Efficient Hydrogen Production by Direct Electrolysis of Waste Biomass at Intermediate Temperatures

Abstract

Biomass has been considered as an alternative feedstock for energy and material supply. However, the lack of high-efficiency and low-cost processes for biomass utilization and conversion hinders its large-scale application. This report describes electrochemical hydrogen production from waste biomass that does not require large amounts of energy or high production costs. Hydrogen was produced by the electrolysis of bread residue, cypress sawdust, and rice chaff at an onset cell voltage of ca. 0.3 V, with high current efficiencies of approximately 100% for hydrogen production at the cathode and approximately 90% for carbon dioxide production at the anode. The hydrogen yields per 1 mg of the raw material were 0.1−0.2 mg for all tested fuels. Electrolysis proceeded continuously at plateau voltages that were proportional to the current. These characteristics were attributable to the high catalytic activity of the carbonyl-group functionalized mesoporous carbon for the anode reaction, and that the major components of biomass such as cellulose, starch, lignin, protein, and lipid were effectively utilized as fuels for hydrogen production.

Oxygen‐Functionalized and Ni+x (x=2, 3)‐Coordinated Graphitic Carbon Nitride Nanosheets with Long‐Life Deep‐Trap States and their Direct Solar‐Light‐Driven Hydrogen Evolution Activity

“…Hydrogen, apromising renewable energy resource, can be produced by variousm ethods such as steam reforming of natural gas, thermolysis, electrolysis, photobiological water splitting and photocatalytic water splitting. [1][2][3][4] Among these methods, photocatalytic water splitting is considered as an environmentally friendly,e fficient, simple and cost-effective process because it utilizes earth-abundant water and solarl ight to produce hydrogen in the presenceo fareusable photocatalyst. However,f or the commercial viability of the photocatalytic hydrogen production method, the solar to hydrogenc onversion (STH) efficiency should be at least 10 %.…”

A Cellulose Electrolysis Cell with Metal-Free Carbon Electrodes

“…The partially oxygenated carbon anode used in this study was synthesized according to a procedure reported previously [15,16]. Briefly, 1.0 g of Ketjen Black (KB) was stirred in 24% HNO 3 diluted to 50 mL at room temperature for 74 h. After filtering and washing, the oxygenated KB was heated at 600 • C for 4 h under an Ar flow to eliminate carboxyl groups preferentially (as opposed to carbonyl groups having higher thermal stability) from the carbon surface.…”

“…Electrolysis at elevated temperatures is also advantageous for the kinetic characteristics of the used electrodes. A recent report indicated a lignocellulosic biomass electrolysis cell using partially oxygenated carbon as the anode at temperatures above 125 • C [15,16]. However, Pt was still necessary for the hydrogen evolution reaction (HER) at the cathode in this cell.…”

Interface‐Engineered Intermediate Temperature Solid Oxide Electrolysis Cell

“…In addition, the available heating source (e.g., nuclear station) is limited. Therefore, intermediate temperature SOEC (IT‐SOEC) that operates around 500–700 °C has recently attracted great interests . Doped ceria is one of the most promising electrolyte materials for IT‐SOEC because of its high oxygen ion conductivity (10 −2 S cm −1 at 600 °C) at intermediate temperature .…”

“…Therefore, intermediate temperature SOEC (IT-SOEC) that operates around 500-700 C has recently attracted great interests. [6,7] Doped ceria is one of the most promising electrolyte materials for IT-SOEC because of its high oxygen ion conductivity (10 À2 S cm À1 at 600 C [8] ) at intermediate temperature. [9] The main problem of doped ceria electrolyte is its strong tendency to reduce Ce 4þ to Ce 3þ during operation.…”