尿素装置与多套三胺的联产

对常压法和高压法三聚氰胺装置与水溶液全循环法尿素装置联产方式进行了介绍,重点对常压法三聚氰胺装置与尿素装置联产时三胺厂甲铵液的3种处理方案进行了分析比较,确定选用中压解吸装置进行处理方案更为合适。对尿素装置与多套三胺装置联产过程中出现的问题及所进行的优化、改造进行了讨论。     

浅析二甲苯装置节能优化

二甲苯装置具有工艺流程复杂、能耗高等特点,在实际的应用过程中能耗大,造成了严重的能源浪费。对二甲苯装置进行用能情况、装置换热网络、装置低温热进行了系统的分析研究,根据实际情况进行了二甲苯装置的用能改造,提高了二甲苯装置的能源利用率,提高了经济效益。     

三聚氰胺与尿素联产工艺及技术改造

河南省中原大化集团有限责任公司采用联产技术对三聚氰胺尾气进行回收,并对原尿素装置进行改造,新增了11万t/a尿素生产装置,并配套增设了尿素水解装置、OAT水解装置、碳铵液回收装置和尿素熔化装置。各装置彼此联系,又相对独立,充分发挥了尿素装置和三聚氰胺装置的联产优势,降低了三聚氰胺的生产成本,确保了污染物的达标排放。     

从聚酯装置与下游装置的衔接分析其经济规模

从剖析聚酯切片的制造成本、强调聚酯装置与下游装置的衔接、借鉴国外聚酯装置的建设经验三个方面进行了分析。提出聚酯装置能力应和下游装置能力相匹配 ,一并进行建设 ,才能取得最佳经济效益。单纯增大装置的规模 ,并不能有效提高建设的经济效益     

复合胎面挤出生产线的改造

为提高挤出胎面质量,对胎面挤出生产线的进料装置、温控装置、贴合装置、冷却装置、裁断装置、吹分装置、分检装置和存放装置进行全面改造,取得了良好的效果。     

对炼油厂常减压装置节能新技术的探讨

炼油厂的常减压装置还应进行系统的节能,通过对炼油厂中常减压装置特点分析,由此常减压装置的节能技术的研究和探讨,从整体上的进行常减压装置节能,同时也从操作层面上研究装置的节能新技术。     

标准表法气体流量标准装置的研制

在分析标准表法气体流量标准装置基本工作原理的基础上对装置结构进行了设计,重点对装置管道压力损失进行了分析计算,对风机选型进行了分析,对装置整体不确定度分配进行了计算,并确定了标准表、温度传感器和压力传感器的选型方案。给出了对装置进行流量稳定性测试及仪表检定实验的结果。对标准表法流量标准装置的普及应用及对流量计研究水平的整体提高有重要意义。     

三甘醇清洗在聚酯装置中的应用

通过对聚酯装置开车前进行三甘醇清洗,摸索出装置在停车后对反应釜进行三甘醇清洗的操作步骤及注意事项,提出了装置的改进方向。装置进行TEG清洗后,提高了熔体品质,降低了排废量。     

结合氧氯化装置实际生产情况谈改造对策

对氧氯化装置的生产原理及工艺流程进行了介绍,同时对氧氯化装置实际运行过程中应注意的问题进行分析,根据氧氯化装置的实际生产情况对其进行改造,并对改造后的氧氯化装置的效果做出阐述。     

催化裂化装置的节能改造及运行分析

催化裂化装置耗能量在整个炼油生产装置耗能总量中占有非常大的比重,所以,对催化裂化装置进行节能改造意义重大。如何对催化裂化装置实现节能改造也是炼化企业中必须解决的问题。某炼化厂对催化裂化装置进行节能改造以后,取得了显著的成果,本文主要是对该催化裂化装置耗能大的原因进行认真分析,把节能前后的各项耗能数据进行对比,并提出进一步的节能改造方案。     

芳香油与油脂植物资源教学实践

精油与油脂分别是芳香油植物和油脂植物提取的天然产品.通过芳香油与油脂植物资源教学实践,探求植物资源学课程适宜的教学内容与方法.从专业特色角度出发,除了讲授常规植物资源总论和植物资源各论,增加了森林植物资源学和植物资源学课内实践（实验）等相关内容,加强学生实践技能培养,提升本科生综合素质.     

