steam treatment

蒸汽处理
  • 文章类型: Journal Article
    地毯清洁指南目前不包括使用抗菌剂,除了体液事件后。为了解决这个差距,我们比较了三种抗微生物剂-两种基于过氧化氢(H2O2)的产品(A和B)和一种基于氯的产品(C)-以及蒸汽处理对两种诺如病毒替代品的功效,特别是猫杯状病毒(FCV)和杜兰病毒(TuV)。这些测试是在具有透水或防水背衬类型的尼龙地毯上进行的。还评估了反复使用抗微生物剂对地毯性能的影响。对于带有透水背衬的地毯,产品A,B,和C实现了0.8、3.1和0.9log10PFU/试样减少的FCV和0.3、2.5和0.4log10TCID50/试样减少的TuV,分别,在30分钟的接触时间之后。对于带防水背衬的地毯,只有产品B实现了5.0log10PFU/优惠券FCV减少和>3.0log10TCID50/优惠券TuV减少,而产品A和C实现了2.4和1.6log10PFU/优惠券的FCV减少和1.2和1.2log10TCID50/优惠券的TuV减少,分别。在具有两种背衬类型的地毯上,蒸汽处理在15秒内实现了≥5.2log10PFU/试片FCV降低和>3.2log10TCID50/试片TuV降低。产品A和B的重复使用降低了地毯背衬的拉伸强度,而产品B的使用导致地毯纤维上的裂纹。总的来说,蒸汽处理15秒对两种地毯都有效,但是只有产品B在具有防水背衬的地毯上暴露30分钟后才达到功效。重要因素在长期护理设施中很常见,尽管它有可能作为传播与医疗保健相关感染相关的药物的工具,包括人类诺如病毒(NoV)。目前,我们对地毯消毒的理解是有限的;因此,地毯上没有商业抗诺如病毒的抗生素。我们的发现表明蒸汽处理,对地毯纤维和背衬的性能影响最小,与测试的三种化学抗菌剂相比,对地毯上的人类诺如病毒替代品更有效。此外,与具有透水背衬的地毯相比,这两个代理人对具有防水背衬的地毯上的化学抗菌剂更敏感。这些发现可以为开发用于被人类诺如病毒污染的地毯的抗微生物剂提供信息。
    Carpet cleaning guidelines currently do not include the use of an antimicrobial, except after a bodily fluid event. To address this gap, we compared the efficacy of three antimicrobials-two hydrogen peroxide-based (H2O2) products (A and B) and one chlorine-based product (C)-and a steam treatment against two norovirus surrogates, specifically feline calicivirus (FCV) and Tulane virus (TuV). These tests were performed on nylon carpets with either water-permeable or waterproof backing types. The effect of repeated antimicrobial use on carpet properties was also evaluated. For a carpet with water-permeable backing, products A, B, and C achieved a 0.8, 3.1, and 0.9 log10 PFU/coupon reduction of FCV and 0.3, 2.5, and 0.4 log10 TCID50/coupon reduction of TuV, respectively, following a 30 min contact time. For carpet with waterproof backing, only product B achieved a 5.0 log10 PFU/coupon reduction of FCV and >3.0 log10 TCID50/coupon reduction of TuV, whereas products A and C achieved a 2.4 and 1.6 log10 PFU/coupon reduction of FCV and a 1.2 and 1.2 log10 TCID50/coupon reduction of TuV, respectively. Steam treatment achieved a ≥ 5.2 log10 PFU/coupon reduction of FCV and a > 3.2 log10 TCID50/coupon reduction of TuV in 15 seconds on the carpet with both backing types. The repeated use of products A and B decreased the tensile strength of the carpet backing, while use of product B resulted in cracks on carpet fibers. Overall, steam treatment for 15 seconds was efficacious on both carpet types, but only product B achieved efficacy after a 30-minute exposure on the carpet with waterproof backing.IMPORTANCECarpets are common in long-term care facilities, despite its potential as a vehicle for transmission of agents associated with healthcare-associated infections, including human norovirus (NoV). Presently, our understanding of carpet disinfection is limited; hence, there are no commercial antimicrobials against norovirus available for use on carpets. Our findings showed that steam treatment, which minimally affected the properties of carpet fibers and backing, was more efficacious against human norovirus surrogates on carpets compared to the three chemical antimicrobials tested. Additionally, the two surrogates were more sensitive to chemical antimicrobials on the carpet with waterproof backing compared to carpets with water-permeable backing. These findings can inform development of antimicrobials for use on carpets contaminated with human norovirus.
