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1.
Environ Res ; 248: 118286, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38280524

RESUMO

This study assesses the environmental impact of pine chip-based biorefinery processes, focusing on bioethanol, xylonic acid, and lignin production. A cradle-to-gate Life Cycle Assessment (LCA) is employed, comparing a novel biphasic pretreatment method (p-toluenesulfonic acid (TsOH)/pentanol, Sc-1) with conventional sulfuric acid pretreatment (H2SO4, Sc-2). The analysis spans biomass handling, pretreatment, enzymatic hydrolysis, yeast fermentation, and distillation. Sc-1 yielded an environmental impact of 1.45E+01 kPt, predominantly affecting human health (96.55%), followed by ecosystems (3.07%) and resources (0.38%). Bioethanol, xylonic acid, and lignin contributed 32.61%, 29.28%, and 38.11% to the total environmental burdens, respectively. Sc-2 resulted in an environmental burden of 1.64E+01 kPt, with a primary impact on human health (96.56%) and smaller roles for ecosystems (3.07%) and resources (0.38%). Bioethanol, xylonic acid, and lignin contributed differently at 22.59%, 12.5%, and 64.91%, respectively. Electricity generation was predominant in both scenarios, accounting for 99.05% of the environmental impact, primarily driven by its extensive usage in biomass handling and pretreatment processes. Sc-1 demonstrated a 13.05% lower environmental impact than Sc-2 due to decreased electricity consumption and increased bioethanol and xylonic acid outputs. This study highlights the pivotal role of pretreatment methods in wood-based biorefineries and underscores the urgency of sustainable alternatives like TsOH/pentanol. Additionally, adopting greener electricity generation, advanced technologies, and process optimization are crucial for reducing the environmental footprint of waste-based biorefineries while preserving valuable bioproduct production.


Assuntos
Ecossistema , Lignina , Ácidos Sulfúricos , Humanos , Pentanóis , Biotecnologia/métodos , Biomassa , Saccharomyces cerevisiae , Hidrólise , Biocombustíveis
2.
Environ Res ; 215(Pt 1): 114291, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36103929

RESUMO

Fermentable sugar production from lignocellulosic biomass has received considerable attention and has been dramatic progress recently. However, due to low enzymatic hydrolysis (EH) yields and rates, a high dosage of the costly enzyme is required, which is a bottleneck for commercial applications. Over the last decades, various strategies have been developed to reduce cellulase enzyme costs. The progress of the non-catalytic additive proteins in mitigating inhibition in EH is discussed in detail in this review. The low efficiency of EH is mostly due to soluble lignin compounds, insoluble lignin, and harsh thermal and mechanical conditions of the EH process. Adding non-catalytic proteins into the EH is considered a simple and efficient approach to boost hydrolysis yield. This review discussed the multiple mechanical steps involved in the EH process. The effect of physicochemical properties of modified lignin on EH and its interaction with cellulase and cellulose are identified and discussed, which include hydrogen bonding, hydrophobic, electrostatic, and cation-π interactions, as well as physical barriers. Moreover, the effects of different conditions of EH that lead to cellulase deactivation by thermal and mechanical mechanisms are also explained. Finally, recent advances in the development, potential mechanisms, and economic feasibility of non-catalytic proteins on EH are evaluated and perspectives are presented.


Assuntos
Celulase , Lignina , Biomassa , Celulase/química , Celulase/metabolismo , Celulose/química , Celulose/metabolismo , Hidrólise , Lignina/química , Estudos Prospectivos , Açúcares
3.
Proc Natl Acad Sci U S A ; 115(10): 2305-2310, 2018 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-29463723

RESUMO

There is a growing research interest in the detection of changes in hydrologic and climatic time series. Stationarity can be assessed using the autocorrelation function, but this is not yet common practice in hydrology and climate. Here, we use a global land-based gridded annual precipitation (hereafter P) database (1940-2009) and find that the lag 1 autocorrelation coefficient is statistically significant at around 14% of the global land surface, implying nonstationary behavior (90% confidence). In contrast, around 76% of the global land surface shows little or no change, implying stationary behavior. We use these results to assess change in the observed P over the most recent decade of the database. We find that the changes for most (84%) grid boxes are within the plausible bounds of no significant change at the 90% CI. The results emphasize the importance of adequately accounting for natural variability when assessing change.

