桉木冷碱浸渍-挤压-硫酸盐法制浆的研究

将冷碱浸渍-挤压作为木片预处理方法,并应用于桉木硫酸盐法制浆的前段。探讨了冷碱浸渍-挤压的最佳工艺条件,研究了蒸煮工艺条件对预处理后料片蒸煮结果的影响,对比了未预处理原料与预处理后料片硫酸盐法蒸煮所得纸浆的强度性能。结果表明,木片经过冷碱浸渍-挤压后,易于蒸煮,从而可减少蒸煮用碱量或降低最高蒸煮温度、缩短保温时间,且蒸煮的均匀性得到改善,筛渣率降低、纸浆强度性能提高。最佳预处理工艺条件为浸渍用碱量2%,浸渍时间2 h,温度25℃,液比1∶5,挤压压缩比3∶1;与未预处理原料硫酸盐法蒸煮(用碱量21%)相比,预处理后料片在总用碱量(浸渍用碱量2%,蒸煮用碱量19%)相同的情况下,成浆卡伯值降低了1.7,细浆得率只降低0.14个百分点,且纸浆强度性能更优,其中,抗张指数、耐破指数、耐折度分别提高了7.0%、5.2%、66%,撕裂指数与未预处理原料硫酸盐法蒸煮所得纸浆相近。     

用木材生产生物燃料与纸浆

杨木木片硫酸盐制浆前,进行缓和的碱抽提处理,抽提出半纤维素用作生物燃料(生物乙醇),在温度90℃,NaOH 1～2M,液比1∶4条件下进行碱处理,不需要高压设备,每吨木片得到半纤维素40～50kg,经碱抽提后木片进行硫酸盐蒸煮,与未经碱抽提木片参照对比,纸浆得率基本相同,但是需要很好地控制碱抽提与硫酸盐蒸煮工艺条件,能缩短蒸煮时间和节省化学品用量。碱预抽提木片得到的硫酸盐纸浆中纤维素/半纤维素的比率稍高,导致纸浆的抗张指数稍有降低(约10%),但是纸浆白度较高且筛渣含量低,为使硫酸盐纸浆的质量和得率保持较高水平,采用缓和的碱预抽提,使半纤维素得率较低,而回收的半纤维素的浓缩和离析比木片自水解或稀酸水解回收糠醛更加容易。     

溶解浆粕制备过程中降低聚戊糖含量的方法

在溶解浆粕的制备过程中,能否大量去除纸浆中的半纤维素从而提高其α-纤维素的比例是关键。研究了由木材原料通过蒸煮制备溶解浆粕过程以及由竹浆直接制备溶解浆过程中降低其半纤维素含量的方法。在由木片为原料通过蒸煮制备溶解浆的实验方案中,主要研究了预水解硫酸盐法中预水解工艺对纸浆中半纤维素含量的影响,认为预水解保温2h能较为有效地降低蒸煮所得纸浆的半纤维素含量;在由竹浆原料直接制备溶解浆的实验方案中,重点研究了酸处理工艺以及碱处理工艺对去除竹浆中的半纤维素以及降解纤维素聚合度方面的影响,并得出酸处理与碱处理相结合的方法能够最大限度地去除半纤维素同时保护纤维素聚合度。     

毛竹浆蒸发器管垢的清洗

毛竹浆蒸发器管垢的清洗抚州造纸厂以毛竹浆为主，配部分马尾松木浆挂面，全部采用硫酸盐法蒸煮生产高强纸板。其碱回收蒸发设备采用ＺＴＺＳＴｌ型五效蒸发器，每日需处理１１５０ｍ３混合黑液，比例２０：８０，黑液中固含量１０７ｇ／Ｌ，蒸发强度１２．２２ｋｇ／ｍ２...     

黑液循环蒸煮木片制浆技术研究

为了提高化学浆得率,提出黑液循环蒸煮木片制浆方法。通过基础实验和工业生产试验研究,得到结果：黑液循环制备化学浆的基础实验用碱量为木片的26%,浆得率为63.6%,比传统碱法制浆工艺得率50.0%提高13.6%;在工业生产试验中,用碱量为木片的18%,结合蒸煮压力波动变化,纸浆平均得率为63.9%,比传统蒸煮制浆工艺得率50%提高13.9%。此外,循环蒸煮获得的纸浆性能良好,从而证明黑液循环蒸煮木片的制浆方法是可行的。     

