Abstract: This disclosure discusses integrating syngas streams with refinery hydrotreators, synthetic hydrocarbon gas to liquid (GTL) processes, and power generation units (such as combined cycle units) to efficiently use hydrogen contained in the syngas produced from heavy hydrocarbons (pet coke, residues, oil, etc.). Membrane separation and pressure swing adsorption is used to separate components of syngas and feed them to refineries, GTL units, and power/steam generation units. Hydrogen-rich refinery purge is used to raise the H2/CO ratio of syngas. A hydrogen-enriched syngas is produced with an H2/CO ratio favorable for the production on synthetic hydrocarbons (greater than about 1.5 to about 2.0 or higher). Pure hydrogen is also produced in a PSA unit, to further raise the H2/CO ratio of the syngas and provide hydrogen feed for refinery hydrotreators and synthetic hydrocarbon units (such as methanol units).