交联聚乙烯的降解及再生利用

本文研究了工艺条件对交联聚乙烯降解作用的影响,在此基础上选择了最佳降解条件。同时研究了交联聚乙烯的降解程度与LDPE的配比和发泡剂AC的用量对发泡性能的影响。发泡材料的表现密度为518～610kg/m~3,可用来制造发泡型电缆填充条和包装材料。     

新型生物质代木包装材料的制备与特性

利用微波发泡方法制备出一种环境友好型的代木包装材料.通过正交实验探讨了不同发泡时间和温度对新材料力学性能的影响,获得了主要的影响因素并且研究各组分的最优配比.结果表明:马铃薯淀粉含量越高,材料抗弯强度和抗压强度逐渐增大;随甘油、瓜尔豆胶添加量增加,发泡材料抗压和抗弯强度均先减小后增大;微波发泡温度以及时间设定为75℃、30 min时材料的抗压性能和抗弯性能较好.采用静态压缩实验比较生物质代木材料与传统代木材料力学性能的差异.     

中温ADC发泡剂对EVA发泡成型条件的研究

研究了中温ADC发泡剂(偶氮二甲酰胺)完全发泡所需条件以及发泡促进剂、交联剂、填料等组分的用量对乙烯-乙酸乙烯酯共聚物(EVA)材料性能的影响。根据试验结果,确定了中温ADC发泡剂完全发泡的模压加热时间、模压加热温度等工艺条件,以及在该条件下各原料组分的最佳配比。该发泡剂及成型条件与常规ADC发泡剂的成型条件相比具有加工时间短、能耗低等优点。     

木质纤维-氨基树脂模塑料的制备与性能研究(摘要)

以生物质资源——农林废弃物(玉米秸秆酶解副产物、麦秆、竹粉、造纸竹污泥)和纸浆为原料,采用纤维表面处理技术提高秸秆中纤维素含量、改善纤维素表面性能,通过逐步缩合聚合和共缩聚手段,制得农作物秸秆木质纤维-氨基树脂模塑料,并对材料的流动性能、力学性能、模塑收缩率等进行了研究。考察了木质纤维原料-农林废弃物资源(玉米秸秆酶解副产物、麦秆、竹粉、造纸竹污泥)、固化剂和增塑剂对氨基树脂模塑料的影响,以期为利用生物质资源制备性能优良的高分子材料提供新的途径。     

LDPE/EVA发泡材料的研制

以偶氮二甲酰胺(AC)为发泡剂，过氧化二异丙苯(DCP)为交联剂，硬脂酸锌(ZnSt)为活化剂，二氧化硅(SiO₂)为匀泡剂，低密度聚乙烯(LDPE)和乙烯-醋酸乙烯酯共聚物(EVA)为发泡塑料载体，研究了发泡材料的最佳原料配比和加工条件，并对发泡材料的各项性能进行了表征。实验发现当PE为70 phr、EVA为13 phr、DCP为2 phr、AC为15 phr时得到的发泡试样综合性能最好。     

生物质活性炭的制备及吸附性能研究

以木屑为原料,磷酸为活化剂,通过单因素实验,研究了原料种类、预处理方式、液固比、活化温度对生物质活性炭得率和吸附性能的影响。结果表明,影响生物质活性炭得率和吸附性能最重要的因素是磷酸溶液与木屑的液固比和活化温度;得到了活性炭最佳制备条件:液固比7、50℃搅拌3 h、450℃活化2 h。该条件下制备的生物质活性炭得率达到40%以上,对湛江松脂加工废水COD降低值在7700 mg/L以上。该活性炭具有较好的吸附性能,为农林废弃物木屑的高效利用提供了有效途径。     

