How to get high added value products for industrial applications from agricultural wastes

Description of the technology

The research group Carbonaceous materials and environment of the University of Alicante has developed a simple process to obtain activated carbon (monolithic) from an agricultural residue scarcely used to date, such as cocoa shell, whose characteristics and technical features make it highly suitable for several industrial applications such as environmental decontamination, liquids and gases treatment and heterogeneous catalysis applications, among others. This process allows developing porous structures in a controlled way, without using binders or additional steps for consolidation. It can be applied to any mixture of agricultural and forestry residues. It is environmentally friendly and its industrial production requires low cost. The research group is looking for companies interested in acquiring this technology for commercial exploitation.

Specifications

Taking into account the above comments, present invention shows an easy synthetic process to obtain activated carbon pieces (monolith) from an agricultural residue unused to date, as it is the cocoa shell. For the preparation of activated carbon from cocoa shell, the required steps are: 1. Mounding of cocoa shell monolith through pressing. 2. Carbonization of monolith on inert atmosphere until a desired temperature, in order to obtain a carbon monolithic. 3. Activation of carbon monolith on carbon dioxide atmosphere, a fixed temperature during a specified time, in order to development porosity on the carbon piece to get an activated carbon monolith. Optionally, before pressing (step 1), the cocoa shell can be washing with acidified water in order to remove the mineral matter of cocoa shell. This pretreatment of cocoa shell are suitable in order to development a higher porosity on the final product. Through this procedure, it is possible to obtain activated carbon monoliths with a well-defined geometrical shape and good mechanical strength (see Figure 1). The activated carbon monoliths obtained are suitable for applications in different industrial sectors because of its porous texture (essentially microporous). This microporosity (pore size lower than 2 nm) is similar that is found with other activated carbon precursors, such as: tar, cellulose, anthracite, etc.

Main advantages of its use

• It allows revaluate vegetable waste into a high added value product for industrial interest.
• It does not required additional steps to strengthen monoliths.
• It has a suitable microporous structure for applications in industrial flows (liquid or gas).
• It is a very simple procedure.
• It is environmentally friendly.
• Raw material does not need additional binders, since show self-binder properties.
• The obtained monoliths have a high mechanical strength.
• This procedure can be applied to any mixture of agricultural or forestry wastes and it requires low cost production.
• This technology allows develop activated carbon with a controlled porous texture.
• This technology is viable (technically and economically).

Applications

• As drying agent.
• Catalyst support.
• Environmental remediation (for example: pollutant removal from air).
• Gas storage.
• Heterogeneous catalyst.
• Purification of gas streams.
• Recovery and concentration of fossil fuels.
• Removal of impurities.
• Separation of gas mixtures.
• Specifically, it is a viable revaluation (technically and economically) of cocoa husks for activated carbon monoliths in applications of different industrial sectors.
• This procedure takes place within the field of materials technology, and in particular, it relates to a method for synthesizing activated carbon monoliths from agricultural wastes.

Additional information (attached documents)

• Activated carbon monolith obtained from cocoa shell during the three different steps (from left to right): mounding, carbonized and activated - Fig1.jpg