•Critical properties, heat capacities, and thermal diffusivities were measured.•Measurements were performed for liquid α-angelica lactone and triacetin.•The thermal conductivities of the compounds under study were calculated.•The compounds under study are involved in the production of fuels and fuel additives. The critical temperatures, critical pressures, heat capacities, and thermal diffusivities of α-angelica lactone and triacetin have been measured. The compounds under study are involved in the production of fuels and fuel additives from lignocellulose. The critical properties of the compounds have also been calculated by the group contribution methods of Wilson and Jasperson (WJ), Nannoolal et al. (NRR), Marrero and Gani, Hukkerikar et al. in two variants (H-sw and H-s). The NRR method provides the best estimation of the critical temperature and pressure of α-angelica lactone: the differences between experimental and estimated values are about 1.6 and 3.0 %, respectively. For triacetin, all the methods used give approximately the same discrepancy between the experimental and estimated critical temperature in the range from 1.2 to 2.0 % which is less than the uncertainty of the measurement. However, the H-s and H-sw techniques slightly overestimate the critical temperature, while the rest of the methods underestimate it. All the methods overestimate the critical pressure of triacetin; the H-s method provides the minimum difference between the measured and calculated values of the critical pressure (1.3 %). The heat capacities of liquid α-angelica lactone and triacetin have been measured at atmospheric pressure in the temperature range from 298.6 to 440.6 K (α-angelica lactone) and from 298.4 to 530.2 K (triacetin). The data obtained have been fitted with first-order polynomials. The heat capacities of the compound under study have also been estimated using the group-contribution method of Kolska et al. This method has been recommended to estimate the heat capacities of α-angelica lactone and triacetin. The thermal diffusivities of liquid α-angelica lactone and triacetin have been measured at atmospheric pressure in the temperature range from 303.15 to 373.15 K. The thermal conductivities have been calculated from the results of the experiment. The experimental data on thermal diffusivity and thermal conductivity have been approximated with linear polynomials. The thermal conductivities of α-angelica lactone and triacetin have been calculated by the methods of Govender et al. and Sastri. In general, the method of Govender et al. gives thermal conductivity values of the compounds under study that are closer to the experimental values than those obtained using the Sastri method.