05/05/2026
What is a Desolventising Toaster?
A DT is a multi-stage thermal processing unit used after solvent extraction to treat the oil-free meal (Extracted marc – which is a mixture of deoiled bran with residual oil and solvent). It uses both direct (open) steam and indirect steam heating to condition the meal before it leaves the plant.
How does it work? — The 3 Stages
1️. Desolventisation
After oil extraction, the meal still contains residual hexane (the solvent). Controlled steam application evaporates and recovers this hexane. This step is critical for safety, solvent economy, and regulatory compliance.
2️. Toasting
Heat treatment here is not just drying — it's a biochemical transformation. The right temperature deactivates anti-nutritional factors, enhances protein digestibility, and improves the overall nutritional profile of the DOC — making it suitable as high-quality animal feed.
3️. Drying & Cooling ( This part can be an integral part of the Desolventiser toaster. Usually, for smaller capacities below 500 MTD, this is done separately in the deoiled meal godown.
Final moisture correction ensures the meal is shelf-stable. Too wet = mould and spoilage. Too dry = dusty, low-density, unmarketable product.
Why does Steam Management matter so much?
The DT consumes nearly 40% of total plant steam — making it the single largest energy consumer in the plant. Improper steam control leads to:
*Hexane Losses — Incomplete desolventisation means solvent escapes unrecovered, raising costs and safety risks.
*DOC Overheating — Excess heat darkens colour, damages protein quality, and reduces market value.
*High Steam Consumption — An unoptimised steam flow inflates energy costs across the entire plant.
