Under 4-year project from 2022 to 2026, Trong Duc Cocoa in Vietnam began feeding 5,000 tons of discarded cocoa pods into a gasifier. Now, the waste helps dry fresh beans in 7 days instead of 15 during the rainy season

Agricultural production often leaves behind large quantities of material that have little immediate value. Finding ways to reuse those leftovers can reduce the burden of disposal while also allowing businesses to recover energy or other useful resources from materials that would otherwise be discarded.

That is the approach being taken by Trong Duc Cocoa Co. Ltd. in southern Vietnam. The cocoa processor has developed a system that puts discarded cocoa pods back into its production process, turning an annual waste stream into a source of heat and biochar.

A large amount of cocoa waste

Trong Duc Cocoa Co. Ltd. experiences the same challenge every year after harvesting and processing raw cocoa fruit. Almost 5,000 tons of empty cocoa pods remain after the beans have been removed.


Only a relatively small portion of a cocoa fruit finally becomes the cocoa material associated with chocolate production. The rest remains as agricultural residue that needs to be handled.

For the processing facility, the resulting mounds of waste may have environmental concerns if the material is simply left to accumulate.

Trong Duc has therefore moved away from treating the pods solely as something to dispose of. Instead, the company has found a way to incorporate them into its own production operations.

The project helped Trong Duc turn a major waste challenge into an opportunity.

Why cocoa pods create such a challenge

Trong Duc is Vietnam's second-largest cocoa producer and buys raw cocoa fruit directly from farmers. Direct getting helps the company maintain bean quality, but it also means the processor receives the outer portions of the fruit along with the beans.

After the beans are removed, each cocoa fruit leaves behind a huge outer shell after the beans are removed.

Those shells represent most of the fruit's overall weight. Consequently, much of the original cocoa fruit continues to be behind once the beans are removed.

For agricultural processors, managing this material can require additional space, labor and disposal arrangements. Rather than continuing to treat the pods as a liability, Trong Duc started searching for ways to use the cocoa pod material.

The resulting solution is based on a circular system in which the discarded material is converted into useful outputs for both energy production and soil use.

From discarded pods to energy and biochar

The process helps to describe how the system operates. The cocoa pods are initially shredded and dried before being fed into a Torch Updraft Gasifier.

Inside the gasifier, temperatures can be near 770 degrees Celsius, or 1,418 degrees Fahrenheit.

The intense heat transforms the cocoa-pod material into biochar. At the same time, the gasification procedure generates a smokeless flame and a clean gas that can serve as an energy source.

Rather than enabling that energy to escape unused, the company puts the clean gas to work generating heat for its operations.

That heat is then used to dry cocoa beans, along with other heat sources.

The outcome is a closed-loop arrangement: material left over after one batch of cocoa is processed becomes part of the energy supply used to process the next batch.

Drying time falls from 15 days to 7

The system addresses a particularly difficult part of cocoa processing: drying beans during Vietnam's rainy season.

Before the new approach was introduced, almost 15 days were required to dry cocoa beans during periods of high humidity. The new process has reduced the drying duration to approximately seven days.

That is close to the drying time achieved during the dry season.

The improvement matters as extended exposure to humid conditions can increase the possibility of mold developing on the beans. The new process minimizes the possibility for developing mold, helping protect the quality of the finished cocoa.

The challenging aspects connected with drying cocoa beans become mainly pronounced during the rainy season, when higher humidity slows moisture removal and elevates the likelihood of mold.

Both issues can reduce the quality and value of dried cocoa beans.

As per the Southeast Asia Development Solutions, the improved process brings the drying performance much closer to conditions normally achieved in the dry season.

Support from SWITCH Asia

The project received support from the European Union-funded SWITCH Asia program.

That support is connected to the project's circular-economy approach. Instead of sending agricultural residue away for disposal, the system keeps the material within the production cycle and extracts additional value from it.

The cocoa pods now serve two important purposes: they provide material for biochar production and contribute to the energy needed for cocoa-bean drying.

Source: THE PULSE

FAQs:

Q1. What happens to cocoa pods after harvesting?

Cocoa pods remain after the beans are removed from the fruit. These leftover shells can create significant waste for cocoa processors.

Q2. Why are cocoa pods considered agricultural waste?

Most of the cocoa fruit does not become chocolate, leaving substantial pod material behind after processing. Managing this material can require additional space, labor and disposal.