4.
J Environ Manage ; 246: 745-757, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31226528

RESUMO

China has begun a rapid move towards Sponge City implementation, which will include widespread installation of various Low Impact Development (LID) stormwater infrastructure. Ambitious goals have been set for all Sponge Cities, including a target capture rate of 80-85% of annual precipitation in Beijing. However, there has so far been limited investigation into whether these goals are obtainable at the catchment scale given the physical restrictions of the existing urban landscape. This paper demonstrates the use of long-term continuous hydrologic modelling to evaluate the potential of meeting rainfall capture goals over a long time period for a case study area in Beijing. Detailed land cover classification derived from satellite imagery aided in the parameterization of a SWMM (Stormwater Management Model) model representing a 133 km2 urban study area. The calibrated and validated model demonstrated satisfactory agreement between computed and observed runoff for a variety of precipitation events ranging from 10 to 207 mm. A synthetic high resolution rainfall time series was generated from historic daily observations then used as input to run the model continuously for a 35 year period. Feasible LID model scenarios based on varying degrees of implementation of rain gardens, permeable pavements and green roofs were compared in terms of their potential volume capture of annual rainfall. Modelling results demonstrated that the conversion of 30% of roof area to green roof, 10% of green areas to rain gardens and 35% of paved areas to permeable pavement could increase the baseline volume capture ratio from 59.9% to 82.2%, indicating that Sponge City goals can be met within the case study area with realistic levels of LID implementation. This study provides a decision-making basis for future planning in the study area.


Assuntos
Hidrologia , Chuva , Pequim , China , Cidades , Movimentos da Água
5.
J Bioenerg Biomembr ; 49(5): 347-355, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28643238

RESUMO

Regulator of the H+-ATPase of the vacuolar and endosomal membranes (RAVE) is essential for the reversible assembly of H+-ATPase. RAVE primarily consists of three subunits: Rav1p, Rav2p and Skp1p. To characterize these subunits, in this study, four strains derived from Saccharomyces cerevisiae BY4742 were constructed with a FLAG tag on the Rav1p and Rav2p subunits. Then, the corresponding RAVE containing complex was isolated by affinity purification. Western blot and MALDI-TOF mass spectrometry analyses showed that the RAVE complex contains not only the known V1-ATPase subunits (Vma1p and Vma2p) but also a newly found Leu1p that interacts with the RAVE subunit. Furthermore, we constructed rav1-/rav2-/vma2-/leu1-deficient recombinants by fusion PCR and homologous recombination and demonstrated that leu1 is indispensable in adjusting the microbial cell to adverse environments and that the function is similar to that of rav1/rav2 but significantly differs from that of vma2. Leu1p probably plays an important role in RAVE regulation of V-ATPase activity in conjunction with RAVE.


Assuntos
Endossomos/ultraestrutura , Membranas Intracelulares/enzimologia , ATPases Vacuolares Próton-Translocadoras/metabolismo , Vacúolos/ultraestrutura , Endossomos/enzimologia , Subunidades Proteicas , Proteínas de Saccharomyces cerevisiae/fisiologia , Vacúolos/enzimologia
6.
Int J Biol Macromol ; 261(Pt 2): 129877, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38307436

