Simulation of a Palm Fatty Acid Distillate-Based Biodiesel Plant Using Homogeneous and Heterogeneous Catalysts

A continuous biodiesel production process from palm fatty acid distillate (PFAD) is simulated in Aspen Plus for process engineering aspects emphasizing the critical points in the entire process. The production process involves acid-catalyzed hydrolysis of residual glycerides of PFAD to additional free fatty acids (FFAs), followed by esterification of the FFAs with methanol for methyl ester production, biodiesel purification, and finally methanol recovery. A two-phase kinetic model was employed with detailed operating conditions for both, homogeneous and heterogeneous catalysts to design the reactors and critical process units. The operating costs of the process using both catalysts are evaluated

Development of polystyrene adsorbents functionalized with heterocyclic ligands for selective adsorption of CO<inf>2</inf> from CH<inf>4</inf> and N<inf>2</inf>

Equilibrium adsorption studies of CO2, CH4 and N2 were carried out with polystyrene based adsorbent, functionalized with heterocyclic ligands, viz. citrazinic acid (CA), 4-hydroxymethyl pyridine (MP) and 2,6-bis-imidazo-1-yl-pyridine-4-carboxylic acid (BIMP) using batch adsorption and pulse chromatography technique. The equilibrium uptakes of CO2, CH4 and N2 for all the adsorbents were determined at atmospheric and high pressures. The equilibrium adsorption constants and selectivities were estimated by fitting of experimental chromatograms obtained from pulse chromatography studies into linear equilibrium dispersive chromatography model using gPROMS. The BIMP functionalized polystyrene adsorbent showed the highest equilibrium uptake and selectivity for CO2

Equilibrium Adsorption Studies of CO<inf>2</inf>, CH<inf>4</inf>, and N<inf>2</inf> on Amine Functionalized Polystyrene

Adsorption of CO2, CH4, and N2 has been investigated using amine functionalized polymeric resins having diethanolamine, imidazole, dimethylamine, and N-methyl piperazine covalently attached to the styrene-divinyl benzene copolymer (PS) matrix. The equilibrium adsorption of CO2, CH4, and N2 was examined on these functionalized polymers at pressures from atmospheric to 40 atm for CO2 and N2 while up to 10 atm for CH4 at 303 K. PS-Imidazole showed the highest adsorption capacity for CO2 as compared to other functionalized polymers. No significant uptake of CH4 and N2 was observed at low pressures by any of the functionalized polymers. The adsorption isotherms were analyzed using dual mode sorption model and Ideal Adsorbed Solution Theory (IAST)

Pulse Chromatographic Studies of Adsorption of CO<inf>2</inf>, CH<inf>4</inf>, and N<inf>2</inf> Using Amine Functionalized Polystyrene Adsorbents

Adsorption of CO2, CH4, and N2 was investigated using pulse concentration chromatography on polystyrene functionalized by covalently attached diethanolamine, dimethylamine, imidazole, and N-methyl piperazine. The adsorption equilibrium constants at different temperatures were estimated by fitting the experimental chromatograms into a non-linear equilibrium dispersive chromatography model using gPROMS. Axial dispersion was found to be the controlling mechanism for dispersion of the chromatograms. The heat of adsorption and corresponding equilibrium selectivities were determined from the adsorption equilibrium constants. The imidazole based adsorbent showed the highest affinity for CO2