Pretreatment Process Research Articles

An Analysis of Dynamic Recrystallization During the Reduction Pretreatment Process Using a Multiscale Model

In this study, a multiscale model is developed through secondary development (UMAT and UEXTERNALDB) in Abaqus with the objective of simulating the thermal deformation process with dynamic recrystallization behavior. The model couples the finite element method (FEM) with the multiphase field model (MPFM), thereby establishing bidirectional coupling between macroscopic mechanical behavior and microstructural evolution. A comparison between the single-element hot compression simulation and experimental results demonstrates that the model accurately simulates both the macroscopic mechanical behavior and microstructural evolution during the thermal deformation process, thereby exhibiting high precision. Simulations of the reduction pretreatment (RP) process under different reduction amounts and billet surface temperatures demonstrate that increasing the reduction amount and billet surface temperature significantly enhances both plastic deformation and the volume fraction of dynamic recrystallization in the billet core. This results in the closure of core voids and the refinement of the core microstructure, thereby providing valuable guidance for the development of optimal reduction pretreatment (RP) processes.

Statistical optimisation of enzymatic pre-treatment process of marigold flower waste for enhanced hydrolysis and complete release of lutein ester through Taguchi orthogonal design

ABSTRACT The lutein ester of the marigold flower is entrapped in the matrix of pectin, cellulose, hemicellulose and lignin which cannot be released by moderate acidic, alkaline treatment or enzymatic treatment with a single enzyme. Five different parameters are optimized in the current study for two response factors: lutein ester extraction (LEEP) and floral solid hydrolyzed percentage (FSHP). Three commercially available enzymes, namely pectinase, cellulase, and xylanase, at various temperatures and time intervals were utilised to optimise the enzymatic hydrolysis of flower biomass. An L27 orthogonal Taguchi experimental design was employed, investigating temperature (25–35 °C), time (10–30 days), and enzyme levels (pectinase, cellulase and xylanase at 0–1 mL). The optimal conditions for 100% lutein ester extraction from marigold flower waste were: temperature 35 °C, 20 days, and enzymes 1 mL/200 g each of pectinase (2600 µPG/g), cellulase (20000 CMC U/g), and xylanase (300000 U/g). Thus, it could be concluded that optimisation by the Taguchi method could be used to develop an enzyme cocktail for the hydrolysis of marigold flowers to obtain the best yield of lutein ester. The aim is to enhance the yield of lutein ester through the optimisation of the enzymatic pre-treatment of the marigold flower.

Genotype and grain pretreatment effects on digestibility of sorghum proteins in the Ethiopian fermented bread

AbstractBackground and ObjectivesSorghum is the principal food source for smallholder farmers in Sub‐Saharan Africa. Animal proteins are beyond economic reach, and only few food legumes are well‐adapted in major sorghum‐growing regions. Hence, sorghum serves as the primary source of protein and calories. However, the low digestibility of its proteins renders the communities vulnerable to protein malnutrition. Several factors, including genotypes and processing methods, have been shown to affect the digestibility of proteins in sorghum food products. The objective of this study was to investigate the impact of grain pretreatment on the protein digestibility of Ethiopian fermented flatbread.FindingsThe effect of four grain pretreatment processes: decortication, sprouting, parching, and untreated control was compared using four diverse sorghum genotypes milled to medium (2 mm) and fine (0.5 mm) particle sizes. The in‐vitro protein digestibility (IVPD) was significantly lower in the parched samples compared to the unprocessed control, while sprouting significantly increased IVPD. Decortication appears to have no impact on IVPD. Finer particle size tended to enhance IVPD in all genotypes and for all pretreatement methods. The treatments had no significant effect on protein content except the sprouting consistently but marginally increased total protein.ConclusionsSprouting sorghum grains can significantly improve the protein digestibility of fermented breads. Given that it involves little cost, the process can be readily adopted by the local community, provided that they are educated about the impact of protein deficiency on the health and productivity of the community.Significance and NoveltyLow‐cost grain pretreatment procedures such as sprouting can have a significant impact on the availability of nutrients, especially protein, the most limiting nutrient in smallholder communities. Combining the procedure with genetically enhanced varieties and improved cropping systems that integrate food legumes can significantly enhnace protein nutrition for smallholder farmers.

