Characteristics of Commercially Available Charcoal and Charcoal Briquettes in the Light of Petrographic Studies

Abstract

As of today, petrographic studies on charcoals and charcoal briquettes in Poland are rarely used as a source of information on the quality of fuels used for grilling. It should be noted that, according to the Polish Standard PN -EN 1860-2, petrographic analyzes of coals and briquettes are obligatory before placing the discussed fuels on the market. However, in the case of the majority of coal and briquette producers, these tests are carried out only once in order to receive a long-term certificate for the entire range of products. Most entrepreneurs believe that the process of producing grill fuels is stable and the parameters of wood used for their production are characterized by a very low variability. The same opinion prevails among the producers of charcoal briquette and is the reason why the tests, which should be carried out for each batch of a product entering the market, are rarely performed. Another argument in favor of the mentioned tests is the fact that fine coal and coal dust of both domestic and foreign origin are used in the production of briquettes. The presented article, based on petrographic analysis of coals and charcoal briquettes, pays special attention to the differences in the content of impurities in the analyzed material from different production periods. The research material was obtained from producers at the beginning of the calendar year (previous year’s production) and in autumn of the year in which the analysis was carried out (current-year production). In addition to the petrographic analysis, showing the percentage of solid contaminants, TOC, analyzes were performed for individual coals and briquettes. Furthermore, petrographic examination of grill ash was carried out. Additional examination of the material in terms of carbon content (TOC) has shown differences between the individual batches from different production periods. Supplementary petrographic analysis of ashes was carried out in order to show the amount of remaining solid impurities in the obtained material after the grilling process. The determination of the amount of remaining solid impurities in the ash was aimed at demonstrating their suitability as additives to gardening soil. The ash admixture in soil is associated with its deacidification in the case of an unwanted pH change during the production of gardening soil and with additional mineralization of the product intended for balcony garden.