Catalytic cracking flue gas desulfurization wastewater flocculant

　　Catalytic cracking flue gas desulfurization wastewater flocculant is a specialized composite flocculant developed for desulfurization wastewater from catalytic cracking units in oil refineries.It is primarily used for the efficient removal of suspended solids from wastewater while avoiding the corrosion and clogging problems associated with traditional flocculants.

　　Typical components include:

　　1.High-molecular-weight organic flocculants:triethanolamine,hydroxyethylidene diphosphonic acid,JQL01 type chitosan quaternary ammonium salt,ethylene glycol and fatty alcohol polyoxyethylene ether(JFC),etc.

　　2.Inorganic flocculants:a mixture of aluminum sulfate and ferrous sulfate.

　　Core functions of catalytic cracking flue gas desulfurization wastewater flocculant:

　　1.Highly efficient removal of suspended solids:Under conditions of pH 6.5-8.0,suspended solids concentration of 1000-5000 mg/L,and water temperature of 45-60℃,after adding 300-500 mg/L of flocculant,the suspended solids in the effluent can be reduced to below 60 mg/L,with a removal rate exceeding 98%.2.Adaptable to Complex Water Quality:Targeting the high chlorine content and high organic matter content of desulfurization wastewater,a chloride-free formula is used to avoid equipment corrosion and filter clogging.

　　Characteristics:

　　1.High Suspended Solids:The flocculant for catalytic cracking flue gas desulfurization wastewater contains a large amount of fine catalyst dust and desulfurization products.

　　2.High COD:Mainly from incompletely burned hydrocarbons and reducing inorganic substances such as sodium thiosulfate and sodium sulfite produced during the desulfurization process.

　　3.Complex Composition:May contain toxic and harmful substances such as heavy metals,cyanides,and polycyclic aromatic hydrocarbons.

　　4.Large Fluctuations in Water Quality:Varies with changes in FCCU operating conditions and desulfurization process parameters.

　　5.High Colloidal Stability:The fine catalyst particles form a stable colloidal system in the water,making them difficult to settle naturally.

　　Working Principle and Mechanism of Flocculants for Catalytic cracking flue gas desulfurization wastewater flocculant:

　　1.Double Layer Compression:High-valence positive ions enter the surface of colloidal particles through electrostatic attraction,displacing low-valence positive ions,thinning the double layer,and causing aggregation when the potential drops to the critical potential.

　　2.Adsorption-Electrochemical Neutralization:Opposite-charged ions or polymers adsorbed on the surface of colloidal particles neutralize some of the charge,reducing electrostatic attraction.

　　3.Adsorption Bridging:Long-chain polymers form"bridges"between multiple particles,promoting the aggregation of small particles into larger particles.

　　4.Netting-Sweeping:The hydrolysis products of the flocculant form a network structure,sweeping away particles in the water for co-settling.

　　Key Precautions:

　　1.Beaker experiments are an absolute prerequisite:Catalytic cracking flue gas desulfurization wastewater flocculant The quality of FCC desulfurization wastewater varies greatly under different refineries and operating conditions.Before selecting the reagent and dosage,systematic beaker experiments must be conducted to optimize the appropriate combination and cost.

　　2.Reagent Preparation and Dosing:Dissolving PAM is crucial.It must be added slowly and evenly using clean water,ensuring sufficient stirring time and intensity(usually≥40 minutes).

　　3.Sludge Treatment:The generated sludge contains catalysts and other substances,which have recycling value.During the sludge dewatering stage of catalytic cracking flue gas desulfurization wastewater flocculant(such as when using plate and frame filter presses or centrifuges),a small amount of CPAM is typically added as a sludge dewatering agent to improve dewatering efficiency and cake solids content.