绿色化学 中英文翻译

-教育精选-Enzymic hydrolysis of steam exploded herbaceous agricultural waste(Brassica carinata) at different particule sizes在不同粒子大小情况下草本农业废弃物(芸苔属植物)的蒸汽爆炸酶水解Abstract摘要The objective of this work was to evaluate the effect of particle size on steam-explosion pretreatment of herbaceous lignocellulosicbiomass. Hemicellulose and cellulose recovery, and effectiveness of enzymic hydrolysis of the cellulosic residue is presented for steam-explosion pretreatment of an agriculture residue (Brassica carinata) using different particle sizes. The parameters tested were: particle size (25, 58 and 812 mm), temperature (190 and 210 8C), and residence time (4 and 8 min). The compositional analysis of filtrate and water insoluble fibre after pretreatment and enzymic digestibility data are presented. Larger steam-exploded particle (812 mm) results in higher cellulose and enzymic digestibilities. The use ofvery small particles in steam explosion would not be desirable in optimising the effectiveness of the process improving economy.这项工作的目的是评估效果的粒子大小对蒸汽爆破预处理木质纤维素的草本生物量。半纤维素和纤维素的复苏,和有效性的纤维素酶法水解的残留提出了蒸汽爆破预处理的农业残留物(芸苔属植物carinata)使用不同的粒子大小。测试参数是:颗粒大小(25,58和812毫米)、温度(190和2108c)和停留时间(4和8分钟)。成分分析的水不溶性纤维的滤液和预处理和酶消化后提出了数据。较大的蒸汽爆炸粒子(812毫米)导致更高的纤维素和酶消化性。 使用非常小的粒子在蒸汽爆炸不会是可取的,在优化的过程的有效性的改善经济。1. Introduction介绍Herbaceous agricultural residues represent a major source of lignocellulosic material with considerable potential for use in biomass-to-ethanol renewable energy schemes. It is estimated that about 100 million tons of these residues are annually generated in the EU1. Selected herbaceous crops includingBrassica carinata are currently under study as potential energy sources2. B. carinata represents a new source of non food raw materials either for biomass to be processed into energy or for products from the seed oil which could betransformed into liquid biofuels and highvalue-added derivatives. Because of the special characteristics of this species, its production may serve for the diversification of agricultural systems of cereals in the Mediterranean region of the EU. The creation of a new market is alsoforeseen in the southern European countries as a solution to a future shortage of feedstocks for biodiesel in this area. Moreover, the lignocellulosic residue generated in this crop could be also an interesting feedstock for ethanol production3.草本农业残留物代表的主要来源与可观的潜力木质纤维材料使用在生物质乙醇可再生能源计划。据估计,大约1亿吨的这些残留物是在欧盟每年生成。选择草本作物includingBrassica carinata正在研究潜在的能量来源。b . carinata代表一个新源的非食品原料或者生物质是加工成能源或产品从籽油可以转化为液体燃料和highvalue-added衍生品。由于这一物种的特殊特征,其生产可能为多样化的农业系统在地中海地区的谷物的欧盟。创建一个新的市场也预见在南部欧洲国家来解决未来生物柴油原料的短缺在这个地区。此外,木质纤维素的残渣产生在这种作物可能也是一个有趣的原料在乙醇生产。Although considerable progress has been made in technology for the conversion of lignocellulosic biomass into ethanol, substantial opportunities still exist to reduce production costs4,5. In this context, enzymic hydrolysis processes are advantageous because enzymes carinata catalyse only specific reactions, consequently there are no side reactions or byproducts and the hydrolysis can potentially be run with yields approaching 100% of theoretical 6. Pretreatment is necessary to achieve reasonable rates and yields in the enzymic hydrolysis of biomass. To open up the lignocellulosic structure to wide microbial degradation, expensive energy demand- ing pretreatment processes are required. In the pretreatment area, the reduction of power for milling is one of the technological improvements that will result in substantially lower ethanol production