Title : A new catalyst for the conversion of aromatics to HC and CO-rich gas
Abstract:
A novel autothermic pyrolysis process followed by a hybrid mobile-fluidized bed catalytic reactor is used to produce carbon nanofilaments (CNF) from waste plastic streams. The autothermic pyrolysis unit produces a gaseous stream rich in aromatic compounds which are precursors of polymeric carbon rather than the targeted CNF. The catalytic production of CNF is favoured by the presence of CO and unsaturated light hydrocarbons (HC), such as
ethylene.
The main target of this work is the formulation and testing of a new catalyst able to reform toluene, an aromatic compounds surrogate molecule, in a way to maximize its conversion into CO and light unsaturated HC.
The new catalyst is made of olivine functionalized with alumina and nickel. The catalyst was prepared by the incipient wetness method through mixing olivine with nickel and aluminium nitrates, then drying and calcining the mixture for 8 hours at 900°C.
The reforming experiments are conducted in a fixed bed reactor. Toluene and water were emulsified with H2O/C ratio equal to one then injected into the reactor.
Preliminary tests, performed at 750° C with two catalytic formulations show that the Ni content is an important parameter. Thus, the toluene conversion was 93% for the 5% Ni catalyst while a 36% conversion was reached with the 1% Ni formulation.
Outlet gases from the reactor were analysed by GC. It was found that the main products were H2 and CO, with 55% and 30% yields, respectively. The formulation containing lower Ni gave a gas product containing more unsaturated HC. The reaction optimization is underway and detailed results along with full mass balances will be presented during the conference.
The catalyst is analysed before and after the experiment through X-ray diffraction, BET, and FEG/SEM microscopy. These analyses provide useful information concerning the crystalline phases present in the catalyst, the specific area changes as well as the changes of the catalyst morphology
