid Ethanol Furfural 14

15 Content (g/100gdm) Results Fiber s sugar content after strong acid hydrolysis of fresh biomass Glucose Xylose Arabinose Fibers of washed biomass Fibers of unwashed biomass 15

16 concentration (g/100 g DM) Results Sugar content after mild pretreatment of the fibers at 121 C for 30 and 60 min Glucose Xylose Arabinose W 30-Un 60-W 60-Un The monomeric sugars were concentrated Pretreatment duration did not influence the sugar concentration 16

17 Ethanol yield (% of the theoretical) Results Ethanol yield in SSF of pretreated pulp from wet fractionation of Salicornia sinus-persica after mild pretreatment C, 30-min, hydrolyzate 121 C, 30-min, water (diluted) 121 C, 60-min, hydrolyzate 121 C, 60-min, water (diluted) 17

18 content (g/100gdm) Results Fiber s sugar content w/wo pretreatment Lactose Glucose Xylose Galactose Fructose Ash 0 Fresh 121 C 150 C 170 C 18

19 Ethanol yiels (% to the theoretical ethanol content) Results Ethanol yields after SSF of fresh and pretreated fibers Fresh 10 minutes 10 minutes 10 minutes Low severity factors Ethanol yield can reach up to 86% when treated at 170 C for 10 minutes 19

20 Conclusion Fresh Salicornia sinus-perica contains more than 70% of water. For such green biomass direct fractionation and fermentation can be advantageous. This allows for water preservation and the ability to run at lower dry matter in the fermentation step. High yield per hectares (green biomass yield up to 50 tons/ha/year) and possibility of harvesting several times per year. Biomass washing does not significantly enhance juice/fibers fermentation. Juice autoclaving does not enhance the ethanol fermentation, however minimize inhibitor s formation. Juice fermentation can obtain up to 100% yield of ethanol (based on theoretical yields). Fibers free sugars content increase with increasing the pretreatment temperature, however the possibility of producing inhibitors increases as well. 20

21 Thank You Ayah Alassali phone: