Apparatus and methods for determination of total and solid carbon content of engine exhaust

A method to determine solid carbon content of internal combustion engine exhaust, the method comprising:

• obtaining an engine exhaust sample from an internal combustion engine of a motor vehicle, the engine exhaust sample including carbon dioxide, carbon-containing solid particles and one or more additional carbon-containing non-solid substances;
• heating the exhaust sample in a first heating device to a temperature and in a presence of oxygen to oxidize at least 95% by weight of the carbon of the one or more additional carbon-containing non-solid substances of the exhaust sample and generating carbon dioxide thereby;
• diluting the exhaust sample with a diluent, wherein the diluent cools the exhaust sample and reduces a concentration of the carbon dioxide of the exhaust sample;
• removing at least 95% by weight of the carbon dioxide from at least a portion of the exhaust sample to provide an exhaust test specimen;
• heating the exhaust test specimen in a second heating device to a temperature and in a presence of oxygen to oxidize at least 95% by weight of the carbon of the carbon-containing solid particles of the exhaust test specimen and generating carbon dioxide thereby;
• cooling the exhaust test specimen in a cooling device,
• determining an overall quantity of carbon dioxide of the exhaust test specimen;
• and
• determining an overall quantity of carbon of the exhaust test specimen using the overall quantity of carbon dioxide of the exhaust test specimen.

An apparatus to determine carbon content in internal combustion engine exhaust, the apparatus comprising:

• an inlet configured to obtain an engine exhaust sample from an internal combustion engine of a motor vehicle;
• a first heating device configured to receive the exhaust sample from the inlet, and heat the exhaust sample to a temperature and in a presence of oxygen to oxidize carbon of one or more carbon-containing non-solid substances of the exhaust sample without oxidizing carbon-containing solid particles of the exhaust sample;
• a diluter configured to receive the exhaust sample from the first heating device, and to dilute the exhaust sample with a diluent which cools the exhaust sample and reduces a concentration of carbon dioxide of the exhaust sample;
• at least one carbon dioxide adsorber configured to receive the exhaust sample from the diluter, and to remove carbon dioxide from at least a portion of the exhaust sample to provide an exhaust test specimen;
• a second heating device configured to receive the exhaust test specimen, and heat the exhaust test specimen to a temperature and in a presence of oxygen to oxidize carbon of carbon-containing solid particles of the exhaust test specimen;
• a cooling device configured to receive the exhaust test specimen from the second heating device, and cool the exhaust test specimen,
• a carbon dioxide analyzer configured to receive the exhaust test specimen from the cooling device, and to determine an overall quantity of carbon dioxide of the exhaust test specimen;
• and
• a computer device configured to determine an overall quantity of carbon of the exhaust test specimen using the overall quantity of carbon dioxide of the exhaust test specimen.