Leak detection and/or prevention for high temperature thermal process systems

A thermal process system, comprising:

• a retort assembly comprising a retort chamber and configured to substantially contain one or more process gases in the retort chamber during a thermal process;
• a heating assembly comprising one or more heating elements and configured to heat the retort chamber;
• a vessel housing positioned around the retort chamber and the one or more heating elements and configured to maintain a pressure or vacuum within the retort chamber;
• a process gas inlet configured to receive the one or more process gases into the retort assembly;
• a sealing gas inlet configured to receive a sealing gas into the vessel housing;
• a gas outlet configured to discharge one or more process gases from the retort assembly out of the thermal process system;
• and
• a leak gas detector downstream of the gas outlet and configured to detect a presence of a leak gas.

A system for recovering carbon, comprising:

• a pyrolysis reactor configured to generate hydrogen gas from a hydrocarbon through pyrolysis, wherein the pyrolysis reactor comprises:
• a retort assembly configured to:
• substantially contain the hydrocarbon and the hydrogen gas in a retort chamber during the pyrolysis;
• and
• house one or more fibrous substrates defining a deposition surface for carbon generated from the pyrolysis of the hydrocarbon;
• a heating assembly comprising one or more heating elements and configured to heat the retort chamber;
• and
• a vessel housing positioned around the retort chamber and the one or more heating elements and configured to maintain a pressure or vacuum within the retort chamber;
• a process gas inlet configured to receive the hydrocarbon into the retort chamber;
• and
• a carbon dioxide inlet configured to receive carbon dioxide from a carbon dioxide source into the vessel housing,
• wherein the retort assembly comprises:
• the retort chamber;
• and
• a removable retort lid configured to contact a wall of the retort chamber at a sealing interface, and
• wherein the sealing interface between the removable retort lid and the retort chamber is configured to form a non-hermetic contact seal.

A method, comprising:

• receiving, by a retort chamber of a retort assembly of a thermal process system, one or more process gases, wherein the retort assembly comprises the retort chamber and a removable retort lid configured to contact a wall of the retort chamber at a sealing interface, and wherein the sealing interface between the removable retort lid and the retort chamber is configured to form a non-hermetic contact seal;
• receiving, by a vessel housing positioned around the retort chamber, a sealing gas;
• maintaining, by the thermal process system, the one or more process gases at thermal process conditions in the retort chamber by at least:
• maintaining a temperature of the one or more process gases in a retort volume within the retort chamber above about 400° C.;
• maintaining a pressure boundary between a vessel volume within the vessel housing and an environment external to the vessel housing;
• and
• maintaining a flow of the sealing gas from the vessel volume into the retort volume to substantially prevent outflow of the one or more process gases at the thermal process conditions.