Refined Surface Area Determination of Graphene Oxide Using Methylene Blue as a Probe Molecule: A Comparative Approach

Abstract In this research, we explored the effectiveness of the methylene blue (MB) adsorption method as an alternative approach for determining the specific surface area of graphene oxide (GO). Initially, through a comparative analysis with reference activated carbon (AC), we identified the limitations of utilizing N2 physisorption for specific surface area determination of GO. Our findings revealed that the standard pretreatment process (heating under vacuum) before N2 physisorption led to damage to the surface oxygen groups on GO, and the measured surface areas (43 m2/g) do not accurately represent the entire surface area. To optimize MB coverage on GO, we conducted adsorption equilibrium experiments, focusing on controlling temperature and pH. The pH was significantly important in regulating the coverage of MB. Under the optimized MB adsorption conditions, the specific surface area of GO was 1555 m2/g. Our assumptions regarding specific surface area calculations were supported by structural characterization of samples with varying MB uptakes. The results confirmed a uniform coverage of MB on GO by SEM-EDX, XRD, and AFM.

Effect of pretreatment and peracetic acid pulping on cellulosic materials converted from spent coffee grounds.

Spent coffee grounds (SCG) are the waste byproducts of coffee brewing. While SCG can be valorized to produce functional biopolymers due to their valuable structural components, the lignocellulosic structure of SCG is resistant to degradation because of the tightly bound lignin. Therefore, a pretreatment step is required before pulping with peracetic acid (PAA), an eco-friendlier alternative to traditional pulping methods, to facilitate the extraction of these desired cellulosic materials. Formic acid:acetic acid:deionized water (FA:AA:W=30:50:20) or 60% (v/v) ethanol pretreatments were applied to SCG to compare the characteristics of the resulting cellulosic materials after PAA pulping. Lignocellulose analysis showed that the lignin content (7.06%) of ethanol pretreated SCG was significantly lower (p<0.05), and the cellulose content (29.52%) was significantly higher (p<0.05) than the untreated SCG (15.50% and 11.50%, respectively), indicating that an adequate amount of lignin was removed to obtain the cellulosic materials after the pretreatment process. Morphological and structural changes in the lignin and hemicellulose were observed in all the pretreated SCG, which further confirmed that these components were degraded with pretreatments and pulping. Ethanol pretreated SCG showed the most optimal results based on the greatest lignin decrease seen from its lignocellulose composition, appearance, and structure. This study exemplified a conversion process to extract cellulosic materials from SCG more efficiently to utilize for cellulose-based products and verify its potential to be valorized as a waste byproduct. PRACTICAL APPLICATION: Coffee companies can provide the spent coffee grounds (SCG) they produce to develop cellulose-based materials to make biodegradable packaging products rather than throwing them out or burning them. Using SCG for producing cellulose-based materials can help promote sustainability and reduce food waste worldwide. SCG can be utilized as an alternative source based on their abundance and desired biopolymeric properties, providing innovative solutions to industries and increasing consumer awareness of this cause.

Simultaneous nitrification and denitrification framework for decentralized systems: Long-term study utilizing rope-type biofilm media under field conditions

This research introduces a novel approach to achieve simultaneous nitrification-denitrification (SND) under dynamic load conditions using a cost-effective rope-type biofilm technology. The approach represents a significant advancement in wastewater treatment, particularly beneficial for remote and decentralized communities. The biofilm-based SND process was developed using a pilot-scale flow-through reactor by implementing upstream carbon management with constant-timer-based aeration control versus dynamic-sensor-based aeration control strategies. The findings indicate that adding an upstream anaerobic pretreatment process to handle excess carbon plays a substantial role in achieving a sustainable SND process under a dynamic load environment using simple aeration on-off control. The most optimal nitrification performance of 0.32 g NH3-N/m2/d (89 % removal) was achieved under a 1-hour ON/30-minute OFF aeration. The process sustained an average bulk liquid DO of 5.16 mg/L and 3.80 mg/L during the aeration ON and OFF periods, respectively, facilitating a 0.13 g N/m2/d (41 %) total inorganic nitrogen (TIN) removal, notably, implementing advanced aeration strategies driven by DO, NH3, and NO3 sensors enhanced TIN removal efficiency to 72 %. The nitrification performance remained comparable (89 % removal), resulting in 3 and 10 mg N/L effluent ammonia and TIN concentration, respectively. Additionally, utilizing two multivariate approaches accounting for 82 % and 64 % of the variance, this study discerned patterns in monitored variables and performance. Additionally, the analysis underscored the difference of bulk liquid DO levels in the biofilm versus suspended systems inhibiting the SND process. Distinct bacterial communities were established in biofilms under aerobic, anaerobic, and SND conditions, with the SND reactor showing a hierarchy of functional group and enzymes, enriched sequentially from heterotrophs to denitrifiers, nitrifiers, and anammox bacteria. These innovations underline the potential of tailored control strategies to enhance a passive biofilm-based SND process efficiency under dynamic conditions, providing scalable solutions for diverse target water quality demands in remote communities and decentralized systems.

