PROCÉDÉ ET APPAREIL DE STOCKAGE D'ÉNERGIE RENOUVELABLE SOUS FORME DE GAZ

摘要

The present invention is in the field of gas production and more particularly relates to a method and an apparatus for the production of product gas from carbonaceous material such as biomass. The method and apparatus according to the invention employ direct heat transfer between carbonaceous material and a hot gas where the product gas is reheated and recycled through a carbonaceous material. The present invention provides a method comprising the steps of: a) heating a gaseous medium by thermal energy, b) transporting the heated gaseous medium to a first reactor containing carbonaceous feed material, c) heating the carbonaceous feed material in the first reactor to a temperature of at least 400 oC by means of the heated gaseous medium so as to form components of a product gas, the gaseous medium of step c) is directed to a second reactor containing carbonaceous feed material and the gaseous medium is forced through the carbonaceous feed material of the second reactor, d) withdrawing at least part of the product gas after the gaseous medium has passed the carbonaceous feed material of the second reactor, and e) recirculating the rest of the gaseous medium to the first reactor thereby continuing the production of product gas through steps (a)-(d), the circulation of gaseous medium from the first reactor to the second reactor continuous until a set point has been reached and/or until a pre-set time has been reached and then the direction in which the gas is circulated is reversed, wherein the heating performed in step (a) is provided by an electrical source.