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  • 文章类型: Journal Article
    丙烯酰胺是在美拉德反应中形成的酰胺,以天冬酰胺为主要氨基酸前体。大量丙烯酰胺的摄入已在动物的激素敏感组织中引起基因毒性和致癌作用。肟天冬酰胺酶是降低马铃薯等食品中丙烯酰胺形成的最有效方法之一。然而,到目前为止,咖啡的感官结果报告并不令人满意。这项研究旨在通过用天冬酰胺酶处理来生产丙烯酰胺含量降低的咖啡,同时保留其原始的感官和生物活性特征。三个阿拉伯咖啡的原始样本,包括两杯特制咖啡,用1000、2000和3000ASNU的酶处理其中一罐咖啡。天冬酰胺和生物活性化合物(绿原酸-CGA,咖啡因,和三角碱)通过HPLC和LC-MS定量测定生豆和烤豆中的含量,同时用CG-MS测定烤豆中的丙烯酰胺和挥发性有机化合物。可溶性固体,可滴定酸度,还测定了pH值。还进行了Q-graders的专业拔罐和消费者感官测试。结果由方差分析-Fisher分析,MFA,PCA和聚类分析,显著性水平设置为p≤0.05。仅蒸汽处理就使丙烯酰胺含量降低了18.4%,平均而言,和6.1%的中烤阿拉伯咖啡和canefora咖啡。当使用1000-3000ASNU时,在中等烘烤的阿拉比卡豆中观察到丙烯酰胺的形成平均减少了32.5-56.0%。在canefora样本中,观察到59.4-60.7%的减少。然而,蒸汽处理主要导致中等烘烤的阿拉比卡样品中的总CGA和内酯减少17.1-26.7%,而食道样品中的总CGA和内酯减少13.9-22.0%,当Trigonelline的变化时,咖啡因,和其他评估的化学参数,包括挥发性的配置文件是最小的。增加酶负荷略微升高酸度。Q-graders和/或消费者在处理样品中观察到的唯一感官变化是酸度适度增加,当3000ASNU用于酸度较低的样品时,在对照样品中失去轻度异味,和增加感觉描述符的感知。选择前者是考虑到用2000和3000ASNU负荷处理的豆类的化学结果相似。
    Acrylamide is an amide formed in the Maillard reaction, with asparagine as the primary amino acid precursor. The intake of large amounts of acrylamide has induced genotoxic and carcinogenic effects in hormone-sensitive tissues of animals. The enzime asparaginase is one of the most effective methods for lowering the formation of acrylamide in foods such as potatoes. However, the reported sensory outcomes for coffee have been unsatisfactory so far. This study aimed to produce coffees with reduced levels of acrylamide by treating them with asparaginase while retaining their original sensory and bioactive profiles. Three raw samples of Coffea arabica, including two specialty coffees, and one of Coffea canephora were treated with 1000, 2000, and 3000 ASNU of the enzyme. Asparagine and bioactive compounds (chlorogenic acids-CGA, caffeine, and trigonelline) were quantified in raw and roasted beans by HPLC and LC-MS, while the determination of acrylamide and volatile organic compounds was performed in roasted beans by CG-MS. Soluble solids, titratable acidity, and pH were also determined. Professional cupping by Q-graders and consumer sensory tests were also conducted. Results were analyzed by ANOVA-Fisher, MFA, PCA and Cluster analyses, with significance levels set at p ≤ 0.05. Steam treatment alone decreased acrylamide content by 18.4%, on average, and 6.1% in medium roasted arabica and canefora coffees. Average reductions of 32.5-56.0% in acrylamide formation were observed in medium roasted arabica beans when 1000-3000 ASNU were applied. In the canefora sample, 59.4-60.7% reductions were observed. However, steam treatment primarily caused 17.1-26.7% reduction of total CGA and lactones in medium roasted arabica samples and 13.9-22.0% in canefora sample, while changes in trigonelline, caffeine, and other evaluated chemical parameters, including the volatile profiles were minimal. Increasing enzyme loads slightly elevated acidity. The only sensory changes observed by Q-graders and or consumers in treated samples were a modest increase in acidity when 3000 ASNU was used in the sample with lower acidity, loss of mild off-notes in control samples, and increased perception of sensory descriptors. The former was selected given the similarity in chemical outcomes among beans treated with 2000 and 3000 ASNU loads.
