GC/MS characterization of effluents front the ozone bleaching of eucalypt kraft pulps

Concerns regarding the possible environmental effects of organochlorine by‐products from bleaching of pulp with chlorine‐based compounds have led to the pulp and paper industry developing new bleaching sequences. Ozone, oxygen and hydrogen peroxide are the main reagents in these Totally Chlorine Free (TCF) bleaching processes.

In this study, eucalypt kraft pulps from a variety of Australian wood sources were subjected to bleaching sequences comprising oxygen, ozone and hydrogen peroxide/alkali extraction stages. The aqueous liquid effluents from each stage were analyzed by GC/MS for aldehydes, ketones, alcohols, carboxylic acids and other by‐products. Pentafluorobenzyl oxime derivatives of the aldehydes and ketones were analyzed by electron impact GC/MS. The major carbonyl compounds detected were formaldehyde, glyoxal, dimethylglyoxal and acetone. An homologous series of n‐aldehydes corresponding to cleavage of ω‐3, 6, 9 and 12 unsaturated fatty acids also was detected. Aromatic aldehydes were identified in the oxygen stage and high consistency ozone stages, but not in any medium consistency ozone or post‐ozone bleach stages. In all stages a series of saturated alkyl carboxylic acids from formic to octacosanoic acid was detected. Formic and acetic acids were present in the highest yield. Only trace quantities of unsaturated fatty acids were detected. Details of these and other compounds detected are discussed.     

针织物节能减排漂染工艺探讨

将新开发的高效前处理、染色助剂应用于针织物实用高效漂染工艺,探讨其应用工艺、产品质量及节能减排效果。分析各类前处理碱氧一浴工艺的特点、应用特性及节能减排效果;阐述涤棉针织物练染一浴工艺,免还原清洗工艺,棉针织物活性染色与抛光一浴工艺及活性染色后皂洗酶后处理工艺。并与相应的传统工艺对比其工艺曲线、质量水平、节能减排效果及污染物浓度降低情况。客观评价各类工艺的优缺点,建议生产厂家根据产品质量要求,选用相应高效助剂,并结合实际生产设备优化工艺后使用,节能减排效果将更加显著。     

Improvement of Palm Oil Biodiesel Filterability by Adsorption Methods

Palm oil biodiesel (POB) is characterized by a very high cold soak filtration time (CSFT), which places the acceptability of this biofuel at risk. Therefore, the effect of four adsorbents, namely diatomaceous earth, natural silicate (NS), neutral bleaching earth (NBE), and acid activated bleaching earth (AABE), at two levels of addition (1 and 5 wt%) or two temperatures (25 and 110 °C) on the precipitate content and CSFT of POB was investigated. The impact on total glycerin content, moisture content, and oxidative stability was also examined. All treatments significantly decreased the precipitate content, total glycerin content, and moisture content, but only treatments with NS, NBE, and AABE at 5 wt% and 25 °C achieved acceptable filterability. The OSI value was also decreased; however, it remained above the ASTM limit. Operational conditions of treatment with AABE were further optimized in a two‐factor, five‐level center composite design. The combination of 0.65 wt% AABE and 10 min at 25 °C decreased CSFT to below the ASTM limit. Lower adsorbent concentrations could be effective down to 0.44 wt%, given a corresponding increase in the contact time up to 30 min.     

对武安高岭土除铁工艺研究

河北武安硬质高岭土粉含Fe2O31.23%，经高梯度磁选后降至0.77%，再用Na2S2O3进行还原溶解后降至0.62%，白度提高了13％，本文介绍了流程及条件试验过程和结果。     

涤棉混纺织物美国白生产工艺

探讨了涤棉织物美国白工艺设计原理,在小样及生产批量试验基础上,确定了较为合适的漂白用剂、工艺流程。生产效果表明,现行美国白生产工艺,满足了客户高质量的要求。     

Surface Characterization of Differently Pretreated Flax Fibers and Their Application in Fiber-Reinforced Composites

Strong natural bast fibers, especially flax fibers, can be used to replace glass fibers in reinforced composites. The properties of natural fibers depend largely on maturity, retting and processing. Two chemical treatments were applied to retted and semiretted flax fibers to create better fiber to resin bonding and to show the effect of retting degree and successive purification processes on the mechanical properties of natural composite materials. Retted and semiretted flax fibers have been scoured and bleached with the objective of removing surface impurities and developing finer structure. To investigate the effect of adhesion promoter on the mechanical properties of natural fiber composite, a composite sample was prepared from bleached retted flax pretreated with adhesion promoter Isostearoyltitanate (ISTT).

After treatments the fibers got cleaner and the measurements showed that the fiber fineness as well as the surface free energy increased. The treatments were accompanied by decrease in the fiber tenacity but it has been found not to be reflected to the final mechanical properties of the composite. No improvement was remarked by using Isostearoyltitanate for surface modification.     

棉织物低温漂白新工艺

本文采用自制的双氧水活化剂,在低温下对棉织物进行双氧水漂白,用中心旋转法并借助微机对漂白工艺进行优化。结果表明,此工艺是可行的,当漂白在70℃进行时,漂白效果优于常规气蒸漂白,而与常规浸漂相似。中心旋转法和回归分析是寻找染整工艺优化区域最为有效的方法之一。     

思茅松硫酸盐化学浆的氧脱木素和多段漂白机理的初步研究

在漂白前进行氧脱木素，能在降低废液污染负荷的同时，还可提高浆的白度，采用ＣＥ０ＨＰ程序，仍可使思茅松硫酸盐浆在试验条件下达到８５％（ＳＢＤ）的高白度水平。红外光谱分析表明，共轭羰基和非共轭羰基等发色基团的破坏和羰基羟基等助色基团的削弱，是提高纸浆白度的主要原因。     

FY—2氧漂稳定剂工艺试验

本文对氧漂稳定剂的应用作了较系统的试验，研制了含有机磷酸盐的氧漂稳定剂，对合成和复配工艺及处方进行反复试验。在此基础上，筛选出ＦＹ－２氧漂稳定剂，经过一系列工艺测试，结果表明，本产品适用于一般氧漂工艺，漂白织物在白度，强力损伤、毛效、手感等方面都明显优于硅酸钠，且完全避免了硅垢。