Glycerol Vapor Assisted Cu Direct Bonding: Implications for 3D Semiconductor Packaging

AbstractAs the scaling down of semiconductor devices reaches its physical limits, 3D stacking packaging technology is emerging as a new miniaturization solution. Among the various 3D packaging technologies, Cu direct bonding is widely adopted due to copper's excellent electrical conductivity and the absence of intermetallic compounds for solder bumps. Since copper readily undergoes oxidation, technologies that prevent Cu surface oxidation during Cu direct bonding are essential. However, current research suggests that the methods require additional pretreatment processes, which demand high costs. In this study, a Cu direct bonding method utilizing glycerol vapor is developed to effectively streamline the pretreatment steps. The potential of glycerol as a reducing agent and antioxidant for Cu is demonstrated using a silicon die sample with a size of 10 × 10 mm2, verified through the X‐ray photoelectron spectroscopy. The Cu direct bonding for 3D semiconductor packaging is successfully performed under glycerol vapor atmosphere, without any plasma pretreatment. The cross‐section of the bonded specimens is examined by scanning electron microscopy, and mechanical reliability is assessed by die shear testing.

Biomimetic nanozyme-based electrochemical sensor integrated with microfluidic cell for on-site uric acid detection

Uric acid (UA) is the key indicator highly associated with gout, and on-site UA detection is of great significance for personalized health management. Herein, we propose an integrated microfluidic electrochemical sensing platform for real-time UA detection. The platform mainly consists of a biomimetic nanozyme-based electrochemical sensor and a microfluidic cell. The biomimetic nanozyme with desirable catalytic activity can effectively promote UA oxidation, and the corresponding working mechanism is clarified through density functional theory calculation. Besides, the well-designed microfluidic cell is capable of impurity removal and sample storage. Based on these designs, the whole process of sample pretreatment and target detection can all be achieved on one integrated platform, allowing for user-friendly test. This developed platform shows satisfactory sensing performance for UA with a detection limit of 4.2 μM. In addition, it is successfully applied to UA determination in artificial saliva and serum samples, showing desirable application prospects in clinical diagnosis.

Development of a fs-pulsed laser pretreatment process on thin-walled nickel to improve adhesion for adhesive bonding applications

Due to its inert surface, producing adhesive bonds on nickel is challenging and requires a surface pretreatment. A laser pretreatment process on nickel is investigated using a Yb:YAG slab laser at 780 fs pulse length. The process is varied in pulse density, pulse energy, and focus position to produce various surface structures on a nanometer scale. The surface structures are categorized topologically in scanning electron microscopy (SEM). Random nanostructures, laser-induced periodic surface structures (LIPSS), and process vapor depositions are observed. To quantify the adhesion properties of the produced surfaces, peel tests are conducted using a two-component epoxy adhesive. All investigated process parameters lead to a significant increase in peel strength; however, high pulse density and high pulse energy in focus lead to the highest peel strengths. These process parameters generally produce LIPSS and process vapor depositions on the surface, which might be linked to the high peel strengths. The analysis of the fracture pattern shows an adhesion failure, and in SEM, a partial failure of adhesive and adherent is visible. The surface structures are fully wetted by the adhesive on a sub-micrometer level. Nanoparticles deposited from the process plasma are broken out of the surface during the peel tests. A general trend to high accumulated fluence for best results in peel strength is shown.

