端羧基网状超支化聚合物阻垢性能的研究毕业论文
2020-06-19 21:46:02
摘 要
在工业生产中,冷却水会持续循环使用,由于一些水的蒸发会增加无机盐的浓度,从而导致设备和管道的结垢。由于在高温高离子浓度体系下,磷系阻垢剂难降解,易污染;聚羧酸阻垢剂阻垢率低,生成絮状钙凝胶;天然阻垢剂稳定性差,投加量大。本文引入超支化聚合物三维结构的优势,制备一种高效并且适合用于高温高浓度体系的新型阻垢剂,并以此为基础探究不同条件对新型阻垢剂阻垢效果的影响。
本课题采用扫描电镜和X射线衍射分析方法,表征实验室自制阻垢剂,并观察其性能变化。
实验结果表明:在Ca2 浓度为1500 mg/L,溶液pH为7,温度为70 °C的条件下,投加量为6 mg/L时阻垢率最高;自制阻垢剂适用水体条件为:水温80 °C以下,pH值范围 5~9,钙离子浓度在2700 mg/L以下的水体系;本实验过程中制备的超支化聚合物对成垢晶体生长的阻碍作用效果远远优于市场上大部分销售的阻垢剂,仅仅略低于PASP,这个结果表明自制的阻垢剂超支化聚合物在钙质盐垢中具有很好的应用前景。
实验过程中,在扫描电镜的结果分析下可以得出,伴随着阻垢剂的添加,成垢晶体的垢质变得松软,易于破裂;在观察X射线衍射的衍射光谱我们可以得出,当加入超支化聚合物后,成垢晶体碳酸钙的结晶速度减慢,晶体在结晶过程中受到阻垢剂的抑制作用,导致晶体变小,晶格发生畸变。因此,实验室自制阻垢剂可以实现对硫酸钙的阻垢作用,其阻垢性能也能满足实验要求。
关键词:超支化聚合物;硫酸钙;新型阻垢剂
Study on Scale Inhibition Performance of Carboxyl Terminated Network Hyperbranched Polymer
ABSTRACT
In industrial production, the cooling water will continue to be recycled, due to the evaporation of some water will increase the concentration of inorganic salts, resulting in equipment and pipeline fouling. the phosphorus scale scale inhibitor is difficult to degrade and pollute; the polycarboxylate scale inhibitor has low scale inhibition rate and the formation of flocculent calcium gel; the natural scale inhibitor has poor stability and large dosage. In this paper, the advantages of three-dimensional structure of hyperbranched polymer were introduced to prepare a new scale inhibitor with high efficiency and suitable for high temperature and high concentration system. The effect of different conditions on the scale inhibition of new scale inhibitor was studied.
In this paper, scanning electron microscopy and X-ray diffraction analysis were used to characterize laboratory self-made scale inhibitors and observe their performance changes.
The results showed that the scale inhibition rate was the highest when the dosage of Ca2 was 1500 mg / L, the pH value was 7 and the temperature was 70 °C, and the scale condition was 6 mg / L. Water temperature below 80 °C, pH range of 5 to 9, calcium ion concentration of 2700 mg / L below the water system; The effect of the hyperbranched polymer prepared on the growth of the crystals was much better than that of the commercially available scale inhibitors, which was only slightly lower than that of PASP, The results showed that the self-made scale inhibitor hyperbranched It has a good application prospect in calcareous salt scale.
In the course of the experiment, it can be concluded by the analysis of the results of scanning electron microscopy, With the addition of scale inhibitor, the scale of the scale crystals becomes soft and easy to break; In observing the diffraction spectrum of X-ray diffraction, we can conclude that when the hyperbranched polymer is added, the crystallization rate of the crystalline calcium carbonate is slowed down and the crystal is inhibited by the scale inhibitor during the crystallization process, Lattice distortion occurs. Therefore, the laboratory self-made scale inhibitor can achieve scale inhibition of calcium sulfate, the scale performance can meet the experimental requirements.
Keywords: hyperbranched polymer; calcium sulfate; new scale inhibitor
目 录
摘 要 I
ABSTRACT II
第一章 文献综述 1
1.1结垢机理 1
1.1.1结晶垢形成的热力学原理 1
1.1.2影响结垢的宏观因素 1
1.2阻垢方法 2
1.3阻垢剂的阻垢机理 2
1.3.1螯合增溶作用 3
1.3.2晶格畸变作用 3
1.3.3凝聚分散作用 3
1.3.4再生-自解脱膜假说 3
1.4阻垢剂研究进展 4
1.4.1天然高分子 4
1.4.2人工合成阻垢剂 4
1.5超支化聚合物 4
1.5.1超支化聚合物在阻垢方面的优势 4
1.5.2超支化阻垢剂的研究进展 5
1.6课题提出和研究内容 6
第二章 实验材料及方法 7
2.1实验试剂及仪器 7
2.1.1实验试剂 7
2.1.2实验仪器 7
2.2实验方法 7
2.3表征方法 8
2.3.1阻垢剂固含量测定 8
2.3.2垢样的SEM表征 8
2.3.3垢样的XRD表征 9
第三章 阻垢性能测试及阻垢机理分析 10
3.1端羧基超支化聚合物阻垢性能 10
3.1.1投加量的影响 10
3.1.2 钙离子浓度的影响 11
3.1.3水体pH的影响 11
3.1.4水体温度的影响 12
3.1.5实验室自制阻垢剂与商业阻垢剂对比 13
3.2硫酸钙垢的SEM分析 14
3.3硫酸钙垢的XRD分析 16
第四章 结 论 17
参 考 文 献 18
致 谢 19
第一章 文献综述
近年来,随着我国水资源的短缺、人口数量的增加和工业生产中的迅速发展,用水量也在急剧增大,如何节约用水已经成为人们生活及工业发展的趋势[1]。除了在源头上减少水的使用量,废水排放和循环利用冷却水对于水资源现状也有着重要作用。然而在冷却水循环利用中存在一个很大缺陷,水垢问题。由于大部分工业用水采用地下水,其一般属于高含盐量、高硬度、高碱度的三高水质,在循环利用中水会蒸发,其三高水质得到进一步的提高,水的浓缩导致水中各种离子浓度增大,因而造成了结垢问题[2]。
1.1结垢机理
1.1.1结晶垢形成的热力学原理
各种水系统中均溶有不同的盐类,在其溶液中一般以离子或螯合物状态存在,而在其过饱和状态,即水中可溶性盐浓度超过它的热力学溶度积Ksp,就会生成晶核,晶核继续生长继而得到沉淀[3]。
在工业生产设备的冷却过程中,部分水由于蒸发冷却而被空气带走,因此部分水在系统中丢失。这部分水并没有带走所溶解的固体,而是将它留在循环系统中,使得循环水中的溶解固体物浓度增加,这就是浓缩现象[4]。当重碳酸盐的浓度达到过饱和状态时,或者在经过换热器传热表面使水温升高时[5],会发生下列反应:
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