Acid Extraction from Liquid Phase Pyrolysis Oil Using Cyanex®923 and Subsequent Solvent Regeneration

Abstract

Liquid phase pyrolysis (LPP) oil, an intermediate from biofuel production using second‐generation biomass, is a promising source of biobased platform chemicals like acetic acid, however, displaying a complex, multicomponent mixture. Reactive extraction with Cyanex®923 was investigated for selective recovery of acids and subsequent solvent regeneration in distillation at 200 mbar. In a three‐stage extraction 81 % of acids were removed from the LPP oil without loss of Cyanex®923 to the raffinate. Solvent regeneration efficiency of acids was up to 99.7 % with mainly acids and water in the distillate.

Production and separation of acetic acid from pyrolysis oil of lignocellulosic biomass: a review

“…10 The recovery of tertiary amines is also a complex and energy-intensive process with the addition of several downstream steps to extract the product. 120,142 Based on previous reports, Painer et al 120 used reactive extraction of acetic acid directly from pyrolysis oil to avoid the water-extraction step, using the commercially available reactive extractant Cyanex®923, which is a mixture of trialkylphosphine oxides. An overall extraction efficiency of 81% was reported with no loss of the extractant in the raffinate phase.…”

“…On the other hand, TOA had a higher partition coefficient in comparison to Cyanex®923 and gave a similar extraction efficiency for acetic acid with no loss of TOA in the aqueous raffinate. 120 It has been established that extracting acetic acid from the aqueous phase is more beneficial than extraction from bio-oil. 124,136,143 One of the most important aspects of the extraction of acetic acid using these methods is the product recovery, which is a complicated and energy intensive process.…”

“…124,136,143 One of the most important aspects of the extraction of acetic acid using these methods is the product recovery, which is a complicated and energy intensive process. 120,121,142 However, there is a dearth of research for methods of effective solvent and product recovery. 121 Cebreiros et al 108 reported acetic acid recovery of 30 L ton −1 of dry biomass after extraction of acetic acid using ethyl acetate.…”

Reactive Distillation for Solvent Regeneration after Biphasic Carboxylic Acid Esterification

“…Acetic acid, e.g., is formed during pyrolysis of non‐food biomass for the production of biogenic fuel. 3, 4 Pulping of biomass produces low molecular weight carboxylic acids through degradation of hemicellulose during the pulping process. 5–7 When carboxylic acids are formed as by‐products, they are often considered as a costly burden in downstream processing.…”

“…8 They can deactivate catalysts in downstream processing of pyrolysis oil. 4 No matter whether these acids are intended products or by‐products, separation is highly appreciated but an economic challenge.…”