costs. Autohydrolysis steam explosion has generally been accepted as one of the most cost-effective method for pretreating lignocellulosic biomass, since no addition of external catalyst is necessary79.The most important variables in steam-explosion pretreatment are time, temperature and chip size. Generally, when larger chips are used, heat transfer problems may result in overcooking of the outside (with the associated formation of inhibitors) of the chip andincomplete autohydrolysis of the interior10. Consequently, prior to steam explosion pre-treatment, particle size has to be reduced, which requires significant amounts of energy. Another constraint for the autohy drolysis steam explosion is the low hemicellulosic sugars yield, and its negative impact on ethanol production economics. Research efforts have been concentrated on maximising cellulose recovery and have failed to recognise the importance of recovering the hemicellulosic component, which is of crucial importance to improve the overall economics of the cellulosic biomass to ethanol process.Thus, it would be desirable to test innovative conditions to improve the economics of the pretreatment stage by reducing electrical power during the milling2.4. Analytical methodsstage, and by optimising the pretreatment recovery of the hemicellulose component, as well as enhancing cellulose hydrolysis. The objective of this work was to evaluate the effect of particle size on the steam-explosion pretreatment of a lignocellulosic agricultural waste (B.carinata).Cellulose recovery, enzymic hydrolysis effectiveness of the solid residue, and sugar composition in the filtrate are presented for steam-explosion pretreatment using different particle sizes.虽然取得了相当大的进展技术转制为木质生物质转化为乙醇,实质性的机会仍然存在以降低生产成本4,5。在这种背景下,酶水解过程是有利的,因为酶催化的反应,carinata只有特定因此没有侧反应或副产品和水解可运行与收益率接近100%的理论6。预处理是必要的来实现合理的利率,收益率在酶水解的生物质。打开木质纤维素的结构,广泛的微生物降解、昂贵的能源需求- ing预处理过程是必需的。在预处理区、降低动力铣是一个技术改进,将导致大幅降低乙醇生产成本。Autohydrolysis蒸汽爆炸通常被认为是最具成本效益的方法之一为预处理木质纤维素的生物质,因为没有添加外部催化剂是必要的79。最重要的变量在蒸汽爆破预处理时间、温度和芯片尺寸。通常,当使用大的芯片,传热问题可能导致像外面的(有相关形成抑制剂)的芯片和不完整的autohydrolysis室内10。因此,蒸汽爆炸前预处理,粒子大小必须减少,这就需要大量的能源。另一个约束的autohy drolysis蒸汽爆炸是低hemicellulosic糖产量,其负面影响乙醇生产经济学。研究工作已经集中在最大化纤维素复苏和未能认识到恢复的重要性hemicellulosic组件,这是至关重要的改善总体经济学的纤维素生物质乙醇的过程。因此,它是理想的测试条件来改善经济创新的预处理阶段通过减少电力milling2.4期间。分析方法阶段,通过优化预处理复苏的半纤维素成分,以及提高纤维素的水解。这项工作的目的是评估效果的粒度在蒸汽爆破预处理的木质纤维素的农业废弃物(B.carinata)。纤维素复苏,酶水解效率的固体残渣,和糖组成的滤液提出了蒸汽爆破预处理使用不同的粒子大小。2. Material and methods材料和方法2.1. Raw material Chipped B. carinata biomass (5% moisture) was provided by the Renewable Energy Development Center at Lubia (Soria, Spain). Raw material was milled using a laboratory hammer mill. Milled material was further separated into three different fractions (25, 58 and 812 mm) using a portable sieve shaker.2.1原料b carinata碎裂的生物量(5%水分)是由可再生能源发展中心Lubia(索里亚、西班牙)。原材料是磨使用实验室锤式粉碎机。研磨材料进一步分为三个不同的分数(25,58和812毫米)使用便携式振动筛。2.2. Steam explosion pretreatmentPretreatment of raw material was carried out by applying Masonite technology. The following parameters were investigated: 190210 8C temperature and 48 min residence time.The steamexplosion pretreatments were carried out in a batch pilot plant described in a previous work11.The pilot plant was equipped with a 2-l reactionvessel designed to reach a maximum operating pressure of 42kg/cm2. The reactor was filled with 100 g of feedstock per batch, and then was heated to the desired tempera-ture, directly with saturated steam. After the explosion, the material was recovered in a cyclone, the wet material cooled to about 40 8C, and then filtered for solid recovery. The solid fraction was analysed for xylans and glucans. The carbohydrate content in the watersoluble extract was also analysed.2.2。 