稳定优级糠醛水分的研究

本文报导了一项稳定糠醛产品低含水量的工业性试验。研究表明提高精制系统的气密性是降低并稳定成品合格水分的基本措施;采用二槽阶梯式粗醛高位槽可以提高脱水塔的操作稳定性,从而提高成品水分含量的稳定性。山西省寿阳县有机化工厂采用上述方法生产的糠醛的含水率长期持续稳定,其位为0.01～0.03％,符合《工业糠醛》国家标准GB1926-80。对比研究结果表明,成品露天贮放,特别是在夏秋多雨季节,是造成贮放产品水分骤升的主要原因,从而说明建库贮放十分必要。     

Effects of formulation and extrusion cooking conditions on furfural and hydroxymethylfurfural content

The objective of this research was to investigate the effects of different ingredients (reducing sugars, leavening agents, citric acid), processing conditions (feed moisture content, exit die temperature), and extrusion cooking methods (with/without CO₂ injection) on furfural and 5-hydroxymethylfurfural (HMF) formation in corn-based extrudates. The decrease in furfural levels was 16% upon addition of sodium-bicarbonate, while the increase was 12% upon addition of ammonium-bicarbonate for extrudates produced at 150 °C and feed moisture content of 22%. The furfural concentration of extrudates produced at 150 °C and feed moisture content of 22% without leavening agents was 810 μg/100 g and increased to 11,901 μg/100 g upon citric acid addition (about a 15-fold increase). Furthermore, both low feed moisture and high exit die temperature had promoting effects on furfural and HMF contents. The CO₂ injection method did not have considerable effect on furfural and HMF levels of the extrudates; however, it positively affected the physical properties of extrudates.     

含钾有机废弃物糠醛渣改土培肥效应研究

在河西走廊的盐化潮土上设置了糠醛渣的改土培肥田间试验,结果表明:甜菜施用糠醛渣与施用化肥比较,土壤容重、全盐、pH分别降低0.21g cm-3、0.36g kg-1、0.37;总孔度、自然含水量、贮水量、团粒结构、有机质、速效N、P、K、CEC分别增加7.93%、79.90g kg-1、131.95m3 hm-3、4.75%、0.61g kg-1、12.96mg kg-1、1.24mg kg-1、6.78mg kg-1、1.89cmol kg-1。施肥成本降低90元hm-2,施肥利润增加1716元hm-2。且施用糠醛渣能提高土壤中磷的活性和磷的利用率。     

吉林省西部重度盐碱土糠醛渣复合改良剂配方研究

通过土壤培养试验,初步研究了不同配比的糠醛渣复合改良剂对吉林省西部重度盐碱土的改良效果,从中找出改良效果较好的改良剂配方。结果表明,糠醛渣改良剂施入重度盐碱土后,土壤的理化性状发生了显著改善,主要表现为:土壤中大粒径(0.25～1 mm)的微团聚体数量明显增加,土壤容重变小,土壤平衡溶液的pH明显下降,CE(电导率)、Na+浓度以及ESP(碱化度)下降,但土壤交换性阳离子总量变化不大。通过试验结果可以看出,在1 500 g盐碱土中加入糠醛渣、石膏和硅酸铝的剂量为60 g、25 g和5 g时,对盐碱土理化性质的改良效果较好。     

甘蔗渣微波辅助定向裂解制备糠醛联产土壤改良剂研究

为提高蔗渣的综合利用效率,采用催化剂定向的蔗渣微波辅助裂解技术,系统探讨了影响糠醛得率的工艺参数,以及裂解残余生物焦经过中和后作为土壤改良剂的使用效果.实验结果表明:当微波裂解功率为900W,添加蔗渣干重的10％的磷酸,1％的硫酸,100％的红壤黏粒时,糠醛的得率最高,为蔗渣干重的4.5％,该处理生物焦具有多孔性,经傅里叶红外光谱分析表明存在有机磷酸酯键和Si-C共价键,表明裂解过程中形成有机无机复合物.生物焦经中和后,对于红壤的改土增产效果显著:盆栽大豆出苗率、株高、地上部干重、地下部干重、根瘤数量、单株结荚数分别比对照提高了33.3％、24.3％、115％、60％、326％和267％.盆栽白菜抗旱存苗率、株高、鲜重、地上部干重、根重分别比对照提高2.3、0.36、12.3、6.8和5.5倍.     

Catalytic pyrolysis of cellulose in sulfolane with some acidic catalysts

Catalytic pyrolysis of cellulose in sulfolane (tetramethylene sulfone) with sulfuric acid or polyphosphoric acid gave levoglucosenone, furfural, and 5-hydroxymethyl furfural (5-HMF) up to 42.2%, 26.9%, and 8.8% (as mol% yield based on the glucose unit), respectively. Pyrolysis behaviors of the intermediates indicated the conversion pathways, and the conversion: levoglucosenone → furfural was found to require water. The control of the water content in the pyrolysis medium was quite effective in controlling the product selectivity between levoglucosenone and furfural: mild vacuum conditions to remove the product water dramatically enhanced the levoglucosenone yield, while steam distillation conditions increased the furfural and 5-HMF yields.     

中国糠醛的国际竞争力研究

采用显示性指标和分析性指标对中国糠醛国际竞争力进行评价,结果表明,中国糠醛出口竞争力很强,但存在附加值低、净贸易条件波动大、生产企业规模小以及国内市场恶性竞争等问题。     

糠醛生产工艺的发展

糠醛是一种重要的化工原料,具有广阔的应用前景。目前,糠醛主要采用一步法生产,该法糠醛收率最高只有 60％,原料得不到充分利用,这是目前制约糠醛工业发展的主要因素。针对这些问题,本文在对糠醛的生产原理、所用催化剂及一步法的生产工艺进行了概要介绍的基础上,重点对两步法糠醛生产工艺以及糠醛生产工艺的最新进展进行了讨论。由于两步法糠醛收率可以达到70％以上,并且能够综合利用原料,所以两步法必将成为今后该领域的重要研究方向。