Method of compacting ash deposited in a particulate filter by providing a low-temperature melting salt to said filter

A method of compacting an ash deposited in a particulate filter for a vehicle exhaust gas system associated with a combustion engine, the method comprising the steps of:

• a) providing a low-temperature melting salt to the particulate filter via the vehicle exhaust gas system during an operation of the combustion engine, whereby the low-temperature melting salt forms a mixture with the ash in the particulate filter,
• wherein the low-temperature melting salt comprises at least one cationic component and at least one anionic component, wherein the at least one cationic component is lithium (Li+), sodium (Na+), potassium (K+), rubidium (Rb+), caesium (Cs+), calcium (Ca2+) or ammonium (NH4+) ion, and the at least one anionic component is fluoride (F−), chloride (Cl−), bromide (Br−), iodide (I−), nitrate (NO3−), or sulphate (SO42−) ion;
• and
• b) heating the particulate filter, by at least one of raising a temperature of an exhaust steam or using a heating element, to a selected compaction temperature, at which selected compaction salt the mixture of the ash and the low-temperature melting salt to compact in the particulate filter.

A vehicle comprising:

• an internal combustion engine;
• an exhaust gas system arranged to convey exhaust gases from the internal combustion engine, the exhaust gas system comprising a particulate filter for trapping ash and/or soot dispersed in the exhaust gases;
• and an oil for use as a lubricant in the internal combustion engine, said oil comprising:
• a base lubrication oil;
• and
• a low-temperature melting salt dispersed in the base lubrication oil, the low-temperature melting salt comprising at least one cationic component and at least one anionic component, wherein the at least one cationic component is lithium (Li+), sodium (Na+), potassium (K+), rubidium (Rb+), caesium (Cs+), calcium (Ca2+) or ammonium (NH4+) ion, and the at least one anionic component is fluoride (F−), chloride (Cl−), bromide (Br−), iodide (I−), nitrate (NO3−), or sulphate (SO42−) ion, wherein when heated releases the low-temperature melting salt into the exhaust gas system and is thereby used to compact ash in the particulate filter of the exhaust system.

An engine system for a vehicle, the engine system comprising:

• an internal combustion engine arranged to be operated by combustion of a fuel in intake air, arranged to be lubricated by means of an engine oil, and arranged to generate exhaust gases upon combustion of a fuel;
• a fuel supply system arranged to convey the fuel to the internal combustion engine;
• an air intake system arranged to convey intake air to the internal combustion engine;
• a lubrication system arranged to convey the engine oil to the internal combustion engine;
• an exhaust gas system arranged to convey the exhaust gases from the internal combustion engine, the exhaust gas system comprising a particulate filter for trapping ash and/or soot dispersed in the exhaust gases;
• and
• a salt dosing unit arranged to provide a low-temperature melting salt to the particulate filter, where the low-temperature melting salt comprises at least one cationic component and at least one anionic component, wherein the at least one cationic component is lithium (Li+), sodium (Na+), potassium (K+), rubidium (Rb+), caesium (Cs+), calcium (Ca2+) or ammonium (NH4+) ion, and the at least one anionic component is fluoride (F−), chloride (Cl−), bromide (Br−), iodide (I−), nitrate (NO3−), or sulphate (SO42−) ion;
• wherein when heated releases the low-temperature melting salt into the exhaust gas system and is thereby used to compact ash in the particulate filter of the exhaust system.