RESUMO

Recently, numerous studies have been conducted on renewable polymers derived from different natural sources, exploring their suitability for diverse biomedical applications. Lignin as one of the main components of lignocellulosic has garnered significant attention as a promising alternative to petroleum-based polymers. This interest is primarily due to its cost-effectiveness, biocompatibility, eco-friendly nature, as well as its antioxidant and antimicrobial properties. These characteristics could be more beneficial when incorporating lignin into the formulation of value-added products. Although lignin has a chemical structure that is suitable for various applications, these characteristics require modifications to guarantee that the resultant materials display the desired biological, chemical, and physical properties when applied in the creation of biodegradable hydrogels, particularly for biomedical purposes. This study delineates the recent modification approaches that have been employed in the creation of lignin-based hydrogels. These strategies encompass both chemical and physical interactions with other polymers. Additionally, this review encompasses an examination of the current applications of lignin hydrogels, spanning their use as scaffolds for tissue engineering, carriers for pharmaceuticals, materials for wound dressings and biosensors, and elements in flexible and wearable electronics. Finally, we delve into the challenges and constraints associated with these materials, discuss the necessary steps required to attain the appropriate properties for the development of innovative lignin-based hydrogels, and derive conclusions based on the presented findings.


Assuntos
Hidrogéis , Lignina , Lignina/química , Hidrogéis/química , Polímeros , Engenharia Tecidual , Eletrônica
7.
Sci Total Environ ; 934: 173199, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38750749

RESUMO

Frequent droughts have caused severe disaster losses in China. Such events can be minimized by enhancing the country's resilience and reducing its vulnerability, where this can ensure socioeconomic stability and sustainable development. Evaluating the vulnerability and resilience to drought is thus crucial for effectively managing the risk of disasters and promoting sustainable socioeconomic development. In this study, we constructed a comprehensive framework to assess the spatiotemporal characteristics of China's vulnerability and resilience to drought at the provincial scale from an input-output perspective by using the Super-efficiency Data Envelopment Analysis (DEA) model and the Super-efficiency Slacks-Based Measure DEA (SBM-DEA) model. This study focused on drought drivers, the disaster-forming environment, drought bearers, disaster intensity, and recovery. The results showed that the vulnerability to drought of 42 % of China's provinces decreased from 2010 to 2022, that of only 29 % of the provinces increased, while the status of a majority of provinces improved in general. The center of gravity of the vulnerability to drought moved toward the southwest over time and a spatial clustering of vulnerability was observed, with High-High clusters moving from the north to the south. Moreover, the resilience to drought declined in 36 % of provinces and increased in only 20 %, reflecting poor resilience overall. The center of gravity of China's overall resilience to drought moved northward, with a relatively stable spatial pattern and prominent clusters of Low-Low resilience indicating a pressing need for improvement. Areas with high vulnerability and low resilience were concentrated in inland western and eastern regions, and this highlights the importance of drought prevention and mitigation in provinces like Xinjiang, Inner Mongolia, Jiangxi, and Fujian. The findings here provide valuable insights for mitigating the risk of drought and promoting sustainable socioeconomic development.

8.
Bioresour Technol ; 399: 130518, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38432544

RESUMO

This study identified the intrinsic relationships among slurry rheology, particle characteristics, and lignocellulosic liquefaction/saccharification based on correlation analysis and principal component analysis during the hydrolysis of sugarcane bagasse pretreated by deep eutectic solvents (DES) and mechanical milling (MM). The DES-MM pretreated lignocellulosic slurry (20% solids) exhibited high apparent viscosity of 1.4 × 104 Pa·s and shear stress of 929.0 Pa under steady state. Glucose production had a negative linear correlation with slurry viscosity (R2, 0.69-0.97), whereas its correlation with yield stress (R2, 0.85-0.98) depended on the particle liquefaction rate. The availability of free water provided a major contribution to improving slurry rheology. However, the size reduction of submillimeter particles and the changes in particle hydrophilicity during liquefaction were not significantly correlated with rheological changes. Various interrelated particle characteristics and rheological changes were integrated into two simple principal variables to predict glucose production with a high R2 of 0.96.


