Abstract-This paper discusses about possible configurations to improve the process with reduction of re-boiler energy demand. The simulations are performed in the Aspen Plus process simulation tool to check the required re-boiler duty. In the new model configuration, the rich solvent to the stripper is split using splitter block and supplied to the stripper section. The re-boiler duty for 85%, 90% and 95% removal efficiency cases are calculated for new model configuration and it is 3255, 3360 and 3614 kJ/kg CO 2 respectively. This is around 10% reduction of re-boiler duty compare to the conventional process.

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The crude glycerol produced as a byproduct of transesterification synthesis has very few applications because it comprises of significant amounts of methanol, catalyst, and soap. On the other hand, transesterifications of highly acidic oil in the presence of an alkaline catalyst are problematic due to the presence of high amounts of free fatty acids. In this study, the free fatty acid level of high acid oil, which was initially determined to be 19.25%, was decreased to permit the direct production of biodiesel via glycerolysis with pure glycerol, making direct transesterification feasible. Through a process of purification, crude glycerol was refined to 92.5% purity. It was revealed that the physiochemical parameters of density, moisture content, ash content, matter organic non-glycerol content, pH, and Na/K concentrations of generated purified glycerol are equal to those of commercially available glycerol. In contrast, glycerolysis treatment successfully decreased the free fatty acid level to less than 2% under optimal conditions, which were determined to be 200 °C, a glycerol-to-oil molar ratio of 4:1, and a KOH catalyst concentration of 1.6 wt.% at 350 rpm. The inclusion of hexane as a co-solvent accelerated the glycerolysis process, and the weight ratio of oil-to-hexane was 8:1. Moreover, it was viable to use waste methanol for biodiesel synthesis and purified crude glycerol as a raw material in a variety of industries, including biodiesel production. In addition, compared to acid esterification, the FFA concentration of oil with a high acid value fell significantly.

Biodiesel is an excellent substitute for fossil diesel, which received a significant attention in recent decades. Catalyst methods are frequently used to produce biodiesel at low temperatures and pressures. The present work investigates the methanolysis of waste cooking oil with the acid value of 1.86 mg KOH/g employing a variety of homogeneous base catalysts, including KOH, NaOH, CH3OK and CH3ONa. Among the studied catalysts, CH3OK produced the highest biodiesel yield at 99.0%, followed by CH3ONa, KOH and NaOH under the identical reaction conditions. The reaction was carried out for 30 min at 600 ºC and a speed of 600 rpm with a molar ratio of 6:1 for methanol-to-waste cooking oil (WCO) and a 1 wt.% catalyst. However, the viscosity, flash point, density and acid value of the biodiesel all met ASTM criteria, indicating that biodiesel made from KOH, NaOH, CH3OK and CH3ONa is of high quality.

Bioenergy, which originated from agricultural crop residue and industrial waste, has been studied for sustainable energy generation. As a raw material for briquettes production, agricultural-crop residue, industrial waste, sewage, sludge, or other plants can be used. Briquettes have numerous advantages as they directly help to reduce waste generation and handling. The possibilities of the briquetting, qualities, and other essential factors for briquette production have been discussed. The alternative methods of Briquetting have been addressed with the comparison. The characteristics of the raw materials for briquettes production have been discussed to identify the best agricultural crop residue for briquettes. The properties of binding agents for the briquetting process have been discussed to identify the most practically available binding agent.