Upgrading of Vapors and Gases from Pyrolysis to Valued Added Gaseous Products
Abstract
This MSc thesis explores biomass pyrolysis and reforming, aiming to convert biomass-derived vapors into useful gases for synthesis and fuel. The study focuses on transforming high molecular weight molecules, like polycyclic aromatic hydrocarbons, and volatile organic molecules such as acids, alcohols, and other substances formed during pyrolysis into essential gases like hydrogen, methane, carbon monoxide, and carbon dioxide.
A dual-reactor system is employed: a CSTR for primary pyrolysis, followed by a PFR or PBR for secondary catalytic processing. Olivine is used as the catalyst.
The research compares three gas upgrading methods: thermal cracking, catalytic cracking, and catalytic steaming (reforming).
Results indicate that the use of olivine as a catalyst in dry and steam reforming leads to a significant increase in hydrogen and carbon monoxide production, with hydrogen yields reaching up to 40% and carbon monoxide up to 35% in the gas mixture. In comparison, thermal cracking resulted in lower hydrogen yields of around 20% and higher methane content.
Further analysis shows that catalytic reforming significantly reduces the presence of oxygenated compounds like acids and alcohols by up to 90%, improving the overall gas quality.