Development Of Scale Inhibitors For Thermal Power Plants And Effects Of Initiators On Their Performance

Thermal power generation water plays an important role in industrial water use.Its cooling water accounts for 70%-80% of the total industrial water consumption.The most effective water saving measure is the recycling water technology.The purpose of this research is to improve the system cycle.Multiples simultaneously reduce scale and corrosion in circulating water.In this study,MA,SSS and HEMA were used as monomers,APS was used as initiator,and tert-butanol was used as molecular regulator.The reaction was carried out by aqueous solution free radical polymerization.The optimal conditions for synthesis were obtained by orthogonal test: the molar ratio of MA,SSS and HEMA was 6:1:0.8,and the molecular regulator t-butanol accounted for 10% of the total monomer.The reaction temperature was 80 ° C.The initiator APS has a total of three gears,5%,10%,and 15%,respectively.The three copolymers MA/SSS/HEMA(APS 5%,10%,15%)are synthesized,and both have good scale inhibition performance.After characterizing the copolymer,it was found that the increase in the amount of the initiator does not change the type of the functional group of the copolymer,but reduces the molecular weight of the copolymer and reduces the carbon chain length of the copolymer.The performance of MA/SSS/HEMA(APS 5%,10%,15%)was characterized by scale inhibition and biodegradation tests.Through the static scale inhibition test,the corrosion and scale inhibitor was tested in a water sample with 5 times of ion concentration,and it was found that MA/SSS/HEMA(APS 5%,10%,15%)was still in the water with a concentration ratio of 5.It can have good scale inhibition performance,that is,it can meet the performance requirements of the circulating water cooling system of thermal power plants with a cycle-by-cycle ratio of 5.Through static scale inhibition test,it is found that with the increase of APS,the molecular weight decreases and the performance gradually increases.Among them,MA/SSS/HEMA(APS 15%)has the best performance.When the dosage is 6mg/L,the water temperature is 80°C.In the calcium carbonate inhibition experiment,the calcium carbonate Ca2+ concentration was 240 mg/L,and the scale inhibition rate was 96%;under the same conditions,the calcium sulfate Ca2+ concentration was 6000 mg/L,and the scale inhibition rate was 95%.It is found that MA/SSS/HEMA(APS 5%,10%,15%)has certain corrosion inhibition performance.With the decrease of APS,the molecular weight increases,the chain grows,and the performance gradually improves.Among them,MA/SSS/HEMA(APS 5%)has the best performance,and the corrosion inhibition rate can reach more than 60%,which has obvious performance advantages over PASP.At the same time,MA/SSS/HEMA(APS 5%,10%,15%)have good biodegradability.The mechanism of scale inhibition and corrosion inhibition of MA/SSS/HEMA(APS 5%,10%,15%)and the effect of initiator on its properties were investigated by GPC and SEM.The results show that the scale inhibition mechanism is mainly It is the following three aspects: chelation of calcium ions,increase of calcium ion solubility;increase of electrostatic repulsion between particles,thereby preventing particles from condensing and growing;can be embedded in the interior of scale-like particles,causing distortion of the lattice of granular particles,hindering It grew up further.The increase of the initiator reduces the molecular weight of the copolymer,shortens the carbon chain length of the copolymer,makes it more easily adsorbed to the scale crystal,hinders its normal growth,and improves the scale inhibition performance.The corrosion inhibition mechanism is mainly the deposition of corrosion current,and a precipitated film with good protection is formed on the surface of the cathode.The copolymer with less initiator,large molecular weight and long carbon chain forms a denser precipitated film and inhibits corrosion.This paper has a total of 39 pictures,12 charts and 125 references.