Phenomenological modeling and evaluation of formic acid pretreatment of wheat straw with an extended combined severity factor for biomass fractionation and enzymatic saccharification to produce bioethanol

2017 ◽  
Vol 81 ◽  
pp. 140-149 ◽  
Author(s):  
Lei Dong ◽  
Ruchun Wu ◽  
Xuebing Zhao ◽  
Dehua Liu
2021 ◽  
Vol 65 (3) ◽  
Author(s):  
Yuan Liang ◽  
Yanbo Yin ◽  
Haifeng Zhou ◽  
Yuanyu Tian

Abstract. Utilization of the huge quantity of sawdust wastes is urgent. In this study, SPORL, dilute acid pretreatment (DA), formic acid pretreatment (FA), ethanol pretreatment (EtOH/H2O), and sulfuric acid catalyzed ethanol pretreatment (EtOH/H2O/H2SO4), on improving enzymatic hydrolysis of mixed sawdust wastes were comprehensively compared. EtOH/H2O/H2SO4 was the most effective pretreatment in lignin removal from sawdust fiber cell wall, while FA was much more effective in hemicellulose removal. After the pretreatments, the crystallinity of cellulose increased because of the removal of amorphous hemicellulose and lignin. Moreover, the fiber surface became coarse and porous, especially after EtOH/H2O/H2SO4, the structure was destroyed into fragments, which enhanced the cellulase accessibility of cellulose. Therefore, the glucose yield of EtOH/H2O/H2SO4 pretreated substrate was highest among these five pretreatments, achieved at 91.4% with a cellulase loading of only 10 FPU/g glucan.   Resumen. Es urgente aprovechar la gran cantidad de residuos de aserrín. En este estudio, SPORL, pretratamiento con ácido diluido (DA), pretratamiento con ácido fórmico (FA), pretratamiento con etanol (EtOH/H2O) y pretratamiento con etanol catalizado con ácido sulfúrico (EtOH/H2O/H2SO4), sobre la mejora de la hidrólisis enzimática de residuos de aserrín mezclado fueron comparados de manera integral. EtOH/H2O/H2SO4 fue el pretratamiento más eficaz para eliminar la lignina de la pared celular de la fibra de aserrín, mientras que el FA fue mucho más eficaz para eliminar la hemicelulosa. Después de los pretratamientos, la cristalinidad de la celulosa aumentó debido a la eliminación de hemicelulosa amorfa y lignina. Además, la superficie de la fibra se volvió gruesa y porosa, especialmente después de EtOH/H2O/H2SO4, la estructura se destruyó en fragmentos, lo que mejoró la accesibilidad de celulasa de la celulosa. Por lo tanto, el rendimiento de glucosa del sustrato pretratado con EtOH/H2O/H2SO4 fue el más alto entre estos cinco pretratamientos, alcanzado al 91,4% con una carga de celulasa de solo 10 FPU / g de glucano.


2005 ◽  
Vol 40 (12) ◽  
pp. 3693-3700 ◽  
Author(s):  
Badal C. Saha ◽  
Loren B. Iten ◽  
Michael A. Cotta ◽  
Y. Victor Wu

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2753
Author(s):  
Xiaogang Chang ◽  
Jingzhi Zhang ◽  
Ruchun Wu ◽  
Xuebing Zhao

In order to more conveniently simulate and optimize the solubilization of sugarcane bagasse components during formic acid (FA) fractionation, an extended combined severity factor (CSFext) was defined to integrate various operation parameters as a single factor. Two phenomenological models based on Arrhenius and Logistic equations were further used to describe the phenomenological kinetics. Different data-processing methods were compared to fit the severity parameters and model constants. Both Arrhenius-based and Logistic-based models show satisfying fitting results, though the values of Arrhenius-based CSFext (A-CSFext) and Logistic-based CSFext (L-CSFext) were somewhat different under the same fractionation condition. The solubilization of biomass components increased with CSFext, but two distinct stages could be observed with inflection points at A-CSFext of 42 or L-CSFext of 43, corresponding to bulk and residual solubilization stages, respectively. For the enzymatic hydrolysis of cellulosic solids, the highest initial enzymatic glucan conversion (EGC@6h) was obtained at A-CSFext of 39–40 or A-CSFext of 40–41; however, for a long hydrolysis period (72 h), relatively high glucan conversion (EGC@72h) was observed at A-CSFext of 42–43 or A-CSFext of 43–44. Post-treatment for deformylation with a small amount of lime could help to recover the cellulose digestibility.


