白砂糖中二氧化硫与色值变化相互关系

亚硫酸法工艺在我国制糖业中占据了主导地位,白砂糖中二氧化硫对白砂糖品质的影响一直是我国制糖业高度关注的课题。文章重点介绍白砂糖中二氧化硫与有色物质的相互作用对色值的影响。     

回收利用亚硫酸降低溴素生产成本

制溴厂通过回收制药企业副产品亚硫酸,来替代传统二氧化硫气体和淡水喷淋反应,降低生产成本,减少环境污染.     

蘑菇中二氧化硫测定方法的探讨——改良的Monier-Williams法

目前,国内对于蘑菇中二氧化硫的测定大多数采用轻工业部部颁标准(QB220-76)中规定的碘标准溶液滴定法,由于,该方法的终点不明显,且由于二氧化硫量少,颜色转变不易观察,滴定往往过量,加之其他物质的干扰,结果偏高。美国FDA早在1985年3月提出规定:添加在任何食品或是食品的配料内的任何亚硫酸盐(二氧化硫、亚硫酸钠亚硫酸氢钾、亚硫酸氢钠、偏亚硫酸氢钠、偏亚硫酸氢钾),只要在产成品内一种亚硫酸盐的可检出的数量在10ppm或以上,必须在该产品的商标上注明。而用QB220—76方法测定,结果往往超过此规定。鉴于上述情况,本法根据FDA规定的AOAC法内“亚硫酸总量”的测定方法,对现有的蘑菇原料,     

基于PLC在糖厂燃硫炉控制系统设计及运用

亚硫酸法制糖工艺是以二氧化硫作为主要的澄清剂,用于对蔗汁的澄清,从而提高糖产品的品质。SO2是燃硫炉通过燃烧硫磺而产生的。燃硫炉是亚硫酸法制糖工艺澄清工段的重要设备,它运行效果的好坏,直接影响到制糖生产过程对糖产品质量的控制、成本的控制、环境的保护。通过对PLC控制系统应用于燃硫炉运行控制的论述,阐述PLC实现对糖厂燃硫炉自动控制系统的应用及推广意义。     

关于海产品中二氧化硫限量的探讨

我国拥有辽阔的海域和漫长的海岸线,海洋资源丰富,特别是拥有丰富的优质海产品。随着国民经济的持续发展,海产品出口量大幅度递增,随之亦不断出现因滥用亚硫酸盐类保鲜剂,引起二氧化硫残留量超标,导致退回或暂停的事件。现通过对我国食品安全标准中二氧化硫、亚硫酸盐类食品添加剂适用范围以及不同标准中海产品类二氧化硫残留量与国际相关标准进行比较,并对亚硫酸盐类在海产品中的使用进行安全评价,建议明确规范亚硫酸盐在海产品中的使用范围,并确立合理的二氧化硫的残留限量,使其更加细化,以便更好地与国际标准接轨。     

国际葡萄酿酒法规(3)

葡萄汁1.二氧化硫处理1.1 定义在已破碎的葡萄或葡萄汁中加入气体二氧化硫,或亚硫酸溶液,或焦亚硫酸氧钾(偏重亚硫酸钾),或亚硫酸铵或焦亚硫酸铵。1.2 目的a)发挥本物质的下列作用:——防止因细菌繁殖造成病酒而使用的杀菌剂;——抗氧化剂;——酵母的选择剂;——有助于产品的澄清:——有助于产品的氰化物分解;b)调节及控制发酵;c)制造中途抑止发酵的葡萄汁。1.3 规定a)二氧化硫的处理应在破碎过程中或结束破碎时进行。b)将二氧化硫均匀地分布在破碎的葡萄及葡萄汁中。c)而且亚硫酸铵和焦亚硫酸铵中的氨离子引入了葡萄汁中,铵离子是酵母成长的促进剂的一部分(见《酒精     

糖浆硫熏散汽箱结构对产品质量的影响

我厂是亚硫酸法糖厂,过去的白砂糖优、一级产率一直徘徊在30～60%,主要是色值达不到指标。在1987年检修期,针对二氧化硫气体经常跟随清净糖浆一起跑到下面糖浆箱后再挥发出来而严重污染车间内空气(甚至造成该处岗位人员无法在岗位处操作)的情况,根     

磷酸法澄清工艺研究初报

对用磷酸替代二氧化硫处理蔗汁的磷酸法澄清工艺进行了初步研究。试验结果表明:以澄清汁钙盐含量、纯度差、清净效率和非糖分除去率为表征的澄清效果,超过了亚硫酸法的,接近或达到了碳酸法的。认为,用该法替代亚硫酸法澄清蔗汁,经济、社会和环境的效益是显著的。     

关于在食品中使用二氧化硫的科学解读

正近日,食品药品监管部门抽检发现,部分蔬菜、水果制品、白砂糖等二氧化硫含量超标。那么,二氧化硫如何应用于食品工业中?对人体健康是否有危害?是否可以应用于果蔬制品、白砂糖及相关制品中?国内外有哪些相关的法规标准?日前,国家食品药品监督管理总局组织有关专家对此进行了解读。二氧化硫是国内外允许使用的一种食品添加剂,通常情况下该物质以焦亚硫酸钾、焦亚硫酸钠、亚硫酸     

