Adsorptive recovery of butanol from acetone butanol and ethanol (ABE) model solution using the kraft lignin isolated from Sterculia foetida shells

Biobutanol is produced from the acetone-butanol-ethanol (ABE) fermentation. The major bottleneck of ABE fermentation is the self-inhibition of cells and the high energy consumption while recovering butanol. Several alternative techniques have been investigated, but the continuous recovery of butanol using the inexpensive and inert material could be a reliable choice. In the present study, the kraft lignin isolated from the novel lignocellulosic biomass, Sterculia foetida shells , was investigated for its selective adsorptive recovery of biobutanol from the simulated ABE solutions. SEM analyses of morphology and syringyl and guaiacyl units from FTIR show that the isolated lignin is in the softwood category. The XRD analysis shows 76.99% of the crystallinity index, which shows the crystalline features of kraft lignin. High thermal stability and surface area from TGA–DSC and BET analysis shows that the isolated lignin can be wisely used as an adsorbent. The isolated lignin maximum butanol adsorption capacity and the rate constant is 393.700 mg/g and 0.0954, respectively. The results show that Sterculia foetida lignin can be used commercially as a potential adsorbent for continuous biobutanol recovery in the ABE fermentation process. Using renewable lignin as an adsorbent is a sustainable approach for the circular bioeconomy as part of the lignocellulosic biorefinery.