Systematic mapping of studies on coal tar and pitch over the last five decades (1970–2023)

Coal tar is the primary source for many basic chemicals and also provides raw materials for a number of other industries. This paper aims to present a systematic mapping and a brief review of the study areas related to coal tar/pitch over the past 50 years based on a search in the Scopus database. From the search carried out, 2477 articles were found, with the following distribution according to the source: 22.5% high temperature coal tar, 16.0% medium and low temperature coal tar, 4.7% tar from gas manufacturing plants, 32.8% coal tar pitch and 24.0% of not clear origin. A careful analysis of the articles led to their classification into 12 study areas. In addition to the classic studies of characterization and obtaining of chemical products, new applications have been developed in recent years, such as raw material for the production of liquid fuels and carbon materials. In the last decade, these studies have evolved beyond the production of traditional materials (e.g., fibers and electrodes) to advanced materials such as graphene and supercapacitors. This work presents the main areas of study of the different tar sources and provides insights into potential directions for future research.