Efficient Plasma Technology for the Production of Green Hydrogen from Ethanol and Water

Abstract

This study concerns the production of hydrogen from a mixture of ethanol and water. The process was conducted in plasma generated by a spark discharge. The substrates were introduced in the liquid phase into the reactor. The gaseous products formed in the spark reactor were hydrogen, carbon monoxide, carbon dioxide, methane, acetylene, and ethylene. Coke was also produced. The energy efficiency of hydrogen production was 27 mol(H2)/kWh, and it was 36% of the theoretical energy efficiency. The high value of the energy efficiency of hydrogen production was obtained with relatively high ethanol conversion (63%). In the spark discharge, it was possible to conduct the process under conditions in which the ethanol conversion reached 95%. However, this entailed higher energy consumption and reduced the energy efficiency of hydrogen production to 8.8 mol(H2)/kWh. Hydrogen production increased with increasing discharge power and feed stream. However, the hydrogen concentration was very high under all tested conditions and ranged from 57.5 to 61.5%. This means that the spark reactor is a device that can feed fuel cells, the power load of which can fluctuate.

Effect of Water Content on Ethanol Steam Reforming in the Nonthermal Plasma

“… 21 This is due to the presence of several chemical bonds in ethanol that are weaker than the chemical bonds in water. 14 , 22 − 25 Therefore, several products can be formed from ethanol. In the dehydration reaction ( eq 8 ), ethylene is formed, which, in subsequent reactions, produces acetylene ( eq 9 ) and coke ( eq 10 ).…”

“…Computer simulations also showed that the dissociation rate constant of ethanol in collisions with electrons is many times greater than the dissociation rate constant of water . This is due to the presence of several chemical bonds in ethanol that are weaker than the chemical bonds in water. ,− Therefore, several products can be formed from ethanol. In the dehydration reaction (eq ), ethylene is formed, which, in subsequent reactions, produces acetylene (eq ) and coke (eq ).…”

“…The methodology and apparatus used in the research were similar to those used in our earlier studies described in our previous papers. ,− A spark reactor powered by an alternating current power supply was used in the research. The apparatus diagram and the devices’ names are shown in Figure .…”

“…Burlica and Wang used reactors with a gliding discharge, where a high-speed gas stream is necessary. Barrier, , corona, microwave, and spark discharge reactors were also insensitive to coke.…”

Hydrogen production by microwave plasma decomposition of H2S at atmospheric pressure with cooling implemented in its afterglow

“…Hydrogen production has been extensively investigated by researchers from various fields owing to its potential applications in fuel cell vehicles, public facilities, and industry, etc to replace fossil fuel energy and to reduce the emission of greenhouse gases and pollution in the environment [1][2][3][4]. As a hydrogen-containing industrial product, hydrogen sulfide (H 2 S) is one of the main by-products in the process of petroleum refining by hydro-desulphurization and in the exploitation of methane in natural gas deposits (up to 45% by weight in some deposits).…”