Cholesterol-lowering activity of plant sterol-egg yolk lipoprotein complex in rats

Free plant sterols cannot be dissolved in oil or water. Using free plant sterols and egg yolks, we developed a plant sterol-egg yolk lipoprotein complex (PSY) that can be dispersed in water and considered suitable for use in processed foods. The cholesterol-lowering activity of PSY was equal to that of free plant sterols and plant sterol esters. Consumption of a freeze-dried PSY-containing omelet reduced serum and hepatic cholesterol concentrations. The results suggest that PSY has cholesterol-lowering activity equivalent to that of free plant sterols and plant sterol esters. Moreover, the cholesterol-lowering activity of PSY was maintained in processed foods.     

Fish oil fatty acid esters of phytosterols alter plasma lipids but not red blood cell fragility in hamsters

In an attempt to combine the hypocholesterolemic properties of plant sterols with the hypotriglyceridemic action of fish oil FA, plant sterols have recently been esterified to fish oil n−3 PUFA. The objective of this study was to determine the effects of plant sterols esterified to n−3 PUFA on plasma lipid levels and erythrocyte fragility. For 5 wk, male Golden Syrian hamsters were fed diets varying in cholesterol and plant sterol content: (i) Noncholesterol (semipurified diet with no added cholesterol or plant sterols) (ii), Cholesterol (0.25% cholesterol) (iii), Sterols (0.25% cholesterol plus 1% nonesterified plant sterols), or (iv) Fish oil esters of plant sterols (0.25% cholesterol plus 1.76% EPA and DHA sterol esters, providing 1% plant sterols). The addition of fish oil esters of plant sterols to the cholesterol diet decreased (P=0.001) plasma total cholesterol levels by 20%, but nonesterified plant sterols did not have such a beneficial impact. In addition, non-HDL cholesterol concentrations were 29% lower in hamsters fed fish oil esters of plant sterols than in hamsters fed nonesterified plant sterols (P<0.0001). Despite higher (P<0.0001) plant sterol levels in whole erythrocytes of hamsters fed nonesterified plant sterols and fish oil esters of plant sterols compared with hamsters fed no plant sterols, no difference was observed in erythrocyte fragility. The present results show that EPA and DHA esters of plant sterols have a hypocholesterolemic effect in hamsters, and that these new esters of plant sterols exert no detrimental effect on erythrocyte fragility.     

Comparative health effects of margarines fortified with plant sterols and stanols on a rat model for hemorrhagic stroke

There is increased acceptance of fortifying habitual foods with plant sterols and their saturated derivatives, stanols, at levels that are considered safe. These sterols and stanols are recognized as potentially effective dietary components for lowering plasma total and LDL cholesterol. Our previous studies have shown that daily consumption of plant sterols promotes strokes and shortens the life span of stroke-prone spontaneously hypertensive (SHRSP) rats. These studies question the safety of plant sterol additives. The present study was performed to determine whether a large intake of plant stanols would cause nutritional effects similar to those seen with plant sterols in SHRSP rats. Young SHRSP rats (aged 26–29 d) were fed semipurified diets containing commercial margarines fortified with either plant stanols (1.1 g/100 g diet) or plant sterols (1.4 g/100 g diet). A reference group of SHRSP rats was fed a soybean oil diet (0.02 g plant sterols/100 g diet and no plant stanols). Compared to soybean oil, both plant stanol and plant sterol margarines significantly (P<0.05) reduced the life span of SHRSP rats. At the initial stages of feeding, there was no difference in the survival rates between the two margarine groups, but after approximately 50 d of feeding, the plant stanol group had a slightly, but significantly (P<0.05), lower survival rate. Blood and tissue (plasma, red blood cells, liver, and kidney) concentrations of plant sterols in the plant sterol margarine group were three to four times higher than the corresponding tissue concentrations of plant stanols in the plant stanol group. The deformability of red blood cells and the platelet count of SHRSP rats fed, the plant sterol margarine were significantly (P<0.05) lower than those of the plant stanol margarine and soybean oil groups at the end of the study. These parameters did not differ between the soybean oil and plant stanol margarine groups. These results suggest that, at the levels tested in the present study, plant stanols provoke hemorrhagic stroke in SHRSP rats to a slightly greater extent than plant sterols. The results also suggest that the mechanism by which plant stanols shorten the life span of SHRSP rat might differ from that of plant sterols.     

