MILD Combustion with Nitrogen and Carbon Dioxide Reforming

Reduced net emissions of carbon dioxide (CO2) are necessary to achieve the goals of limited global warming and ensure a sustainable future for our society. This proposal presents a versatile and scalable process for management and valorization of CO2 and nitrogen.

Starting from biomass residues, a first step in the proposed scheme involves a pyrolysis process that results in the release pyrolysis oil of rather low heating value.

However, combustion under very diluted conditions using a Moderate or Intense Low-oxygen Dilution (MILD) concept allows for efficient and low-pollutant energy conversion. The MILD combustion process is utilized for a CO2 reforming step resulting in generation of syngas.

The pyrolysis and the reforming are supplied by heat from the MILD combustion that can be further supplemented by intermittent energy sources such as solar and wind power.

The residual char product from the pyrolysis step can be upgraded by activation with CO2 and utilized for adsorption of nitrogen from biomass. The nitrogen-enriched char can then be used for soil carbonization and nitrification. The concept thus addresses the objective of CO2 and nitrogen management with efficient renewable resource deployment.

It also adopts a circular approach as it can employ biomass residues as raw material and combines the production of heat and syngas with that of porous biochar materials for several possible utilizations.

The process can be adapted by multiple parameters and optimized for different conditions and purposes, and rather than optimizing on a single product or aspect, the concept brings a holistic view.

The development of the process will include experimental research with state-of-the-art analysis methods, based on laser diagnostics and neutron scattering, combined with numerical modeling of the thermochemical processes. Life-cycle analysis will be made during the project to guide process development and assess its impact.