Kariba weed (Salvinia molesta) was used as biomass feedstock for ethanol production by separate hydrolysis and fermentation (SHF). Monosaccharides from Kariba weed hydrolysate were produced using thermal acid hydrolysis, sonication, and enzymatic saccharification. The optimal conditions for thermal acid hydrolysis of 12% (w/v) Kariba weed slurry were evaluated as 200 mM HNO3 at 121 °C for 60 min yielding 10.2 g/L monosaccharides. Sonication for 45 min before enzymatic saccharification yielded more monosaccharides to 18.7 g/L. Enzymatic saccharification with 16 U/mL Cellic CTec2 produced 35.4 g/L monosaccharides. Fermentation was performed using Saccharomyces cerevisiae, Kluyveromyces marxianus, or Pichia stipitis with sonicated Kariba weed hydrolysate. The control fermentations were carried out using Kariba weed hydrolysate without sonication. The improvement of ethanol production from sonicated Kariba weed hydrolysate using P. stipitis produced 15.9 g/L ethanol with ethanol yield coefficient YEtOH = 0.45, K. marxianus produced 14.7 g/L ethanol with YEtOH = 0.41. S. cerevisiae produced the lowest yield of 13.2 g/L ethanol with YEtOH = 0.37 as it utilized only glucose not xylose. Sonication of Kariba weed was essential in the ethanol production to enhance the productivity of monosaccharides. P. stipitis was determined as the best yeast species using hydrolysates with the mixture of glucose and xylose to produce ethanol.

Enhanced Bioethanol Fermentation by Sonication Using Three Yeasts Species and Kariba Weed (Salvinia molesta) as Biomass Collected from Lake Victoria, Uganda

This research was conducted to investigate mortality using logistic regression (Models) for River red-gum (Eucalyptud camaldulensis Dehnh) in Afaka Forest Reserve, Kaduna, Nigeria. Stratified random sampling and proportional sampling allocation were used in selecting plots and individual trees for measurements. Data on live and dead trees were recorded, variables measured are diameter, total tree heights, spacing and age of the stands within the plots. Diameter at the breast height (DBH) was measured using diameter tape while Haga Altimeter was used in taking the total height of the sampled stands. The Data collected were divided into four portions. Three portions (75%) for model calibration adopting logistic regression model, 25% were used for model validation of logistic model generated.  Chi square test of goodness-of-fit, Negelkerke R2, Cox and snell R2 values were used for model evaluation. The positive regression coefficients (16.737, 49.266 and 1.992) showed by Dbh, Height and age (as independent variables) indicated positive future mortality effects on the stands; as the trees ages and increases in size and height, the chances of mortality will increase. At the present age and sizes of the stands the fitted model shows no significant relationship between the current age, height and size of the stands, as such the notion held by the management of the plantation that Eucalyptus cannot grow for many years and in large sizes is not true. There is therefore, need for periodic re-measurement of the stands to evaluate future effect of the variables (Age, Dbh and height) on mortality.

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Modeling Tree Mortality for Eucalyptus camaldulensis (Dehnh) Stands in Afaka Forest Reserve, Kaduna-Nigeria

This study describes the production of lignocellulosic bioethanol from highland bamboo (Yushania alpina) via pressurized hot water pretreatment, dilute acid hydrolysis and fermentation using Saccha...

Cellulosic ethanol production from highland bamboo (Yushania alpina) grown in Ethiopia

Pongamia pinnata, a tree bearing oil seeds, has been one of the prime focus among nonedible oil sources for biodiesel production in most parts of India. The oil cake obtained after the extraction of oil serves as an adequate source of cellulose, hemicellulose, proteins, lipids, and starch. The scarce literature data available suggest very low conversion rate of complex sugars to fermentable sugars and further to bioethanol. In the present work, a sulfuric acid hydrolysate obtained from Pongamia oil cake (POC) under microwave irradiation was anaerobically fermented using Bacillus cereus ATCC 14579. Under anaerobic and acidic conditions, the process parameters affecting the bioethanol production efficiency (BPE) were screened and optimized using statistical experimental designs. Of the seven parameters screened (glucose concentration, yeast extract as nitrogen source, agitation speed, pH, inoculum size, fermentation time, and temperature), only 3 were found to be significant and to increase BPE. The significant parameters were optimized using the Box-Behnken experimental design to obtain an optimal condition of 9 g/l reducing sugars, pH 4.6 maintained with acetate buffer, and fermentation period of 51 h that yielded 92% BPE with 4.2 g/l ethanol. Moreover, it was observed that the use of a buffer system to maintain broth pH, especially acetate buffer, significantly improved BPE. Low concentration of fermentation inhibitors is the key factor for improved BPE. The research outcome suggests that the production of dual fuel from Pongamia pinnata, viz. biodiesel and bioethanol, could not only improve the process economics but also reduce waste generation.

