Terephthalic acid (TPA) is a commodity chemical made by treating p-xylene (pX) with oxygen (O2) via the so-called Mid-Century (MC) process. TPA is a key ingredient to make polyethylene terephthalate plastic used in water bottles. The MC process uses a stirred reactor in which O2 is dispersed through an acetic acid solution of pX and catalyst (Co/Mn/Br). However, O2 starvation in the liquid phase causes incomplete oxidation necessitating product purification in a catalytic hydrogenation unit that accounts for nearly 50%, 16% and 33% of the overall capital investment, operating costs and greenhouse gas emissions, respectively. To mitigate O2 starvation, an alternate reactor technology is presented wherein the continuous and dispersed phases are reversed by spraying the liquid phase as fine droplets into a vapor phase containing O2 to increase the gas–liquid interfacial area. As a result, the spray reactor produces polymer-grade TPA in one step, eliminating the hydrogenation unit. Life cycle assessment confirms that the spray process without the hydrogenation unit significantly lowers global warming, acidification and other harmful emissions when compared to the MC process.