In this chapter, the numerical simulation of pressure and temperature characteristics in fire-tube boilers operating with alcohol-based fuels, such as ethanol and methanol, is explored. Alcohol-based fuels are considered a sustainable alternative to traditional fossil fuels, especially in smart manufacturing contexts. A small-scale fire-tube boiler prototype was designed using SolidWorks and thermally analyzed in ANSYS Fluent to assess pressure and temperature distributions. The study evaluates the effect of varying water flow (25 m/s, 30 m/s, 35 m/s, and 40 m/s) on the boiler’s performance and examines how different boiler casing materials, including brass, stainless steel, and steel, impact heat transfer efficiency and pressure dynamics. The results reveal that the selection of casing material significantly influences the overall performance, highlighting the importance of material choice in enhancing boiler efficiency with alcohol-based fuels. This chapter contributes to the advancement of energy-efficient combustion technologies, supporting the transition to cleaner fuel systems in smart manufacturing.