Monday, September 9, 2019

The Solvay process for sodium carbonate Research Paper

The Solvay process for sodium carbonate - Research Paper Example n) whereby sodium bicarbonate NaHCO3 precipitates and converts to sodium carbonate (Na2CO3) while both carbon dioxide (CO2) and water (H2O) are liberated as gases. This paper critically investigates the thermodynamics of final reaction of the Solvay process (calcination step) during the industrial production of sodium carbonate. The thermal decomposition of sodium bicarbonate NaHCO3 (commonly known as calcination reaction) normally involves heating Sodium hydrogen carbonate to temperatures above 80Â °C. Although the calcinations reaction normally takes place at temperatures of or above the thermal decomposition of the reactant, it occurs below the melting point of the product material. Calcination is the last step in the production of soda ash. The process begins with an aqueous solution of sodium chloride which is introduced into ammonia followed by carbonization. The ammonium carbonate produced (NH4HCO3) then reacts with NaCl to produce Sodium carbonate (NaHCO3) and ammonium chloride (NH4Cl). The result is heated to release carbon dioxide (CO2) which is the recycled. The calcinations process as mentioned before receives NaHCO3 and produce Na2CO3 carbon dioxide and water (Barner & Scheuerman, 2012).The bicarbonate then undergoes a dehydration reaction in which it gradually breaks down into sodium carbonate, water and carbon dioxide as shown below: The decomposition of NaHCO3 depends on a number of factors. The pressures at which the carbon dioxide and water are taken back play a big role. It has been reported that the decomposition occurs at 270oC on the higher side and as low as 38oC in one research. The decomposition is crucial in pore formation of sodium carbonate. In most researches the decomposition temperature was set between 121oC and 149oC for optimized conditions. The largest specific area was reported to occur between the temperatures of 204oC and 316oC in a draft oven. The activation energy is higher than 3kcal/mole in diffusion controlled processes

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