一步法CO_2气体混合机的仿制和选用

近年来,国产的软饮料CO_2气体混合机由原来的“二步法”混合灌装正在向一步法混合灌装过渡,目前国内已有许多厂家生产仿制。但有些仿制机仍存在一些问题。一步法,即在制作饮料时,饱和CO_2的水与原糖浆进行定量混合,形成符合标准糖度与浓度的含CO_2气体饮料,对不同的品种,根据产品标准,所含气量(气压)不等:果汁型饮料,含气量应≥2.5倍;果味型及可乐型饮料应≥3倍。有些仿制混合机没有注意到设计这一设备中的关键问题,因而它无法达到含气量的要求。首先要了解CO_2气体溶水的性能,尽量为多溶解CO_2提供条件。CO_2在水中的溶解度与水温有明显的关     

基于可控等值比法实时分析低温加热状态下烟草CO的释放量

为评价低温加热状态下烟草CO的释放特性,采用基于可控等值比法的稳态燃烧热解装置和非散射红外分析仪联用系统(SSTF-NDIR)建立了低温加热状态下烟草CO释放量实时定量分析方法,考察了温度和等值比(φ)对烟草CO释放量的影响。结果表明:1基于可控等值比法的SSTF-NDIR测试系统,可实时分析低温加热状态下烟草CO释放量。2当φ相同时,与高温燃烧状态相比,低温加热状态下烟草的CO释放量明显偏低;温度对低温加热状态下烟草CO释放量影响较小。3当固定温度为450℃时,随着贫氧程度的增加,CO释放量先快速增加后趋于稳定。     

造纸法再造烟叶CO和焦油释放量影响因素研究

为探索影响造纸法再造烟叶CO和焦油释放量的主要因素,考察了不同涂布率与造纸法再造烟叶CO和焦油释放量的相关性,研究了烟梗与碎片比例、片基定量、外加纤维种类、填料种类以及碳酸钙用量对片基CO和焦油释放量的影响。结果表明:（1）CO释放量与涂布率呈负相关,而焦油释放量与涂布率呈正相关;（2）一定范围内,烟梗与碎片比例增加或者使用未漂白的外加纤维都会增加片基CO和焦油释放量,可能是烟梗和未漂白纤维中含有较高的木质素或者果胶;（3）增加碳酸钙用量可使单位质量片基中可燃烧的有机物质减少,降低CO和焦油释放量;（4）降低片基定量或者改善填料种类可以改变片基微观结构,增加透气度,降低片基 CO和焦油释放量。因此,在保证产品品质和加工工艺的前提下,可综合考虑上述方法降低造纸法再造烟叶烟气中CO和焦油含量。      

草酸钾添加量对卷烟纸热解性能及主流烟气的影响

通过在卷烟纸上添加不同量的草酸钾,采用常规烟气分析、同步热分析,研究其对卷烟纸热解性能及主流烟气的影响.结果表明:在卷烟纸上添加草酸钾后对卷烟主流烟气中的焦油和CO有一定的降低作用,随着添加量的继续增加,抽吸口数、CO和焦油释放量均呈先下降后缓慢上升趋势;在草酸钾添加量为1.5%时,其降焦及降CO效率最高;随着草酸钾添加量的增加,卷烟纸热解起始温度降低,在200～300℃时反应活化能降低.     

水及可乐中邻苯二甲酸二(2-乙基)己酯的迁移规律

研究不同温度、不同储存时间条件下邻苯二甲酸二(2-乙基)己酯(DEHP)在聚对苯二甲酸乙二醇酯(PET)瓶装水、可乐饮料中的迁移规律。结果显示:随着环境温度的升高和储存时间的延长,无论是中性的水还是高酸性的可乐饮料,DEHP的浓度均显著增加;而且温度对DEHP迁移的影响较时间更显著。但在常温条件下,水中的DEHP的迁移在360d时达到最高,而可乐饮料中DEHP的变化相对复杂。但本研究结果显示,PET瓶装酸性可乐饮料及中性纯净水中的DEHP均小于安全限值(1.5mg/L)。     

温度与甘油对烟草颗粒热解及释烟特性的影响

为揭示加热状态下烟草颗粒烟气释放规律,采用湿法造粒技术,利用热分析仪(TGA)和锥型量热仪(CONE)研究甘油添加量与温度对其热解和烟气释放特性的影响。结果表明:①添加甘油可降低烟草颗粒主要失重过程温度,增加低温下失重比例,并提高低温下失重速率。②增加甘油含量,烟草颗粒起始释烟速率增大,累积释烟总量增加,但过高的添加量(35%)会降低累积释烟总量;导热性较好的烟草样品释烟速率最大;甘油的添加降低了CO释放量,但与添加量的关系不明显。③升高温度,烟气释放速率增大,释烟过程缩短,累积释烟总量先增大后降低,温度过高(400℃)烟草颗粒发生燃烧;烟气中CO与CO2释放量随温度升高大幅增加,且两者释放规律与烟气释放规律一致。     

