Recovery of Biomass-Derived Polyols by Pressure Swing Adsorption: Experiments, Simulations, Scale-up Implementation and Economic Analysis

Abstract

Biomass as a fuel is an important development for limiting greenhouse gas emissions and replacing fossil fuels. 1,3-Propylene glycol (1,3-PG) is a valuable chemical product obtained from bioglycerol hydrogenolysis. However, 1,3-PG is always mixed with ethylene glycol (EG) and 1,2-propylene glycol (1,2-PG), the properties of which are similar to those of 1,3-PG, making it costly to obtain a high-purity 1,3-PG product through distillation. Adsorption is a promising process for polyol separation, and a highly practical molecular sieve 10X (MS 10X) was employed as an adsorbent in this study to purify 1,3-PG from polyol mixtures. The adsorption capacity increased while the separation factor decreased with increasing pressure, and 160 kPa was chosen as a suitable operating pressure. The Freundlich isotherm described polyol adsorption on MS 10X well, and EG (1,2-PG) selectively adsorbed on MS 10X over 1,3-PG. This adsorption was a spontaneous physisorption process, and the entropy effect was the main driving force for selective adsorption. A pressure swing adsorption (PSA) system with dual beds for purifying 1,3-PG was designed rigorously by simulation, and the product purity exceeded 99.99%. Finally, a continuous distillation unit was designed to recover 1,3-PG, and the energy and equipment costs of both processes were compared. The designed PSA process could reduce energy costs by 60% and total annual cost by 39.6% over distillation.

Introduction of hydrogen bond recognition sites in ZIF‐71 for effective separation of bio‐diols in aqueous solutions

“…Various strategies for the separation of 1,3‐PDO and 2,3‐BDO have been reported, such as distillation, 11 solvent extraction, 12 reactive extraction, 13 and adsorption 9,14–18 . Adsorption has the advantages of less equipment investment, simple process, environmental protection, and low energy consumption 19 . A variety of adsorbent materials have been employed to adsorb 1,3‐PDO and 2,3‐BDO, including resins, 9,14 zeolites, 15–17 and metal–organic frameworks (MOFs) 18 …”

“…9,[14][15][16][17][18] Adsorption has the advantages of less equipment investment, simple process, environmental protection, and low energy consumption. 19 A variety of adsorbent materials have been employed to adsorb 1,3-PDO and 2,3-BDO, including resins, 9,14 zeolites, [15][16][17] and metal-organic frameworks (MOFs). 18 Typically, hydrophilic adsorbent SIM-1 preferentially adsorbed 1,3-PDO over 2,3-BDO, which showed a high 1,3-PDO adsorption capacity (123.0 mg/g).…”

Recent advances in software tools for adsorption science and engineering

“…In a typical adsorption process, the adsorption and desorption processes are repeated in a cyclical manner, by manipulating the column pressure or temperature, which leads to the separation of gas molecules with high purity, low operating cost, and long service time. 1,2 Because of these advantages, the adsorption processes have been used in many industries, which include air separation, 3,4 light hydrocarbon processing, 5,6 and hydrogen production from coke oven gas, 7 fuel gas, 8,9 or syngas. [9][10][11] Moreover, many studies about sustainability adopt the adsorption processes such as CO 2 capture, 12,13 biogas upgrading, 14,15 and green hydrogen production from the sustainable energy.…”