Steam distillation of lignin to remove odor

Abstract

Given the relentless depletion of raw materials on a global scale, there is a constant and pressing quest for resources that align with sustainability principles. As industry advances and the global population grows, the escalating use of fossil raw materials poses environmental challenges, including pollution and global warming. Endeavors are underway to identify eco-friendly and sustainable resources for novel energy and materials. Lignocellulosic materials, particularly lignin, could be considered as promising alternative, eco-friendly, and sustainable resources to address the environmental concerns related to fossil fuels and their rapid depletion. However, commercial acceptance of lignin products may be hindered if they emit volatile organic compounds guaiacol, as they must comply with emission standards, and consumers may reject them due to an unpleasant odor. In the present work for the first, the main effort has been put into minimizing the odor removal of kraft lignin specifically acid-washed (AW), which had around 35 % of moisture content. using steam distillation method. Headspace solid-phase microextraction gas chromatography-mass spectrometry (SPME-GC-MS) has been utilized for the qualitative and quantitative analysis to measure the release of unpleasant odorous compound such as guaiacol, other volatile sulfur species like dimethyl disulfide (DMDS). Furthermore, identification of substances was based on mass spectra and retention indices, while the quantification was accomplished through headspace sampling (HS). The results of this study demonstrate the feasibility of utilizing steam distillation as a promising approach for odor reduction strategies with potential industrial applications. Specially the vacuum-assisted steam stripping, shows effectiveness in removing odorous compound from kraft.