Introduction

The invention designed to be fitted onto glass melting furnaces, consists of a system to capture and convert part of the heat contained within the combustion exhaust gases into electric energy. The system embeds a direct thermodynamic engine cycle, that can be combined with others to optimize the energy harvesting process. Different units are combined to optimize the energy harvesting process and to enhance the flexibility of the energy usage. The electric energy produced can be combined with other external sources, preferably renewable (wind, solar), to boost the impact on the furnace optimised energy management.

Technical features

The electricity produced can be sold on the market as an energy recovery product or be used for the operation of the electrical auxiliaries of the furnace itself, such as the melting electrodes. This  can also be used to feed an electrolyzer to produce both hydrogen and oxygen that feed the furnace combustion process to reduce emissions.

Other components of the system are:

• A chemical reactor for gas fuel reforming using heat content from the combustion exhausts;
• A fuel desulphurisation unit fed with the hydrogen produced by the electrolyzer;
• An heat exchanger based on phase change materials to introduce thermal inertia into the system that can be used by other systems (i.e fuel pre heating).

All system components are at TRL 7-9 (demonstrative – commercial).

Possible Applications

• Melting glass furnaces;
• Any industrial systems with available exhaust heat at high temperature.

Advantages

• Reduction of fossile fuel consumption (natural gas);
• Reduced energy consumption;
• Reduction of production costs for a reusable (green) material (glass);
• Reduced CO2 emissions;
• Electric energy production from heat recovery.