STEP carbon capture – The barium advantage

High‐Solar‐Efficiency Utilization of CO2: the STEP (Solar Thermal Electrochemical Production) of Energetic Molecules

“…The portfolio of STEP processes continues to grow and develop [103][104][105][106][107][108][109][110], iron, a basic commodity, currently accounts for the release of one-quarter of worldwide CO 2 emissions by industry, which may be eliminated by replacement with the STEP iron process. The unexpected solubility of iron oxides in lithium carbonate electrolytes, coupled with facile charge transfer and a sharp decrease in iron electrolysis potentials with increasing temperature, provides a new route for iron production.…”

Sustainable Electrochemical Synthesis of Large Grain- or Catalyst-Sized Iron

“…The electrolysis potential is measured as the voltage between the anode and the cathode at constant current. We have previously reported on STEP cathode or oxygen anode potentials in a variety of molten carbonates [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] During electrolysis, the iron product accumulates at the cathode, which is subsequently removed and cooled. Details of STEP electrolysis are provided in references [5][6][7][8].…”

“…The general solar thermal electrochemical process (STEP) of sunlight to decrease (endogenic) electrolysis potentials leads to high solar energy conversion efficiencies [6][7][8][9][10][11]. A variety of other STEP electrolyses have been demonstrated to decrease CO 2 including the production of cement, ammonia, fuels, and carbon for the direct removal of atmospheric or smokestack carbon dioxide [10][11][12][13][14][15][16][17][18][19][20]. Fundamental, electrochemical, and impurity effects on STEP iron have been investigated [8], and the general effects of alkali earth and hydroxide on STEP processes in molten carbonates have been reported [14][15][16][17][18][19][20].…”

“…A variety of other STEP electrolyses have been demonstrated to decrease CO 2 including the production of cement, ammonia, fuels, and carbon for the direct removal of atmospheric or smokestack carbon dioxide [10][11][12][13][14][15][16][17][18][19][20]. Fundamental, electrochemical, and impurity effects on STEP iron have been investigated [8], and the general effects of alkali earth and hydroxide on STEP processes in molten carbonates have been reported [14][15][16][17][18][19][20]. The fundamental increase in solar electrolysis efficiency with the use of solar thermal has been analyzed for CO 2 and H 2 O splitting theoretically [10][11][12] and experimentally [13][14][15] and the fundamental endogenic decrease in electrochemical potential with the increasing temperature demonstrated for a number of STEP processes [10][11][12][13][14][15][16][17][18][19][20].…”

“…Fundamental, electrochemical, and impurity effects on STEP iron have been investigated [8], and the general effects of alkali earth and hydroxide on STEP processes in molten carbonates have been reported [14][15][16][17][18][19][20]. The fundamental increase in solar electrolysis efficiency with the use of solar thermal has been analyzed for CO 2 and H 2 O splitting theoretically [10][11][12] and experimentally [13][14][15] and the fundamental endogenic decrease in electrochemical potential with the increasing temperature demonstrated for a number of STEP processes [10][11][12][13][14][15][16][17][18][19][20]. The requisite solar thermal heating for any given process will depend on the current density, which controls the overpotential and the net difference between the thermoneutral potential and the applied electrolysis potential.…”