辅助材料设计参数对烤烟型卷烟烟气焦油、烟碱和CO释放量的影响

为探索辅助材料与卷烟烟气化学成分之间的关系,研究了卷烟纸定量、卷烟纸透气度、成形纸透气度、接装纸透气度和滤棒吸阻对卷烟主流烟气焦油、烟碱和CO释放量的影响,并通过辅材设计参数的组合设计,建立了辅材设计参数预测焦油、烟碱和CO释放量的数学模型.结果表明:①卷烟纸定量增加CO释放量增加;②卷烟纸透气度增加,焦油、烟碱和CO释放量降低;③滤棒吸阻增加,焦油和烟碱释放量降低;④接装纸透气度增加,焦油、烟碱和CO释放量显著降低;⑤成形纸透气度增加,焦油、烟碱和CO释放量降低,降低程度与配合使用的接装纸透气度有关;⑥焦油、烟碱和CO释放量预测模型的预测值与实测值基本吻合.     

Ce改性贵金属催化剂降低卷烟烟气中CO性能的研究

以浸渍法制备了一系列添加CeO2的Pd-Ce/NaZSM-5负载型催化剂。以CO氧化为模型反应,考察了反应温度、Ce含量、预还原、空速及水蒸气等对CO氧化性能的影响,并利用XRD和XPS等手段对催化剂体相及表面结构进行了表征。结果表明:加入CeO2作助剂可明显提高催化剂的活性,且催化转化率随着反应温度及Ce含量的增加而增加,随着空速的增加而降低,催化剂对水蒸气不敏感,在水蒸气存在的条件下反应可连续进行720h以上保持CO完全转化,H2还原作用使催化剂活性有所提高。XRD测试结果表明,催化剂中Pd组分处于高分散状态,CeO2的引入促进了Pd物种在NaZSM-5载体上的分散。表面XPS分析证实催化剂表面Pd物种处于较高的氧化状态,且CeO2与Pd物种间存在协同作用。Pd的高分散及其与CeO2的相互作用是催化剂具有高活性的关键。通过使用二元复合滤棒,考察了Pd-Ce/NaZSM-5负载型催化剂降低卷烟烟气中CO的作用。结果表明,与对照样相比,主流烟气CO释放量可降低22%。     

茉莉、玫瑰格瓦斯饮料的研制

研究了玫瑰、茉莉2种花卉格瓦斯饮料的生产工艺。探讨了花卉原料浸提液的料水比、温度、pH值和发酵技术参数等对饮料口感、色泽、CO2压力的影响。结果显示:以玫瑰花为原料,采用料水比1∶90、pH值4.5、糖4%、接入5%接种量的香槟酵母,在25℃下发酵6d,在此条件下,发酵型含气花卉饮料,酸甜爽口,风味独特。     

阿斯巴甜:新一代甜味剂

<正> 人们喝饮料不再只为了止渴,味道、保健也成为大众注意的焦点。阿斯巴甜这种新一代的甜味剂适用于各种饮料,并能提供许多蔗糖缺少的特质。 美国纽特凯可公司(The NutraSweet Kelco Company)的阿斯巴甜可用于各种不同的饮料及食品中。饮料方面包括豆浆、即溶饮品、纤维饮品、特饮、汽水、果汁、可乐、运动饮料、牛奶和酸奶等;食品方面包括薄荷糖、糖果蜜饯、甜品、小食、口香糖、麦片、果冻、糖浆、果酱、冰淇淋、巧克力等。     

Mineral CO2 sequestration by steel slag carbonation

Mineral CO2 sequestration, i.e., carbonation of alkaline silicate Ca/Mg minerals, analogous to natural weathering processes, is a possible technology for the reduction of carbon dioxide emissions to the atmosphere. In this paper, alkaline Ca-rich industrial residues are presented as a possible feedstock for mineral CO2 sequestration. These materials are cheap, available near large point sources of CO2, and tend to react relatively rapidly with CO2 due to their chemical instability. Ground steel slag was carbonated in aqueous suspensions to study its reaction mechanisms. Process variables, such as particle size, temperature, carbon dioxide pressure, and reaction time, were systematically varied, and their influence on the carbonation rate was investigated. The maximum carbonation degree reached was 74% of the Ca content in 30 min at 19 bar CO2 pressure, 100 degrees C, and a particle size of <38 microm. The two most important factors determining the reaction rate are particle size (<2 mm to <38 microm) and reaction temperature (25-225 degrees C). The carbonation reaction was found to occur in two steps: (1) leaching of calcium from the steel slag particles into the solution; (2) precipitation of calcite on the surface of these particles. The first step and, more in particular, the diffusion of calcium through the solid matrix toward the surface appeared to be the rate-determining reaction step. The Ca diffusion was found to be hindered by the formation of a CaCO3-coating and a Ca-depleted silicate zone during the carbonation process. Research on further enhancement of the reaction rate, which would contribute to the development of a cost-effective CO2-sequestration process, should focus particularly on this mechanism.     

