Domenico Sanfilippo

One-Step-Hydrogen: a new direct route by water splitting to hydrogen with intrinsic CO2 sequestration

Publisher Summary The One-Step-Hydrogen process is aimed to produce hydrogen from water splitting and also to tackle the carbon management issue targeting a zero carbon emission at lower costs than allowed by the Best Available Technologies (BAT). Well known water possesses an oxidizing potential which can be utilized in a simple water splitting application where it reacts with selected metals to give pure hydrogen. So combining in a cycle the water oxidative potential and the reverse action by a reducing agent like hydrocarbons, it allows the hydrogen production and as well as the intrinsic carbon dioxide sequestration. This chapter proposes this new process. In the first step, a suitable oxide takes up the oxygen from water splitting producing hydrogen. The solid acts as an oxygen storage medium. Such “lattice” oxygen is in turn released through one or more elemental steps. The overall reaction is endothermic and an energy supply is needed to close the energy balance. The decoupling of the overall reaction into three separated reactions allows the process to overcome the thermodynamics constraints of the overall equilibrium. The major breakthrough is however the exit of the two main products—hydrogen and carbon dioxide—from two different vessels, so that the carbon dioxide, once water is condensed, is pure and ready to be buried.

General Mechanism for the oxidative coupling of methane

A detailed mechanism, composed of 27 reactions, for the oxidative coupling of methane is described. The main products may derive either from a surface route or from a gas phase pathway. The kinetic parameters of the model, handled by a computer program, have been calculated from general chemical laws. The proposed mechanism has been calibrated on the data of the Li/MgO catalyst, studied by Lunsford and co-workers. The key steps are discussed in details and the fair good agreement between calculated and experimental data is given.

SNOW : Styrene from ethane and benzene

Publisher Summary Styrene is one of the most important monomers for the production of polymers, resins, and rubbers. Styrene production exceeds 25 million MT/y. The biggest consumer of styrene monomer (SM) is polystyrene (PS). Other major derivatives are expanded polystyrene (EPS), SB latex, SB rubber, styrene block copolymers (e.g., ABS, MBS, and SBS), and unsaturated polyester resins. SM is a commodity, and a lower production cost is a critical factor in the value chain of its derivatives. The styrene market has been growing at a rate of 4.4% yearly for the past several decades. It is expected that worldwide capacity will expand by 5.5 million MT over the next five years. There are two commercial routes for the synthesis of SM: (1) the classic and largely applied EB/SM route and (2) alternatively and to a lower extent, (