Developing zirconium xerogel coagulants for deep removal of phosphorous

Deep removal of phosphorous (P) from water is a necessary measure to solve the eutrophication problem. Coagulation is both a basic treatment method for P removal and an important pretreatment process for membrane filtration. However, few coagulants can meet the both requirements. Based on the analysis on the hydrolysis behaviors of some earth-abundant metals and the solubility products of their phosphates, a series of zirconium xerogel coagulants (ZXC) was fabricated with a novel approach (the sol-gel method) and was evaluated for the removal of both organic and inorganic P in coagulation and coagulation-ultrafiltration. In terms of P removal and anti-fouling of membrane, the resultant ZXC outperformed polyzirconium chloride (PZC), polyaluminum chloride (PAC), polyferric sulfate (PFS), as well as titanium xerogel coagulant (TXC) in a wide range of pH and dose. The rapid hydrolysis of Zr4+ and the formation of Zr3(PO4)4 with a rather low solubility product are attributable to the great performance of ZXC in coagulation. This study highlights the potential of ZXC as an effective solution for enhancing the treatment of water and wastewater, particularly in achieving deep P removal and improving membrane fouling resistance, thereby contributing to more sustainable and efficient strategies for addressing eutrophication and pollutant removal.

Mitigating Membrane Fouling in Abattoir Wastewater Treatment: Integration of Pretreatment Step with Zwitterion Modified Graphene Oxide–Polyethersulfone Composite Membranes

Composite polyethersulfone (PES) membranes containing N-aminoethyl piperazine propane sulfonate (AEPPS)-modified graphene oxide (GO) were integrated with either of the two pretreatment processes (activated carbon (AC) adsorption or polyelectrolyte coagulation) to assess their effectiveness in mitigating membrane fouling during the treatment of abattoir wastewater. The AEPPS@GO-modified membranes, as compared to the pristine PES membranes, showed improved hydrophilicity, with water uptake increasing from 72 to 118%, surface porosity increasing from 2.34 to 27%, and pure water flux (PWF) increasing from 235 to 673 L.m−2h−1. The modified membranes presented improved antifouling properties, with the flux recovery ratio (FRR) increasing from 59.5 to 93.3%. This study compared the effectiveness of the two pretreatment processes, AC, coagulation, and the integrated system (coagulation/AC-UF membrane), in the removal of natural organic matter (NOM) and improvement of abattoir wastewater’s pH, electrical conductivity, TDS, and turbidity. The integrated systems produced improved water quality in terms of pH, EC, TDS, turbidity, and organic content. The fluorescence excitation–emission matrix (FEEM) analysis exhibited almost no fluorescence peak post-treatment following organic loading removal. The quality of the water met the South African non-potable water reuse standards. The sole membrane treatment systems exhibited good fouling resistance without the pretreatment systems; however, integrating these systems can offer extended longer filtration periods, thereby assisting in cost aspects of the abattoir wastewater treatment system.

Graphene electrochemical biosensors combining effervescent solid-phase extraction (ESPE) for rapid, ultrasensitive, and simultaneous determination of DA, AA, and UA

Simultaneous monitoring of key metabolites like dopamine, ascorbic acid, and uric acid is essential for early disease diagnosis and evaluating treatment. Electrochemical techniques are increasingly used for precise, point-of-care testing (POCT) of these metabolites. Herein, a sample pretreatment method called effervescent solid-phase extraction (ESPE) was proposed for efficient enrichment of trace analytes for electrochemical detection. In an ESPE process, effervescent tablets made of gold nanoparticle-decorated graphene oxide (Au/GO) were first self-dispersed in a test solution to promote the enrichment of analytes on the Au/GO adsorbents, followed by the addition of flocculant effervescent tablets to cause Au/GO sheets to form self-assembled aggregates, which then can be efficiently collected by the foam electrodes. The entire sample pretreatment process operates without external power and takes only 5 min. With the assistance of the ESPE method, our electrochemical sensors achieve an ultralow detection limit for dopamine, ascorbic acid, and uric acid of 80 pM, 1.8 nM, and 460 pM, respectively, which are two to three orders of magnitude lower than the results obtained by the drop casting technique. The enhancement mechanism of our approach is based on increasing the contact probability with analytes through dynamic dispersion of the Au/GO adsorbents, in contrast to the static diffusion mechanism relied on Brownian motion. We also show that combining the ESPE solution kit with a portable micro-electrochemical workstation can attain the same detection level as HPLC in real urine samples. The proposed ESPE approach holds great promise for POCT applications in 2D material-based biosensors.