蒸汽爆破预处理预处理的原料是由硬质纤维板技术应用。以下参数进行了调查:190210 8 c温度和48分钟停留时间。steamexplosion的预处理进行了一批试验工厂在之前的工作描述11。飞行员工厂配备了2 l reactionvessel旨在达到最大操作压力的42公斤/平方厘米。反应堆充满了100 g的每批原料,然后被加热到所需的蛋彩画真正的,直接与饱和蒸汽。爆炸发生后,材料被发现在一个气旋,湿材料冷却到约40 8 c,然后过滤固体复苏。分析了固体分数为xylans和葡。碳水化合物含量水溶性的提取也进行了分析。2.3. Enzymic hydrolysisAfter pretreatment the water-insoluble fibre was enzymically hydrolyzed to determine the maximumobtainable sugar yield. The cellulolytic complex employed in enzymic tests (Celluclast 1.5 L) was a gift fromNOVO Nordisk (Denmark). Cellulase enzyme loadingwas 15 filter paper unit (FPU)/g substrate. Fungalb-glucosidase (Novozyme 188, Novo Ltd.) was used to supplement the b-glucosidase activity with an enzyme loading of 12.6 international unit (IU)/g substrate.Enzymic hydrolysis was performed at 50 8C on a rotary shaker at 150 rpm for 72 h and at 2% (w/v) substrate concentration.2.3。 酶水解预处理后的水不溶性纤维是enzymically水解来确定maximumobtainable糖产量。 纤维素酶的复杂的用于测试(Celluclast 1.5 L)是一个礼物fromNOVO诺(丹麦)。纤维素酶酶loadingwas 15滤纸单元(FPU)/ g衬底。Fungalb-glucosidase(Novozyme 188,Novo Ltd。)是用来补充b葡糖苷酶活性与酶加载12.6国际单位(IU)/ g衬底。 进行酶水解在50 8 c在旋转瓶在150转72 h和在2%(w / v)衬底浓度。2.4. Analytical methodsThe raw material composition was analysed following the corresponding ASTM1214. Total carbohydrates were determined according to the Puls method15.Glucose concentration was measured by HPLC using a HewlettPackard 1050 equipped with a refractive index detector. HPLC analyses were carried out using an AMINEX HPX-87P carbohydrate analysis columnoperating at 85 8C with deionized water mobile-phase at a flow rate of 0.6 ml/min.2.4。 分析方法原料成分分析以下相应的ASTM1214。总碳水化合物被确定根据脉冲法15。葡萄糖浓度测定采用高效液相色谱法测定使用HewlettPackard 1050配备了示差折光检测器。高效液相色谱法进行了分析使用一个AMINEX hpx - 87 p碳水化合物分析columnoperating 85 8 c与去离子水流动相的流速为0.6毫升/分钟。3. Results and discussionTable 1shows the composition of raw material. In order to improve the accuracy of the assay a sequential extraction with solvents (ethanol/toluene) and hot water was performed. About 21% ofB. carinata dry matter consists of organic solvent and water extractives, which is similar to values for other herbaceous agricultural residues including fescue and switchgrass 16. Thehemicellulose fraction comprises 21.9% of raw material,xylose being the main sugar (82%). Cellulose and lignin content (32.7 and 18.7%, respectively) are in the range reported for lignocellulosic biomass of food crops like sunflower stalks or wheat straw17.3。结果与讨论表1显示了原材料的组成。为了提高精度的分析顺序提取与溶剂(乙醇/甲苯)和热水了。b大约21%。carinata干物质由有机溶剂和水来自采掘,类似于其他草本农业残留值包括羊茅和柳枝稷16。这个半纤维素部分包括21.9%的原料,木糖被主要的糖(82%)。纤维素和木质素含量(32.7和18.7%,分别)在范围报告的木质生物质农作物像向日葵秸秆或麦秸17。表1The raw material milled to different particle sizes (25, 58and812 mm) was subjected to different steam a explosion pretreatments (190 and 210 8C temperature, and 4 and 8 min residence time).Table 2 shows the composition of water-insoluble fibre of B. carinata biomass from pretreatment conditions assayed. As expected, steam explosion pretreatment preferentially attacked the hemicellulose components. More severe pretreatment conditions produced higher solubilisationof hemicellulosic fractions and, under the chosen conditions (4 and 8 min, and 190 and 210 8C), all original hemicellulose was recovered as monomeric sugars while no oligomers were found in the water-soluble fraction. This observation differs from literature results