农林废弃物气化合成混合醇生命周期环境影响分析

生物质热化学气化合成混合醇技术具有工艺相对简单、产物的能源化工应用广泛等优点,为准确评价该技术的资源能源消耗、辨析合成燃料的环境性能,基于生命周期分析框架和ReCiPe2016中点评价方法,对农林废弃玉米秸秆和木屑经气化、催化合成混合醇工艺的清单和9种环境影响类型开展分析和比较。结果表明：农林业阶段均为环境影响的主要阶段,秸秆混合醇生命周期影响高于木屑混合醇。前者的臭氧层耗竭潜值、海洋和淡水富营养化潜值、全球变暖潜值均为木屑混合醇相应结果的9倍以上。废弃物原料高碳含量和高混合醇收率有利于降低资源消耗和环境影响。与石化汽油相比,秸秆和木屑混合醇的全球变暖和化石能源消耗潜值均降低40%以上。     

生物质空气气化过程的有效能分析

以空气为气化介质,选取松木、玉米秸秆、木屑为气化原料,运用ASPEN PLUS软件并结合Fortran编程对基于自热固定床反应器的生物质气化过程进行了模拟,探讨了空气当量比(ER)和生物质含水量对干气低位热值、气化炉温度、干气组成和气化有效能效率的影响. 结果表明,在生物质含水量一定时,随ER增加,干气低位热值降低,气化温度升高,干气中CO含量先增加后减少,H2含量降低,有效能效率先升高后降低;ER一定时,随生物质含水量增加,干气低位热值降低,气化温度先降低后升高,干气中CO含量降低,H2含量先升高后降低;当松木、玉米秸秆、木屑的含水量为20%(w)、ER分别取0.25, 0.2和0.15时,最大有效能效率分别为61.67%, 60.23%和54.98%.     

土壤中蔗髓缓冲包装材料高效降解菌的筛选与鉴定

以蔗髓为原料、亚硫酸氢镁法制浆废液为胶黏剂制备的蔗髓缓冲包装材料为研究对象,从土壤中筛选出其高效降解菌株,并进行鉴定,确定菌株的稳定性。采用平板水解圈法和失重法进行菌株筛选,同时采用扫描电子显微镜(SEM)对蔗髓缓冲包装材料(BPCPMs)降解前后的形貌进行表征。利用培养特征、形态学、分子生物学方法进行菌株鉴定。筛选出效果稳定的蔗髓缓冲包装材料高效降解菌株ZS0918,经基因鉴定该菌株为杂色曲霉(Aspergillus versicolor)。SEM结果表明,在霉菌作用下,BPCPMs表面出现大小不一的孔洞,材料变薄,发生显著降解。     

共混法制备聚丙烯开孔泡沫材料的研究

采用高熔体强度聚丙烯(HMSPP)/线性低密度聚乙烯(LLDPE)共混的方法在自制超临界CO2动态发泡模拟机上制备了开孔性泡沫材料。研究了发泡温度和共混体系原料配比对聚丙烯开孔发泡性能的影响。结果表明:LLDPE的加入使HMSPP的结晶性能发生变化,形成分散晶区;发泡温度为140℃时,HMSPP/LLDPE共混体系质量配比为90/10的发泡样品泡孔形貌最好,而当发泡温度为130℃时,质量配比为70/30的共混体系发泡效果更好,形成明显开孔结构;同一发泡温度下,LLDPE用量对发泡效果影响很大;HMSPP/LLDPE质量配比为70/30时,发泡样品开孔率最大。     

Mass and heat balance calculations and economic evaluation of an innovative biomass pyrolysis project

Biomass can be converted into flammable gas, charcoal, wood vinegar, wood tar oil and noncombustible materials with thermo-chemical pyrolysis reactions. Many factors influence these processes, such as the properties of the raw materials, and temperature control and these will affect the products that are produced. Based on the data from a straw pyrolysis demonstration project, the mass and heat balance of the biomass pyrolysis process were analyzed. The statistical product and service solutions (SPSS) statistical method was used to analyze the data which were monitored on-site. A cost-benefit analysis was then used to study the viability of commercializing the project. The analysis included net present value, internal rate of return and investment payback period. These results showed that the straw pyrolysis project has little risk, and will produce remarkable economic benefits.     

