Application Of PAN-based Carbon Fiber In Desulfurization And Denitration Seawater Recovery System

Carbon fiber（CF）is widely used in electrochemical capacitors and otherlarge-scale energy storage device of electrode materials, while some of the surfacetreatment of etching the surface of the carbon fibers，introducing large amount ofoxygen and nitrogen functional groups in the carbon fiber surface, which can not onlyimprove the specific surface area of carbon fiber, but also increase the surface activityof the carbon fiber.In this paper, polyacrylonitrile (PAN) based CF electrode were modified usingrecurrent galvanic pulses technique and the activated carbon electrodes with highperformance were prepared therefore. Its electro-catalytic properties were studied byelectrochemical testing methods such as cyclic voltammetry and chronoamperometry.Besides, a preliminary study of the electro-catalytic activity of PAN-CF electrodeused for seawater desulfurization recovery system and power plant desulfurizationdesulfurization, denitrification and mercury integration process absorbs the liquidbyproduct ammonium nitrite.In this paper, the results were obtained as following:(1) Cyclic voltammetry curves show that, MPAN-CF wire beam electrode forSO32-of NaCl solution containing different concentration of Na2SO3, its startingoxidation potential than before modification is obvious negative, it has more obviouselectric catalytic activity of SO32-anodic oxidation than before modified PAN-CFelectrode.(2) The original recovery system seawater desulfurization has large aeration,and the drainage pH and the higher energy consumption problem of COD standard, soelectrochemical-chemical compound oxidation treatment method (MPAN-CF brushfor the anode and PAN-CF brush for cathode) is established. In a mixing ratio is1~3:1, a blending ratio is2:1and residence time is2min, oxidation efficiency of SO32-can reach more than90%; After2min composite oxidation treatment continuingaeration2min, SO32-oxidation efficiency increased from91.2%to95%, and the pH value increased from5.91to6.04, chemical oxidation aeration treatment alone after4min SO32-oxidation efficiency is only88%, composite oxide can save a part of theresidence time, continuous aeration can improve the efficiency of SO32-oxidation andpH; A complex blend of seawater through composite oxidation or chemical oxidationaeration alone, and then continue the second mixing, when the secondary blendingratio is0.5:1, pH value is close to drainage index pH=6.8, so this compound oxidationmethod can significantly improve the recovery efficiency of the SO32-oxidativecapacity and pH values.(3) In order to get full use of ammonium nitrite in absorption solution fromflue gas simultaneous deslufurization, denitrification and demercurization process,here the electrochemical oxidation method was used to transform ammonium nitriteinto ammonium nitrate. Constructs PAN based carbon fiber brush for anode, titaniumcathode and0.05mol·L-1NaNO2+0.05mol·L-1（NH4)2SO4（pH=7.0，5L）simulationof the absorption liquid circulation flow electrochemical oxidation electrolytic cell.Under neutral condition,600mA constant current electrochemical oxidation of nitriteion conversion rate of98.1%by22h. Considering the stability of carbon anode andeconomic factors, it is advisable to select16h electrochemical oxidation time, thenitrite ion remaining concentration close to0.01mol·L-1, conversion rate can reach72%.