Value addition to Pongamia biodiesel industry through bioethanol production from pressed oil cake using Bacillus cereus

Bioethanol is promising alternative fuel due to its less effect to environment. It is produced from bio-sources, such plant materials. Yeast and NPK have been reported as the ingredients in affecting bioethanol fermentation. The aim of this study was to examined the effect of yeast and NPK in bioethanol fermentation using the pericarp of “Abacaxi” pinnapple cultivar (Ananas comosus cv. “Abacaxi”). The pericarp juice of “Abacaxi” pineapple was made by blending the fresh pericarp and aquadest (1 : 1.5). The juice was then mix with dry commercial yeast (1 g, 2.5 g and 5 gr) and NPK  (1 g, 2 g, 3 g). A total of 9 treatments were used in fermentation.  Each treatment was replicated three times, brought the total sample was 27. The percentage of bioethanol for each treatment was measure using alcoholmeter for six days (24 h, 48 h, 72 h, 96 h, 120 h and 144 h). The result show that the percentage of bioethanol produced in this study varies among different treatment and fermentation time. Yeast and NPK gave significant effect in bioethanol fermentation, with the combination of 5 g yeast and 3 g NPK gave the highest percentage of bioethanol in 144 h of fermentation. Based on the result of this study, the pericarp of “Abacaxi” pineapple is potential bio-source for bioethanol fermentation.

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The Effect of Yeast, NPK and Fermentation Time in Bioethanol Fermentation from “Abacaxi” Pinapple Pericarp

An evaluation of sugar content and bioethanol potential of some freshwater biomass namely; Eichhornia crassipes (Water Hyacinth) Pistia stratiotes (Water Lettuce) and Salvinia molesta (Water Fern) was carried out in a batch hydrolysis and fermentation processes. Determinations of xylose and glucose content were achieved using phloroglucinol and Dinitrosalicylic assay respectively. While the amount of glucose in E. crassipes, P. stratiotes and S. molesta were 0.08, 0.07 and 0.04 g/L, that of xylose were found to be 0.11, 09 and 0.07 g/L respectively. The results of analysis of biofuel potential show that maximum ethanol yield of 25 cm3 was observed in E. crassipess, 25 cm3 in P. stratiotes and 20 cm3 was found in S. molesta after 21days of fermentation and this gave a corresponding mean yield of 18.3 cm3, 17.6 cm3 and 15.0 cm3 respectively. The study concludes that the sugar content in the freshwater biomass determined the amount of ethanol yield. While there are no significant differences in the bioethanol production potential between the three biomass samples, E. crassipess and P. stratiotes have higher yield than S. molesta.

http://article.sciencepublishinggroup.com/pdf/10.11648.j.ijrse.20130206.12.pdf

Evaluation of Sugar Content and Bioethanol Potentials of Some Freshwater Biomass

The economic and ecological problems associated with fossil fuel have raised interest in biofuel research in recent times in different parts of the world. The use of Eucalyptus forest waste biomass with no appreciable value to industries or for food as alternative and cost effective feedstock for bioethanol production was evaluated in this study. E. camaldulensis biomass (bark and leaves) were pretreated separately with acid (2M H2SO4) and Microwave irradiation (250V, 50Hz) prior to fermentation with Bacillus subtilis and Escherichia coli isolated from surrounding soil. Higher yield of reducing sugar were obtained from bark (43 %) and leaves (38.5 %) pretreated by microwave irradiation as compared with acid treated plant biomass. Similarly, Bioethanol volume and concentration of 34.89 g/l and 0.51 % respectively were higher in Microwave irradiated bark of E. camaldulensis at 21 days of fermentation when E. coli and B. subtilis were used in synergy The least bioethanol volume yield of 18.79 g/l and concentration of 0.12 % when bark and leaves of E. camaldulensis were combined was obtained on day 7 of fermentation using E. coli. The study concludes that the amount of dried wastes generated (37.8 kg) from one average stand of Eucalyptus tree could yield significant volume (131,884.2 g/l) of bioethanol when B. subtilis and E. coli are used in synergy.

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Bioethanol Production from Eucalyptus camaldulensis Wood Waste Using Bacillus subtilis and Escherichia coli Isolated from Soil in Afaka Forest Reserve, Kaduna State Nigeria

Muhammad Muktar Namadi

Papers

Evaluation of Sugar Content and Bioethanol Potentials of Some Freshwater Biomass

Bioethanol Production from Eucalyptus camaldulensis Wood Waste Using Bacillus subtilis and Escherichia coli Isolated from Soil in Afaka Forest Reserve, Kaduna State Nigeria