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  • 文章类型: Journal Article
    制造具有高物理性能的可持续结构材料以替代工程塑料是现代工业的主要挑战,和木头,作为地球上最丰富的可持续天然原料,受到了研究人员的极大关注。研究人员一直致力于提高木材的物理性能,以取代塑料。然而,也很难以低成本满足实际需求。在这里,我们报告了一种简单有效的自上而下的策略,将散装天然bass木转化为高性能结构材料。这种三步策略涉及通过煮沸NaOH和Na2SO3的水性混合物来处理bass木来部分去除半纤维素和木质素,并对脱木质素的木材进行高压蒸汽处理(HPST),然后进行热压,这使得木材能够快速均匀地吸收水分。HPST处理的致密脱木素木材(HDDW)的拉伸强度为〜420MPa,这是6.5倍,比天然bass木(〜65MPa)。我们系统地研究了影响这种木材材料拉伸强度的各种因素,并探讨了这些因素影响拉伸强度的原因,以及通过HPST吸收的水分与HDDW增加的拉伸强度之间的内在联系。通过我们的实验,我们实现了HDDW的增强机理和制备HDDW的最佳实验条件。
    The fabrication of sustainable structural materials with high physical properties to replace engineering plastics is a major challenge for modern industry, and wood, as the most abundant sustainable natural raw material on the planet, has received a great deal of attention from researchers. Researchers have made efforts to enhance the physical properties of wood in order to replace plastics. However, it is also difficult to meet practical demands at a low cost. Herein, we report a simple and efficient top-down strategy to transform bulk natural basswood into a high-performance structural material. This three-step strategy involves partial removal of hemicellulose and lignin via treating basswood by boiling an aqueous mixture of NaOH and Na2SO3, and a high-pressure steam treatment (HPST) was applied to delignified wood followed by hot-pressing, which allowed the wood to absorb moisture uniformly and quickly. HPST-treated dense delignified wood (HDDW) has a tensile strength of ~420 MPa, which is 6.5 times better than natural basswood (~65 MPa). We systematically investigated the various factors affecting the tensile strength of this wood material and explored the reasons why these factors affect the tensile strength, as well as the intrinsic connection between the moisture absorbed through HPST and the increased tensile strength of HDDW. Through our experiments, we realized the enhancement mechanism of HDDW and the optimal experimental conditions for the fabrication of HDDW.
