Abstract
In order to diminish the climat changes due to greenhouse gases, the capture from the source, transport and storage of carbon
dioxide is one of the environmental priorities of the EU until 2050. Transportation of this gas through pipelines (one of the
solutions with most advantages in transport) can be done at ambient temperature only at high pressures, so the carbon dioxide to
remain in the supercritical state. In case of underground pipelines, there is a risk of cracking at the wall of the pipe, with the
release into the atmosphere of a large quantity of gas. The authors demonstrate the existence of a threshold at which the
properties of the material change from ductile to brittle properties due to depressurization of the pipe, which has the effect of a
rapid drop of the temperature in the crack. This paper presents the factors influencing the ductile-brittle transformation and the
factors influencing this transition. Changing to brittle proprieties into the material of the pipe, leads to a rapid increase of the hole
through which the CO2 leaks. As these pipes are part of a vast network, the amount of carbon dioxide released into the
atmosphere can be considerable, affecting the neighboring ecosystem, contributing to the local change of temperature regime and
to global warming, by the high concentration of CO2 in a large area.