Hydrogen production by means of catalytic gasification of plastics

"Gasification processes can play a key role in the clean energy production from fossil and non-conventional fuels because of its transformation in a synthetic gas (syngas) rich in hydrogen and carbon monoxide. Fluidized bed reactors, both bubbling and circulating, allow use a catalytic or reacting solid material in partial or total substitution of the bed in order to promote the dehydrogenation of the fuel. The catalyst has, depending on the operating conditions of reactor and of fuel type, a strong influence on the hydrogen yield; otherwise, the effect of catalyst add to a fluidized bed can decrease with time due to progressive deactivation. The experimental tests demonstrated that the utilization of a low-cost bed material (olivine), recognized in the literature as a good catalyst for gasification process of biomass and plastics, allows enhancing the de-hydrogenation of a polymer used as fuel (PE) by producing an hydrogen-rich syngas and a coke phase. The tests also indicated that the olivine underwent a chemical interaction with the CnHm intermediate products so that it was not capable to catalyse the de-hydrogenation process for long time because of unavoidable loss of metals diffused and linked to the carbonaceous solid (coke)."