二氧化硫对测定啤酒中双乙酰的影响

使用邻苯二胺(EBC法)测定啤酒中双乙酰含量时，啤酒中存在的亚硫酸氢盐会影响测定结果的准确性。而采用改进方法(CC法)可避免测定中的误差。通过对两种分析方法的对比实验，结果表明，使用EBC分析法测定时，二氧化硫会影响双乙酰的测定结果；而CC法具有高精确度和速度快的优点，该方法的主要不同之处是，蒸馏物是在强酸溶液中进行收集的。     

柚皮提取果胶沉淀条件的研究

研究了用沉淀法以柚皮为原料提取果胶时工艺条件。通过对乙醇沉淀和硫酸铝盐析时各种影响因素的研究 ,分别得到较佳工艺条件 ,为批量生产提供了依据。     

提高石灰消和度的研究

糖厂是石消耗大户，如何提高石灰消和度以降低石灰耗量在国内报道甚少，本文探讨了超声波及电磁搅拌对石灰消和的作用。试验表明，两种途径在一条件下都录同程度地提高 石灰中有效氧化钙含量。     

Novel process for simultaneous removal of NO(x) and SO2 from simulated flue gas by using a sustainable Ag(I)/Ag(II) redox mediator

The objective of this work is to develop a sustainable process for simultaneous removal of waste gases such as NO, NO2, and SO2 by an electrochemically generated Ag(I)/Ag(II) redox mediator system. High removal efficiency was achieved for NO and SO2 by the wet scrubbing method at room temperature and atmospheric pressure. This removal is achieved through oxidation and absorption by contacting the gaseous stream with redox mediator ions that offer specific or selective solubility for the solute gases to be recovered in a wet scrubber. The process parameters such as gas velocity, liquid velocity, Ag(I) concentration, and HNO3 concentration were investigated to explore the possibility of complete removal of waste gases. The Ag(I)/Ag(II)-based mediated electrochemical oxidation process proved to be quite effective for simultaneous removal of NO, NO(x), and SO2 from the simulated flue gas mixtures containing NO and SO2 over a wide concentration range of 100-400 ppm. Studies were carried out with individual gas components for the mixture, and the effect of input NO and input SO2 concentrations on the NO(x) and SO2 removal efficiencies at 20 degrees C was examined. Complete oxidation of NO to NO2 with 100% NO removal efficiency and 92% NO(x) removal efficiency was achieved along with 100% SO2 removal efficiency, highlighting a potentially far greater efficiency of the Ag(I)/Ag(II)-based system in functionality and selectivity. Active research work in this direction is anticipated in the near future.     

烟草中多元酸和高级脂肪酸的分析

采用甲酯化、萃取和GC法定量分析了卷烟烟丝中的多元酸如草酸、丙二酸、丁二酸、苹果酸和柠檬酸和高级脂肪酸如月桂酸、肉豆蔻酸、棕榈酸、亚油酸和硬脂酸。分析步骤为 :将含有己二酸 (内标 )的烟末放入硫酸 -甲醇中 ,在室温下酯化 2 2h ,随后用二氯甲烷萃取 3次 ,用饱和氯化钠溶液洗涤 ,在无水硫酸钠上干燥 ,最后进行气相色谱分析。测定了 11种牌号卷烟的有机酸 ,并进行了比较。分析结果表明 :①在所测定的卷烟中 ,所有牌号卷烟烟丝中的苹果酸、草酸、柠檬酸和亚油酸的含量均远远高于其它有机酸的含量 ;②混合型卷烟中柠檬酸和草酸的含量明显高于烤烟型卷烟 ;③混合型卷烟中的棕榈酸和亚油酸含量低于烤烟型卷烟。     

Minimization of artifacts in sulfuric acid mist measurement using NIOSH Method 7903

NIOSH Method 7903 employs a silica gel tube for sulfuric acid mist measurement in workplaces. However, SO2 gas present in the sample volume can be transformed into sulfate in the sampling process causing an artifact that is reported as sulfuric acid. A sampling train incorporating a honeycomb denuder system was applied for field sampling at seven phosphate fertilizer plants to evaluate its use for reducing the artifact sulfate concentration while preserving the actual sulfuric acid mist concentration. The denuder system was designed to remove SO2 gas before the air entered the silica gel tube and to monitor SO2 concentration at the same time. A deactivation model was also applied to correct for the presence of the artifact. The denuder system had 95.7 +/- 6.8% collection efficiency for SO2 gas, and the impact of sulfate aerosol on SO2 collection was negligible. SO2 concentrations at the seven plants ranged from 34 ppb to 5.6 ppm. The honeycomb denuder system and the deactivation model were shown to reduce the artifact sulfate concentration by 70% and 39%, respectively. However, they were still higher than the sulfate aerosol concentration measured by a cascade impactor. One possible reason is the residual sulfate in the glass fiber filter and the silica gel.     

