Air-ink: ink from air pollution

Is it possible to reduce CO2 emissions and at the same time make ink from air pollution?  It sounds too good to be true. Indian startup Graviky Labs says they are able to do this with their new Kaalink technology. By fitting a device on a tail pipe the exhaust fumes can be captured and be purified chemically so that a black ink from carbon particles remains. The particles are about 1/30 the diameter of a human hair.
About 45 minutes of car exhaust is necessary to produce 30 milliliters of ink. The Asian beer brand Tiger is the first to use this Air-ink. They give the ink to street graffiti artists. Unfortunately it is not (yet) possible to print with Air-ink.
It makes sense that an Indian company is the first to invent this. Delhi is the most polluted city in the wold.