This study aims to assess methane (CH 4) and carbon dioxide (CO 2) concentrations in the ventilation systems of two coal mines (A and B) in the Santa Catarina coal deposit in southern Brazil (Paraná Basin, Bonito Formation), and estimate their greenhouse gas (GHG) emissions. The highest CH 4 levels (1.8%) were recorded in strong methane emanation areas in mine A, below the lower explosive limit (5%). The IPCCrecommended methods significantly overestimated the methane emission (up to 80%) when compared to the experimental data measured for each mine. Application of an alternative method made it possible to estimate direct CO 2 emissions, indicating that CO 2 accounted for 22 to 77% of total GHG emissions. Carbon dioxide emissions are generally not included in GHG emission inventories, indicating that the coal industry underestimates the contribution of this gas. As such, it is recommended that the methodology used for these calculations be revised and that specific emission factors be applied for each mine. In order to improve the accuracy of inventories, more sampling needs to be carried out in all operational and abandoned mines.

The use of polymeric films incorporated with zeolite‐TiO2 composites associated with UV radiation can be an alternative in the removal of volatile organic compounds (VOCs) through the adsorption and photodegradation processes. This study produced poly(lactic acid) (PLA) films incorporated with 13× zeolite, TiO2, and 13×‐TiO2 zeolite composite to remove n‐butanol and evaluate the by‐products generated in the process. The results showed that 13× zeolite and TiO2 added individually or as a composite to PLA, gave the polymer matrix a significant increase in the removal capacity of n‐butanol. The best performance was presented by the zeolite‐TiO2, composite, confirming a synergistic effect. However, the formation of CO and CO2 exceeded the expected values, with the verification that the polymeric matrix underwent photodegradation action by TiO2. The polymeric film only containing zeolite is the most suitable for the removal of VOCs, as it did not present degradation of the PLA, generating a lower concentration of by‐products.

A characterization of the air in underground coal mines is important, therefore, it is possible that it is focused on the safety of the work and the environment. (CH4) and Carbon Dioxide (CO2) along the ventilation system of three coal mines, named (A, B and C), all located in the South Catarinense deposit, Paraná Basin, Bonito Formation, the Barro Branco layer (mines A and C) and Bonito layer (mine B) and also, make estimates of the emission of greenhouse gases (CH4 and CO2). From collection that the first campaign as samples were collected with bags in mines A and B, other campaigns such as collections Were carried out with borosilicate collecting flasks. Surveillance, temperature, pressure and humidity measurements were also carried out at different points of the mines for a higher flow rate determination. Gas analyzes were performed by gas chromatography. The results indicated as higher concentrations of CH4 are present in Mine A, but all concentrations are below the explosive limit of this gas (50,000 ppm). CO2, despite having similar concentrations in the three mines, also stands out at mine A, presenting higher concentrations in emanation areas determined for NR15 (3,900 ppm) and MSHA (5,000 ppm). As emission estimates of CH4 and CO2 (GHG) were carried out with different methodologies in which they differ according to the values of emission, concentration, coal production and total ventilation flow. Taking into account that the results obtained in Brazil refer to the emission of CH4 in underground coal mines, in which, considering the mining characteristics, it is estimated that the values found in the literature overestimate the values emitted by each mine. It should be noted that the results obtained in this study are an attempt to improve the emission calculations. However, to improve the accuracy of inventories, more sampling should be done covering all mines in operation in the country.