摘要
针对工业循环水处理系统中使用磷系缓蚀阻垢剂带来的磷排放问题,以马来酸酐和3-巯基丙酸为主要原料,在催化剂作用下应用＂一步法＂合成S-羧乙基硫代琥珀酸（CETSA）无磷缓蚀阻垢剂,通过红外（IR）、核磁共振（13CNMR）等方法对其结构进行了表征。采用碳酸钙沉积法、旋转挂片法对CETSA的阻垢缓蚀性能进行评价,考察了加药量、水温、p H值、水流转速等对CETSA阻垢缓蚀性能的影响。结果表明,当加药量为110 mg/L、循环水温度低于50℃、p H值为6~8、水流转速低于100 r/min时,CETSA对A3碳钢的腐蚀率小于0.25mm/a,最大缓蚀率可达61.3%,最大阻垢率达88.4%。CETSA是一种小分子多羧酸结构,其具有较高的缓蚀阻垢性能可能是因为与水中的钙镁离子发生了螯合,生成了稳定的络合物抑制结垢,同时非极性键、烷基等亲水基吸附于金属表面,电负性较高的O、S元素与Fe产生强吸附,形成的致密保护膜有效抑制了金属腐蚀。经测算,10%水剂的CETSA生产成本约为3 047元/t,总磷减排量可达3~5 g/m3循环水排水。研究表明,CETSA可替代传统磷系缓蚀阻垢剂,适于电力、钢铁、化工、油田等行业的循环冷却水系统。
The paper is aimed to introduce its method for synthesizing the carboxyalkylthiosuccinic acids（ CETSA） by way of maleic anhydride and 3-mercaptopropionic acid in a single step catalysis,so as to get rid of the discharge of phosphorus for the traditional corrosion and the scale inhibition in the industry-purposed water circulation system,characteristic of IR and13 CNMR chelates. In this paper,we have also evaluated the corrosion and the scale inhibition function of CETSA through the calcium carbonate precipitation and the specimen rotation. In order to increase the success rate of our synthesis system,we have also examined the impacts of the sample dose,water temperature and the water flow velocity on the performance. The results of our investigation and experiments have shown that the maximum corrosion inhibition rate tends to reach 61. 3% under the conditions,when the CETSA dosage was 110 mg / L and the water temperature was between30 ℃ and 50 ℃,with the p H value being kept from 6 to 8. What is more,when the rotation rate was less than 100 r / min and the corrosion rate of A3 carbon steel was less than 0. 25 mm / a,the maximum scale inhibition rate could be as high as to reach88. 4%. Since CETSA was a small molecular structure with multi-carboxylic acid,it would be possible for CETSA to have higher corrosion and scale inhibition to chelate calcium ions in the water to form a stable complex chelate. At the same time,the non-polar bond,alkyl and other hydrophilic groups can also be adsorbed onto the metal surface,so as to result in a compact protective film which can also inhibit the metal corrosion due to the strong adsorption function between O,S and Fe. So far as we know,the water-preparation agent in producing 10% of CETSA can be made as high as about 3 047 yuan per ton,it is realistic to replace the traditional phosphorus-based corrosion and scale inhibitor to use recycled water drainage to achieve 3-5 g per cubic meter to the total emission reduction of the phosphorus drainage.Thus,the CETSA synthesis method we have developed in this paper proves to be suitable for the industrial water recirculation system in power industry,iron-steel industry,chemical industry and oil-refinery industry.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2015年第5期209-213,共5页
Journal of Safety and Environment
基金
安徽省科技攻关项目(12010402103)
江苏省科技支撑计划项目(BY2015027-03)
江苏省2013年度普通高校研究生科研创新计划项目(CXZZ13_0737)
关键词
环境工程学
有机化学
S-羧乙基硫代琥珀酸
阻垢
缓蚀
environmental engineering
organic chemistry
carboxyalkylthiosuccinic acids
scale inhibition
corrosion inhibition