Microwave-associated ZnCl2 pretreatment followed by enzymatic hydrolysis for high-efficiency production of nanocellulose from Eucalyptus dissolving pulp

Herein, we developed a novel microwave-associated ZnCl2 pretreatment followed by enzymatic hydrolysis for high-efficiency and environmentally friendly production of nanocellulose. With a short pretreatment time (60 s), nanocellulose was yielded with a high overall yield of 87.99 % from Eucalyptus Dissolving Pulp (EDP). Characterization analysis revealed that microwave-associated ZnCl2 pretreatment can efficiently swollen the structure of EDP, and after enzymatic hydrolysis, the nanocellulose in spherical shape was formed with abundant functional groups, low crystalline index, and poor thermal stability. By Energy Dispersive X-Ray Spectroscopy (EDS) and inductively coupled plasma mass spectrometry (ICP-MS) analysis, approximately 20 wt% of zinc distributed on the surface and in the interior of cellulose, that may lead to the low Zeta potential of the nanocellulose and the formation of nanospheres. Furthermore, through optimization of the pretreatment process, it was feasible to increase the solid concentration of EDP to 3 wt% while concurrently reducing the ZnCl2 concentration to 0.1 mol (ZnCl2·9H2O). Under this condition, ultrafine cellulose nanocrystals (CNC) and cellulose nanofiber (CNF)/CNC blend were produced with an outstanding yield of 93.3 %. Moreover, the recyclability of ZnCl2 post-pretreatment was demonstrated, as ZnCl2 could be efficiently reused for subsequent pretreatment cycles. Notably, even after five cycles of recycling, the nanocellulose yield remained consistently above 90 %. Overall, this study highlights the viability and sustainability of microwave-assisted ZnCl2 pretreatment for efficient nanocellulose production, offering a sustainable and cost-effective route for industrial-scale applications.

Maximizing microbial activity and synergistic interaction to boost biofuel production from lignocellulosic biomass.

Addressing global environmental challenges and meeting the escalating energy demands stand as two pivotal issues in the current landscape. Lignocellulosic biomass emerges as a promising renewable bio-energy source capable of fulfilling the world's energy requirements on a large scale. One of the most important steps in lowering reliance on fossil fuel and lessening environmental effect is turning lignocellulosic biomass into biofuel. As carbon-neutral substitutes for traditional fuel, biofuel offer a solution to environmental concerns compared to conventional fuel. Effective utilization of lignocellulosic biomass is imperative for sustainable development. Ongoing research focuses on exploring the potential of various microorganisms and their co-interactions to synthesize diverse biofuels from different starting materials, including lignocellulosic biomass. Co-culture techniques demonstrate resilience to nutrient scarcity and environmental fluctuations. By utilising a variety of carbon sources, microbes can enhance their adaptability to environmental stressors and potentially increase productivity through their symbiotic interactions. Furthermore, compared to single organism involvement, co-interactions allow faster execution of multistep processes. Lignocellulosic biomass serves as a primary substrate for pre-treatment, fermentation, and enzymatic hydrolysis processes. This review primarily delves into the pretreatment, enzymatic hydrolysis process and the biochemical pathways involved in converting lignocellulosic biomass into bioenergy.

Corn biomass as a feedstock for biorefinery: a bibliometric analysis of research on bioenergy, biofuel and value‐added products

AbstractLimited research has been dedicated to exploring the potential reuse and creation of value‐added products from corn stover. Existing gaps in current research underscore the need for waste biorefineries that adhere to the principles of a circular bioeconomy to maximize the value of corn stover. This review uses bibliometric analysis from the past decade to examine the potential and pathways for converting corn stover into energy and value‐added products within the biorefinery framework. The data were processed using the Web of Science® database and analyzed with the VosViewer® bibliometric software's, Bibliometrix package in R and Gephi, generating keyword‐based maps. A total of 2557 experimental articles and 30 reviews on corn stover research were analyzed. The bibliometric study revealed that the primary research focuses on pretreatment technologies for converting corn stover into value‐added products, bioenergy and biofuels. The main technologies employed include acid, alkaline and enzymatic hydrolysis, as well as torrefaction anaerobic digestion and steam explosion. The pretreatment processes yield sugars, xylooligosaccharides and organic acids. Additionally, the studies explored the use of corn stover biochar for soil remediation and adsorption processes. This review aims to enhance the understanding of technological pathways explored in previous research, contributing to the evaluation of sustainable processes for utilizing corn stover byproducts. Ultimately, it promotes environmentally conscious agroindustry practices that align with circular economy principles and sustainable development.

