草浆造纸行业清洁生产技术研究

介绍了草浆造纸废水的来源、特点及对环境的影响。通过工程实例研究了草浆造纸行业实现清洁生产的关键技术。通过对造纸黑液提取木质素制备木质素磺酸钙粘结剂,实现废弃物的资源化。通过"化学絮凝+ABR+氧化沟"组合处理工艺对中段水的深度处理及回用,基本实现废水的零排放,节约了水资源。该工程实现了生产、水循环、废物资源化利用一体化的清洁生产模式,为造纸行业的清洁生产提供借鉴。     

Enhancement of Enzymatic Saccharifi-cation of Wheat Straw Residue by Ammonium Sulfite Pretreatment

Efficient utilization of wheat straw residue(WSR) from pulp mills is an important priority for the sustainable development of the pulp and paper industry. In this study, the effects of ammonium sulfite(AS) pretreatment with different AS charges(wt%) and pretreatment temperatures on the chemical composition and enzymatic hydrolysis of WSR were studied. The results revealed that more lignin was removed with the increase of pretreatment temperature and AS charge. The degradation of hemicellulose became severe at high pretreatment temperature, while cellulose remained stable during the pretreatment process. The enzymatic hydrolysis efficiency of pretreated WSR was increased and then decreased with the increase of the AS charge and pretreatment temperature. The AS charge exerts a stronger effect on enzymatic hydrolysis efficiency than the pretreatment temperature. Glucan and xylan conversion ratios up to 88.9% and 44.9%, respectively, were obtained. The highest total sugar conversion ratio was 67.0% when WSR pretreated with 16% AS at 165℃ was hydrolyzed with a cellulase loading of 40 FPU per gram of glucan.     

纤维分析仪在再造烟叶生产中的运用

利用Morfi纤维分析仪对不同浓度、不同温度、不同存放时间、碳酸钙添加比例不同的烟草浆进行纤维检测分析,寻找适宜的检测条件,并检测生产线各工序段浆料,验证纤维分析的可靠性,以期将纤维分析仪运用到再造烟叶领域,实现对造纸法再造烟叶浆料的检测分析。研究结果表明,烟草浆纤维分析所需的样品量应为100 mg/L,用于纤维分析的样品温度应与室温接近,烟草浆样品存放时间的长短对纤维分析结果无影响,纤维分析仪将碳酸钙误判为细小纤维而进行分析使得细小纤维面积比例这一检测项目与真实值有所偏离。     

Preparation and characterization of polypropylene–wheat straw–clay composites

Preparation of polypropylene hybrid composite consisting of wheat straw and clay as reinforcement materials was investigated. The composite samples were prepared through melt blending method using a co-rotating twin-screw extruder. The composition of constituents of hybrid composite such as percentages of wheat straw, clay and maleic anhydride grafted polypropylene as a coupling agent was varied in order to investigate their influence on water absorption and flexural properties. The XRD analysis of composite samples containing clay showed shift in d₀₀₁ peak to lower 2θ indicating slight intercalation of polymer in clay sheets. The results of the study indicate that the increase in wheat straw and clay content in a composite increases the flexural modulus and reduces the resistance for water absorption. The increase in PP-MA coupling agent also increases the flexural modulus and resistance for water absorption. The morphological study by scanning electron microscope reveals that the addition of coupling agent increases the interfacial adhesion between the fibers and polymer matrix which is evidenced further from increased flexural modulus. Further, the particle size of wheat straw was analyzed before and after extrusion in order to investigate the effect of extrusion on wheat straw dimensions. The addition of clay as additional filler had no significant role on water absorption and flexural properties of the composite.     

阳离子改性稻草处理印染废水研究

将稻草秸秆粉与2,3-环氧丙基三甲基氯化铵(EPTMAC)在NaOH催化下,于85℃反应6 h,合成季铵化度为97%的稻草季铵盐(QAS-RS),用于染料废液的处理,研究了QAS-RS用量、pH值和染液种类对脱色效果的影响。结果表明,0.13 g/L QAS-RS能使浓度为100 mg/L活性染料和酸性染料染液迅速脱色,COD去除率和脱色率最高达99.5%和98%,最低为86.3%和94%。     

葵花秸秆刨花板的开发前景

介绍了国内外人造板资源状况、人造板发展现状和市场需求趋势,重点讨论了葵花秸秆刨花板的技术现状、市场前景和经济效益.指出了采用葵花秸秆生产刨花板具有良好的市场前景和经济效益.     

Enzymatic production of Xylooligosaccharide from selected agricultural wastes

Four different agricultural wastes, namely tobacco stalk (TS), cotton stalk (CS), sunflower stalk (SS) and wheat straw (WS) were tested for the production of Xylooligosaccharide (XO). XO production was performed by enzymatic hydrolysis of xylans which were obtained by alkali extraction from the agricultural wastes. Depending on the source, it was found that these four agricultural wastes contained different amount of xylan, cellulose and lignin and the xylan obtained from these source contained different amount of sugar and uronic acid. The highest amount of arabinose was in xylan from WS while the other xylans mainly had xylose and small amount of glucose. Different xylanase preparations were evaluated for production XO from these xylan sources. Aspergillus niger xylanase produced lower amount of XO from wheat straw xylan (WSX) than cotton stalk xylan (CSX), sun flower xylan (SSX) and tobacco stalk xylan (TSX) while Trichoderma longibrachiatum xylanase hydrolyzed highly branched WSX better. The HPLC analysis of the hydrolysis products indicated that depending on structure and composition of xylan, A. niger xylanase produced less amount of xylose than T. longibrachiatum xylanase, and the hyrolysis product of A. niger xylanase contained different amount of oligosaccharides (X2 > X3 > X4 > X5 > X6, >X6). Regardless of the structural differences of the xylan types presented in this paper, all xylans generated XO with different degree of polymerization (DP), but the DP of XO depended on the enzyme specificity and the structure of substrate.     

秸秆锅炉水冷振动炉排动态特性分析

根据刚度等效原理，将水冷振动炉排简化成壳模型，运用ANSYS对结构进行模态分析和谐响应分析，验证系统激励频率10．4Hz基本能引起整体结构均匀共振，同时根据分析结果对结构进行优化。     

Development of AFEX-based consolidated bioprocessing on wheat straw for biohydrogen production using anaerobic microflora

Consolidated bioprocessing (CBP) of wheat straw (WS) pretreated via ammonia fiber expansion (AFEX) for hydrogen production was discussed in this study. Results indicate that rotted wood crumb is a good mixed natural-microflora seed source for biohydrogen production from WS. The hydrogen-producing capability of the inoculum could be improved by an enrichment treatment. In order to enhance the digestibility of WS, AFEX pretreatment conditions were investigated. The optimal conditions were determined to be 100 °C, 1:1 (w/w) ammonia to biomass loading, and 30min residence time. The yield of H₂ was 67.8% higher using AFEX-pretreated WS than using untreated material. Moreover, degradation products derived from AFEX pretreatment exerted no impact on hydrogen fermentation if controlled below 1.5% substrate-loading-equivalent. In addition, the maximum AFEX-WS conversion and H₂ production were achieved at substrate loading of 0.8%. This work indicates that CBP offers a promising platform for direct and cost-effective cellulosic hydrogen production compared to separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF).