Comparison between solid-state and powder-state alkali pretreatment on saccharification and fermentation for bioethanol production from rice straw

Extracting ethanol by steam directly from fermented solid-state bagasse is an emerging technology of energy-efficient bioethanol production. With continuous solid-state distillation (CSSD) approach, the vapor with more than 25 wt% ethanol flows out of the column. Conventionally, the vapor was concentrated to azeotrope by rectification column, which contributes most of the energy consumption in ethanol production. As an alternative, a process integrating CSSD and vapor permeation (VP) membrane separation was tested. In light of existing industrial application of NaA zeolite hydrophilic membrane for dehydration, the prospect of replacing rectification operation with hydrophobic membrane for ethanol enriching was mainly analyzed in this paper. The separation performance of a commercial PDMS/PVDF membrane in a wide range of ethanol–water-vapor binary mixture was evaluated in the experiment. The correlation of the separation factor and permeate flux at different transmembrane driving force was measured. The mass and energy flow sheet of proposed VP case and rectification case were estimated respectively with process simulation software based on experimental data. Techno-economic analysis on both cases was performed. The results demonstrated that the additional VP membrane cost was higher than the rectification column, but a lower utilities cost was required for VP. The discount payback period of supplementary cost for VP case was determined as 1.81 years compared with the membrane service lifetime of 3 years, indicating that the hybrid CSSD-VP process was more cost effective and energy efficient.

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Bioethanol production: An integrated process of low substrate loading hydrolysis-high sugars liquid fermentation and solid state fermentation of enzymatic hydrolysis residue

Bioresource Technology ◽

10.1016/j.biortech.2012.07.118 ◽

2012 ◽

Vol 123 ◽

pp. 699-702 ◽

Cited By ~ 10

Author(s):

Qiulu Chu ◽

Xin Li ◽

Bin Ma ◽

Yong Xu ◽

Jia Ouyang ◽

...

Keyword(s):

Solid State ◽

Enzymatic Hydrolysis ◽

Solid State Fermentation ◽

Bioethanol Production ◽

Integrated Process ◽

Liquid Fermentation ◽

Hydrolysis Residue

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A study on alkali pretreatment conditions of sorghum stem for maximum sugar recovery using statistical approach

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq120826008n ◽

2014 ◽

Vol 20 (2) ◽

pp. 261-271 ◽

Cited By ~ 6

Author(s):

Maryam Nikzad ◽

Kamyar Movagharnejad ◽

Farid Talebnia ◽

Ghasem Najafpour ◽

Farahi Hosein

Keyword(s):

Sorghum Bicolor ◽

Alternative Energy ◽

Solid Loading ◽

Bioethanol Production ◽

Alkali Pretreatment ◽

Model Predictions ◽

Pretreatment Time ◽

Pretreatment Conditions ◽

Energy Production System ◽

Central Composite

Bioethanol production from lignocellulosic biomass provides an alternative energy-production system. Sorghum bicolor stem is a cheap agro-waste for bioethanol production. In this study, response surface methodology (RSM) was used to optimize alkali pretreatment conditions for sorghum bicolor stem with respect to substrate concentration, NaOH concentration and pretreatment time based on a central composite rotary design. The main goal was to achieve the highest glucose and xylose yields after enzymatic hydrolysis. Under optimum conditions of pretreatment i.e. time 60.4 min, solid loading 4.2%, and NaOH concentration 1.7%, yields of 98.94% g glucose/g cellulose and 65.14% g xylose/g hemicelluloses were obtained. The results of a confirmation experiment under the optimal conditions agreed well with model predictions. Pretreatment of sorghum bicolor stem at the optimum condition increased the glucose and xylose yields by 7.14 and 3.02 fold, respectively. Alkali pretreatment showed to be a great choice for the pretreatment of sorghum bicolor stem.

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OPTIMISASI PRODUKSI ENZIM LAKASE PADA FERMENTASI KULTUR PADAT MENGGUNAKAN JAMUR PELAPUK PUTIH Marasmius sp. : PENGARUH UKURAN PARTIKEL, KELEMBAPAN, DAN KONSENTRASI Cu

JURNAL SELULOSA ◽

10.25269/jsel.v3i02.45 ◽

2016 ◽

Vol 3 (02) ◽

Cited By ~ 1

Author(s):

Cornelius Damar Hanung ◽

Ronald Osmond ◽

Hendro Risdianto ◽

Sri Harjati Suhardi ◽

Tjandra Setiadi

Keyword(s):

Particle Size ◽

Solid State ◽

Moisture Content ◽

Rice Straw ◽

Solid State Fermentation ◽

Carbon Sources ◽

White Rot Fungi ◽

Batch Process ◽

Solid Substrate ◽

White Rot

White rot fungi of Marasmius sp. is a fungus which produce laccase in high activity. Laccase is one of the ligninolityc enzymes that capable to degrade lignin. This ability can be used for the pretreatment of lignocellulosic materials in the bioethanol production. Laccase was produced in flask by batch process using Solid State Fermentation (SSF). The optimisation was conducted by statistically of full factorial design. The particle size, moisture content, and Cu concentration were investigated in this study. Rice straw was used as solid substrate and the glycerol was used as the carbon sources in modified Kirk medium. The results showed that particle size of rice straw did not affect significantly to the enzyme activity. The highest laccase activity of 4.45 IU/g dry weight was obtained at the moisture content of 61% and Cu concentration of 0.1 mM.Keywords: laccase, Marasmius sp., optimisation, rice straw, solid state fermentation ABSTRAKJamur pelapuk putih, Marasmius sp. merupakan jamur yang menghasilkan enzim lakase dengan aktivitas tinggi. Lakase merupakan enzim ligninolitik yang dapat mendegradasi lignin. Kemampuan ini dapat digunakan untuk proses pengolahan awal bahan lignoselulosa pada pembuatan bioetanol. Produksi lakase dilakukan dalam labu dengan modus batch menggunakan fermentasi kultur padat. Optimisasi produksi enzim lakase dengan metode fermentasi padat dilakukan dengan rancangan percobaan faktorial penuh. Pengaruh ukuran partikel, kelembapan, dan konsentrasi Cu diuji dengan medium penyangga jerami dengan menambahkan gliserol dalam medium Kirk termodifikasi sebagai sumber karbon. Penelitian ini menunjukkan bahwa ukuran jerami tidak berpengaruh signifikan terhadap aktivitas enzim. Aktivitas enzim lakase maksimum terjadi pada saat kelembapan 61% dan konsentrasi Cu 0,1 mM dengan aktivitas enzim lakase/berat kering tertinggi mencapai 4,45 IU/g.Kata kunci: lakase, Marasmius sp., optimisasi, jerami, fermentasi kultur padat

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