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  • 文章类型: Journal Article
    生杏仁与沙门氏菌暴发和与单核细胞增生李斯特菌污染有关的多次召回有关。虽然蒸汽处理已被批准用于常规和有机全杏仁的巴氏杀菌,对水分活度(aw)如何影响杏仁净化蒸汽处理的有效性的了解有限。因此,这项研究旨在评估和比较蒸汽治疗对无害李斯特菌和屎肠球菌NRRLB-2354,已知的非致病性替代品的疗效,杏仁。它还试图研究杏仁的aw对蒸汽处理期间细菌抗性的影响。在100-135°C的温度下进行蒸汽处理之前,用~8log10CFU/g的屎肠球菌或无精打采乳杆菌接种杏仁核,并平衡至aw0.25或0.45。我们的结果表明,与屎肠球菌相比,无花乳杆菌对蒸汽的抵抗力较低,当杏仁的表面温度达到100-130°C时,无毒乳杆菌减少1.2-2.6log10CFU/g,屎肠球菌减少1.0-2.0log10CFU/g,取决于杏仁的aw。获得的DL。innocua,100-130°C-值为2.0-16.6s,和DE。屎,100-130°C-值为4.0-21.8s,取决于杏仁的aw。总的来说,蒸汽温度升高和杏仁aw降低了蒸汽灭活过程中无烟乳杆菌和屎肠杆菌的耐受性。此外,z值表明,与无害乳杆菌相比,杏仁上的屎肠球菌对蒸汽温度的变化不太敏感,尤其是在较低的aw。ZL。无毒值分别为36.6°C和35.7°C,而ZE.在aw为0.25和0.45的杏仁中,faecium值分别为48.9°C和42.7°C。这项研究的结果表明,蒸汽处理可作为控制生杏仁病原体污染的有效干预措施。
    Raw almonds have been associated with Salmonella outbreaks and multiple recalls related to Listeria monocytogenes contamination. While steam treatment has been approved for pasteurizing both conventional and organic whole almonds, there is limited understanding of how water activity (aw) influences the effectiveness of steam treatments in decontaminating almonds. Hence, this study aimed to assess and compare the efficacy of steam treatments against Listeria innocua and Enterococcus faecium NRRL B-2354, the known non-pathogenic surrogates, on almonds. It also sought to investigate the impact of almond\'s aw on bacterial resistance during steam treatments. Almond kernels were inoculated with ~8 log10 CFU/g of either E. faecium or L. innocua and equilibrated to aw 0.25 or 0.45 before being subjected to steam treatments at temperatures of 100-135 °C. Our results revealed that L. innocua exhibited lower resistance to steam compared to E. faecium, with 1.2-2.6 log10 CFU/g reductions for L. innocua and 1.0-2.0 log10 CFU/g reductions for E. faecium when the surface temperature of almonds reached 100-130 °C, depending on the aw of the almonds. The obtained DL. innocua, 100-130°C-values were 2.0-16.6 s, and DE. faecium, 100-130°C-values were 4.0-21.8 s, depending on the aw of almonds. In general, elevating steam temperatures and almond aw decreased the tolerance of L. innocua and E. faecium during steam inactivation. In addition, the z-values indicated that E. faecium on almonds was less sensitive to change in steam temperature compared to L. innocua, especially at lower aw. The zL. innocua-values were 36.6 °C and 35.7 °C, while zE. faecium-values were 48.9 °C and 42.7 °C in almonds with aw 0.25 and 0.45, respectively. Results from this study suggest that steam treatments serve as effective interventions for controlling pathogen contaminations in raw almonds.
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  • 文章类型: Journal Article
    在冬季严寒爆发期间,对受牛结核病影响的农场进行净化可能非常具有挑战性。蒸汽处理已经引起了实际的兴趣,但是需要关于这种治疗是否能够灭活病原体的信息,牛分枝杆菌.这项研究是为了评估使用加压蒸汽灭活土地分枝杆菌,牛分枝杆菌在各种表面上的替代品。
    钢制载盘,木头,或橡胶接种6.32±0.38log10土工菌。当保持在-20°C的背景温度时,4°C,或21°C,这些载体圆盘用加压蒸汽(120°C±5°C)处理5、10、15或20s。测定了土工分枝杆菌菌落形成单位的减少以及圆盘顶面和底面的温度。
    在所有三个背景温度下通过10s的蒸汽处理实现了6log10M.terrae在钢和木盘上的完全失活。相比之下,需要20s的蒸汽处理才能完全灭活橡胶盘上的分枝杆菌。对应于分枝杆菌灭活所需的更长的治疗时间,在所有三个背景温度下,橡胶盘底部表面的温度上升速度明显慢于钢盘和木盘。
    结果表明,用加压蒸汽处理具有在冬季或低于冰点温度下对分枝杆菌污染的表面进行有效和有效的消毒的潜力。
    UNASSIGNED: Decontamination of farms affected by bovine tuberculosis could be very challenging during outbreaks occurring in the winter with freezing temperatures. Steam treatment has been of practical interest, but information is needed on whether such treatment is able to inactivate the causative agent, Mycobacterium bovis. This study was to evaluate the use of pressurized steam for inactivation of Mycobacterium terrae, a surrogate for M. bovis on various surfaces.
