Application of Response Surface Method for Optimization of Biodiesel Production Directly from Wet Microalgae Assisted by Radio Frequency Heating

Abstract The emerging paradigms of Beyond-5G, 6G and Super-IoT will demand for Radio Frequency (RF) passive components with pronounced performance, and RF-MEMS technology, i.e. Microsystem-based RF passives, is a good candidate to meet such a challenge. As known, RF-MEMS have a complex behavior, that crosses different physical domains (mechanical; electrical; electromagnetic), making the whole design optimization and trimming phases particularly articulated and time consuming. In this work, we propose a novel design optimization approach based on the Response Surface Method (RSM) statistical methodology, focusing the attention on a class of RF-MEMS-based programmable step power attenuators. The proposed method is validated both against physical simulations, performed with Finite Element Method (FEM) commercial software tools, as well as experimental measurements of physical devices. The case study here discussed features 3 DoFs (Degrees of Freedom), comprising both geometrical and material parameters, and aims at optimizing the RF performance of the MEMS attenuator in terms of attenuation (S21 Scattering parameter) and reflection (VSWR – Voltage Standing Wave Ratio). When validate, the proposed RSM-based method allows avoiding physical FEM simulations, thus making the design optimization considerably faster and less complex, both in terms of time and computational load.

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Optimization of Lipid Extraction from Municipal Scum Sludge for Biodiesel Production Using Statistical Approach

International Journal of Renewable Energy Development ◽

10.14710/ijred.6.2.171-179 ◽

2017 ◽

Vol 6 (2) ◽

pp. 171 ◽

Cited By ~ 3

Author(s):

Samir Hag Ibrahim ◽

Emad Hamza

Keyword(s):

Response Surface ◽

Response Surface Method ◽

Design Of Experiment ◽

Statistical Approach ◽

Lipid Extraction ◽

Biodiesel Production ◽

Box Behnken Design ◽

Steepest Ascent ◽

Screening Design ◽

Surface Method

Design of Experiment (DoE) as a statistical method was applied for optimizing lipid extraction conditions from scum sludge. Four different extraction variables were optimized namely methanol to hexane ratio (%), solvent to sludge ratio (ml/g), temperature (oC), and extraction time (h). Process optimization was conducted through three main steps: 1) 2k factorial screening design; 2) Steepest ascent method; and 3) Box-Behnken design and response surface method. Based on 2k factorial screening design, methanol to hexane ratio, solvent to sludge ratio and temperature were identified as highly significant variables affecting lipid extraction from scum sludge. Based on screening results, the steepest ascent method was used followed by Box-Behnken design and Response Surface Method (RSM) were then applied for optimization. The maximum extracted lipid of 29.4% (wt lipid/wt dry sludge- %) was achieved at 40% methanol to hexane ratio (%), 40 solvent to sludge ratio (ml/g), 90oC and 6 hours extraction time. The results revealed that lipid extraction increases with reducing the methanol to hexane ratio, increasing solvent to sludge ratio and increasing temperature The results demonstrated the potentiality of scum sludge for biodiesel production from scum sludge compared with the amount of lipid extracted from primary and secondary sludge reported by other studies. Keywords: Box-Behnken design, Design of Experiment (DoE), lipid extraction, Scum sludge, response surface method (RSM). Article History: Received Feb 16th 2017; Received in revised form May 5th 2017; Accepted June 4th 2017; Available onlineHow to Cite This Article: Ibrahim, S.N.H, and Hamza, E.A. (2017). Optimization of Lipid Extraction from Municipal Scum Sludge for Biodiesel Production Using Statistical Approach. International Journal of Renewable Energy Development, 6(2), 171-179.https://doi.org/10.14710/ijred.6.2.171-179

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