Corn cob waste valorization


Corn cob waste valorization

Kumwe Harvest is a new, post-harvest processor of maize, founded in Rwanda with the aim of improving the lives and incomes of smallholder farmers by innovating the post-harvest process and linking farmers to higher value commercial markets as a result.


Kumwe is a post-harvest processor of maize with a new model to transform the traditional post-harvest process into a quick, efficient and mechanized operation. The company purchases unshelled maize on the cob immediately after harvest, transporting it to a central processing facility for immediate threshing and drying, and then delivering it to local agri-businesses.

The downside of this model is that cob waste now accumulates at this central processing facility. In principle this could be returned to maize farmers, but due to the low value of the material versus transport costs, this is not economical. Currently the only buyer is a nearby mushroom farm, but only for a fraction of the cobs and production at Kumwe is ramping up. Processing the corn cobs into higher value products would solve the waste issue.

In order to solve the waste accumulation problem, the following solutions will be developed:

  • Corn cobs can be converted into non-carbonized briquettes using a manual press or a briquetting machine. Setting up this process can also support add-on concepts in the future, such as the two ones mentioned next:
  • Further processing of the cobs to activated carbon (biochar), through pyrolysis, and using this material for water purification.┬áThis is an innovative and sustainable way to solve water quality problems for nearby communities by using local materials.
  • Processing the cobs into boards that can be using for insulation or to make basic furniture (in a similar way to how IKEA planks are made from compressed sawdust).┬áThis product could be sold to local construction and furniture businesses, as an
    eco-friendly alternative to wood.


Through this project we intend to play a part in the achievement of the following UN Sustainable Development Goals:

SDG 3: Ensure healthy lives and promote well-being for all at all ages. One of the targets of this SDG is to substantially reduce the number of deaths and illnesses from hazardous chemicals and air, water and soil pollution and contamination.

Bringing to the local market a cooking fuel which is a better alternative compared to coal. Burning bio-briquettes has a much smaller impact on indoor air quality.

SDG 4: Ensure that all learners acquire the knowledge and skills needed to promote sustainable development through education for sustainable development and sustainable lifestyles.

Creating awareness for local people about alternative (sustainable) sources of energy and value-added materials achieved by an integral waste management, through educational programs.

SDG 6: Support and strengthen the participation of local communities in improving water and sanitation management.

This goal would be supported if the concept of using corn cob waste for water filtration proves to be viable and can be implemented locally.

SDG 8: Achieve higher levels of economic productivity through diversification, technological upgrading and innovation, including through a focus on high-value added and labor-intensive sectors.

Valorization of agricultural waste into alternative biomass energy sources (briquettes) and value-added materials (filtration material and cobsulate).

Main Activites

  • Conceptual design of the briquettes/pellets production process
  • Support for ordering equipment and possibly also for installation and commissioning
  • Prototypes of insulation material and filtration material
  • Setting up the educational program
Donate Become Partner
No vacancies available at this time.





Close out

View other projects

Do you need engineers to realise your project? Let us know!