Sustainable Activated Carbon from Agricultural Waste: A Study on Adsorption Efficiency for Humic Acid and Methyl Orange Dyes

In this study, porous activated carbon was produced from coffee waste and used as an effective adsorbent for the removal of humic acid (HA) from seawater and methyl orange (MO) dye from aqueous solutions. Phosphoric acid H3PO4 was used as an activating agent for the chemical activation of these agricultural wastes. The characterization of the activated carbon obtained using a scanning electron microscope (SEM), Fourier-transform infrared (FTIR) spectroscopy analysis, X-ray diffraction (XRD) and the Brunauer–Emmett–Teller (BET) method revealed that the activated carbon products exhibited high porosity and the formation of various functional groups. The effects of different parameters were examined using batch adsorption experiments, such as the adsorbent masses, pH, initial pollutant concentration and contact time. The results show that the performance increased with an increased adsorbent mass (up to 0.25 g/L) and decreased initial concentration of the adsorbent tested. On the other hand, this study clearly showed that the adsorption efficiency of the MO on the raw spent coffee grounds (SCGs) waste was around 43%, while no removal was observed for the humic acid. The experiments demonstrated that the activated carbon synthesized from the used coffee grounds (the efficiency was compared with commercial activated carbon (CAC) with a difference of 13%) was a promising alternative to commercially available adsorbents for the removal of humic acid from seawater. To understand and elucidate the adsorption mechanism, various isothermal and kinetic models were studied. The adsorption capacity was analyzed by fitting experimental data to these models. The experimental data for methyl orange dyes were analyzed using Langmuir and Freundlich isothermal models. The Freundlich isotherm model provided a superior fit to the equilibrium data, as indicated by a higher correlation coefficient (R2) than that of the Langmuir model. The maximum adsorption was observed at pH 3. The Freundlich adsorption capacity was found to be 333 mg/g adsorbent. The PAC showed a high adsorption capacity for the MO and HA. The PAC showed the highest adsorption capacities for the HA and MO compared with the other adsorbents used (SCGs and CAC) and would be a good material to increase the adsorption efficiency for humic acid removal in the seawater pretreatment process. In addition, the prepared AC BET surface area was 520.40 m2/g, suggesting a high adsorption capacity. This makes the material potentially suitable for various applications that require a high surface area. These results indicate that high-quality sustainable activated carbon can be efficiently produced from coffee waste, making it suitable for a wide range of adsorbent applications targeting various pollutants.

Recovery of ammonia assimilating microbiome after Cr (VI) shock by bio-accelerators

The pretreatment process is often unable to completely intercept heavy metals in wastewater, facing a huge risk of leakage, increasing the difficulty of treating pollutants in the subsequent biochemical process or even leading to the collapse of the system, and facing the difficulty of inoperability and rehabilitation. Heterotrophic ammonia assimilation has the potential to maintain some stability after heavy metal shock, thanks to its rapid microbial proliferation, robust resistance to high loads, remarkable environmental adaptability, and inherent stability. Bio-accelerators dosing strategies could strengthen the performance recovery ability of traditional bio-system after heavy metal impact. However, no recovery strategies for inhibiting HAA have been reported. Herein, three bio-accelerants, specifically, vitamin A, 6-benzylaminopurine, and α-ketoglutaric acid, were investigated for their potential to restore the HAA system impacted by 20 mg/L Cr (VI). The three bio-accelerants effectively mitigated the toxicity of the HAA system, resulting in a 60.4% increase in NH4+-N removal efficiency within just 6 days with cytokinin. During toxicity remediation, three bio-accelerants facilitated the production of extracellular protein components in soluble microbial products and stimulated the secretion of extracellular polymeric substances. The three bio-accelerants enhanced competition among genera and influenced community assembly processes to regulate community structure and enhance functional gene expression. This study offers a practical approach to enhancing the HAA process and remediating microbial toxicity.