Coupling of dry matter and nitrogen accumulation in ryegrass

The logistic model has proven very useful in relating dry matter production of warm season perennial forage grasses to applied nitrogen. A recent extension of the model coupled dry matter and plant N accumulation through a common response coefficient c. The objective of this analysis was to apply the extended logistic model to cool season Gulf annual ryegrass (Lolium multiflorum Lam.) and to establish a common response coefficient c between accumulation of dry matter and plant N. Analysis of variance established the validity of this hypothesis. The model accurately described response of dry matter, plant N removal, and plant N concentration to applied N, with an overall correlation coefficient of 0.9954. Furthermore, the model closely described the relationship between yield and plant N removal, as well as between plant N concentration and plant N removal. The logistic equation is well-behaved and simple to use on a pocket calculator. It can be used to estimate yields and plant N removal in evaluation of agricultural production and environmental quality.     

三聚氰胺装置与大尿素装置联产改造

河南煤业化工集团中原大化公司的尿素装置与三聚氰胺装置联产后,由于大量甲铵返回,造成系统的能耗和物耗大幅上涨。经过对系统进行分析和计算,制定了改造方案,进而实现了尿素装置高负荷、安全和经济的运行。     

植物纤维增强混凝土研究进展

随着我国“双碳”战略的持续推进,绿色低碳环保的天然纤维在水泥基材料中的应用已成为建筑行业的研究热点,得到了广泛关注。但植物纤维的力学性能差,同时存在老化和粘结力减弱等问题,很难直接应用于混凝土基体。本文综述了植物纤维的微观结构和性能,植物纤维对混凝土力学性能、耐久性和热物理性能等宏观性能的影响,植物纤维增强混凝土凝结时间、界面粘结和内养护的微观演变机制。讨论了植物纤维增强混凝土中基体改性和纤维改性的方法,深入了解不同方法的作用机理,寻求更加有效地改善性能的途径。剑麻纤维和竹纤维对混凝土性能有良好的提升作用,应用最为广泛。最后展望了植物纤维的可持续发展方向,为今后进一步研究植物纤维增强混凝土提出参考建议。     

草木灰促进CaO粉末高温烟气脱硫实验研究

为了研究草木灰添加剂对氧化钙脱硫性能的影响,用HSC5分析了在200~1 000℃的温度范围内草木灰对氧化钙脱硫过程的改善,分别以CaO和CaO与草木灰的混合物为吸收剂进行实验,并加以比较。研究了加入草木灰添加剂后,对高温烟气脱硫性能和固定床干法烟气脱硫最佳温度的影响,草木灰配比对氧化钙脱硫性能的影响等。结果表明,加入一定量的草木灰,可以显著提高脱硫效率和钙利用率。当温度在800~900℃时,草木灰与氧化钙的配比为10∶100时效果最好,脱硫效率可达96.2%,钙利用率57%。     

植物精油的生物活性及其在有害生物控制上的应用

植物精油是一类广泛应用于食品、医药、化妆品的植物次生代谢物,很多精油具有杀虫、抗菌活性.就植物精油在有害生物控制上的应用,简要概述了植物精油的杀虫、杀菌活性及精油在有害生物防治中的可能用途和经济可行性.     

Comparison of corrosion and scaling behaviour of two acid - dosed seawater distillation plants

Probe and coupon measurements in the Hong Kong MSF plant, which employs external feed deaeration and scavenging, have shown lower carbon steel corrosion rates than in the Jersey plant where no external deaeration is provided. This difference is partly due to the persistent need in the latter plant to remove fouling by acid cleaning, which has not been required in Hong Kong. Even when this additional corrosion is allowed for, the Hong Kong plant appears to enjoy a carbon steel corrosion rate significantly lower than that of the Jersey plant. The extent to which these differences may be due to the method and degree of deaeration and the resulting mechanisms of corrosion are discussed.