Based on theoretical calculations, new schemes to increase the deuterium density in palladium over its initial value are presented. A high deuterium concentration in palladium is needed for application to solid-state fusion. The first deuterium enrichment scheme makes use of plasma ion implantation, which consists of a cylindrical palladium rod (target) preloaded with deuterium atoms, coated with diffusion barrier material, and immersed in a deuterium plasma. The palladium rod is connected to a high-power modulator, which provides a series of negative voltage pulses. During these negative pulses, deuterium ions fall on the target, penetrate the diffusion barrier, and are implanted inside the palladium. For reasonable system parameters allowed by current technology, theoretical calculations indicate that the saturation deuterium density after prolonged ion implantation can be several times the palladium atomic number density. The second deuterium enrichment scheme makes use of temperature gradient effects on the deuterium solubility in palladium. A heat source at temperature T2 and a heat sink at temperature T1 (where T2 > T1) are in contact with two different parts of a palladium sample, which has been presoaked with deuterium atoms and has been coated with diffusion barrier material or has been securely locked in a metal case. The temperature gradient created in the sample from such an arrangement forces the deuterium atoms in the hot region to migrate into the cold region, resulting in higher deuterium density in the cold region.