Introduction

A new process for the treatment and conversions of carbonaceous wastes to “clean” fuel gases such as hydrogen and methane,  without emitting polluting gases into the environment. The new process is based on the integration between a hydrogasification reactor and a new generation steam reforming unit driven by renewable energy sources. It allows treatment and energy upgrading of different kind of mixed carbonaceous wastes (e.g. biowastes, plastic wastes, etc.) without emitting into the atmosphere harmful gases (e.g. combustion flue gases, dioxins, etc.). The carbonaceous waste is converted to “clean” fuel gases, such as hydrogen and/or methane, having an energy value higher than any other Refuse Derived Fuel (RDF) obtainable from the same feedstock.

Technical features

The process is based on a hydrogasification step combined with a new generation steam reforming unit: in the hydrogasification reactor the feedstock is reacted with hydrogen produced in the same process loop by steam reforming driven with “emission-free” renewable sources. Thus, no combustion will take place in the process. Overall, the process allows energy recovery from mixed carbonaceous wastes (e.g. biowastes, plastic wastes, etc.) to produce hydrogen and/or methane at controlled rates. Currently, processes recovering energy from wastes have several drawbacks: use of high temperatures (>700°C), which require costly materials, low efficiency, while combustion and partial oxidation lead to polluting gas emissions (e.g. dioxins). Hydrogasification at “low” temperatures (<500°C) mitigates the above issues but requires hydrogen supply to feed the process. The invention overcomes this limitation because hydrogen is internally generated in the developed process. TRL: 3

Possible Applications

• Waste management in small/large plants;
• Production of methane or methane/hydrogen mixtures for the current energy market (gas grid, mobility, etc.);
• “Green hydrogen” production for the emerging hydrogen value chain;
• Chemical storage of renewable energy;
• Decarbonization and CO2 capture.

Advantages

• Energy recovery from wastes without combustion, i.e. without polluting gas emissions in the environment;
• Production of “clean” fuel gases (hydrogen and methane);
• Flexibility on the production of methane/hydrogen mixtures with controlled compositions;
• Chemical storage of renewable energy.