Strategic techniques for upgrading bio‐oil from fast pyrolysis: a critical review
Luciana R Santos, Daniela R. Araujo, Marco Antônio Siqueira Rodrigues
Abstract
Abstract Pyrolysis has been the subject of extensive scientific research due to its potential application to various waste streams and byproducts from different production systems. One of its main products is the liquid fraction known as bio‐oil – a complex material composed of a wide variety of organic molecules and a significant water content. Bio‐oil has strong potential for use in the production of biosolvents, biofuels, and specialty chemicals. However, the separation of its components remains a major challenge to its application in industrial processes. Given this context, this article provides a critical review of the technological routes employed for bio‐oil upgrading. The analysis of technological methods included feedstock types, pyrolysis process parameters, separation techniques applied to bio‐oil, and emerging approaches for its refinement. The results indicate that highly purified bio‐oil fractions are not a common outcome in the literature that was analyzed. Instead, the upgraded fractions tend to reflect the concentration of specific components or the separation of certain chemical groups. Among the reviewed applications, studies focused on bio‐oil refining for energy purposes show greater technological progress than those that aimed to produce other chemical inputs. One possible reason for this trend is that biofuel production allows for the achievement of desirable physicochemical properties without the need to replicate the chemical composition of fossil fuels exactly.