Calculation and optimization of the copper (II) sulphate monohydrate from copper (II) sulphate pentahydrate production process in a fluidized bed dryer

Abstract

In this paper the process of the copper (II) sulphate monohydrate from copper (II) sulphate pentahydrate (also known as a Blue vitriol or Bluestone) production was analyzed. Copper (II) sulphate pentahydrate is one of the most important copper salts which has been known since the ancient Egyptians. In the nineteenth century its application as a fungicide was discovered which provoked wide industrial production. Molecule of the copper (II) sulphate pentahydrate is a crystalohydrate with five water molecules linked by chemical bonds to a molecule of the copper (II) sulphate. Copper (II) sulphate exists as a series of compounds that differ in their degree of hydratation. The anhydrous form is a pale green or gray-white powder, whereas the pentahydrate (CuSO4∙5H2O), the most commonly encountered salt, is bright blue. In order to obtain copper (II) sulphate monohydrate from copper (II) sulphate pentahydrate, it is necessary to remove four water molecules. To determine the optimum temperature and time required for the removal of four water molecules from a molecule of pentahydrate in this work thermogravimetric (TGA) analysis was performed. Thermogravimetric (TGA) analysis - dehydration of copper (II) sulphate pentahydrate is done using simultaneous TG-DSC thermal analyzer DTG-Q600 SDT from TA Instruments. Analysis was carried out for two types of samples, the samples containing particles of the average diameter equal to 0.17 mm and the particles of the average diameter 0.5 mm. In addition, fluidization and drying curve were determined using a semiindustrial fluidization column. On the top, the industrial fluidization column, aimed to produce 300 tonnes per month of copper (II) sulphate monohydrate, was designed. Material and energy calculations were performed using software packages Simprosys 3.0 and SuperPro Designer 5.1. Simprosys 3.0 is a software package designed for the modeling and simulation of a drying process, as well as for 20 different unit operations. SuperPro Designer 5.1 facilitates modeling, evaluation and optimization of different industrial processes including drying. These software packages were applied for the calculation of the air flow rate, heat exchange and for the scoping of a dryer.

U ovom radu analiziran je proces dobijanja bakar(II)-sulfat-monohidrata iz bakar(II)-sulfat-pentahidrata, poznatijeg kao 'plavi kamen', u sušnicama sa fluidizovanim slojem. Bakar( II)-sulfat-pentahidrat je kristalohidrat u čijoj su kristalnoj strukturi četiri molekula vode vezana za bakar(II)-jon dok je peti molekul vode slobodan, tj, vodoničnim vezama povezan za sulfat-anjon. Optimalna temperatura zagrevanja kao i dužina zagrevanja za uklanjanje četiri molekula vode iz molekula pentahidrata utvrđeni su na osnovu termogravimetrijske (TGA) analize. Za analizu su upotrebljene čestice različite granualcije: srednjeg prečnika 0,17 mm i 0,5 mm. U poluindustrijskom postrojenju određene su krive fluidizacije i krive sušenja analiziranih uzoraka. Nakon laboratorijskih i poluindustrijskih eksperimenata izvršeno je materijalno i energetsko bilansiranje realnog postrojenja sa kapacitetom proizvodnje od 300 t mesečno. Proračuni neophodne količine agensa za sušenje i dimenzija postrojenja izvršeni su korišćenjem programskih paketa SuperPro Designer 5.1 i Simprosys 3.0. Takođe, analizirana je i mogućnost recirkulacije agensa za sušenje.