湿地松硫酸盐法一级与二级蒸煮的研究

进行了广东湿地松硫酸盐法一级与二级蒸煮的研究,对两种蒸煮结果作了比较。结果表明:广东湿地松的化学成份与马尾松相似,但其纤维平均长度比马尾松小;硫酸盐法蒸煮过程脱木素的规律与马尾松相同。采用活性碱浓度为139/l(Na_20计)的黑液进行第一级蒸煮后,加入低碱量白液进行第二级蒸煮的二级蒸煮法,可以提高纸浆的得率;第一级蒸煮采用高硫化度的黑液,可以提高木素的溶出率,降低纸浆的高锰酸钾值,若蒸煮到纸浆的高锰酸钾值相同,则用高硫化度黑液预蒸煮的纸浆得率比较高。广东湿地松纤维平均长度为2.96mm,浆张裂断长为6000米左右,耐破指数4.9—5.3kPa·m~2/g,撕裂指数19—22mN·m~2/g。     

带有升流式厌氧污泥反应床的纸浆厂废水零排放模型

建立包括蒸煮车间、蒸发站、碱回收炉、升流式厌氧污泥反应床（UASB）和苛化车间的制浆厂废水零排放模型。通过模型分析和模拟运算,得到以下结论：（1）蒸煮能耗、木片固形物含量、纸浆固形物含量对排水量的影响较大,当浆蒸煮能耗小于或者等于4100MJ,木片固形物含量大于或者等于61.8%,纸浆固形物含量小于或者等于56.8%时,系统排水量小于或者等于0;（2）蒸煮能耗、纸浆得率、洗涤水量是影响系统热能剩余的主要因素,在蒸煮能耗1900～4400MJ,纸浆得率45%～60%,洗涤水量4000～9000kg范围内,系统热能剩余。     

思茅松硫酸盐蒸煮工艺技术条件的优化

实验通过常规硫酸盐蒸煮法对思茅松木片进行了蒸煮,研究了蒸煮条件对细浆得率和纸浆质量的影响,同时进行了蒸煮工艺技术条件的优化。保持液比为1∶4.0的条件下,通过改变其他蒸煮条件(蒸煮温度、保温时间、用碱量、硫化度)探索出两个细浆得率能达到47%的优化的蒸煮工艺技术条件。     

楠竹预水解硫酸盐法制浆工艺

以楠竹为原料生产竹浆粕,对水预水解和硫酸盐法蒸煮的工艺条件进行优化。结果表明:水预水解阶段最优工艺条件为P因子1000;硫酸盐蒸煮阶段最优工艺条件为H因子1000、用碱量17%(Na2O计)、硫化度20%。按此工艺条件所得的浆粕α-纤维素含量94.55%,黏度1096mL·g-1,细浆得率33.59%,卡伯值10.76,聚戊糖含量4.81%。     

烧碱-蒽醌法低温制杨、桦木薄木片浆

为了节约木材资源,我厂用烧碱-蒽醌法对杨、桦木薄木片(厚3～10毫米)进行了蒸煮制浆试验,与原用厚木片(厚25～35毫米)制浆比较(见附表),取得了极其明显的效果。从蒸煮条件对比中看出,薄木片制浆有以下优越性。 1.在纸浆硬度相同,不增加浆渣的情况下,可减少用碱量3％,细浆收获率提高2％。     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.     

Analysis for organic residues from aids to polymerization used to make plastics intended for food contact

Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (¹     

Tests of potential functional barriers for laminated multilayer food packages. Part II: Medium molecular weight permeants

Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.     

The Ministry of Environmental Protection Issued "Feasible Technology Guidelines for Pollution Prevention and Control in Wood Pulping Process of the Paper Industry (Trial)" and Two Other Guiding Technical Documents

On December 27t＂, 2013, the Ministry of Environmenta Protection announced that, in order to implement ＂The Environmental Protection Law of the People＇ s Republic of China＂, improve the working system in environmenta protection technologies, and promote technologica advancement in pollution prevention, the Ministry of Environmental Protection sponsored the formulation of three guiding technical documents including ＂Feasible Technology Guidelines for Pollution Prevention and Contro n Wood Pulping Process of the Paper Industry （Trial）＂     

1~(st) Intelli-Tissue~ EcoEc Tissue Machine Supplied by PMP Group Successfully Put into Operation in China

正On April 29th,2014,Intelli-Tissue EcoEc tissue machine supplied by PMP Group successfully put into operation at Hebei Xuesong Paper Co.,Ltd.,this is the first such kind of paper machine of PMP Group in China.