Energy consumption evaluation of fuel bioethanol production from sweet potato

The energy consumption for different operative conditions and configurations of the bioethanol production industrial process from an experimental variety of sweet potato (Ipomea batatas) K 9807.1 was evaluated. A process simulation model was developed using Super Pro Designer (R) software. The model was based on experimental data gathered from our laboratory experiments and technology and equipment suppliers. The effects of the dry matter ratio of sweet potato to water, the fermentation efficiency, and sweet potato sugar content, on the energy consumption (steam and electricity) were respectively evaluated. All factors were significant. The best ratio of dry matter to total water to work with fresh sweet potato was 0.2 kg dry sweet potato/kg water, as for greater ratios was not found a significant reduction in energy consumption. Also, the drying of the sweet potato previous its processing was studied. It presented an energy consumption greater than the energetic content of the bioethanol produced. (C) 2013 Elsevier Ltd. All rights reserved.