Significantly enhancing enzymatic saccharification of poplar waste through the effective removal of lignin and hemicellulose by 1-butanol-Na3PO4-water treatment

Na3PO4-H2O-assisted 1-butanol pretreatment was established for changing the structure of poplar waste and improving its enzymatic efficiency. After poplar waste was pretreated at 180 °C for 60 min, 51.3 % of xylan and 52.5 % of lignin were eliminated. After the enzymatic saccharification of treated poplar waste, the yield of reducing sugars reached 75.3 %. A series of characterizations demonstrated that Na3PO4-H2O-assisted 1-butanol pretreatment altered the poplar composition with improved cellulose accessibility from 231.2 to 459.5 mg/g and reduced surface area of lignin from 384.2 to 255.3 m2/g. Molecular simulations, quantum chemical calculations and independent gradient model analysis were performed on the poplar model, and the 1-butanol-Na3PO4-H2O pretreatment resulted in the increase of electrostatic and van der Waals repulsion forces in lignin and xylan, explaining the efficient lignin and xylan removal. A comprehensive interpretation of mass balance and energy flow was applied to assess the entire pretreatment process. This eco-friendly 1-butanol-Na3PO4-H2O pretreatment effectively broken the encapsulation of cellulose by enzyme inhibitors and improve biomass pretreatment effect.

Influence of the water content in polyamide 6 on atmospheric pressure plasma jet pre-treatment and adhesion for adhesive bonding

AbstractTo quantify the influence of absorbed water in PA6 on the pre-treatment and bonding process, an unfilled and unreinforced PA6 material is investigated in a dried and saturated state. The material is pre-treated by atmospheric pressure plasma jet (APPJ) with varying jet distances. The surfaces are investigated by contact angle measurements, DSC and FTIR to detect molecular and morphological changes in the surface. To evaluate the bonding strength, samples are bonded with a two-component polyurethane adhesive and a two-component acrylate adhesive and tested in a lap shear and a tensile configuration. The results show that water content has a significant influence on the effectivity of the pre-treatment process and the resulting bonding strength and failure mechanism. The adhesion is majorly affected, however these effects do not influence the macroscopic wetting behavior and cannot be measured in contact angles. FTIR spectra and DSC scans do not show significant changes in molecular groups or crystallinity that would explain the observed adhesion improvement in dried samples. High bonding strength is only achieved with adherents at low water content.

A Review of the Technological Aspects and Process Optimization of Bioethanol Production From Corn Stover Biomass: Pretreatment Process, Hydrolysis, Fermentation, Purification Process, and Future Perspective

ABSTRACTBioethanol, a sustainable energy solution derived from renewable biomass, has gained prominence, with corn stover emerging as a substantial biomass resource in Indonesia. Corn stover, a corn residue, is one of the top three agricultural wastes worldwide and is abundantly available. However, a significant portion of corn stover is burned in fields rather than utilized for bioethanol production, whereas it has potential as a bioethanol feedstock. As the world strives to realize sustainable and environmentally friendly energy security, bioethanol production from corn stover can be one of the solutions to be developed. Nonetheless, the current immaturity of bioethanol production technology is one of the causes of large‐scale production failure. The present paper comprehensively reviews the technological aspects and process optimization of bioethanol production using corn stover as a feedstock comprising pretreatment, hydrolysis, fermentation, and bioethanol purification processes. According to our critical review, ammonia fiber expansion (AFEX) pretreatment is the most effective conventional pretreatment, with glucose yield up to 90%. Moreover, ultrasound appears to be the most viable option for nonconventional pretreatment of corn stover for producing bioethanol. However, combining ultrasound pretreatment and dilute aqueous ammonia produced 80.6% sugar output. Furthermore, enzymatic hydrolysis emerges as the most effective saccharification, yielding up to 81.39%. Moreover, the fermentation process of corn stover with the saccharification and co‐fermentation (SScF) method and the process optimization with response surface methodology (RSM) could produce bioethanol with a concentration of up to 59.8 g/L and 92.07% ethanol yield, respectively. This review also reveals that pervaporation for the purification process is the best choice for producing bioethanol with high purity up to &gt; 99%. In addition, this method could reduce the energy used by 6.6% lower, 24.2% lower carbon footprint, and have the lowest total capital and production costs compared to conventional molecular sieves and extractive distillation. We believe this review article can provide a reference for selecting the best bioethanol production process from corn stover for further research.