Repurposed Materials Challenge: Post-Soda Lime (20 K € in Prizes)

Mario HonrubiaRecent ChallengesSustainability Challenges

Despite its high efficiency and effectiveness, Solvay soda production is burdened with large amounts of waste and by-products from the process, which account for approximately 40 % of the soda ash production volume. Can you help CIECH to find new applications (apart from agriculture) for post-soda lime or add value by improving its properties? Join the ennomotive challenge (click on the button below), register, and download the complete description of this competition. 

Summary of the Post-Soda Lime Challenge

Post-soda lime, waste originated in soda production, is obtained by separating the solid phase present in the distillation fluid. In Polish facilities, distillation sludges, after washing (in order to remove chlorides), are directed to compaction on filter presses.  It mainly contains calcium carbonate, calcium sulfate, magnesium hydroxide, silica, lime scale solids, and unreacted calcium hydroxide, calcium and sodium chloride (full composition can be downloaded after joining the challenge). Post-soda lime is applied in agriculture as a calcium fertilizer, containing 50% water and up to 3% of chlorides.  The agricultural use of “soda-lime” is related to its seasonal sales and is limited to Poland only. The low added value really limits the transportation feasibility to a radius of 100 km anyway.

What CIECH is looking for

CIECH, a leading European soda manufacturer, is seeking for new applications for “post-soda lime” such as new marketable solutions or products (other than calcium fertilizers for agriculture): 
  • Propose new application areas for post-soda lime and provide its chemical and physical properties.
  • Provide the process/technology description for the conversion process of the existing material into the new product.
  • Possible/assumed economic effects (Business Case).
Existing applications from other industries can be submitted as proposed solutions. 

Evaluation criteria

All proposed solutions will be evaluated by the following criteria:
  • Technical feasibility.
  • The highest volume of material used (partial volumes will be also evaluated)
  • The best Business Case (the lowest operational cost and the highest value)
  • The lowest hazard of the product generated or solution provided.


This is a 2-round tournament with the following timeline:
  • 1st round – 6 weeks + 3 weeks for evaluation
  • 2nd round – 4 weeks + 2 weeks for evaluation

Prize: 20,000 EUR

The participants that submit the best solutions from Round 1 will share 5,000 EUR,  as long as they continue participating and deliver detailed solutions in Round 2.  The best solution from Round 2 that meets the evaluation criteria will be awarded 12,000 EUR. The second and third best solutions will also receive 1,500 EUR each. The client may be interested in further collaborating with the participants in the development of the proposed solutions. Participate in the challenge