Thermal energy-driven mechanical compression humidification-dehumidification water purification

A method for purifying water via thermal-energy-driven mechanical compression humidification-dehumidification, comprising:

• directing a flow of a feed liquid into a feed-liquid input and out of a feed-liquid output for a humidification chamber in at least one humidifier;
• directing a flow of a carrier gas into a carrier-gas input and out of a carrier-gas output for the humidification chamber in the at least one humidifier;
• directly contacting the carrier gas flow with the feed liquid in the humidification chamber to humidify the carrier gas with water evaporated from the feed liquid, producing a humidified gas flow;
• directing the humidified gas flow through a humidified-carrier-gas conduit to a carrier-gas input for a dehumidification chamber in at least one dehumidifier;
• compressing the humidified gas flow in a compressor in or coupled with the humidified-carrier-gas conduit;
• directing the compressed humidified gas flow into the carrier-gas input and out of a carrier-gas output for the dehumidification chamber in the at least one dehumidifier;
• dehumidifying the compressed humidified gas flow in the dehumidification chamber to condense purified water from the compressed humidified gas flow;
• then
• directing the dehumidified compressed gas flow from the carrier-gas output of the dehumidifier through a dehumidified-carrier-gas conduit;
• using a heater to heat the dehumidified compressed gas flow in the dehumidified-carrier-gas conduit;
• expanding the heated and dehumidified compressed gas flow in an expander in or coupled with the dehumidified-carrier-gas conduit, wherein the expansion of the heated and dehumidified gas flow generates motion, and wherein the motion generated in the expander is transferred to the compressor via a mechanical connection, where the compressor uses the transferred motion to compress the humidified gas flow;
• then
• using a heat recovery system to extract heat from expanded dehumidified gas flow after leaving the expander;
• using the heat recovery system to transfer the heat extracted from expanded dehumidified gas flow to the dehumidified compressed gas flow in the dehumidified-carrier-gas conduit after the dehumidified compressed gas flow leaves the dehumidification chamber but before the dehumidified compressed gas flow enters the expander;
• and
• releasing an expanded gas flow without closed-loop recycling of the released gas flow through the above steps.