复合CMA环保型融雪剂的融冰能力研究

采用自制的工业化试验装置和工艺流程,以生物质(秸秆、木屑等)热解废液(木醋液)为原料,制备出以醋酸钙镁盐为主要成分的CMA类环保型融雪剂.研究了复合CMA环保型融雪剂的融冰能力及其不同组分配比对融冰能力的影响规律,结果表明:当液体融雪剂(20%)中醋酸镁和醋酸钙的体积比达到7:3时融冰能力达到最大值91%,达到了国家标...     

Fe-Zn共改性ZSM-5催化作用下生物质快速热解特性研究

选取木屑和花生壳作为原料进行生物质热解，研究有机产物分布，催化剂使用Fe、Zn两种金属元素进行改性。通过X射线衍射（XRD）、扫描电镜（SEM）、傅里叶红外（FT-IR）、比表面积测试（BET）对Fe-Zn改性的ZSM-5进行分析。使用闪速裂解-气质联用仪（PY-GC/MS）对原料进行热解，探究生物质催化热解的产物分布变化。催化剂的使用使得芳烃类产物产率获得较大提升，在木屑热解中，Fe负载的分子筛催化获得了酚类的最高产率，比ZSM-5催化热解产率提升18.30%。金属改性催化剂在花生壳热解中，大幅提升了芳烃类产物产率，其中Zn负载催化剂芳烃类产物产率最高，Zn负载催化热解比直接热解的酚类产率降低了18.92%。Zn负载催化获得了最低的酮类产率，与直接热解相比酮类产率降低19.74%，显示出较强的脱羟基效果。此外Zn负载催化和Fe-Zn双金属负载催化在花生壳热解中都大幅降低了酸类产物产率，与直接热解相比酸类产率分别降低了30.46%、36.71%。     

产氢用生物质球磨预处理工艺的优化试验

本研究采用球磨法对产氢用生物质进行预处理,以酶解后还原糖得率作为考察指标,采用电镜对粉碎后物料进行分析,并利用DPS 7.05分析软件进行试验设计和数据分析,对球磨处理工艺进行优化。分析了原料初始粒径、球料比和球磨时间对酶解糖化过程的影响,得出球料比为显著影响因素,球磨预处理最佳工艺参数为：原料初始粒径0.45 mm,球料比20∶1,球磨时间1 h,在此条件下,还原糖得率为74.50%。     

产氢用生物质球磨预处理工艺的优化试验

本研究采用球磨法对产氢用生物质进行预处理,以酶解后还原糖得率作为考察指标,采用电镜对粉碎后物料进行分析,并利用DPS 7.05分析软件进行试验设计和数据分析,对球磨处理工艺进行优化。分析了原料初始粒径、球料比和球磨时间对酶解糖化过程的影响,得出球料比为显著影响因素,球磨预处理最佳工艺参数为:原料初始粒径 0.45 mm,球料比20∶1,球磨时间 1 h,在此条件下,还原糖得率为 74.50%。     

Gesundheitliche Beurteilung von Packstoffen heute

Evaluation of Packaging Materials from the Viewpoint of Health In the past three decades, the conventional materials used for food packaging, such as wood, straw, metallic sheet, stoneware, porcelain and glass, have been more and more replaced by the new packaging material, plastic. The macromolecular synthetic resins are, as such, hygienically unobjectionable and especially suitable as packaging materials, since they are insoluble due to their high molecular weight. For the production of plastics, however, low molecular additives are used, which might migrate from the plastics and contaminate the packed foodstuffs. Modification of analytical methods has enabled us to recognize that residual traces of starting materials, such as acryl nitrile, vinyl chloride etc., which are objectionable from the viewpoint of health, may be present in plastic packaging materials. This aspect is critically evaluated and the criteria discussed, on the basis of which the Federal Center for Health may accept additives for plastics used in consumer articles according to the law governing food and consumer articles.     