working with hardwood and softwood 18,19, and so post- cellulose hydrolysis is not needed to increase fermentable sugar yield from solubilised hemicelluloses after steam explosion pretreatment ofB. carinatastraw. It is interesting to note that, during steam explosion pretreatment, the proportion of sugars solubilised was dependent on the type of hemicellulosic sugars. As can be seen, arabinan was completely solubilised in all conditions assayed. The increase in the temperature of pretreatment to 210 8C resulted in increased dissolution of galactans and xylans. In relation to cellulose content, solubilisation increased as pretreatment conditions were more drastic. The cellulose content in the pretreated biomassvaried between 39 and 62%, depending on the pretreatment severity. The cellulose content in the water insoluble fibre was higher at larger particle size for all conditions tested. 原料磨到不同粒径(25日and812 58 mm)受到不同的蒸汽爆炸的预处理(190和210 8 c温度、和4和8分钟停留时间)。表2显示了水不溶性纤维的组成carinata生物质预处理条件下b从化验。正如预期的那样,蒸汽爆破预处理优先攻击了半纤维素成分。更严重的预处理条件产生更高的溶液化hemicellulosic的分数,根据选择的条件(4和8分钟,190年和210年的8 c),所有原始半纤维素被恢复为单体的糖而不寡聚物被发现在水溶性部分。这一观察结果与文献使用硬木和软木(18、19),因此纤维素水解后是不需要增加可发酵糖产量从蒸汽爆炸后水溶性纤维素预处理b。carinatastraw。 有趣的是,我们注意到,在蒸汽爆破预处理、水溶性糖的比例是依赖于类型的hemicellulosic糖。可以看到,arabinan完全水溶性在各种条件下的化验。温度的增加预处理到210 8 c导致增加galactans和xylans解散。 与纤维素含量、溶液化增加预处理条件更激烈。纤维素含量在62%和之间biomassvaried进行预处理,根据严重程度的预处理。纤维素含量高的水不溶性纤维在大颗粒大小对所有条件测试。表2Table 3shows the sugar composition (g/100 g of raw material) of the filtrate after pretreatment. There was increased hemicellulose-sugar degradation at higher temperature and residence time. At high process severity there are more losses of hemicellulosic sugars, regardless of particle sizes. All hemicellulosic sugars were recovered as monomeric sugars in the water-soluble fraction, and no oligomers were detected. Moreover, the proportion of monomers found in the liquid media depends on the type of sugar. A significant destruction of xylose was obtained at 210 8C (about 40%); however, galactose, arabinose and mannose were less vulnerable to acid- catalysed degradation and almost quantitative recoveries of sugars solubilised were found in the filtrate.表3显示了糖成分(g / 100 g的原材料)的滤液预处理后。有增加半纤维素糖降解在更高的温度和停留时间。在高过程有更多的损失严重程度的hemicellulosic糖,无论粒子大小。所有hemicellulosic糖被恢复为单体的糖在水溶性分数,没有低聚物被发现。此外,单体的比例中发现液体媒体取决于类型的糖。一个重大的破坏得到木糖在210 8 c(大约40%);然而,半乳糖、阿拉伯糖、甘露糖不太容易受到酸-催化降解和几乎定量的复苏中发现的水溶性糖的滤液。表3Much of the technoeconomic analysis of biomass pretreatment has emphasized the importance of the three main paramenters in optimising the process and ensuring maximum substrate utilisation: (a) recovery of cellulose in the water insoluble fibre; (b) susceptibility of cellulose to enzymic attack; and (c) recovery of hemi cellulosic sugars in the filtrate.Fig. 1shows the cellulose recovery yield in the water-insoluble fibre for all pretreatment conditions and chip size tested. Yield is expressed as glucose in the water insoluble fibre divided by the potential glucose in the raw material. As can be observed, the particle size has a significant influence on cellulose recovery. At larger particle size, more cellulose recovery was obtained. At 25 mm particle size cellulose recovery of 84% at 190 8C4 min and 57% at 210 8C8 min were obtained. In contrast, higher cellulose recoveries (99% at 190 8C4 min and 88% at 210 8C8 min) were obtained at larger particle sizes (8 12 mm).大部分的technoeconomic分析生物质预处理已经强调了三个主要参数的重要性在优化过程和确保最大基质利用率:(一)复苏的纤维素在水中不溶性纤维;(b)易感性的纤维素酶来攻击;和(c)复苏的半纤维素糖类在滤液无花果。1显示了复苏在水不溶性纤维素纤维的产量和芯片尺寸所有预处理条件测试。