Assuntos
Celulase , Saccharum , Celulose , Hidrólise , Glucose , Reologia
9.
Bioresour Technol ; 395: 130358, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38253243

RESUMO

This study investigated an innovative strategy of incorporating surfactants into alkaline-catalyzed glycerol pretreatment and enzymatic hydrolysis to improve lignocellulosic biomass (LCB) conversion efficiency. Results revealed that adding 40 mg/g PEG 4000 to the pretreatment at 195 °C obtained the highest glucose yield (84.6%). This yield was comparable to that achieved without surfactants at a higher temperature (240 °C), indicating a reduction of 18.8% in the required heat input. Subsequently, Triton X-100 addition during enzymatic hydrolysis of PEG 4000-assisted pretreated substrate increased glucose yields to 92.1% at 6 FPU/g enzyme loading. High-solid fed-batch semi-simultaneous saccharification and co-fermentation using this dual surfactant strategy gave 56.4 g/L ethanol and a positive net energy gain of 1.4 MJ/kg. Significantly, dual assistance with surfactants rendered 56.3% enzyme cost savings compared to controls without surfactants. Therefore, the proposed surfactant dual-assisted promising approach opens the gateway to economically viable enzyme-mediated LCB biorefinery.


Assuntos
Celulose , Glicerol , Hidrólise , Celulose/metabolismo , Tensoativos , Biomassa , Fermentação , Glucose
10.
Int J Biol Macromol ; 264(Pt 2): 130674, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38458273

RESUMO

Microcrystalline cellulose (MCC) was successfully synthesized from sugarcane bagasse using a rapid, low-temperature hydrochloric acid (HCl) gas treatment. The primary aim was to develop an energy-efficient "green" cellulose extraction process. Response surface methodology optimized the liquid-phase hydrolysis conditions to 3.3 % HCl at 117 °C for 127 min to obtain MCC with 350 degree of polymerization. An alternative gas-phase approach utilizing gaseous HCl diluted in hot 40 °C air was proposed to accelerate MCC production. The cellulose pulp was moistened to 15-18 % moisture content and then exposed to HCl gas, which was absorbed by the moisture in the cellulose fibers to generate a highly concentrated acidic solution that hydrolyzed the cellulose. The cellulose pulp was isolated from depithed bagasse through soda pulping, multistage bleaching and cold alkali purification. Hydrolysis was conducted by saturating the moist cellulose fibers with gaseous HCl mixed with hot air. Extensive analytical characterization using FT-IR, XRD, SEM, TGA, DSC, particle size, and porosity analyses verified comparable physicochemical attributes between MCC samples prepared via liquid and gas phase methods. The gas-produced MCC revealed 85% crystallinity, 71 Å crystallite dimensions, and thermally stable rod-shaped morphology with an average diameter below 200 µm. The similar material properties validate the proposed gas-based technique as an equally effective yet more energy-efficient alternative to conventional aqueous acid hydrolysis for fabricating highly pure MCC powders from lignocellulose. This sustainable approach enables the value-addition of sugarcane bagasse agro-industrial residue into cellulosic nanomaterials for wide-ranging industrial applications. In summary, the key achievements of this work are rapid MCC production under mild temperatures using HCl gas, optimization of liquid phase hydrolysis, successful demonstration of gas phase method, and extensive characterization verifying equivalence between both protocols. The gas methodology offers a greener cellulose extraction process from biomass.


Assuntos
Celulose , Saccharum , Celulose/química , Hidrólise , Ácido Clorídrico/química , Saccharum/química , Espectroscopia de Infravermelho com Transformada de Fourier
11.
Sci Total Environ ; 900: 165591, 2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-37478945