Cellulose ◽  
2019 ◽  
Vol 26 (8) ◽  
pp. 4731-4742 ◽  
Author(s):  
Sujuan Yuan ◽  
Xingxiang Ji ◽  
Hairui Ji ◽  
Zhongjian Tian ◽  
Jiachuan Chen

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1360
Author(s):  
Ekaterina Budenkova ◽  
Stanislav Sukhikh ◽  
Svetlana Ivanova ◽  
Olga Babich ◽  
Vyacheslav Dolganyuk ◽  
...  

Enzymatic hydrolysis of cellulose-containing raw materials, using Aspergillus niger, were studied. Filter paper, secondary cellulose-containing or starch-containing raw materials, miscanthus cellulose after alkaline or acid pretreatment, and wood chip cellulose, were used as substrates. The study focused on a wild A. niger strain, treated, or not (control), by ultraviolet (UV) irradiations for 45, 60, or 120 min (UV45, UV60, or UV120), or by UV irradiation for 120 min followed by a chemical treatment with NaN3 + ItBr for 30 min or 80 min (UV120 + CH30 or UV120 + CH80). A mixture of all the A. niger strains (MIX) was also tested. A citrate buffer, at 50 mM, wasthe most suitable for enzymatic hydrolysis. As the UV exposure time increased to 2 h, the cellulase activity of the surviving culturewas increased (r = 0.706; p < 0.05). The enzymatic activities of the obtained strains, towards miscanthus cellulose, wood chips, and filter paper, were inferior to those obtained with commercial enzymes (8.6 versus 9.1 IU), in some cases. Under stationary hydrolysis at 37 °C, pH = 4.7, the enzymatic activity of A. niger UV120 + CH30 was 24.9 IU. The enzymatic hydrolysis of secondary raw materials, using treated A. niger strains, was themost effective at 37 °C. Similarly, the most effective treatment of miscanthus cellulose and wood chips occurred at 50 °C. The maximum conversion of cellulose to glucose was observed using miscanthus cellulose (with alkaline pretreatment), and the minimum conversion was observed when using wood chips. The greatest value of cellulase activity was evidenced in the starch-containing raw materials, indicating that A. niger can ferment not only through cellulase activity, but also via an amylolytic one.


Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 487
Author(s):  
Dimitrios Ilanidis ◽  
Stefan Stagge ◽  
Leif J. Jönsson ◽  
Carlos Martín

Biochemical conversion of wheat straw was investigated using hydrothermal pretreatment, enzymatic saccharification, and microbial fermentation. Pretreatment conditions that were compared included autocatalyzed hydrothermal pretreatment at 160, 175, 190, and 205 °C and sulfuric-acid-catalyzed hydrothermal pretreatment at 160 and 190 °C. The effects of using different pretreatment conditions were investigated with regard to (i) chemical composition and enzymatic digestibility of pretreated solids, (ii) carbohydrate composition of pretreatment liquids, (iii) inhibitory byproducts in pretreatment liquids, (iv) furfural in condensates, and (v) fermentability using yeast. The methods used included two-step analytical acid hydrolysis combined with high-performance anion-exchange chromatography (HPAEC), HPLC, ultra-high performance liquid chromatography-electrospray ionization-triple quadrupole-mass spectrometry (UHPLC-ESI-QqQ-MS), and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Lignin recoveries in the range of 108–119% for autocatalyzed hydrothermal pretreatment at 205 °C and sulfuric-acid-catalyzed hydrothermal pretreatment were attributed to pseudolignin formation. Xylose concentration in the pretreatment liquid increased with temperature up to 190 °C and then decreased. Enzymatic digestibility was correlated with the removal of hemicelluloses, which was almost quantitative for the autocatalyzed hydrothermal pretreatment at 205 °C. Except for the pretreatment liquid from the autocatalyzed hydrothermal pretreatment at 205 °C, the inhibitory effects on Saccharomyces cerevisiae yeast were low. The highest combined yield of glucose and xylose was achieved for autocatalyzed hydrothermal pretreatment at 190 °C and the subsequent enzymatic saccharification that resulted in approximately 480 kg/ton (dry weight) raw wheat straw.


