Babcock launches ethane BOG reliquefaction technology

Neale Campbell, Managing Director, Babcock LGE said: “ecoETHN is a breakthrough addition to our portfolio of gas handling technologies. We continue to challenge ourselves and develop solutions that we believe will meet the current and future needs of our customers while providing environmental and commercial benefits within the gas handling market.”

ecoETHN is designed to handle ethane cargoes with high methane content of up to 2.0 mol% in the liquid phase, and also effectively handles methane enrichment in the BOG more efficiently than conventional reliquefaction solutions.

Utilising Babcock’s SuperCooler and VGC technologies, the system allows selection of BOG compression and refrigerant systems removing the traditional constraint to fully condense the BOG in a single step, thus maximising efficiency.

When combined with ethane fuelled engines, the system uses cold energy in the low temperature ethane fuel stream, to increase the efficiency of the overall system by cooling the BOG. A portion of the methane rich stream can also be blended into the fuel, reducing the amount of valuable ethane component in the cargo that would otherwise be consumed as fuel.

In addition, low and medium pressure methane rich gas streams from the reliquefaction system can be used as fuel for auxiliary power generators, thus utilising an even greater proportion of the methane-rich BOG rather than fuels such as LSFO or MGO, bringing environmental benefits.

The system has the additional benefit of utilising the BOG ‘fuel’ in the auxiliary engines during loading, when, generally, the main engine is not consuming any fuel – improving the loading rate and creating further cost savings to end-users.

On a typical deep-sea voyage, ecoETHN, when integrated with ship main engine and power generation systems needs only one reliquefaction system, giving CAPEX and OPEX benefits. It is a cost effective solution that minimises both capital and operational expenditure through the unique combination of reliquefaction and a fuel delivery system, and is already attracting significant interest from a number of global ship owners and shipyards.