Diffusion and adsorption of uranyl carbonate species in nanosized mineral fractures

Atomistic simulations were performed to study the diffusion and adsorption of Ca(2)UO(2)(CO3)3 and of some of its constituent species, i.e., UO(2)2+, CO(3)2–, and UO(2)CO3, in feldspar nanosized fractures. Feldspar is important to uranium remediation efforts at the U.S. Department of Energy Hanford site as it has been found in recent studies to host contaminants within its intragrain fractures. In addition, uranyl carbonate species are known to dominate U(VI) speciation in conditions relevant to the Hanford site. Molecular dynamics (MD) simulations showed that the presence of the feldspar surface diminishes the diffusion coefficients of all of the species considered in this work and that the diffusion coefficients do not reach their bulk aqueous solution values in the center of a 2.5 nm fracture. Moreover, the MD simulations showed that the rate of decrease in the diffusion coefficients with decreasing distance from the surface is greater for larger adsorbing species. Free energy profiles of the same species adsorbing on the feldspar surface revealed a large favorable free energy of adsorption for UO(2)2+ and UO(2)CO3, which are able to adsorb to the surface with their uranium atom directly bonded to a surface hydroxyl oxygen, whereas adsorption of CO(3)2– and Ca(2)UO(2)(CO3)3, which attach to the surface via hydrogen bonding from a surface hydroxyl group to a carbonate oxygen, was calculated to be either only slightly favorable or unfavorable.     

CO2 capture in different carbon materials

In this work, the CO(2) capture capacity of different types of carbon nanofibers (platelet, fishbone, and ribbon) and amorphous carbon have been measured at 26 °C as at different pressures. The results showed that the more graphitic carbon materials adsorbed less CO(2) than more amorphous materials. Then, the aim was to improve the CO(2) adsorption capacity of the carbon materials by increasing the porosity during the chemical activation process. After chemical activation process, the amorphous carbon and platelet CNFs increased the CO(2) adsorption capacity 1.6 times, whereas fishbone and ribbon CNFs increased their CO(2) adsorption capacity 1.1 and 8.2 times, respectively. This increase of CO(2) adsorption capacity after chemical activation was due to an increase of BET surface area and pore volume in all carbon materials. Finally, the CO(2) adsorption isotherms showed that activated amorphous carbon exhibited the best CO(2) capture capacity with 72.0 wt % of CO(2) at 26 °C and 8 bar.     

Effects of surface heterogeneity on the adsorption of CO₂ in microporous carbons

Carbon capture combined with utilization and storage has the potential to serve as a near-term option for CO(2) emissions reduction. CO(2) capture by carbon-based sorbents and CO(2) storage in geologic formations such as coal and shale both require a thorough understanding of the CO(2) adsorption properties in microporous carbon-based materials. Complex pore structures for natural organic materials, such as coal and gas shale, in addition to general carbon-based porous materials are modeled as a collection of independent, noninterconnected, functionalized graphitic slit pores with surface heterogeneities. Electronic structure calculations coupled with van der Waals-inclusive corrections have been performed to investigate the electronic properties of functionalized graphitic surfaces. With Bader charge analysis, electronic structure calculations can provide the initial framework comprising both the geometry and corresponding charge information required to carry out statistical modeling. Grand canonical Monte Carlo simulations were carried out to determine the adsorption isotherms for a given adsorbent-adsorbate interaction at temperature/pressure conditions relevant to carbon capture applications to focus on the effect of the surface functionalities. On the basis of the current work, oxygen-containing functional groups were predicted to enhance CO(2) adsorption in microporous carbon materials in the absence of water vapor, and the hydrated graphite was found to hinder CO(2) adsorption.     

