Document Type: Research Paper
Membrane Industry Development Institute, Tehran, Iran
Amirkabir University of Technology
Sharif University of Technology
amirkabir university of technology
Department of Chemical Engineering, Faculty of Petroleum and Chemical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
In this work, sweeping gas membrane distillation (SGMD) process was used for concentrating of glucose syrup. The main questions in this work include: is SGMD process practical for concentrating of glucose solution prior the fermentation step in bioethanol process?, and are the commercially available hydrophobic membranes sufficient enough to develop the SGMD process in pilot scale for this issue?. To answer these questions, SGMD process was performed using three commercial membranes made of PP, PVDF and PTFE. All membranes characterized using scanning electron and atomic force microscopes for their morphological and topographical features. Important operating parameters including feed temperature (45-65 oC), feed flow rate (400-800 mL/min), feed concentration (10-50 g/L), and gas flow rate (0.113-0.453 Nm3/h) were studied for their effects on the permeate flux and the optimized parameters were then reported. Moreover, the influence of three flow arrangements of SGMD module (co-current, counter-current and cross-current) on the permeate flux was studied. The best performance (the highest permeate flux and rejection) was achieved when the PTFE membrane (0.22 µm) was used under the optimum operating conditions (feed temperature: 65 oC; feed flow rate: 600 mL/min; gas flow rate: 0.453 Nm3/h; feed flow channel depth: 2 mm; and the cross-current flow arrangement). Results indicated that SGMD process is a promising option for concentrating of the sugar syrup prior the fermentation step in the bioethanol production process.