A solution polymerization process for producing ethylene-based polymer includes introducing ethylene monomer, hydrocarbon solvent, and Ziegler-Natta catalyst into an entrance of a solution polymerization reactor. An ethylene-based polymer is produced by solution polymerizing the ethylene monomer in hydrocarbon solvent. Subsequently, a catalyst deactivator is introduced into x the exit of the solution polymerization reactor, thereby producing hydrochloric acid byproduct. The catalyst deactivator includes long chain carboxylate and at least one cation selected from Groups 1, 2, and 12 of the IUPAC periodic table, with the exception of calcium. The catalyst deactivator reduces the effectiveness of the Ziegler-Natta catalyst and neutralizes the hydrochloric acid by forming a chloride salt other than calcium chloride.