scholarly journals Coprocessing consortium - year 1 progress report - sub-unit 06 integrated two stage process development

1991 ◽  
Author(s):  
J F Kelly ◽  
P Rahimi
Keyword(s):  
Process Development ◽  
Progress Report ◽  
Two Stage ◽  
Stage Process

scholarly journals Two-Stage Biodiesel Synthesis from Used Cooking Oil with a High Acid Value via an Ultrasound-Assisted Method

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3703
Author(s):  
Ming-Chien Hsiao ◽  
Wei-Ting Lin ◽  
Wei-Cheng Chiu ◽  
Shuhn-Shyurng Hou
Keyword(s):  
Acid Value ◽  
Molar Ratio ◽  
Optimal Conditions ◽  
Two Stage ◽  
Cooking Oil ◽  
High Acid ◽  
Used Cooking Oil ◽  
Biodiesel Synthesis ◽  
Stage Process ◽  
Ultrasound Assisted

In this study, ultrasound was used to accelerate two-stage (esterification–transesterification) catalytic synthesis of biodiesel from used cooking oil, which originally had a high acid value (4.35 mg KOH/g). In the first stage, acid-catalyzed esterification reaction conditions were developed with a 9:1 methanol/oil molar ratio, sulfuric acid dosage at 2 wt %, and a reaction temperature of 60 °C. Under ultrasound irradiation for 40 min, the acid value was effectively decreased from 4.35 to 1.67 mg KOH/g, which was decreased to a sufficient level (<2 mg KOH/g) to avoid the saponification problem for the subsequent transesterification reaction. In the following stage, base-catalyzed transesterification reactions were carried out with a 12:1 methanol/oil molar ratio, a sodium hydroxide dosage of 1 wt %, and a reaction temperature of 65 °C. Under ultrasound-assisted transesterification for 40 min, the conversion rate of biodiesel reached 97.05%, which met the requirement of EN 14214 standard, i.e., 96.5% minimum. In order to evaluate and explore the improvement of the ultrasound-assisted two-stage (esterification–transesterification) process in shortening the reaction time, additional two-stage biodiesel synthesis experiments using the traditional mechanical stirring method under the optimal conditions were further carried out in this study. It was found that, under the same optimal conditions, using the ultrasound-assisted two-stage process, the total reaction time was significantly reduced to only 80 min, which was much shorter than the total time required by the conventional method of 140 min. It is worth noting that compared with the traditional method without ultrasound, the intensification of the ultrasound-assisted two-stage process significantly shortened the total time from 140 min to 80 min, which is a reduction of 42.9%. It was concluded that the ultrasound-assisted two-stage (esterification–transesterification) catalytic process is an effective and time-saving method for synthesizing biodiesel from used cooking oil with a high acid value.

scholarly journals Food behavior change in late-life widowhood: A two-stage process

Appetite ◽  
2015 ◽  
Vol 95 ◽  
pp. 399-407 ◽  
Author(s):  
Elisabeth Vesnaver ◽  
Heather H. Keller ◽  
Olga Sutherland ◽  
Scott B. Maitland ◽  
J.L. Locher
Keyword(s):  
Behavior Change ◽  
Late Life ◽  
Food Behavior ◽  
Two Stage ◽  
Stage Process

High-efficiency CuInSe2 solar cells prepared by the two-stage process

Solar Cells ◽  
1989 ◽  
Vol 27 (1-4) ◽  
pp. 299-306 ◽  
Author(s):  
Bulent M. Basol ◽  
Vijay K. Kapur ◽  
Richard C. Kullberg
Keyword(s):  
Solar Cells ◽  
High Efficiency ◽  
Two Stage ◽  
Stage Process
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