Fish residue fuel for cruise ships

A Dutch company plans to use abandoned fish in a new initiative to use green energy to operate large cruise ships.

The new idea is to use the remains of fish processed for food and mixed with other organic waste, to generate biogas that will then be liquefied and used instead of fossil fuels in Norwegian cruise ship Hortigrotten.

Heavy fossil fuels used for trans-ocean transport are an increasing problem, because they are more polluted than fuel used in land vehicles. They release sulfur and other contaminants, which contribute to air pollution as well as climate change.

The conversion of ships to use biogas would reduce pollutants and reduce greenhouse gas emissions.

Hertigrotten operates a fleet of 17 vessels and by 2021 aims to convert at least six ships to use biogas and liquefied natural gas - fossil fuels but cleaner than many alternatives - and large batteries capable of storing energy from renewable sources.

The 125-year-old company also banned one-use plastic materials in an effort to be more environmentally sustainable and it operates sea cruises in the North and South Poles, two highly sensitive environments.

Biogas can be generated from most forms of organic waste by accelerating and activating the natural decomposition process to capture methane gas produced. All food industries produce organic waste, but are often disposed of in landfills, contributing to greenhouse gas emissions because they decompose.

Maritime transport has been further scrutinized, as many ships use heavy fuel oil because of its cheap price, and daily greenhouse gas emissions from the world's largest cruise ships can be as large as the emissions of one million vehicles on the road.