Potassium Hydroxide – Pellets (KOH)

POTASSIUM HYDROXIDE (KOH) – aka Caustic Potash

A deliquescent solid that can efficiently absorb adequate moisture and carbon dioxide from the atmosphere. This inorganic base is also known as caustic potash [3].

INTRODUCTION

• Potassium hydroxide is a highly alkaline inorganic compound that is also known as Lye. The estimated amount of potassium hydroxide typically used in the United States of America is 440,000 metric tons [3] [6].
• It is adequately supplied in the market under the unusual names of various labels like Caustic potash solution, Potash lye, Potassium hydroxide (pellets), EPA Pesticide Chemical Code 075602, Alkaline Iodide-Sodium Azide Solution and Potassium hydroxide, 1.0N Standardized Solution in methanol [7].
• It is obtainable in the packaging of 25g, 50g, 250g, 500g, 1kg, 2.5kg, and 12kg in poly bottles or drums [8].

Structure

The molecular structure of potassium hydroxide is shown below.

Figure 1: Structure of potassium hydroxide [6].

PROCEDURE

The standard procedure of proper preparation of potassium hydroxide commercially is described below in precise detail [1].

The economic production of pure potassium hydroxide occurred by typically using membrane cell technology that efficiently is less efficient energy utilizing and modern technology. This membrane cell is made up of the following components discussed below [2].

• Anode: It is made up of titanium-coated properly around the anode.
• Cathode: Liquid mercury acts as a cathode that is present at the visible bottom of the cell.
• Power supply: For the developed generation of reliable electricity during the specific process of electrolysis.
• Non-permeable membrane: To allow specific ions to pass through it and prevent the rest of the ions from passing across the membrane.
• Brine solution: Potassium chloride is used as a brine solution in a membrane cell.

Figure 2:Manufacturing KOH using  Membrane cell technology [1].

Preparation method:

• The aqueous solution of potassium chloride is typically formed and properly used as a brine in the membrane cell.
• By traditionally using power supply batteries, an electric current is efficiently generated that plays a pivotal role in the electrolysis of potassium chloride. This electrolysis leads to the gradual formation of positive (K+) and negative (Cl-) ions in the solution [3].
• The respective ions move towards their selective electrodes that are carefully separated by the non-permeable membrane.
• Potassium ions pass through the impermeable membrane but hydrogen or chlorine ions typically fail to do so.
• Potassium ions react with hydrogen and oxygen atoms present in the brine to form potassium hydroxide. Hydrogen and chlorine gas are released as a byproduct.
• Chemical reaction: The chemical reaction that undoubtedly occurs during the preparation procedure is displayed below [4].

2KCl + 2H₂O ➔ Cl₂ + H₂ + 2KOH

• In the end, the purity of potassium hydroxide naturally produced is undoubtedly enhanced by intentionally using evaporators. These evaporators help in evaporating liquid solution and leaving behind pure powder form of potassium hydroxide.

SPECIFICATIONS

The specifications of potassium hydroxide are described below in the table [9] [10] [11].

APPLICATIONS

Caustic Potash realistically is a valuable chemical utilized in the largest volumes in industrial or commercial sectors. Following are some applications of potassium hydroxide that are described below [3] [4] [5].

• Versatile cleaning agent: Potassium hydroxide represent a substantially strong base and acts as a cleaning agent. It is exhausted in detergents and soaps.
• Valuable fertilizer: It is utilized in the production of numerous herbicides, fertilizers, and other chemicals that are important in the agricultural industry.
• Sustainable food industry: Potassium hydroxide is equally used in the organic food industry for various purposes like in the successful production of delicious chocolate and in softening of olives. It is used in removing peels of organic vegetables and luscious fruits.
• Formidable batteries production: Potassium hydroxide is typically used in the successful production of formidable batteries.
• Organic dyes and specific Photographic chemicals: It also acts as a pivotal constituent of organic dyes and is additionally used as a photographic chemical.
• Synthetic rubber: potassium hydroxide is traditionally used in the economic production of synthetic rubber at the industrial level.
• pH Stabilizer: It is utilized as a pH stabilizer in skincare products because it is an essential constituent of skincare and cosmetic products.

SAFETY AND HAZARDS

Potassium hydroxide is a very corrosive and dangerous chemical. The safety and hazards are described below [1][3].

• Inhalation: In case of inhaling the mist, vapors, or powder of potassium hydroxide, irritation or burning sensation of mucus membranes may occur because it is corrosive in nature.
  First Aid Measure:
  Immediately move the person to fresh air or an uncontaminated place where he can breathe easily. On severe burning sensation, seek medical advice.

• Ingestion: In case of ingesting this corrosive chemical, it can cause nausea, internal bleeding, burning, vomiting, and low blood pressure.
  First Aid Measure:
  Do not induce vomiting. Immediately move the person to fresh air. On severe symptoms, seek medical advice.

• Skin Contact: It can burn the skin severely because it is a highly reactive compound.
  First Aid Measure:
  Instantly remove the contaminated clothes. Wash the face and skin continuously for 15 to 20 minutes or until the burning sensation ends.

• Eyes Contact: It can cause redness, itching, temporary and permanent damage to the eyes because of its corrosive nature.
  First Aid Measure:
  Wash the eyes immediately with plenty of water. Seek medical advice.

• Safety Measures: Wear proper chemical-resistant clothes or lab coats during experimentation procedures. Use protective goggles and gloves for preventing any kind of contact with the chemical. Use a face shield for preventing the splashes of chemical.

REFERENCES

1. OXY – Caustic Potash Handbook
2. Vynova – Converting from Mercury to Membrane Cells
3. Encyclopedia.com – Potassium Hydroxide
4. GI Chemicals – Potassium Hydroxide
5. World of Chemicals – How to make caustic potash?
6. The Derm Review – Potassium Hydroxide- Why Is Potassium Hydroxide Used? And Do You Need To Be Careful With This Ingredient?
7. PubChem NCBI NIH – 2.4.1 Mesh Entry Terms
8. Sigma-Aldrich – Potassium hydroxide
9. Fisher Scientific – Potassium Hydroxide
10. Sigma-Aldrich – Potassium hydroxide
11. PubChem NCBI NIH 3 Chemical and Physical Properties