(200g) A Novel Reduced Pressure Hybrid Solar/Electric Reactor for Producing Magnesium Metal Via Carbothermal Reduction

A novel 10kW hybrid/solar reactor operating at a temperature up to 1650°C and pressure down to 1 mbar for magnesium metal production via carbothermal reduction reaction (C + MgO → CO + Mg) is presented. The unique reactor design includes a pneumatic actuated shutter that moves the solar concentrator and replaces it with a section of refractory insulation in front of the aperture to block the thermal radiation from the inside of the heated chamber when solar radiation is not applied. During daytime concentrated solar power is used to drive the chemical reaction and substitute high peak cost electricity. During nighttime off-peak low cost electricity is used to enable a 24/7 operation. Compared to solar-only applications which are limited to daylight operation, a hybrid solar/electric concept increases the plant’s capacity factor and minimizes the financial risk. Key R&D efforts are determining the feasibility of heating the reactor tube using concentrated sunlight in addition to direct electrical resistance as well as the efficient collection of Mg avoiding back-reaction of Mg(v) and CO to MgO and C.