Thermochemical Conversion of Hazelnut Shell to Gaseous Products for Production of Hydrogen

Abstract

The gasification of biomass is a thermochemical process, which results in a high production of gaseous products and small quantities of char and ash. Steam reforming of hydrocarbons, partial oxidation of heavy oil residues, selected steam reforming of aromatic compounds, and gasification of coals and solid wastes to yield a mixture of H2 and CO (syn gas), followed by water-gas shift reaction to produce H2 and CO2, are well established processes. Hydrogen is a sustainable, non-polluting source of energy that can be used in mobile and stationary applications. The samples, both untreated and impregnated with K2CO3, were pyrolyzed from 298 K (initial temperature) to 650, 672, 700, 725, 750, 775, 800, 825, 850, 875, 900, 925, 950, 97, 1000 and 1025 K, and 975, 1075, 1175 and 1225 K temperatures. Alkali pyrolytic runs were carried out in the presence of 10.0, 20.0, 30.0 and 50.0 wt% K2CO3 of used shell sample. Steam gasification runs were carried out at 925, 975, 1025, 1075, 1175 and 1225 K temperatures. The ratios of water-to-hazelnut shell sample (W/HS) were 0.7 and 1.9 in steam gasification runs. The total volume and the yield of gas from both pyrolysis increase with increasing temperature. The highest hydrogen-rich gas yields were obtained from the alkali (30% K2CO3) at 1025 K and from steam gasification (W/HS = 1.9) at 1225 K runs.