产量是表示为葡萄糖水不溶性纤维的除以潜在葡萄糖的原料。可以观察到,颗粒大小有显著影响纤维素复苏。在较大的粒子大小、更多的纤维素得到复苏。在25毫米粒度纤维素回收率为84%在190 8分钟,57%在210年c4 8 c8分钟取得了。相比之下,高纤维素的复苏(99%在190 8分钟,88%在210年c4 8 c8 min)获得了在大粒径(8 12毫米)。Fig1Fig. 2shows the recovery of hemicellulosic-derived (xylosearabinosemannosegalactose) in the filtrate after pretreatment. The recovery yield is expressed as sugars in the filtrate divided by potentia sugars in raw material. The recovery of hemicellulosic- derived sugars was slightly higher under mild tempera- ture conditions (190 8C) and larger residence time (8 min). Under these conditions, above 50%hemicellulosic- derived sugars recovery was obtained. The particle size does not appear to affect this parameter. In previous studies using a softwood material (pine) at the same pretreatment condition20, chip size affected strongly the hemicellulosic-derived sugar recovery. This could be due, not only to the different hemicellulosic-derived sugar composition in softwood but different heat transfer into the herbaceous particles. Herbaceous chips may heat more rapidly than wood chips and the size of chips, in the range tested, was not important at temperatures and residence times studied in this work.图2显示了复苏的hemicellulosic-derived(xylosearabinosemannosegalactose)在预处理后的滤液。 恢复产量表示为糖滤液除以力糖原料。hemicellulosic复苏衍生糖略高,真正的条件下温和的蛋彩画法(190 8 c)和较大的停留时间(8分钟)。在这些条件下,50%以上hemicellulosic -衍生糖得到复苏。粒子大小似乎没有影响到这个参数。在先前的研究中使用软木材料(松树)在同一预处理条件20,芯片尺寸影响强烈的hemicellulosic-derived糖复苏。这可能是由于,不仅不同hemicellulosic-derived糖成分在软木但不同传热到草本粒子。草本芯片可能热更迅速比木屑和大小的芯片,在本试验范围,不是重要的在温度和住宅次研究工作。Fig2Fig. 3 shows the enzymic hydrolysis yield of the water-insoluble fibre (expressed as a percentage of the glucose produced in the hydrolysis divided by the potential glucose), after different pretreatments. The enzymic hydrolysis yield depended on the temperature of pretreatment. Enzymic hydrolysis yield increased as the temperature was raised. Lower hydrolysis yields were obtained at 190 8C and 4 and 8 min pretreatment conditions, but there were no significant differences with particle sizes.图3显示了酶水解产生的水不溶性纤维(表示为一个百分比的葡萄糖产生水解除以潜在葡萄糖),在不同的预处理。酶水解产生依赖于温度的预处理。酶水解收率增加温度提高。降低水解收率在190 8 c和4和8分钟预处理条件,但没有显著差异粒径。Fig3Almost 100% of the theoretical enzymic hydrolysis yield was obtained at 210 8C, for both residence time studied and particle size of 25 and 58 mm. Lower enzymic saccharification (85%) was obtained at 210 8C, 4 min and a particle size between 8 and 12 mm.The optimum pretreatment conditions for the maximum recovery of hemicellulose and cellulose, and for the maximumcellulose enzymatic digestibility are not all the same (Figs. 13). In general, pentosans in the liquidfraction and cellulose in the water insoluble fraction require mild severity treatments to be recovered in high yield, but, these are obtained at the expense of decreasing enzymic hydrolysis yield. This fact was not so evident when larger particle sizes (812 mm) were used at the highest temperature tested (210 8C). At this temperature cellulose recoveries in water-insoluble fraction and enzymic hydrolysis close to 90% were obtained.几乎100%的酶水解得到的理论产量在210 8 c,对于停留时间研究和颗粒大小25和58毫米。降低酶糖化(85%)是在210年获得8 c,4分钟和颗粒大小的8至12毫米的最佳预处理条件的半纤维素和纤维素最大复苏,maximumcellulose酶消化率并不都是一样的(无花果。13)。一般来说,聚糖在液体中分数和纤维素在水中不溶性分数需要温和的严重程度,治疗恢复正常高收益,但是,这些都是获得以牺牲减少酶水解屈服。这个事实并不如此明显当大粒径(812毫米)都是用在最高温度测试(210 8 c)。在这个温度在水不溶性纤维素的复苏分数和酶水解得到接近90%。To facilitate the comparison of pretreatment conditions focused on the maximum recovery of cellulose on the maximum cellulose accessibility to enzymic attack,