Separation of lignin and protic ionic liquids from sugarcane straw pretreatment liquor using layered double...

Achieving effective separation of lignin and protic ionic liquids from sugarcane straw liquor is essential for adding value to the biomass. In this study, layered double hydroxides were used to adsorb lignin at different superficial velocities and temperatures, with the aim of optimizing breakthrough time, exhaustion time, adsorption efficiency, and productivity. The results revealed that superficial velocity significantly influenced adsorption parameters, whereas temperature did not exert significant effects within the studied range. Empirical models were validated with a relative error of <5 %, confirming their reliability in predicting process performance. Under optimized conditions, layered double hydroxides achieved effective lignin separation, with high adsorption efficiency and desorption capacity, enabling the recovery of protic ionic liquids. Nuclear magnetic resonance spectroscopy was used to assess the structural integrity of the purified protic ionic liquids and lignin. In conclusion, layered double hydroxides were effective in separating lignin and recovering protic ionic liquids from the pretreatment liquor. The findings also provide insights into the interactions between lignin, protic ionic liquids, and layered double hydroxides, supporting the design of cost-effective and efficient adsorption processes. Thus, this study contributes to the development of green technologies for separation processes, underscoring the potential of layered double hydroxides.