Shock treatment of corn stover

Abstract

Corn stover digestibility was enhanced via shock treatment. A slurry of lime-treated corn stover was placed in a partially filled closed vessel. From the ullage space, either a shotgun shell was fired into the slurry, or a gas mixture was detonated. Various conditions were tested (i.e., pressures, depth, solids concentrations, gas mixtures). A high pressurization rate (108,000 MPa/s shotgun shells; 4,160,000 MPa/s hydrogen/oxygen detonation) was the only parameter that improved enzymatic digestibility. Stoichiometric propane/air deflagration had a low pressurization rate (37.2 MPa/s) and did not enhance enzymatic digestibility. Without shock, enzymatic conversion of lime-treated corn stover was 0.80 g glucan digested/g glucan fed with an enzyme loading of 46.7 mg protein/g glucan. With shock, the enzyme loading was reduced by ∼2× while maintaining the same conversion. Detonations are extraordinarily fast; rapidly cycling three small vessels (0.575 m each) every 7.5 s enables commercially relevant shock treatment (2,000 tone/day). © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:815-823, 2017.

Assessment of shock pretreatment and alkali pretreatment on corn stover using enzymatic hydrolysis

“…To disrupt mechanically, the microscopic biomass structure, corn stover was shock pretreated using shock waves generated by detonating explosive gas (H 2 + O 2 ). 24 The 2-L shock tube was filled with a biomass slurry (5% biomass loading) and sealed with an impact wrench.…”

“…23 Combining shock and lime pretreatments improves enzymatic digestibility of lignocellulose. 11,20,21,24,25 In previous studies on the MixAlco™ process, alkaline OLP and SLP were neutralized by bubbling carbon dioxide through the liquid slurry. Calcium carbonate has low solubility in water, so an excess amount of calcium carbonate can be added to the fermenter.…”

Assessment of corn stover pretreated with shock and alkali using methane‐arrested anaerobic digestion

“…The NaOH pretreatment experiments are described in a previous study 19 . Details for shock treatment are described in detail in previous studies 30–32 . In this study, corn stover was pretreated using the recommended two‐step process from a previous study: (1) shock treatment of an aqueous slurry of raw corn stover with headspace containing stoichiometric mixture of hydrogen and oxygen, initial pressure 5.52 bar (abs), followed by detonation of explosive gas (H 2 + O 2 ) with a glow plug; and (2) NaOH treatment using 4 g OH − /100 g dry biomass maintained at 50°C for 1 h 19 …”

“…19 Details for shock treatment are described in detail in previous studies. [30][31][32] In this study, corn stover was pretreated using the recommended two-step process from a previous study: (1) shock treatment of an aqueous slurry of raw corn stover with headspace containing stoichiometric mixture of hydrogen and oxygen, initial pressure 5.52 bar (abs), followed by detonation of explosive gas (H 2 + O 2 ) with a glow plug; and (2) NaOH treatment using 4 g OH À /100 g dry biomass maintained at 50 C for 1 h. 19 Shock treatment is estimated to cost $5/ton, 32 which is much smaller than conventional chemical pretreatments estimated to cost about $45/ton. 33 To maintain consistency in methodology across multiple pretreatment studies, the loading for NaOH was quantified based on the hydroxide group (g OH À /100 g dry biomass) according to Equation (1).…”

Identificação e caracterização da primeira exoxilanase da família 11 de hidrolase de glicosídeo a partir do estudo do metatranscriptoma de um consórcio derivado da compostagem

“…37,104 As abordagens recentes na hidrólise da lignocelulose empregam o uso de coquetéis com enzimas de fungos que, apesar de efetivos na hidrólise de polissacarídeos, requerem que a biomassa passe por um pré-tratamento severo para remover a lignina, diminuir a cristalinidade da celulose e aumentar a acessibilidade às enzimas. 105 Além disso, esses coquetéis devem ser usados em altas concentrações. 106 • Identificar qualitativamente as diferenças na degradação do bagaço de cana-de-açúcar;…”