RESUMO

The dynamic interplay between climate change and socioeconomic development has brought about significant changes in drought hazard, vulnerability, and risk within the global socioeconomic system. However, there is a prevailing lack of understanding about how these changes will manifest in an increasingly globalized economy under global warming. To address this knowledge gap, this study utilizes various climatic, geographical, and socioeconomic data from historical period and future projections to comprehensively map and assess the changes in global drought vulnerability and risk of population in the 2030s and 2050s under the SSP126, SSP245, and SSP585 scenarios. This study finds that the future population at risk of drought is projected to increase by 21.96 % - 25.95 % in the 2030s and 36.64 % - 45.40 % in the 2050s, driven by rapid population growth and substantial changes in drought hazard and vulnerability. This includes varying increases in drought hazard in approximately 58 % of global land area, alongside decreases in drought vulnerability in 50 % - 80 % of global land areas. Most arid and semi-arid regions, including Africa, Central Asia, West Asia, and Australia with less developed economies, are more susceptible to the adverse effects of climate change, leading to significant increases in future drought hazards, vulnerability, and risk, particularly under higher emission scenarios. In contrast, most humid and semi-humid regions exhibit varying degrees of drought vulnerability and risk of population across regions, despite the overall increasing drought hazard, with disproportionate impact of climate change and socioeconomic development. Specifically, projected increases in drought vulnerability and risk are observed in the Amazon, central and western U.S., while decreases are projected in the eastern part of China delimited by the Hu Line, southern India, Japan, Korea, most of Southeast Asia, northern Europe, and South America excluding the Amazon. The eastern U.S. is expected to experience reduced vulnerability but increased drought risk. This study can assist decision makers to develop targeted strategies and measures of adaptation and mitigation in an increasingly globalized economy under global warming.

12.
Bioresour Technol ; 369: 128500, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36535614

RESUMO

Propionic acid (PA) hydrolysis of corncob for xylooligosaccharides (XOS) production has the advantages of simple operation, high XOS yield and less by-products, but the high price of PA limits its application. Therefore, partially replacing PA with less expensive organic acids, such as formic acid (FA) and acetic acid (AC), may lower the cost of hydrolysis in XOS production. This work investigated the feasibility of XOS production from corncob using a tri-acid mixture of FA, AC and PA. A high XOS yield of 69.1 % was achieved under the optimal FA:PA:AC volume ratio of 1:5:4 at 150 °C for 50 min. Overall, in the XOS production from corncob, it was able to replace 60 % of PA with FA and AC, and decreased the hydrolysis temperature from 170 °C to 150 °C, all of which were important to lower the cost of XOS production using organic acid hydrolysis.


Assuntos
Oligossacarídeos , Zea mays , Hidrólise , Glucuronatos , Ácidos
13.
Bioresour Technol ; 385: 129439, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37414345

RESUMO

The enzymatic hydrolysis cost of lignocellulose can be reduced by improving enzymatic hydrolysis and recycling cellulase by adding additives. A series of copolymers P(SSS-co-SPE) (PSSPs) were synthesized using sodium p-styrene sulfonate (SSS) and sulfobetaine (SPE) as monomers. PSSP exhibited upper critical solution temperature response. PSSP with high molar ratio of SSS displayed more significant improved hydrolysis performance. When 10.0 g/L PSSP5 was added to the hydrolysis system of corncob residues, and substrate enzymatic digestibility at 72 h (SED@72 h) increased by 1.4 times. PSSP with high molecular weight and moderate molar ratio of SSS, had significant temperature response, enhanced hydrolysis, and recovering cellulase properties. For high-solids hydrolysis of corncob residues, SED@48 h increased by 1.2 times with adding 4.0 g/L of PSSP3. Meanwhile, 50% of cellulase amount was saved at the room temperature. This work provides a new idea for reducing the hydrolysis cost of lignocellulose-based sugar platform technology.


Assuntos
Celulase , Zea mays , Zea mays/química , Hidrólise , Lignina/química , Celulase/química , Biotecnologia , Polímeros
14.
Environ Sci Pollut Res Int ; 30(32): 78030-78040, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37311860

RESUMO

Microalgae CO2 sequestration has gained considerable attention in the last three decades as a promising technology to slow global warming caused by CO2 emissions. To provide a comprehensive and objective analysis of the research status, hot spots, and frontiers of CO2 fixation by microalgae, a bibliometric approach was recently chosen for review. In this study, 1561 articles (1991-2022) from the Web of Science (WOS) on microalgae CO2 sequestration were screened. A knowledge map of the domain was presented using VOSviewer and CiteSpace. It visually demonstrates the most productive journals (Bioresource Technology), countries (China and USA), funding sources, and top contributors (Cheng J, Chang JS, and their team) in the field of CO2 sequestration by microalgae. The analysis also revealed that research hotspots changed over time and that recent research has focused heavily on improving carbon sequestration efficiency. Finally, commercialization of carbon fixation by microalgae is a key hurdle, and supports from other disciplines could improve carbon sequestration efficiency.


