Project

Use of co-products

Valorization of co-products

In the sunliquid® process which converts agricultural residues such as straw into cellulosic ethanol, two other co-products are derived: a solid one, lignin, and a liquid one, vinasse. Lignin can be used as a combustible material in a combined heat and power (CHP) plant to produce steam and green electricity for the process. Vinasse can be used as a fertilizer on the fields or energetically in a CHP plant. This makes the process highly sustainable and energetically neutral without the need for additional fossil resources.

Thermal usage of lignin

Lignin is a solid co-product of the hydrolysis step and can be used as a source of energy for the process. The LIGNOFLAG Consortium will deliver the lignin to a CHP plant nearby the cellulosic ethanol plant in order to produce the steam and electricity needed for the sunliquid® process. In-depth calculations have shown that this combination enables the sunliquid® plant the highest CO₂ reduction of up to 95 % while making it energy self-sufficient.

The LIGNOFLAG Consortium is developing the infrastructure and processes needed to efficiently use lignin as a raw material for thermal production in a CHP plant. This includes:

• Establishment of the most practical transportation channel for the lignin from the cellulosic ethanol plant to the CHP plant
• Evaluation and definition of the detailed design of required equipment (e.g. pipes, conveyor belts) as well as planning and engineering activities

Vinasse as a fertilizer

Vinasse is a liquid co-product of the fermentation process, which can be used as an agricultural fertilizer. The LIGNOFLAG Consortium is evaluating the possibility to use vinasse from the cellulosic ethanol production as a fertilizer for local agriculture. Using the vinasse from the sunliquid® process as fertilizer, will bring back the nutrients to the fields where they originated closing the nutrient cycle. Within LIGNOFLAG, the project team will test and optimize the vinasse under real conditions. This includes:

• Analysing current practices and needs of local farmers’ for fertilization
• Analysing various options to transport the vinasse from the plant to the farmers and how it can be stored
• Analysing of the composition of vinasse and the evaluating of how additives or blends with other substances and materials can increase the value of vinasse as a fertilizer
• Conducting field tests, in which vinasse is applied to a test field that grows a variety of plants
• Identify and completing the needed documents to certify vinasse as a fertilizer so it can be applied to agricultural land
• Defining the specifications for vinasse and requirements for the equipment and machines for the most suitable and efficient application on the field.