Heat-transfer-liquid-operated turbine and compressor
An energy storage and retrieval system including an air chamber, a first air compressor operating with Heat Transfer Liquid (HTL-compressor) connected to the air chamber, a second turbine, operating with Heat Transfer Liquid (HTL-turbine) connected to the air chamber, accepting compressed air from the air chamber and producing work. Related apparatus and methods are also described.
1 . A method for converting waste heat of exhaust gas to work
while reducing CO 2 emission in the waste heat, comprising:
feeding into a direct contact heat exchanger an exhaust gas that comprises CO 2 and a heat transfer liquid (HTL) that comprises molten salt, thereby resulting in mixing the HTL with the exhaust gas and heating of the HTL to obtain heated HTL;
wherein the HTL comprises a CO 2 -capturing material to absorb the CO 2 from the exhaust gas, and said mixing resulting in the CO 2 -capturing material capturing the CO 2 from the exhaust gas, thereby reducing an amount of CO 2 in the exhaust gas;
operating an HTL-turbine for performing an isothermal or quasi-isothermal expansion with the heated HTL following said mixing; and
producing work using the HTL-turbine.
2 . The method of claim 1 ,
wherein the HTL exits the heat exchanger at a temperature of about the entrance temperature of the exhaust gas, while the exhaust gas exits the heat exchanger at a temperature about the entering temperature of the HTL.
3 . The method of claim 1 ,
wherein said CO 2 capturing material solidifies upon absorbing CO 2 , and the method further comprising removing the CO 2 capturing material which has absorbed CO 2 from the exhaust gas before reaching the HTL-turbine.
4 . The method according to claim 1 wherein the CO 2 -capturing material comprises a material selected from a group consisting of:
CaO;
MgO;
NaCO 3 (+H 2 O);
NaCO 3 ;
KCO 3 (+H 2 O);
KCO 3 ; and
Na 2 O.
5 . The method according to claim 1 , wherein producing work comprises producing electricity.
6 . The method according to claim 1 , wherein CO 2 capturing material which has absorbed CO 2 from the exhaust gas is removed before reaching the HTL-turbine.
7 . The method according to claim 1 , wherein the molten salt is in a molten state in a temperature range of between 140° C.-530° C.
8 . The method according to claim 1 , wherein said heating comprises heating the HTL that comprises molten salt to a temperature above 670K, using a direct heat exchanger and waste heat of exhaust gas.
9 . The method according to claim 1 , wherein interaction of the CO 2 capturing material with the CO 2 produces a new material which is removable from the HTL;
wherein the method further comprising removing the new material from the HTL.
10 . A method for converting waste heat of exhaust gas to work while
reducing CO 2 emission in the waste heat, comprising:
feeding into a direct contact heat exchanger an exhaust gas that comprises CO 2 and a heat transfer liquid (HTL) that comprises molten salt thereby resulting in mixing the HTL with the exhaust gas and heating of the HTL to obtain heated HTL;
wherein the HTL comprises a CO 2 capturing material, to absorb CO 2 from the exhaust gas, and said mixing resulting in the CO 2 -capturing material capturing the CO 2 from the exhaust gas, thereby reducing an amount of CO 2 in the exhaust gas;
operating an HTL-turbine for performing an isothermal or quasi-isothermal expansion with the heated HTL following said mixing; and
producing work using the HTL-turbine;
wherein interaction of the CO 2 capturing material with the CO 2 produces a new material which is removable from the HTL;
wherein the method further comprises removing the new material from the HTL.
11 . A method for converting waste heat of exhaust gas to work while reducing CO 2
emission in the waste heat, comprising:
feeding into a direct contact heat exchanger an exhaust gas that comprises CO 2 and a heat transfer liquid (HTL) that comprises molten salt, thereby resulting in mixing the HTL with the exhaust gas and heating of the HTL to obtain heated HTL;
wherein the HTL comprises a CO 2 capturing material to absorb CO 2 from the exhaust gas, and said mixing resulting in the CO 2 -capturing material capturing the CO 2 from the exhaust gas, thereby reducing an amount of CO 2 in the exhaust gas;
operating an HTL-turbine for performing an isothermal or quasi-isothermal expansion with the heated HTL following said mixing; and
producing work using the HTL-turbine;
wherein said CO 2 capturing material solidifies upon absorbing CO 2 , and the method further comprising removing the CO 2 capturing material which has absorbed CO 2 from the exhaust gas before reaching the HTL-turbine.