A conversion of a real refinery naphtha cut (low quality) to a strong anti-knocking upgraded fuel is proposed. The ultimate upgraded fuel could potentially replace the harmful gasoline ether oxygenates (MTBE, ETBE, TAME) from the refinery blended gasoline pools with an in situ and an environmentally friendly catalytic process. An integrated application of heterogenised homogeneous catalysis in aqueous media will take place in the proposed fuel upgrade process. Aqueous biphasic Rh/TPPTS-catalysed hydroformylation reaction of olefins present in a real Greek refinery naphtha cut comprises the first part of the two-step proposed process. The second part of the proposed naphtha upgrade process is the in situ hydrogenation of the hydroformylated product catalysed by Ru/TPPTS complex in aqueous media. Both catalytic systems of Rh/TPPTS and Ru/TPPTS have been revealed as effective catalytic systems for biphasic hydroformylation and biphasic hydrogenation of complicated mixtures, respectively. The properties of the ultimate upgraded fuel will be determined and the whole industrial process will be modelled and simulated facilitating the implementation of the proposal at the industrial field. This “green” process, with potential refinery application, which offers an easy and efficient recovering of the catalyst by using simplified techniques, it will increase the concentration of oxygen on the ultimate fuel improving its combustion properties. The new composition of the final fuel will contain less harmful and water-soluble compounds than MTBE/ETBE/TAME, the FON (Front Octane Number) and the RON (Research Octane Number) of the ultimate fuel will be raised, the produced long-chain alcohols should achieve a better solubility in the fuel and it will improve the storage stability of the ultimate fuel by reducing the content of olefins, diolefins and aldehydes.
The ban on TEL (Tetra-Ethyl Lead) in the early of 1970s and also the installation of the two-way and then three-way catalytic converters in automobile exhaust since 1975, which were intolerant of lead, led the refinery industry to the use of high-octane oxygenated components, called “oxygenates” (US CAA Amendments 1977, 1990; EU Fuel Quality Directive 98/70/EC; Directive 2009/30/EC). Hitherto, ether oxygenates (MTBE, ETBE, TAME) are added to certain gasoline (petrol) formulations to improve combustion efficiency and to increase the octane rating, known as gasoline ether oxygenates (GEOs) or fuel-ethers. Greece, as well as Germany, Italy, Finland and France, produces and uses methyl tert-amyl ether (TAME) as GEO. The production capacity in TAME of the Aspropyrgos refinery in Greece is approximately 128,000 tpa, while the European production capacity in TAME for 2011 was ca. 586,000 tonnes. However, despite the fact that TEL was replaced by GEOs, due to the environmental consequences and the severe human health effects of the former; it is worthy of remark that the GEOs took the place of TEL as suitable octane boosters in the refinery blended gasoline pool and not as environmentally benign compounds (Bonventre et al. 2012). An environmentally friendly two-step in situ synthesis of an upgraded fuel that could replace the harmful TAME from the refinery blended gasoline pool is being investigated. Moreover, it is noteworthy that the ultimate product (fuel) will contain more oxygen providing better combustion properties and bigger octane numbers. The standard properties of the ultimate upgraded fuel will be fully determined and the whole industrial process will be modelled and simulated facilitating the implementation of the proposal at the industrial field.
To the best of our knowledge, this will be the first integrated application of aqueous heterogenised homogeneous catalysis in fuel upgrade with a potential in situ replace of the harmful gasoline ether oxygenates from the refinery blended gasoline pools. The high-tech equipment of Hephaestus Advanced Lab could fully cover the research and developments needs of the proposed project.
The ban on GEOs in many states of US, due to the environmental restrictions, reveals that there is a need of replacing GEOs in refineries. The proposed environmentally benign process will offer an upgraded fuel not by putting additives, as usually, but by in situ conversion of an existing low quality feedstock to strong anti-knocking ingredients of gasoline.