    UNASSIGNED: Carrier disks made of steel, wood, or rubber were inoculated with 6.32 ± 0.38 log10 M. terrae. While being held at background temperatures of -20°C, 4°C, or 21°C, these carrier disks were treated with pressurized steam (120°C ± 5°C) for 5, 10, 15, or 20 s. Reduction in colony forming units of M. terrae and temperatures on the top and bottom surfaces of the disks were determined.
    UNASSIGNED: Complete inactivation of 6 log10 M. terrae on steel and wood disks was achieved by 10 s of steam treatment at all three background temperatures. In comparison, 20 s of steam treatment was needed for the complete inactivation of mycobacteria on rubber disks. Corresponding to the longer treatment time required for mycobacterial inactivation, temperatures on the bottom surface of the rubber disks rose substantially slower than those of the steel and wood disks at all three background temperatures.
    UNASSIGNED: The results suggested that treatment with pressurized steam has potential for efficient and effective disinfection of surfaces contaminated by mycobacteria at or below freezing temperatures in winter.
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  • 文章类型: Journal Article
    表面氧空位(Vo)调节是通过降低CO2的活化能垒来提高电化学CO2还原反应(CO2RR)性能的有效策略;然而,缺乏对局部原子结构的精确控制严重阻碍了Vo激活的CO2RR电催化剂的大规模应用。在这里,通过使用蒸汽辅助化学气相沉积方法将Vo引入过渡金属纳米颗粒(NP)中,开发了一种促进CO2活化的有效策略。随着蒸汽过程,将丰富的表面Vo引入组装的Ni-Fe双金属NPs复合材料(H-NiFe/NG)中,将表面Ni/Fe原子调整为低价配位不饱和Ni(1)/Fe(2)位点,作为富电子中心吸附和激活惰性CO2分子。制备的H-NiFe/NG复合材料表现出优异的催化性能,在-0.80V(vsRHE)下的最大法拉第效率为94%,用于CO生产,具有显着的稳定性。密度泛函理论计算证实,表面Vo周围的Ni原子显着降低了COOH*中间体形成的能垒,这给出了将CO2还原为CO的低过潜力,表现出优异的CO2RR性能。这种一般的合成策略为在过渡金属上引入表面Vo以进行有效的CO2还原提供了新的见解。
    Surface oxygen vacancies (Vo ) regulation is an effective strategy to improve the electrochemical CO2  reduction reaction (CO2 RR) performance by lowering the activation energy barrier of CO2 ; however, the lack of precise control over the local atomic structures severely hinders the large-scale application of Vo -activated electrocatalyst for CO2 RR. Herein, an efficient strategy to facilitate CO2  activation is developed by introducing Vo into transition metal nanoparticles (NPs) with a steam-assisted chemical vapor deposition method. With the steam process, abundant surface Vo are introduced into the assembled Ni-Fe bimetallic NPs composite (H-NiFe/NG), which adjust surface Ni/Fe atoms to low-valent coordinatively unsaturated Ni (+1)/Fe (+2) sites, serving as electron-rich centers to adsorb and activate inert CO2  molecules. The as-prepared H-NiFe/NG composite exhibits excellent catalytic performance with a maximum Faradaic efficiency of 94% at -0.80 V (vs RHE) for CO production with remarkable stability. The density function theory calculations corroborate that the Ni atoms around surface Vo significantly lower the energy barrier for COOH* intermediate formation, which gives a low overpotential for reducing CO2  to CO, exhibiting superior CO2 RR performance. This general synthetic strategy provides a new insight to introduce surface Vo on transition metal for efficient CO2  reduction.
