Energy efficiency improvement of cane sugar factories by drying of bagasse with superheated steam

Abstract

Bagasse drying with superheated steam offers the advantage of producing approximately 15% more power than with a conventional co-generation plant. Based on a fibre content of 14% on cane a power export of up to 140 kWh/t cane is achievable compared to 122 kWh/t cane in case of a conventional highly efficient co-generation plant. The operational results of a 12 t/h bagasse drier in Australia are briefly described and a concept of integrating a bagasse steam drier system in a modern highly energy efficient cane sugar plant is explained. This encompasses changes in the boiler capacity, turbogenerators and evaparation plant lay-out. Based on power export prices in the range of USD50–85/MWh the payback period of a bagasse steam drier system can be estimated with 3–6 years.

Experimental efficiency analysis of sugarcane bagasse boilers based on the first law of thermodynamics

“…In their analysis of the influence of this effect, Sosa-Arnao and Nebra [21] proposed a solution involving drying the bagasse with the boiler exhaust gases, an approach that was implemented in the Goiana sugar factory, as reported in [22]. An alternative solution based on drying the bagasse with superheated steam is analysed in [23], considering the influence of increasing steam consumption in factory cogeneration systems.…”