Techno-economic analysis of hydrogen production from dehydrogenation and steam reforming of ethanol for carbon dioxide conversion to methanol

Decreasing carbon dioxide (CO2) emission by converting to higher-valued product has become of interest. Hydrogen (H-2) is an important feedstock required in thermochemical conversion of CO2 to chemicals such as methanol. The cost and availability of H-2 affect the cost of CO2 conversion. This study is focused on the process simulation of H-2 production from ethanol feedstock. Steam reforming of ethanol is compared with dehydrogenation of ethanol to H-2 with valued products including ethyl acetate and acetaldehyde. Form this study, steam reforming of ethanol presents the lowest cost of H-2 production at 1.58 USD/kg H-2 while dehydrogenation of ethanol presents the cost at 3.24 and 1.97 USD/kg H-2, respectively. Although presenting the lowest cost, steam reforming of ethanol provides a net positive CO2 emission in the overall CO2 conversion to methanol process. In contrast, ethanol dehydrogenation to H-2 and byproducts, ethyl acetate and acetaldehyde, promotes a net negative CO2 emission of -819.20 kg/ton methanol and -5.42 kg/ton methanol, respectively. The results present a decreasing CO2 emission with an increasing cost of H-2 production. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

The study indicates that steam reforming of ethanol is the method with the lowest cost for hydrogen production, while dehydrogenation of ethanol to produce hydrogen and byproducts can reduce carbon dioxide emissions.