Application of pulsed corona induced plasma chemical process to an industrial incinerator

Pulsed corona induced plasma chemical process (PPCP) has been investigated for the simultaneous removal of NO(x) (nitrogen oxides) and SO2 (sulfur dioxide) from the flue gas emission. It is one of the world's largest scales of PPCP for treating NO(x) and SO2 simultaneously. A PPCP unit equipped with an average 120 kW modulator has been installed and tested at an industrial incinerator with the gas flow rate of 42 000 m3/h. To improve the removal efficiency of SO2 and NO(x), ammonia (NH3) and propylene (C3H6) were used as chemical additives. It was observed that the pulsed corona induced plasma chemical process made significant NO(x) and SO2 conversion with reasonable electric power consumption. The ammonia injection was very effective in the enhancement of SO2 removal. NO removal efficiency was significantly improved by injecting a C3H6 additive. In the experiments, the removal efficiencies of SO2 and NO(x) were approximately 99 and 70%, respectively. The specific energy consumption during the normal operation was approximately 1.4 Wh/m3, and the nanopulse conversion efficiency of 64.3% was achieved with the pulsed corona induced plasma chemical process.     

Novel dry-desulfurization process using Ca(OH)2/fly ash sorbent in a circulating fluidized bed

A dry-desulfurization process using Ca(OH)2/fly ash sorbent and a circulating fluidized bed (CFB) was developed. Its aim was to achieve high SO2 removal efficiency without humidification and production of CaSO4 as the main byproduct. The CaSO4 produced could be used to treat alkalized soil. An 83% SO2 removal rate was demonstrated, and a byproduct with a high CaSO4 content was produced through baghouse ash. These results indicated that this process could remove SO2 in flue gas with a high efficiency under dry conditions and simultaneously produce soil amendment. It was shown that NO and NO2 enhanced the SO2 removal rate markedly and that NO2 increased the amount of CaSO4 in the final product more than NO. These results confirmed that the significant effects of NO and NO2 on the SO2 removal rate were due to chain reactions that occurred under favorable conditions. The amount of baghouse ash produced increased as the reaction progressed, indicating that discharge of unreacted Ca(OH)2 from the reactor was suppressed. Hence, unreacted Ca(OH)2 had a long residence time in the CFB, resulting in a high SO2 removal rate. It was also found that 350 degrees C is the optimum reaction temperature for dry desulfurization in the range tested (320-380 degrees C).     

融合株Q4413的L-赖氨酸生产研究

Q4413菌株系北京棒状杆菌1134衍生物与枯草芽孢杆菌151衍生物的原生质体的融合株。Q4413株培养在甜菜(糖蜜含糖量12.6％)、K_2HPO_40.15％、MgSO_40.04％、玉米浆1.2％、(NH)_4)_4SO_44％,VH、VB分别为50μg/dl培养基的小型发酵罐内,pH6.5～7.2,30～32℃,发酵75小时。pH值由氨水调节,发酵过程补加糖3.6％。平均产L-赖氨酸6.5％,平均转化率40.2％。 Q4413融合株遗传性能稳定,是一株具有王业生产价值的菌株。     

Sulfur dioxide treatment from flue gases using a biotrickling filter-bioreactor system

Complete treatment of sulfur dioxide (SO2) from flue gases in a two-stage process consisting of a biotrickling filter followed by biological post-treatment unit was investigated. The biotrickling filter could remove 100% of influent SO2 from simulated flue gas at an empty bed residence time of 6 s for a concentration range of 300-1000 ppm(v). All the absorbed SO2 was recovered in the biotrickling filter liquid effluent as sulfite (a product of chemical reaction of SO2) and sulfate (product of biological oxidation of sulfite). The biotrickling filter liquid effluent was further processed biologically in a single post-treatment unit consisting of a combined anaerobic and microaerophilic reactor for the simultaneous reduction of sulfate and sulfite to sulfide and oxidation of sulfide to elemental sulfur. The post-treatment unit could effectively treat the biotrickling filter effluent and produce elemental sulfur. The sulfur production efficiency of the reactor reached about 80% of the SO2 treated. This new biological treatment system seems to be a promising alternative for flue gas desulfurization.     

Flue gas treatment for SO2 removal with air-sparged hydrocyclone technology

Laboratory results from an initial study on the removal of SO2 from gas mixtures are reported using air-sparged hydrocyclone (ASH) technology. Tap water and alkaline solutions were used for absorption, and the influence of gas flow rate, water flow rate, and length of the ASH unit were investigated. The research results indicate thatthe air-sparged hydrocyclone can be used as a highly efficient absorber for SO2 emissions. The ASH allows for 97% SO2 removal using water alone for sulfur dioxide content in the gas phase of 5 g/m3. All SO2 is removed in weakly alkaline solution (0.01 mol NaOH/dm3).