Potassium dihydrogen phosphate (Monopotassium phosphate)
Acidity Regulators
Nutritional Enhancers
Emulsifiers
7778-77-0
E340
KH₂PO₄
$1.94 ~ $2.91
Food
Free sample from 100g(NF)
One unit of:25kg/carton
One unit of:25kg/carton
25kg/carton
Product Info
What is Potassium dihydrogen phosphate (Monopotassium phosphate)?
Monopotassium phosphate is a crystalline, water-soluble salt used extensively in agriculture as a high-efficiency fertilizer source of potassium and phosphorus, and in the food industry as a buffering agent, stabilizer, and nutrient supplement (E340(i)).
How is Potassium dihydrogen phosphate (Monopotassium phosphate) made?
| Step No. | Production Stage | Key Action | Control Point & Note |
|---|---|---|---|
| 1 | Raw Material Dosing | Precisely measure and feed high-purity Phosphoric Acid (H₃PO₄) and a potassium source (e.g., Potassium Hydroxide, KOH, or Potassium Carbonate, K₂CO₃) into the reactor. | Raw material purity directly impacts the final product quality (e.g., heavy metals content). The molar ratio of acid to base must be strictly controlled to ensure the correct phosphate salt is formed. |
| 2 | Neutralization Reaction | React the phosphoric acid with the potassium source in a stirred, temperature-controlled reactor. The reaction is exothermic. | Continuously monitor and control the reaction temperature to prevent boiling. The most critical parameter is the endpoint pH, which must be 4.2 - 4.5 to ensure the formation of monopotassium phosphate (KH₂PO₄). |
| 3 | Solution Purification | Filter the hot reaction solution to remove any insoluble impurities. Activated carbon may be used for decolorization if necessary. | The clarity and color of the filtered solution are key indicators of purity. This step is crucial for removing suspended solids and ensuring compliance with insolubles specifications. |
| 4 | Crystallization | Cool the purified, saturated solution under controlled conditions in a crystallizer to induce the formation of KH₂PO₄ crystals. | The cooling rate and level of supersaturation are the primary controls. These determine the final crystal size, shape, and uniformity. Slower cooling generally produces larger crystals. |
| 5 | Centrifugation & Washing | Separate the formed crystals from the mother liquor using a centrifuge. Wash the crystal cake with a small amount of deionized water. | Ensure efficient solid-liquid separation to achieve a low-moisture cake. The washing step is vital for removing residual mother liquor and improving the purity (assay) of the final product. |
| 6 | Drying | Dry the wet crystals in a fluid bed dryer or rotary dryer to remove remaining moisture to the required specification. | Drying temperature and time must be carefully managed to prevent thermal decomposition or crystal damage. The final moisture content (e.g., <0.2%) is a critical quality parameter affecting stability and caking. |
| 7 | Sieving & Packaging | Sieve the dried product to break up any agglomerates and ensure a uniform particle size distribution. Package into sealed, moisture-proof bags. | Verify particle size meets customer specifications. Final QC checks on a representative sample confirm assay, pH, and purity. Packaging must be airtight to prevent moisture absorption and caking. |
Technical Specifications
| CAS Number | 7778-77-0 |
| Chemical Formula | KH₂PO₄ |
| Solubility | freely soluble in water (~208 g/L at 25 °C), insoluble in ethanol |
| Storage Conditions | store in cool, dry environment, protect from moisture |
| Shelf Life | 24 Months |
Applications & Usage
Common Applications:
used in foods (energy drinks
creamers
processed cheese
baked goods)
fertilizers
lab buffers
Mechanism of action:
| Parameter | Potassium dihydrogen phosphate (Monopotassium phosphate) |
|---|---|
| Functional Category | pH Buffering Agent; Leavening Acid; Sequestrant; Yeast Nutrient |
| Key Ingredients | Potassium dihydrogen phosphate (KH₂PO₄) |
| Mechanism of Action | Acts as an acidic salt to buffer system pH, maintaining it in a specific acidic range; reacts with alkaline leavening agents (e.g., sodium bicarbonate) to release CO₂ for leavening; chelates polyvalent metal ions to inhibit oxidative degradation; serves as a source of potassium and phosphorus for yeast nutrition. |
| Application Effect in Product | Provides controlled leavening in baked goods for desired texture and volume; maintains stable pH in beverages and powdered mixes, preventing precipitation and color shifts; acts as a yeast nutrient to support consistent fermentation; improves product stability by sequestering pro-oxidant metal ions. |
Comparison:
| Product Name | Category/Type | Key Features | Strengths (vs peers) | Weaknesses (vs peers) | Best Use Cases | Why Choose |
|---|---|---|---|---|---|---|
| Potassium dihydrogen phosphate (MKP) | Water-Soluble P & K Fertilizer | N-P-K: 0-52-34. High purity, high solubility, low salt index, nitrogen-free. | Provides both P and K without nitrogen, allowing precise nutrient control. Very low in chloride and other contaminants. | More expensive per unit of nutrient than some alternatives. Lacks nitrogen. | Hydroponics, fertigation, and foliar sprays during flowering and fruiting stages to boost root growth, fruit set, and quality. | When you need a highly soluble, pure source of P and K for sensitive crops or growth stages where nitrogen should be limited. |
| Monoammonium phosphate (MAP) | Water-Soluble N & P Fertilizer | N-P-K: 11-52-0 or 12-61-0. High P content, provides ammonium nitrogen, acidic reaction. | Excellent P source combined with N for vegetative growth. Acidifying effect helps nutrient availability in alkaline soils. | Contains nitrogen which may be undesirable at later growth stages. Lacks potassium. | Starter fertilizers and fertigation during early plant establishment and vegetative growth. Lowering pH of irrigation water. | When phosphorus is the primary need along with a small amount of nitrogen, especially for young plants. |
| Potassium nitrate (KNO₃) | Water-Soluble N & K Fertilizer | N-P-K: 13-0-46. Provides nitrate N and K. High solubility, low chloride. | Supplies two critical nutrients (N and K) in a highly available form. Nitrate nitrogen is immediately available to plants. | Lacks phosphorus. Nitrate can be prone to leaching in sandy soils. | Fertigation and foliar feeding during periods of rapid growth and fruit development where both N and K are needed. | To supply readily available nitrogen and potassium together, without adding phosphorus or chloride. |
| Potassium sulfate (SOP) | Water-Soluble K & S Fertilizer | N-P-K: 0-0-52 + 18% S. Low chloride, provides sulfur. | Virtually chloride-free, making it safe for sensitive crops. Provides essential sulfur. | Lower solubility and dissolves slower than MKP or KNO₃. Can be more expensive. | Chloride-sensitive crops (e.g., berries, potatoes, citrus). Soils deficient in sulfur. Late-season applications to improve quality. | For a chloride-free potassium source, especially when the crop also requires sulfur. |
| Urea Phosphate (UP) | Water-Soluble N & P Fertilizer | N-P-K: 17-44-0. High solubility, provides urea N and P, very strong acidifying effect. | The most acidic common fertilizer; excellent for clearing scale from drip irrigation lines and lowering high pH water. | High acidity can harm equipment or plants if not handled correctly. Lacks potassium. | Fertigation in systems with very hard water or high soil pH. As a cleaning agent for irrigation systems. | When a strong acidifying effect is required along with N and P to manage high alkalinity in water or soil. |
Technical Documents
Available Documentation
Certificate of Analysis available
Safety Data Sheet (SDS)
SDS available
Certificate of Analysis (COA)
Quality assurance documentation
Technical Data Sheet
Detailed technical specifications