The electrical energy to be stored will power an electrolyser to produce SynGas. It will be followed by a methanation reaction (Sabatier process) to obtain SNG. The SNG can be injected in NG grid or/and stored to be used in mobility. If the electricity used for the electrolysis has a renewable origin, SNG will be a sustainable low carbon renewable fuel, alternative to fossil Natural Gas.

The SynGas is obtained from an alkaline water electrolysis performed in a patented electrolyzer build with carbon-based electrodes and without gases separation - the O2 oxides directly the carbon of the electrode producing CO/CO2, which mixes with the H2 generating Syngas (GSYF Technology). Next path is a CO2 methanation process to obtain SNG: CO2 + 4H2 → CH4 + 2H2O AH=-165 kJ/mol

The methanation involve topics as thermodynamics, reaction mechanism and kinetic. The interest in the Sabatier reaction has provoked efforts in developing new and improved catalytic system. The CO2 methanation is an exothermic reaction favored at low temperature and high pressure, with a production of large amounts of heat per volume, compared with a low pressure process. Performances for higher SNG selectivity are influenced by the catalytic structure, temperatures of 450-650 K, and pressure of 1.5 MPa.

The product line is a compact Synthetic fuel' module of 5kW to 10 kW (1.000 lge/y), for back-up of Renewable Energies in off-grid applications, to replace conventional lead batteries. A Synthetic Fuel module is composed by:

  • A Electrolyzer GreenSynFuel to produce SynGas;
  • A catalyst reactor to produce Methanol;
  • A ICE methanol generator;
  • A Methanol tank;
  • A control unit.

The diagram bellow presents the module elements.

 Diagram of module elements

The module is connected to the Renewable primary energy source; it stores the excess energy produced (energy that is not consumed by the load) as Methanol. When the energy demand is not satisfied by the RES supply, the gap will be covered by an ICE generator fuelled by the stored Methanol. An automatic control unit/smart grid will manage the entire module. In future the ICE generator can be replaced by a DMFC, if technology proof to be reliable. A battery buffer will regulate the interactions among several energy sources. Models to produce other fuels (DME, diesel, gasoline, …) are in Agenda.

SynGas production

Laboratorial tests of mono cell electrolyser have been performed to proof the concept and to optimize operational parameters (voltage, temperature, electrolyte concentration, catalyst effect). These tests have been carried out with support of ISEL (Lisbon Engineering School).

Laboratorial tests