Assuntos
Dióxido de Carbono , Microalgas , Bibliometria , Sequestro de Carbono , China
15.
Bioresour Technol ; 371: 128591, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36627085

RESUMO

A new cutting-edge lignocellulose fractionation technology for the co-production of glucose, native-like lignin, and furfural was introduced using mannitol (MT)-assisted p-toluenesulfonic acid/pentanol pretreatment, as an eco-friendly process. The addition of optimized 5% MT in pretreatment enhanced the delignification rate by 29% and enlarged the surface area and biomass porosity by 1.07-1.80 folds. This increased the glucose yield by 45% (from 65.34 to 94.54%) after enzymatic hydrolysis relative to those without MT. The extracted lignin in the organic phase of pretreatment exhibited ß-O-4 bonds (61.54/100 Ar) properties of native cellulosic enzyme lignin. Lignin characterization and molecular docking analyses revealed that the hydroxyl tails of MT were incorporated with lignin and formed etherified lignin, which preserved high lignin integrity. The solubilized hemicellulose (96%) in the liquid phase of pretreatment was converted into furfural with a yield of 83.99%. The MT-assisted pretreatment could contribute to a waste-free biorefinery pathway toward a circular bioeconomy.


Assuntos
Glucose , Lignina , Lignina/química , Glucose/metabolismo , Furaldeído , Pentanóis , Manitol , Simulação de Acoplamento Molecular , Hidrólise , Biomassa
16.
Int J Biol Macromol ; 239: 124260, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-37004931

RESUMO

A novel gel-based wearable sensor with environment resistance (anti-freezing and anti-drying), excellent strength, high sensitivity and self-adhesion was prepared by introducing biomass materials including both lignin and cellulose. The introduction of lignin decorated CNC (L-CNC) to the polymer network acted as nano-fillers to improve the gel's mechanical with high tensile strength (72 KPa at 25 °C, 77 KPa at -20 °C), excellent stretchability (803 % at 25 °C, 722 % at -20 °C). The abundant catechol groups formed in the process of dynamic redox reaction between lignin and ammonium persulfate endowed the gel with robust tissue adhesiveness. Impressively, the gel exhibited outstanding environment resistance, which could be stored for a long time (>60 days) in an open-air environment with a wide work temperature range (-36.5 °C-25 °C). Based on these significant properties, the integrated wearable gel sensor showed superior sensitivity (gauge factor = 3.11 at 25 °C and 2.01 at -20 °C) and could detect human activities with excellent accuracy and stability. It is expected that this work will provide a promising platform for fabricating and application of a high-sensitive strain conductive gel with long-term usage and stability.


Assuntos
Lignina , Nanocompostos , Humanos , Celulose , Polímeros , Biomassa , Condutividade Elétrica , Hidrogéis
17.
Sci Total Environ ; 876: 162549, 2023 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-36871707

RESUMO

With rapid socioeconomic development, oil is widely used in all aspects of modern society. However, the extraction, transport, and processing of oil inevitably lead to the production of large quantities of oily wastewater. Traditional oil/water separation strategies are often inefficient, costly, and cumbersome to operate. Therefore, new green, low-cost, and high-efficiency materials must be developed for oil/water separation. As widely sourced and renewable natural biocomposites, wood-based materials have become a hot field recently. This review will focus on the application of several wood-based materials in oil/water separation. The state of research on wood sponges, cotton fibers, cellulose aerogels, cellulose membranes, and some other wood-based materials for oil/water separation over the last few years and provide an outlook on their future development are summarized and investigated. It is expected to provide some direction for future research on the use of wood-based materials in oil/water separation.


