Refining of Raw Cane Sugar

Sugar refining is a multi-stage process that transforms raw sugar juice or raw sugar into high-purity, food-grade crystalline sugar. Each step plays a critical role in removing impurities, reducing color, and improving crystallization. Here's a summary of the major stages involved: 🏗️ Raw Sugar Handling ↓ 🧴 Affination ↓ 💧 Melting ↓ ⚗️ Clarification ↓ 🧲 Filtration ↓ 🎨 Decolorization ↓ 🔥 Evaporation & Liquor Concentration ↓ 🧪 Crystallization ↓ 🌬️ Drying & Cooling ↓ 📦 Screening & Packaging 1. Raw Sugar Handling Before refining begins, raw sugar must be properly received, stored, and prepared. This stage includes: Receiving and Inspection : Raw sugar is delivered via trucks, railcars, or ships and inspected for moisture, color, grain size, and contamination. Sampling protocols ensure representative analysis, and substandard sugar may be rejected or diverted. Storage and Inventory Management : Accepted sugar is stored in silos or warehouses with mo...

Once raw sugar has been cleaned and melted, it enters one of the most transformative stages in the refining process: carbonation . This step is all about clarity — removing suspended impurities, reducing color, and setting the stage for high-quality crystallization. In this post, we’ll explore how carbonation works, why it’s essential, and how refineries optimize it for performance, yield, and sustainability. 🧪 What Is Carbonation? Carbonation is a chemical clarification method that uses lime (Ca(OH)₂) and carbon dioxide (CO₂) to precipitate impurities from sugar liquor. The goal is to form fine particles of calcium carbonate (CaCO₃) that trap and carry away colorants, ash, proteins, and other non-sugar materials. Think of it as a controlled snowstorm inside a tank — tiny calcium carbonate flakes form and settle, sweeping impurities down with them. This process takes place in a specialized vessel called a carbonator — a large, temperature-controlled tank equipped with agitators an...

Rotary pressure filters are extensively utilized in the sugar industry to filter carbonated liquor , a solution consisting of sugar and lime that has undergone carbonation to eliminate impurities. These filters are known for their ability to conduct both pressure filtration and cake washing within a single unit. A rotary pressure filter comprises a cylindrical drum that rotates at a gradual pace either horizontally or vertically. The drum is partitioned into multiple sections, each equipped with its individual filter medium, commonly made of cloth, and designated process zone. The drum is enclosed within a pressure vessel, which contains the feed slurry, wash liquid, and filtrate. Rotary pressure filter involves several key steps for proper filtration- Distribution: Carbonated liquor, containing a mixture of sugar crystals and molasses, is evenly distributed onto a filter medium (typically a cloth) that covers a rotating drum. The drum is divided into compartments, each filled with t...

 To dissipate the adverse effects Dextran and Starch may cause in the refining process, Dextranase & Amylase enzymes are used. Alpha amylase is used in sugar refinery to hydrolyze starch into glucose and other sugars that can be crystallized or fermented. Starch is an impurity in sugarcane juice that causes viscosity and filtration problems, delays or inhibits crystallization, increases sugar losses in molasses, and impedes decolorization in refining. Alpha amylase can reduce the starch content and improve the quality and yield of sugar. Alpha amylase can also enhance the flavor and color of sugar by producing maltose and other dextrins. The ideal temperature for alpha-amylase in sugar refining varies depending on the source and type of the enzyme. Generally, alpha amylase is a thermally stable enzyme that can work between 40-70°C. Although activity of some fungal alpha-amylases may increase with temperature as high as 70-90°C. The ideal temperature of the enzyme in sugar refi...

This article provides an overview of the adverse role of Dextran and Starch in the sugar production process, including their effects on the process house and measures to control them. Dextran Leuconostoc mesenteroides is a type of lactic acid bacteria that can break down sucrose into dextrose and levulose through a biological process. Dextrose and Levulose are monosaccharide isomers of Glucose and Fructose. Leuconostoc mesenteroides produces an enzyme called dextran sucrase during the break-down which causes the polymerization of dextrose into a polysaccharide called dextran. C12H22O11 => C6H12O6+C6H12O6 => (C6H12O6)n Sucrose => Dextrose + Levulose => Dextran Dextran isn’t a specific molecule but rather a group of long chain polysaccharides which have a varying range of molecular weight from 2000 to 20000. Dextran is formed when many glucoses is attached together at ɑ 1,6 by glycosidiclinkages. It may also have branches at ɑ 1,2 or ɑ 1,4 or ɑ 1,4. Generally, it has more tha...

Milk of lime(MOL), also known as lime slurry or lime milk, is a suspension of calcium hydroxide Ca(OH)2 in water. It is used in the sugar industry for pH correction and as an auxiliary of flocculation in bleaching of the sugar solution. Milk of lime plays an important role in improving the quality and purity of the sugar product. Lime is an essential and inexpensive clarifying agent used in juice clarification processes such as sulphitation, and carbonation. Preparation of Milk of Lime requires careful selection of raw materials, proper slaking process, adequate mixing and storage conditions, and regular quality control. In this blog post, we will discuss some of the factors that influence the preparation of milk of lime for sugar industries, and provide some tips and best practices to optimize the process. Lime is available in various forms such as quicklime, limestone, and hydrated lime. The raw materials for preparing milk of lime are quicklime (CaO) and water (H2O). As Quicklime an...

The carbonation process is a widely used method for refining sugar from raw sugar melt. It involves the reaction of calcium hydroxide and carbon dioxide to form calcium carbonate, which precipitates and removes impurities and colorants from the sugar solution. The carbonation process has several advantages, such as low capital and operating costs, high color and turbidity removal efficiency, low sugar loss and environmental friendliness. In this blog post, we will explain the main steps and equipment involved in the carbonation process, as well as some tips and best practices to optimize its performance. The goal of the carbonation process is to eliminate impurities that make raw melt liquor cloudy. Carbonation is typically used in refineries before any decolorizing process. It has a positive effect on sugar liquors, reducing color by 40-50% and ash content by 20-25%. Lime and carbon dioxide are added to the sugar liquor to create calcium carbonate precipitates that absorb impurities a...

After carbonation has done its job — removing suspended solids and reducing color — sugar liquor still contains dissolved ions and trace colorants that can interfere with crystallization and final product quality. That’s where ion exchange resins come in. Acting like molecular magnets, these resins polish the liquor by swapping unwanted ions for more desirable ones, helping refineries achieve the clarity and consistency needed for premium sugar. Let’s explore how the process works, what types of resins are used, and why this step is critical in the refining sequence. 🧲 What Are Ion Exchange Resins? Ion exchange resins are synthetic polymer beads designed to attract and hold specific ions from solution. They work through a reversible chemical exchange — trading ions in the resin for those in the sugar liquor. There are two main types: Cation exchange resins : Remove positively charged ions like calcium (Ca²⁺), magnesium (Mg²⁺), and iron (Fe²⁺), typically exchanging them for sodium (N...