Macadamia nut shells for producing activated charcoal

Types of food materials: Macadamia nut shells
Products obtained from research: Activated carbon and activated carbon with the ability to absorb ethylene to extend the shelf life of Barracuda mangoes (Namdokmai Sithong)
Products for sale: Diffuser from macadamia charcoal under the brand “MACADACOAL by PhanKlin”

Researcher: Asst. Prof. Dr. Wirongrong Tongdeesoontorn and team, Mae Fah Luang University
Adopter: Mr. Simeown Todsawongwat

When mangoes begin to ripen, they release ethylene gas. If the gas is absorbed, it will help delay the ripening and extend the shelf life of mangoes. This research used macadamia nut shells to produce activated charcoal. Activated charcoal from macadamia nut shells is used in the packaging and making trays for mangoes to absorb ethylene gas. As a result, the mangoes delay the ripening and extend the shelf life of mangoes, making it is suitable for transportation and export.

The first production process for making activated charcoal from macadamia nut shells begins with washing the macadamia nut shells with clean water. After that, the cleaned macadamia nut shells are dried under the sun and burned at a temperature of 650-900^oC. The charcoal obtained from the burning is ground and selected the size of 600 microns or equivalent to 28 mesh (Tyler). The finely ground macadamia charcoal is put in the oven at a temperature of 110-120^oC. The second process is to produce activated charcoal by taking the macadamia charcoal obtained from the first process and mixing it with phosphoric acid (H₃PO₄) to burn the macadamia shells into charcoal (carbonization) again with a smokeless electric furnace at a temperature of 500^oC. Then allow it to cool and rinse the activated charcoal with water. After that, put the activated charcoal in the oven at a temperature of 110-120^oC. This results in 25.94% activated charcoal from the weight of the fresh shells (both the outer shell and shell) with a porosity value, volumetric density, and iodine absorption within the range of the standard value of activated carbon according to the Thai Industrial Standards (TIS).

For testing the ability to absorb ethylene gas, it was found that the activated charcoal from macadamia shells can absorb ethylene gas in the containers. It can absorb ethylene approximately 60-80% of the total concentration. Then the application of preserving Barracuda mangoes was studied by packing the activated charcoal in the form of sachets (containing the charcoal) and molded pulp trays (mixing the charcoal into the trays). It was found that the activated charcoal from macadamia shells in both forms – sachets and molded pulp trays – could slow down the physical and chemical changes of the mangoes from ethylene gas. It showed that the use of the activated charcoal from macadamia shells to delay the ripening and to extend the shelf life of mangoes was suitable for transportation and export. However, absorbing too much ethylene could cause anthracnose disease, so the activated charcoal should be balanced.

Currently, the research led to its commercial use as an essential oil diffuser by Mr. Simeown Todsawongwat. The product name is diffuser from macadamia charcoal under the brand “MACADACOAL by PhanKlin”.

Project “Utilization of macadamia shell waste for activated charcoal production and its application as ethylene absorber for extending the shelf life of mango cv. ‘Namdokmai Sithong’

Supported by the National Research Council of Thailand (Fiscal year 2020)

Researcher

Asst. Prof. Dr. Wirongrong Tongdeesoontorn and team
School of Agro-Industry, Mae Fah Luang University
333 Moo1, Thasud, Muang, Chiang Rai, 57100
Email: wirongrong.ton@mfu.ac.th

---

Figure of the work

Application of the research

Product name: Diffuser From Macadamia Charcoal
Owner: Mr. Simeown Todsawongwat
Brand: MACADACOAL by PhanKlin
Facebook page https://www.facebook.com/profile.php?id=61551042323256&mibextid=ZbWKwL