Assuntos
Celulose , Lignina , Biomassa , Óleos
18.
Bioresour Technol ; 382: 129176, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37187334

RESUMO

To improve the CO2 dissolution and carbon fixation in the process of microalgae capturing CO2 from flue gas, a nanofiber membrane containing iron oxide nanoparticles (NPsFe2O3) for CO2 adsorption was prepared, and coupled with microalgae utilization to achieve carbon removal. The performance test results showed that the largest specific surface area and pore size were 8.148 m2 g-1 and 27.505 Å, respectively, when the nanofiber membrane had 4% NPsFe2O3. Through CO2 adsorption experiments, it was found that the nanofiber membrane could prolong the CO2 residence time and increase CO2 dissolution. Then, the nanofiber membrane was used as a CO2 adsorbent and semifixed culture carrier in the Chlorella vulgaris culture process. The results showed that compared with the group without nanofiber membrane (0 layer), the biomass productivity, CO2 fixation efficiency and carbon fixation efficiency of Chlorella vulgaris with 2 layers of membranes increased by 1.4 times.


Assuntos
Chlorella vulgaris , Microalgas , Nanofibras , Dióxido de Carbono , Ciclo do Carbono , Biomassa , Nanopartículas Magnéticas de Óxido de Ferro
19.
Bioresour Technol ; 368: 128356, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36414144

RESUMO

The valorization of organosolv pretreatment (OP) is a required approach to the industrialization of the current enzyme-mediated lignocellulosic biorefinery. Recent literature has demonstrated that the solvolysis happening in the OP can modify the soluble components into value-added active compounds, namely organosolv modified lignin (OML) and organosolv modified sugars (OMSs), in addition to protecting them against excessive degradation. Among them, the OML is coincidental with the "lignin-first" strategy that should render a highly reactive lignin enriched with ß-O-4 linkages and less condensed structure by organosolv grafting, which is desirable for the transformation into phenolic compounds. The OMSs are valuable glycosidic compounds mainly synthesized by trans-glycosylation, which can find potential applications in cosmetics, foods, and healthcare. Therefore, a state-of-the-art OP holds a big promise of lowering the process cost by the valorization of these active compounds. Recent advances in organosolv modified components are reviewed, and perspectives are made for addressing future challenges.


Assuntos
Alimentos , Lignina , Biomassa , Glicosilação
20.
Biotechnol Adv ; 62: 108059, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36402253

RESUMO

Enzymatic hydrolysis is a critical process for the cellulase-mediated lignocellulosic biorefinery to produce sugar syrups that can be converted into a whole range of biofuels and biochemicals. Such a process operating at high-solid loadings (i.e., scarcely any free water or roughly ≥ 15% solids, w/w) is considered more economically feasible, as it can generate a high sugar concentration at low operation and capital costs. However, this approach remains restricted and incurs "high-solid effects", ultimately causing the lower hydrolysis yields with increasing solid loadings. The lack of available water leads to a highly viscous system with impaired mixing that exhibits strong transfer resistance and reaction limitation imposed on enzyme action. Evidently, high-solid enzymatic hydrolysis involves multi-scale mass transfer and multi-phase enzyme reaction, and thus requires a synergistic perspective of transfer and biotransformation to assess the interactions among water, biomass components, and cellulase enzymes. Porous particle characteristics of biomass and its interface properties determine the water form and distribution state surrounding the particles, which are summarized in this review aiming to identify the water-driven multi-scale/multi-phase bioprocesses. Further aided by the cognition of rheological behavior of biomass slurry, solute transfer theories, and enzyme kinetics, the coupling effects of flow-transfer-reaction are revealed under high-solid conditions. Based on the above basic features, this review lucidly explains the causes of high-solid hydrolysis hindrances, highlights the mismatched issues between transfer and reaction, and more importantly, presents the advanced strategies for transfer and reaction enhancements from the viewpoint of process optimization, reactor design, as well as enzyme/auxiliary additive customization.


Assuntos
Celulase , Lignina , Hidrólise , Lignina/química , Celulase/química , Glucose/metabolismo , Água , Biomassa
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