Biomass Sorghum: Effect of Acid, Basic and Alkaline Peroxide Pretreatments on the Enzymatic Hydrolysis and Ethanol Production

Abstract Quercus infectoria is one of the most abundant native oak species in the Kurdistan region of Iraq. This study focused on utilizing leaves of Quercus infectoria for ethanol production in the region. A typical three-step conversion process of acid pretreatment, enzymatic hydrolysis, and yeast fermentation was investigated to produce ethanol from the leaves. Under the selected acid pretreatment and enzymatic hydrolysis conditions, the glucose and xylose concentrations in the hydrolysates reached 11.4 g/L and 16.8 g/L, respectively, with the corresponding sugar conversions of 42.8% and 99.8%. A yeast strain, Kluyveromyces marxianus, was used to ferment mono-sugars in the hydrolysates for ethanol production. The ethanol production rate and conversion of K. marxianus in the fermentation were 0.17 g/L/h and 27%. The techno-economic analysis further concluded that a regional ethanol biorefinery can be established in the Zawita sub-district, Iraq to utilize Q. infectoria leaves to produce 200,000,000 kg ethanol/year with a positive energy balance of 745,052,623 MJ/year. The net annual revenue of the biorefinery is $123,692,804. The payback period of the biorefinery is 10 years.

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Ethanol Production from Waste of Cassava Processing

Applied Sciences ◽

10.3390/app8112158 ◽

2018 ◽

Vol 8 (11) ◽

pp. 2158 ◽

Cited By ~ 3

Author(s):

Daiana Martinez ◽

Armin Feiden ◽

Reinaldo Bariccatti ◽

Katya de Freitas Zara

Keyword(s):

Enzymatic Hydrolysis ◽

Ethanol Production ◽

First Generation ◽

Chemical Compositions ◽

Energy Matrix ◽

Average Yield ◽

Ph Values ◽

Cassava Bagasse ◽

High Starch ◽

By Products

Cassava processing produces by-products such as brown bark, between bark, disposal, bran, fiber and bagasse. Cassava bagasse is characterized as a source of starch that can be converted into sugars to obtain biofuels. The objective of this work was to produce ethanol from this cassava processing residue and to evaluate its contribution potential in the Brazilian energy matrix. Cassava processing residues were obtained from four different starch manufacturers in Brazil. Analysis of the chemical compositions of these samples provided the content of starch, sugar, crude grease, moisture, ash and also their pH values. For the ethanol process, the samples were submitted to enzymatic hydrolysis using the alpha-amylase and amyloglucosidases enzymes, followed by fermentation and distillation. The samples showed high starch indices, approximately 64% on average. The average yield of ethanol obtained was 30% after treatment of the sample like this. Considering the estimated volume of cassava bagasse in Brazil, it is possible to produce an average of 789 million cubic meters per bagasse, replacing about 24% of the first generation ethanol. Cassava bagasse can be considered an interesting biomass for the production of biofuels, contributing to the expansion of the energy matrix.

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Ethanol Production from Non-Detoxified Steam-Exploded Corn Stover Subsequent Enzymatic Hydrolysis by Two Toxin-Tolerant Yeast Strains

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.365.145 ◽

2011 ◽

Vol 365 ◽

pp. 145-149

Author(s):

Xun Men ◽

Xiu Shan Yang ◽

Shen Tian

Keyword(s):

Enzymatic Hydrolysis ◽

Ethanol Production ◽

Corn Stover ◽

Fermentation Process ◽

Ethanol Concentration ◽

Enzymatic Hydrolysate ◽

Yeast Strains ◽

Inhibitory Compounds ◽

Operation Cost ◽

Detoxification Process

Fermentation process for ethanol production from steam-exploded corn stover using toxin-tolerant yeast strains was carried out in order to reduce the water consumption and operation cost. The substrate from steam-exploded did not undergo a detoxification process by wash, and was directly hydrolyzed by enzymes. Two toxin-tolerant stains, Y1 and Y5, were tested to ferment the enzymatic hydrolysate slurry directly to ethanol. In the enzymatic hydrolysate slurry containing inhibitory compounds, the strain Y1 and Y5 could convert the sugar to ethanol with ethanol concentration of 47.0 g/L and 47.2 g/L corresponding to 95.9% and 96.4% of the theoretical maximum, respectively.

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