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  • 文章类型: Journal Article
    蔬菜加工果渣含有有价值的物质,如天然色素,可作为功能成分重复使用。由于大量的水,它们是一种不稳定的材料。我们研究的目的是评估预处理方法(热或非热)如何影响冷冻干燥过程后从甜菜汁和果渣中获得的粉末的性质。将原料蒸或超声处理10或15分钟,然后挤进果汁和果渣。将两种挤压的产品冷冻干燥。干物质含量;L*,a*,和b*颜色参数;并分析了甜菜碱色素的含量。预处理增加了果汁中红色和黄色的比例。蒸汽和超声引起干燥果渣中参数b*的显著降低。在用超声和蒸汽预处理15分钟后,观察到冻干物中的甜菜碱显着增加。作为所有实验的结果,干燥的果汁和果皮也可以用作着色剂源。然而,由于其额外的内部物质以及更好的储存特性,pomaces具有更高的潜力。几个小时后,果汁很粘,没有准备好使用。
    Vegetable processing pomace contains valuable substances such as natural colors that can be reused as functional ingredients. Due to a large amount of water, they are an unstable material. The aim of our research was to assess how the pretreatment method (thermal or nonthermal) affects the properties of powders obtained from beet juice and pomace after the freeze-drying process. The raw material was steamed or sonicated for 10 or 15 min, and then squeezed into juice and pomace. Both squeezed products were freeze-dried. The content of dry substance; L*, a*, and b* color parameters; and the content of betalain pigments were analyzed. Pretreatments increased the proportion of red and yellow in the juices. Steam and ultrasound caused a significant reduction in parameter b* in the dried pomace. A significant increase in betanin in lyophilizates was observed after pretreatment with ultrasound and steam for 15 min. As a result of all experiments, dried juices and pomaces can also be used as a colorant source. However, there is higher potential with pomaces due to their additional internal substances as well as better storage properties. After a few hours, juice was sticky and not ready to use.
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  • 文章类型: Journal Article
    The effects of argon and nitrogen cold plasma treatments on the lipolytic enzymes activity in wheat germ were investigated. Using argon as plasma gas, the residual activity of lipase and lipoxygenase decreased to 42.50% and 87.72%, respectively after 30 min. Switching plasma input gas to nitrogen, the residual activities of lipase and lipoxygenase after the same time of atmospheric cold plasma (ACP) treatment were 77.50% and 92.52%, respectively. The antioxidant potential and phenolic compounds show no significant difference during ACP duration. However, the remaining activities of lipase and lipoxygenase after 30 min steam autoclaving were 6.25% and 18.60%, respectively. Also, the antioxidant activity and total phenolic content reduced by 14.70% and 30.80%, respectively. In brief, the ACP treatment efficiency was function of the input gas and the treatment time. The presented results about the input gas impacts would be useful in industrial development of ACP application for wheat germ stabilization.
