Decarbonisation Technology - November 2021

GTL fuels are non-toxic, biodegradable and are significantly less harmful to the environment and human health

pollution components as those emitted from road transport vehicles, power plants and waste incineration. However, most of the sulphur is removed from diesel for land-based transport, and SO 2 , NOx and PM are effectively cleaned from the flue gas from the larger power plants. By comparison, addressing of emissions from maritime activity has been insufficient. Maritime movement still represents a large portion of local pollutant inventories, specifically near coastal areas, with 70% of the emissions being deposited within 400km of land. 3 In addition to the noxious gases being emitted from the running engines of incoming and outgoing vessels, there is the considerable added impact of pollution emitted from auxiliary engines running idly to support the onboard electrical-based activity of big vessels from cargo ships and crude tankers to cruise liners while they are docked in port. As well as a potential drop-in fuel for support boat and smaller coastal craft, GTL is now a serious contender as an alternative drop-in fuel for auxiliary engines of larger ships. As an added benefit to support the shipping industry, projects to integrate GTL fuelling options for logistics companies’ HGVs at ports have already commenced. MARPOL set for change Marine pollution is regulated internationally, and one of the key international conventions for the Although LNG is increasingly used to propel larger cargo ships to help combat marine emissions, GTL as a drop-in fuel can power many smaller support boats

However, it is in maritime transportation that GTL fuel may see its greatest uptake.

GTL for shipping The maritime industry plays a very significant role in the world’s economy. While 90% of world trade, mainly undertaken by huge sea-going vessels such as cargo ships and crude tankers, is apparent to most people, there is a vast maritime sub-industry supporting their efforts – from pilot boats and docking tugs to barges and other small coastal vessels. Total maritime activity, therefore, is responsible for about 2.5% of global greenhouse emissions – or around 940 million tonnes of CO 2 annually. 2 With emissions consisting of sulphur oxides (SOx), carbon dioxide (CO 2 ), nitrogen oxides (NOx) and particulate matter (PM) from diesel fuel used to power all these vessels, they are now under close scrutiny by environmental authorities globally. Although LNG is increasingly being used to propel larger cargo ships in order to help combat marine emissions, an opportunity to use GTL as a drop-in fuel to power the many hundreds of thousands of smaller support boats and coastal craft has also been identified. The majority of these smaller vessels still use reciprocating diesel engines powered by intermediate or marine diesel fuel oils – otherwise known as ‘bunker oil’, derived from crude oil. These fuels produce high emissions, including CO 2 , NOx, SOx and PM. Combustion of bunker oil generates the same