Hall L, 2nd pm, Day 4, Thursday Abstracts

Session S3. East Asian joint session: Critical SDGs in highly industrialized economies

A hydrogen supply chain consists of the production, transportation, storage, and distribution of hydrogen as an energy source. A variety of decision variables should be determined along the supply chain including technological options of producing hydrogen, phase of hydrogen, location and capacity of treating facility, and the amount of transportation between the regions. The optimization problem can be effectively formulated and solved for this complex systems. In this presentation, we have investigated for the optimal strategy for hydrogen supply chain and present the optimal solution to the case of South Korea.

CuInS₂ (CIS) is a solar absorber with the energy band gap of 1.5 eV, suitable for hydrogen production from water splitting. The types of conductivity (n- or p-type) of CIS photoelectrode can be tuned as a function of Cu/In concentration ratio. In this report, CIS films were deposited using spray deposition onto ITO-coated glass substrates from aqueous solutions consisted of copper (II) chloride, indium chloride and thiourea. First, the ratios of the precursor solutions were varied and the transition from n- to p-type conductivity was observed. Next, Zn-doped CuInS₂ (Zn-CIS) thin films exhibited p-type conductivity from electrochemical measurements. XRD results reveal the cubic-structured Zn-CIS films. The successive shift of XRD patterns toward higher angles with zinc molar fraction is evident of the formation of Cu-In-Zn-S solid solution. LSV results shows that the photocurrent density of Zn-CIS film reached 2.5 mA/cm², higher than the bare CIS (0.3 mA/cm²). Finally, n-type ITO thin film was deposited onto the p-type CIS. Here, we want to demonstrate that suitable match of the p-n junction can create a high efficient photoelectrode for hydrogen production from water.

The electrochemical reduction of CO₂ recently draws great attention because of its sustainable capability of producing fuels and chemicals. However, the high over potential of CO₂ reduction reaction-oxygen evolution reaction (CO₂RR-OER) have been pointed out as an obstacle of commercialization. Herein, we propose electrochemical co-production of CO₂RR and oxidative reforming of organic materials. The oxidative reforming of organic materials not only potentially reduces operating cell voltages but also improves system economic feasibility by producing more valuable chemicals than oxygen. We introduces an automated and generalized platform for the techno- economic alanysis (TEA) of electrochemical coproduction system and investigate the 16 candidates of CO₂RR for cathode and 18 candidates of organic oxidation reaction for anode. The TES platform generates a product oriented process systems design including reaction, separation, and recycle. Global sensitivity analysis of Faraday efficiency, current density, and overpotential for the levelized cost of each product to understand which index should be improved first. Hydrogen, carbon monoxide, formic acid, glycoladehyde, ally alcohol, ethylene glycol, acetic acid, and propanol can be the promising candidate for the CO₂RR and 2,5-Furandicarboxylic acid (FDCA), oxalic acid, acrylic acid, glycolic acid, lactic acid, 2-furoic acid, and ethyl acetate can be the promising candidate for the anodic oxidation.