新型橡胶助剂——高沸醇木质素的研制

采用1,4 丁二醇水溶液为溶剂的高沸醇溶剂法,从松木、稻草等原料制备纤维素与高沸醇木质素。使用上述原料,在190～220℃的1,4 丁二醇水溶液中蒸煮1～3h后,分离反应产物,得到固体纤维素与高沸醇木质素-丁二醇溶液。不溶于水的高沸醇木质素通过加水沉淀的方法,从反应后的液体混合物中分离。从松木和稻草制备沸醇木质素的得率分别大于25%和11%。从松木中提取的沸醇木质素的w(灰分)=0 6%,而传统造纸黑液制得木质素磺酸钙的w(灰分)=21 4%。沸醇溶剂法是一种节能、无污染的制备纤维素与木质素的好方法。高沸醇木质素具有较高的反应活性,可以与甲醛反应,形成木质素改性树脂。添加高沸醇木质素改性树脂可以改善NBR橡胶的性能,尤其是扯断伸长率从270%提高到540%,其改性效果优于木质素磺酸盐改性树脂(扯断伸长率330%)。沸醇木质素是一种新型的橡胶添加剂,有良好的应用前景。     

秸秆苯酚选择性液化研究

苯酚液化是生物质液化的重要手段,农作物秸秆是一种不均一的原料,而完全液化将其看作是 "单一"的原料,针对这一问题本研究采用选择性液化处理方式对小麦秸秆进行了苯酚液化,并对比了选择性液化与完全液化。结果表明:低温下适当的浓硫酸用量、较高的苯酚用量、适当的反应时间有利于保留纤维素而选择性液化半纤维素和木质素;与完全液化处理方式相比,选择性液化反应条件温和,保留了大量的纤维素,大大提高了原料利用价值。通过均匀试验和数据回归分析并实验验证得到选择性液化优化条件为:浓硫酸用量占总反应体系质量分数的 3.0%,反应温度 100℃,反应时间 30 min,苯酚与秸秆质量比 3:1,纤维素残留率达 70%,而液化产物结合酚质量分数可达 100%。     

Steam pretreatment of Salix to upgrade biomass fuel for wood pellet production

Steam explosion (SE) pretreatment is served to separate the main components of woody biomass. In general there is a noticeable gap in literature in terms of application of steam explosion process to upgrade biomass fuel for wood pellet production. In order to study the influence of steam explosion pretreatment on biomass fuel, Salix wood chips was used as raw material. Four different SE experiments were performed by varying two key process factors; time and temperature. Elementary quality and ash properties of the pretreated residue were investigated. Moreover, physical and thermochemical properties of the pellet, produced from the residue, were also investigated. Reduction in ash content especially in alkali metals was observed in steam treated residue. Pretreatment of biomass also enhanced carbon content and reduced oxygen amount in the fuel which enhanced the heating value of the fuel. Moreover, pretreatment enhanced pellet density, impact resistance, and abrasive resistance of pellet. However, small degradation in ash fusion characteristics and char reactivity was also observed as the severity of the process increased.     

Fuel characteristics of agropellets fabricated with rice straw and husk

Our aim was to identify the potential of rice straw (RS) and rice husk (RH) as raw materials for pellet production. Compared to woody biomass, RS and RH can be easily dried, but contain significant levels of ash. Higher heating values of oven-dried RS and RH are slightly lower than those of commercial wood pellets. RS and RH contain substantially more silicon, potassium and calcium than larch sawdust. However, ash and moisture contents of RS was significantly reduced following a 15-week exposure period on rice paddy. These results suggest that RS and RH present suitable alternatives to wood as raw materials for pellet production due to their availability, relatively high calorific value and low moisture content. The durability of RS and RH pellets improved steadily with increasing pelletizing temperature and time. Pelletization under appropriate conditions also enabled the durability and bulk density of RS and RH to be improved, enhancing their potential as alternative combustion fuels.