Modeling the effect of time and temperature on respiration rate of pomegranate arils (cv. "Acco" and "Herskawitz")

Understanding the effect of time and temperature on the respiration rate (RR) of fresh-cut produce, towards the design of a suitable modified atmosphere packaging (MAP) system, requires an adequate mathematical model for prediction of RR as a function of both time and temperature. This study investigated the effect of temperature (5, 10, and 15 °C) and storage time (1 to 5 d) on the RR (R(O2) and R(CO2)) of 2 pomegranate cultivars (cv. "Acco" and "Herskawitz") fresh arils. R(O2) and R(CO2) were 3 to 4 folds significantly higher with increased temperature from 5 to 15 °C and were within the range of 2.51 to 7.59 mL/kg h and 2.72 to 9.01 mL/kg h, respectively, for both cultivars. At 15 °C R(CO2) increased significantly from 8.4 to 25.96 mL/kg h from day 1 to 5, respectively, while at 5 °C R(CO2) changed from 2.9 to 2.05 mL/kg h from day 1 to 5. Temperature had the greatest influence on RR and the interaction of time and temperature also significantly affected R(O2) and R(CO2). The respiratory quotient (RQ) estimated by linear regression was 0.98 at 95% significant level. The dependence of RR on temperature and time was accurately described with a combination of an Arrhenius-type and power equation model for and of fresh pomegranate arils.     

Microbiological and sensory changes in "Morcilla de Burgos" preserved in air, vacuum and modified atmosphere packaging

"Morcilla de Burgos" is the most popular blood sausage in Spain. Traditionally, this product is distributed and sold without packaging in the local market. To extend its shelf-life and expand the market, different packaging methods have been employed and compared: "morcilla" stored in air (without packaging), in vacuum and in modified atmosphere packaging (MAP) using three different CO(2) concentrations 30%, 50% and 80% and balanced with N(2). Total viable count (TVC), psychrotrophs, lactic acid bacteria (LAB), pseudomonads, enterobacteria, moulds and yeasts, enterococci, Staphylococcus aureus, and sulfite reducing clostridia were analysed during storage at 4°C. Sulfite-reducing clostridia, pathogenic staphylococci, and enterococci were not detected in any sample. In air-stored "morcilla" a significant increase in all microbial groups was observed during storage. Pseudomonads were the predominant microorganisms reaching a population higher than 8 log cfu/g after 27 days of storage. On the other hand, a decrease in pH was noticed in MAP and in vacuum packaged "morcilla" (pH 4.73) during storage. At the same time, LAB becomes the predominant species in all these packaged samples. The rest of the microbiota did not grow during storage. In "morcilla" packed with 50% and 80% of CO(2), counts of pseudomonads and enterobacteria were lower than found in the vacuum packs. Sensory analysis showed that shelf-life of "morcilla" stored in air did not exceed 17 days, while samples packed under vacuum and with 30% CO(2) were acceptable until 22 days of storage. "Morcillas" packaged with 50% and 80% CO(2) were sensorially acceptable for 32 days.     

CO2处理对磨盘柿果实质地及品质的影响

以磨盘柿为原料,采用不同浓度CO2气体处理,定期观察分析柿果硬度、果胶含量、果胶酶活性、果实品质等变化,结果表明,70％CO2处理的柿果保硬时间较长,同时品质最好。     

暖啤的研制

以大麦芽、大米为主原料,大枣、生姜、焦香麦芽为辅料酿造暖啤的操作要点。原料的选择、预处理、生产工艺流程及成品酒的质量指标。     

基于芦山纱特征的三绞三罗织物性能分析及试织

芦山纱织物表面均匀分布稳定清晰的纱孔,呈现若隐若现的亮点而独具特色。文章对芦山纱独特的二绞二罗组织的结构进行了分析,研究了织物表面的细小纱孔和独特亮点等特征,并基于芦山纱以基础组织为地、罗组织为花的组织特征,进一步采用棉纱作经纬原料,以变化斜纹组织为地组织,三绞三罗组织为提花组织,研制了三绞三罗织物。根据不同经纬线密度的配置试织试样,对其进行织物悬垂性、折皱回复性、拉伸性能的测试。结果表明,经纬原料线密度配置与罗组织分布对织物的抗折皱性和拉伸强力具有一定的影响。     

酒精酵母的复合诱变与甜高梁秆汁培养基的优化

以甜高粱秆汁为基本原料,采用UV和DES复合诱变后获得酵母菌株FUD-3,再通过响应面法优化培养基中的营养因子CO(NH2)2、MgSO4、KH2PO4、CaCl2和FeCl3,提高了酒精的得率.结果表明:用驯化的方法使酒精酵母耐糖能力提高,通过UV与DES复合诱变的方式进行酵母的选育,以提高其产率.采取响应面法对发酵培养基进行优化,得到各因素的最佳质量浓度CO(NH2)2、MgSO4、KH2PO4、CaCl2和FeCl3的添加量分别为4.8318g/L、1.3734g/L、4.8114g/L、5.8571g/L0.6962g/L.训育后的酵母F-1与经过复合诱变优化后的酵母FUD-3发酵相比:残糖由26.41g/L减到9.24g/L、酒精产率由80.28%提高为93.46%,酒精的产量79.29g/L增加为100.44g/L,提高了26.67%.