This study presents experimental and numerical results on the fundamental multiphase burning characteristics of n-butyl acetate (BA) and its blends with n-heptane one diesel surrogate. Included were bio-synthesized BA (SBA), neat BA (NBA), BA/n-heptane mixtures, #2 pump diesel (PD), certification diesel fuel (CDF), four-component (DS4) and five-component (DS5) diesel surrogates for the CDF, and BA/DS4 mixtures. The configuration of an isolated droplet burning under conditions which promote spherical symmetry of the burning process was used as the platform to examine the influence of parameters such as the initial droplet diameter (0.3 mm ≤ D0 ≤ 0.8 mm) and mixture fraction. The one-dimensional gas transport that results from spherical symmetry enabled numerical modeling of some of the experimental data presented in this thesis. Besides, BA droplet combustion under elevated pressures (up to 10 bar) was also conducted in a buoyancy-driven convective environment. In the atmospheric pressure experiments of SBA and NBA, the results showed nearly identical burning rates and relative positions of the spherical flame to the droplet, despite SBA containing approximately 6% impurities as by-products. For BA/n-heptane mixtures, the burning rates were similarly very close with the flame being drawn closer to the droplet surface as the BA fraction increased. Adding BA to DS4 increased the mixture burning rate and lowered soot production. DS5 was found to be less desirable for study in the experiments because of the propensity of bubble nucleation on the support fibers. Results from the experiments at elevated pressure showed that the BA burning rate significantly increased with pressure, and flames were elongated owing to a convective gas flow that was enhanced with pressure. Numerical simulations were carried out using the OpenSMOKE++ framework, specifically to simulate burning of BA and its blends with n-heptane. Simulations using the reduced mechanism were successful and good agreement was found with measured droplet and flame diameters for BA. Flame extinction for BA was predicted by the numerical model but was not shown in the experiments due to the very small extinction diameters. Simulations of BA droplet burning were extended to D0 up to 4 mm showing the role of D0 on the droplet combustion process. Regarding BA/n-heptane mixtures, the influence of BA mixture fraction on BA/heptane blends were also well predicted. The information provided in this thesis resulted in a comprehensive dataset of droplet burning parameters for the fuel systems investigated that was valuable for validating the numerical simulations. These findings also provide valuable insights into the potential of BA as a sustainable fuel additive, with potential for reduced particulate emissions and petroleum consumption. The methodologies and findings of this work are more broadly applicable to other fuel systems, and offer a pathway in future studies for predicting biofuel and fuel blend combustion processes, thereby contributing to advances in sustainable fuel solutions to the climate change problem.