Glacial Acetic Acid (99% min) - Taiwan

Brief Overview

Glacial Acetic acid is the concentrated variant of acetic acid, also known as ethanoic acid, with the molecular formula CH₃COOH. It acts as a weak monoprotic acid, readily releasing a proton from its acid functional group (-COOH) to form the acetate anion, a conjugate base. Functioning as a polar protic solvent, it easily dissolves and mixes with other polar solvents like water. However, its polar nature makes it insoluble and unable to mix with non-polar solvents such as octane.

When used as a primary reagent, acetic acid readily creates various organic reagents like acetyl chloride and ethanol through substitution and reduction reactions, respectively. Moreover, it can corrode metals like iron, magnesium, and zinc, producing hydrogen gas and metal acetates. Notably, aluminum develops a protective layer of aluminum oxide, granting it acid resistance and making aluminum tanks a suitable choice for transporting acetic acid. Alternatively, high-density polyethylene (HDPE) drums are also effective transport vessels due to their resistance against the effects of acetic acid.

Manufacturing Process

Method 1: Methanol Carbonylation

The synthesis of acetic acid involves methanol carbonylation, where the introduction of metal carbonyl into methanol occurs through either the rhodium-catalyzed Monsanto process or the iridium-catalyzed Cativa process. However, the advancement of the iridium-catalyzed Cativa process rendered the Monsanto process obsolete. The Cativa process, known for its economic and environmentally sustainable nature, swiftly became the primary method for producing acetic acid.

Method 2: Acetaldehyde Oxidation

Another approach to acetic acid production entails oxidizing acetaldehyde, obtained from the oxidation of butane and hydration of ethylene through the Wacker process. The resulting crude acetaldehyde undergoes purification via extractive distillation followed by fractional distillation. This refined acetaldehyde then undergoes further oxidation to yield acetic acid.

Method 3: Fermentation Techniques

Acetic acid synthesis also involves oxidative fermentation utilizing acetic acid bacteria Acetobacter in alcoholic content or anaerobic fermentation employing anaerobic bacteria Acetobacterium. The Acetobacter method proves more cost-effective for acetic acid production compared to other fermentation methods.

Textile Industry

Glacial acetic acid, which is the concentrated form of acetic acid, serves several purposes in the textile industry:

1. **Dyeing:** It's used to regulate pH levels in dye baths. Maintaining specific pH conditions is crucial for effective dye fixation onto textiles. Glacial acetic acid helps to achieve and maintain the optimal pH for proper dye absorption and colorfastness.

2. **Textile Finishing:** In finishing processes, glacial acetic acid acts as a softening agent. It can modify the feel or texture (softness or stiffness) of fabrics, contributing to their final quality. Additionally, it may be utilized in certain finishes to impart a glossy appearance to textiles.

3. **pH Adjustment:** Apart from dyeing, it's employed across various treatments in textile processing, ensuring the materials undergo processes under specific pH conditions for desired results. It can help with improving dye penetration or setting and can neutralize alkaline residues from previous treatments.

4. **Cleaning and Maintenance:** Sometimes diluted acetic acid solutions are used for cleaning and maintaining equipment in the textile industry. Its mild acidic nature can effectively remove mineral deposits and stains without causing harm to machinery.

Glacial acetic acid, due to its versatile properties, plays a significant role in dyeing, finishing, pH control, and maintenance processes within the textile industry.