Purification of xylose in simulated hemicellulosic hydrolysates using a two-step emulsion liquid membrane process

Removal of acetic acid from simulated hemicellulosic hydrolysates by emulsion liquid membrane with organophosphorus extractants

“…The emulsification was conducted at 12,000 rpm for 10 minutes, and the volume ratio of the stripping solution to the membrane solution was 1. The same water-jacketed batch reactor and mixing system as in the ELM works of Lee (2013) and Lee (2014) were used to consistently disperse 70 cm 3 of the w/o emulsion into 420 cm 3 of the feed solution during each ELM run. Double emulsions were formed in the reactor that was maintained at 25 o C, and stirred at 360 rpm in all of the runs.…”

“…Thus, organophosphorus compounds were tested for their efficacy as the extractant to help remove acetic acid selectively from simulated hemicellulosic hydrolysates and simultaneously attain a high degree of extraction and enrichment ratio in the current ELM system. The aim of this work was to develop a more energy-efficient ELM process where the extraction rate of acetic acid is extremely high and the total operation time is much shorter than that required to meet the extraction efficiency of acetic acid obtained in the work of Lee (2014). In order to achieve this, therefore, the effects of various experimental variables on the separation of acetic acid from simulated hemicellulosic hydrolysates were investigated in the ELM system with organophosphorus extractants.…”

“…In order to achieve this, therefore, the effects of various experimental variables on the separation of acetic acid from simulated hemicellulosic hydrolysates were investigated in the ELM system with organophosphorus extractants. For consistency, the composition of the simulated hydrolysates was very similar to that of the works of Lee (2013), Lee (2014) and Lim and Lee (2014), which was determined on the basis of concentrations of main constituents in real hemicellulosic hydrolysates.…”

“…Actually, the first ELM step of Lee (2014) is an unparalleled separation process for removal and recovery of acetic acid in hemicellulosic hydrolysates, and is also applicable to various hemicellulosic hydrolysates obtained by autohydrolysis as well as dilute acid hydrolysis of lignocellulosic biomass. However, a total operation time of 14 minutes required to remove most acetic acid might be too long.…”

“…Among them, it is expected that a two-step ELM process (Lee, 2014) will be the most commercially practical. In the ELM process, a mixture of xylose, acetic acid and sulfuric acid was used as a simulated hemicellulosic hydrolysate.…”