REAKTOR ◽  
2017 ◽  
Vol 16 (4) ◽  
pp. 199
Author(s):  
Fahriya Puspita Sari ◽  
Nissa Nurfajrin Solihat ◽  
Sita Heris Anita ◽  
Fitria Fitria ◽  
Euis Hermiati

ENHANCEMENT OF REDUCING SUGAR PRODUCTION FROM OIL PALM EMPTY FRUIT BUNCH BY PRETREATMENT USING ORGANIC ACID IN PRESSURIZED REACTOR. Organic acids are potential to create more environmentally friendly process in the pretreatment of lignocellulosic biomass for bioethanol production. This study was aimed to investigate the influence of organic acid pretreatment in reducing sugar production in a pressurized reactor with various resident times and temperatures on enzymatic hydrolysis of OPEFB. Two different organic acids (maleic acid and oxalic acid) were used in the pretreatment of oil palm empty fruit bunch (OPEFB) using a pressurized reactor. Factorial design using three different temperatures (170, 180, and 190°C) and four resident times (15, 30, 45, and 60 min) were employed, followed by enzymatic hydrolysis. Each condition conducted two repetitions. Analysis was conducted on the reducing sugar that was produced after saccharification by means of the severity factor of each pretreatment condition. Maleic acid showed higher reducing sugar yield with lower severity factor than oxalic acid with the same operating conditions. The highest yield of reducing sugars (80.84%) was obtained using maleic acid at 170 for 60 minutes with severity factor of 1.836. Keywords: bioethanol; organic acid pretreatment; pressurized reactor; severity factor; oil palm empty fruit bunches;   Abstrak Asam organik berpotensi dalam membantu proses praperlakuan dari biomassa lignoselulosa untuk memproduksi bioetanol yang ramah lingkungan. Penelitian ini bertujuan untuk mengetahui pengaruh asam organik, suhu dan waktu operasi terhadap produksi gula pereduksi dengan reaktor bertekanan pada tandan kosong kelapa sawit. Dua asam organik yang berbeda yaitu asam oksalat dan asam maleat digunakan untuk proses praperlakuan tandan kosong kelapa sawit (TKKS) dengan bantuan reaktor bertekanan. Dalam proses praperlakuan digunakan tiga suhu yang berbeda yaitu suhu 170, 180, dan 190°C dan empat waktu operasi 15, 30, 45, dan 60 min yang dilanjutkan dengan proses hidrolisis enzimatis. Setiap kondisi dilakukan dua kali pengulangan. Analisa yang digunakan adalah analisa uji gula pereduksi dan severity factor pada kondisi tiap praperlakuan. Asam maleat menunjukkan hasil yang lebih baik dengan severity factor yang lebih rendah dibandingkan menggunakan asam oksalat dengan kondisi operasi yang sama. Hasil yang didapatkan menunjukkan bahwa praperlakuan tandan kosong kelapa sawit dengan bantuan reaktor bertekanan memiliki rendemen gula pereduksi optimum sebesar 80,84% dengan menggunakan asam maleat pada suhu 170°C selama 60 menit dengan severity factor sebesar 1,836. Kata kunci: bioetanol; praperlakuan asam organik; reaktor bertekanan; severity factor; tandan kosong kelapa sawit.


Sign in / Sign up

Export Citation Format

Share Document