IMPROVING ENERGY EFFICIENCY AND SUSTAINABILITY OF INDUSTRIAL THERMAL DRYING SYSTEMS USING SIMPROSYS SOFTWARE

Industrial thermal drying plays a major role in many industries such as the food, pharmaceutical, chemical and mineral processing. Thermal drying process is highly energy intensive. In developed countries, up to one fifth of the rational industrial energy consumption goes into thermal drying operations. With industrial drying efficiencies ranging only from 30 to 60 percent, there is great potential for improvement. The aim of this work is to present different options for improving dryer energy efficiency for two cases, viz., coal drying and spray drying of sodium palconate using a new software package entitled "Simprosys" (http://www.simprotek.com). This is accomplished by recovering heat from exhaust streams from the dryer. Through Simprosys simulation, the use of recycling exhaust air from dryer or recycling a part of dried material back into the dryer enables one to improve the energy efficiency of a drying system. However, recovering heat from exhaust air to preheat the fresh air results in significant increase in the energy efficiency in case of a coal drying system. Another way of improving sustainability is the use of renewable sources of energy for air heating which is also analyzed using Simprosys. The spray drying flow sheet was analyzed in the same fashion with similar conclusions. The main advantage of Simprosys is that it allows rapid evaluation of alternate flowsheets to evaluate and optimize overall energy efficiency and sustainability.