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  • 文章类型: Comparative Study
    In this study, the effects of high hydrostatic pressure (HHP) and steam on biochemical composition and non-volatile taste active compounds of oysters Crassostrea hongkongensis were investigated. The moisture content in steamed oysters significantly decreased when compared to raw samples, subsequently their crude protein, crude lipid, glycogen and ash contents (% wet weight) were all increased (P < 0.05). In addition, though the moisture content in HHP oysters decreased, no significant differences were observed in proximate compositions compared to raw oysters, except crude protein. There were no significant differences in saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) profiles between raw and HHP oysters, however, C20:3n6 content in HHP oysters was significantly higher than that in raw samples (P < 0.05). The PUFA profile of steamed oysters, mostly contributed by n-3 PUFA, was significantly higher than that of both raw and HHP samples (P < 0.05). Major free amino acids (FAA) (taste activity value, TAV > 1) in oysters with three treatments were alanine, glycine, glutamic acid and histidine, and their contents were significantly higher in raw and HHP groups than that in steamed group. The 5\'-inosine monophosphate (IMP) and 5\'-guanosine monophosphate (GMP) in HHP and steamed oysters decreased compared to raw samples, while AMP content in steam oysters were significantly increased (P < 0.05). The equivalent umami concentration (EUC) of oysters of raw, HHP and steamed groups were 8.80, 3.66 and 1.44 g MSG/100 g, respectively, with significant differences observed among different treatments (P < 0.05). Succinic acid was the major organic acid in raw and HHP oysters, while lactic acid was the major organic acid in steamed groups. Further, Na+, K+, PO43- and Cl- were the main inorganic ions (TAV > 1), and their contents were significantly higher in raw and HHP groups than that in steamed group (P < 0.05). This study demonstrated that HHP treatment slightly influenced the changes in the biochemical composition and non-volatile taste active compounds to raw oysters, compared to steamed process.
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  • 文章类型: Journal Article
    鉴于现有中密度纤维板(MDF)废物的预期增加,以及目前处置能力不足和不令人满意,需要开发回收废料的有效方法。在这项研究中,蒸汽精制作为水解树脂的方法的潜力,隔离纤维,并获得可用于在生物炼制的背景下进一步利用的富含半纤维素的提取物。两种不同的中密度纤维板废料样品,以及杨树(Populusspp。)和云杉(云杉属。)用于基准测试的木片,在2.47至3.95的严重程度范围内进行治疗。分离的纤维和提取物部分进行了产量分析,碳水化合物的含量,酸,降解产物,和氮。通过蒸汽精制废MDF,可以获得收率超过70%的纤维部分和包含多达30%碳水化合物的提取物,用于进一步加工。在低严重程度时,大多数基于氮的化合物被溶解。增加严重度导致提取物中的氮减少,因为氮化合物转化为挥发物。不可水解的树脂残留物残留在纤维上,与治疗严重程度无关。与基准样本相比,废物MDF的提取物部分显示出8的高pH和大量的乙酸和甲酸。另一方面,糠醛和5-羟甲基糠醛(5-HMF)的产生受到抑制。可以观察到废弃MDF和常规木材之间碳水化合物水解行为的明显差异。尤其是,含甘露糖的成分似乎对MDF分馏产生的环境中的水解反应具有抗性。
    In view of the expected increase in available waste medium-density fiberboard (MDF) and the current insufficient and unsatisfactory disposal capacities, efficient ways of recycling the waste material need to be developed. In this study, the potential of steam refining as a method to hydrolyze the resins, isolate fibers, and obtain a hemicellulose-rich extract available for further utilization in the context of a biorefinery was assessed. Two different MDF waste samples, as well as poplar (Populus spp.) and spruce (Picea spp.) wood chips for benchmarking, were treated over a severity range from 2.47 to 3.95. The separated fiber and extract fractions were analyzed with regard to yield, content of carbohydrates, acids, degradation products, and nitrogen. A fiber fraction of more than 70% yield and an extract containing up to 30% of carbohydrates for further processing can be gained by steam-refining waste MDF. At low severities, most of the nitrogen-based compounds are solubilized. Increasing the severity leads to a decrease in nitrogen in the extract as the nitrogen compounds are converted into volatiles. A non-hydrolysable resin residue remains on the fibers, independent of the treatment severity. In comparison to the benchmark samples, the extract fraction of waste MDF shows a high pH of 8 and high amounts of acetic and formic acid. The generation of furfural and 5-hydroxymethylfurfural (5-HMF) on the other hand is suppressed. Distinct differences in carbohydrate hydrolysis behavior between waste MDF and conventional wood can be observed. Especially, the mannose-containing constituents seem to be resistant to hydrolysis reactions in the milieu created in MDF fractionation.
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