Lignin as a renewable resource for bio-oil and oligomers production. An environmental perspective

The depletion of fossil resources and climate change is already a fact that entails a great concern among the population. Efforts to search for renewable resource alternatives with low environmental impact is now a priority for authorities, industries and society in general. Added to this, there is the problem of the high demand for goods and services by the population, which continues to increase, leading to a high production of waste. In this context, the lignocellulosic biomass has a key role, as it is used in large industrial activities, such as the food industry, paper production and livestock farming, among others. To this end, the amount of lignin produced is very significant, which turns into the need to search for process alternatives for its recovery and valorization. Its calorific capacity allows a two-fold benefit, firstly because of its capacity to be used as a renewable fuel and for the production of natural chemicals, such as phenolic compounds, antioxidants, and bioplastics, and secondly because of the reduction in the amount of lignocellulosic waste released to the environment. This is the focus of this manuscript, where a large-scale modeling of a lignin valorization process to obtain bio-oil and oligomers is developed. In addition, to evaluate its suitability, an environmental study has been carried out, applying the Life Cycle Assessment methodology, and a techno-economic analysis as well. The results obtained have shown that the use of residual lignin as a raw material to obtain value-added products is viable both environmentally and techno-economically.