CO₂ Adsorption in Ash Pellets for Microalgal Cultivation

GRANTED INVENTION PATENT

 

Technology Title: CO₂ Adsorption in Ash Pellets for Microalgal Cultivation

 

Inventors:

 

Bruna da Silva Vaz (Lattes CV)
Michele Greque de Morais (Lattes CV)
Jorge Alberto Vieira Costa (Lattes CV)

 

Academic Unit: School of Chemistry and Food – EQA

 

Overview:
Coal-fired power plants are significant sources of environmental pollution, emitting large quantities of pollutants and solid waste (ash) during electricity generation. CO₂ sequestration presents a viable option to reduce emissions without requiring underground reservoirs or changes to the current energy matrix. Coal ash is a low-cost alkaline residue suitable for mineral carbonation due to its high calcium oxide content. Based on this, these industrial wastes can be recovered and/or reused as low-cost adsorbents and/or nutrients through the cultivation of microalgae and/or cyanobacteria using coal ash pellets enriched with carbon dioxide (CO₂).

 

Description:
The present invention relates to the development of an innovative technology to reuse solid residues and gaseous effluents from thermal power sources by cultivating microalgae and/or cyanobacteria using coal ash pellets enriched with carbon dioxide (CO₂).

 

Problem Solved:
This patent aims to contribute to the recycling and/or reuse of industrial waste as bioengineering material through pelletization, while minimizing environmental issues caused by CO₂ emissions into the atmosphere (greenhouse effect and global warming). It also reduces microalgal production costs by utilizing alternative carbon sources such as CO₂ and minerals present in the ash.

 

Applications:
The technology has potential applications in treating gaseous effluents using flue gases generated during the combustion of coal (mineral or biomass), petroleum, petroleum derivatives, ethanol, wood (whole or fragmented), paper, cellulose, and residues from pulp and paper industries. It also applies to the treatment of solid waste (coal ash) in thermal power plants. By cultivating microalgae and/or cyanobacteria with CO₂-enriched coal ash pellets, these microorganisms produce organic matter rich in minerals, vitamins, carbohydrates, lipids, pigments, proteins, essential amino acids, and polyunsaturated fatty acids. These compounds can be converted into food, biopolymers, biofuels, and/or pharmaceuticals.

 

Advantages:

  • Enhanced biofixation capacity due to higher availability of adsorbed gas in the pellets and easy release after saturation;
  • Excellent flow properties and narrow particle size distribution;
  • High capacity for incorporating active substances or compounds;
  • Great dispersion in the culture medium;
  • Simultaneous valorization of solid and gaseous waste streams.
 

Patent Status: Granted. PATENT LETTER NO. BR 10 2014 017697 7, issued on April 13, 2021.
Technology Readiness Level (TRL): TRL/MRL 1

 

Abstract: Available at this link.