Kimia Industri - Pembuatan Pulp dan Kertas (Diagram Alir proses) (Bag. 2 - Akhir)

Summary

This video tutorial delves into the processes involved in woodchip, pulp, and paper production. It explains the stages of creating woodchips, from debarking to chipping and sorting. The pulp production process is detailed, covering cooking, washing, delignification, and bleaching. Finally, the paper production process is explored, including stock preparation, pressing, drying, calendaring, and finishing. The script highlights key industrial techniques and machinery used in each stage, providing an informative overview of these complex manufacturing operations.

Takeaways

• 😀 The first step in the wood preparation process is cutting wood into logs of 2-3 meters in length and 30 cm in diameter, which are then transported via conveyor belt to the debarker.
• 😀 In the debarking stage, the logs' bark is removed in the debarking drums, producing wood without bark, which is sent to the chipping machine.
• 😀 The chipping machine then shreds the wood into small chips, which are screened to separate standard-sized chips (10-25 mm in length and 5-8 mm in thickness).
• 😀 The chips that meet the standard size are then stored in a designated storage area.
• 😀 The next process is cooking, where the wood chips are mixed with a chemical solution (white liquor) in a high-pressure vessel known as the digester, breaking down the wood to produce pulp and black liquor.
• 😀 After cooking, the pulp undergoes a washing process in several stages, starting with denoting, which removes wood knots that remain in the pulp.
• 😀 Screening is the next step, aimed at separating contaminants based on their size and weight, using a vibrating screen.
• 😀 The pulp is then subjected to a washing process to remove organic and inorganic contaminants that dissolve in water.
• 😀 Oxygen delignification follows, where the pulp is treated with oxygen and sodium hydroxide to reduce lignin content, preparing the pulp for bleaching.
• 😀 The bleaching process involves multiple stages, using chemicals like chlorine dioxide (Cl2), oxygen (O2), and sodium hydroxide (NaOH) to improve the brightness and cleanliness of the pulp.
• 😀 After bleaching, the pulp is dried, pressed, and formed into sheets, which are then cut, stacked, and packaged for storage and distribution.

Q & A

What is the first step in the wood preparation process for pulp production?

The first step involves transporting wood logs (2-3 meters long and 30 cm in diameter) using a conveyor belt to the debarker, where the bark is removed.

What happens during the chipping process?

In the chipping process, the debarked logs are sent to a chipper, where they are cut into wood chips. These chips are then screened to separate the acceptable sizes, which should be 10-25 mm in length, 10-25 mm in width, and 5-8 mm in thickness.

What is the role of the digester in pulp production?

The digester is used to cook the wood chips with white liquor (a mixture of NaOH and Na₂SO₄). This process breaks down the lignin in the wood, producing pulp (POP) and black liquor.

What are the stages involved in washing the pulp?

Washing the pulp involves multiple stages: denoting (removing wood knots), screening (separating impurities based on weight and size), and washing with a rotating washing system to remove water-soluble impurities.

How does oxygen delignification improve pulp quality?

Oxygen delignification involves using oxygen and NaOH to reduce the lignin content in the pulp before bleaching. This process enhances the quality of the pulp by making it cleaner and more suitable for the bleaching process.

What chemicals are used during the bleaching process, and what is its purpose?

During bleaching, chemicals such as chlorine (Cl₂), sodium hydroxide (NaOH), and oxygen (O₂) are used. The purpose is to increase the brightness of the pulp, remove impurities, and reduce the lignin content to achieve a high-quality white pulp.

What is the function of the dewatering process in pulp production?

The dewatering process involves mechanically pressing the pulp to remove excess water and form solid sheets with a lower moisture content, which is essential before drying and further processing.

What happens during the drying stage of pulp production?

In the drying stage, the pulp sheets are exposed to hot air, which reduces their moisture content to around 10%. This step ensures that the pulp is properly dried before it is cut into sheets.

What is the role of calendering in paper production?

Calendering involves passing the paper through rollers to smooth and compact the sheets, ensuring that they meet the required thickness, smoothness, and quality standards.

What are the final stages of paper production after drying?

After drying, the paper moves through rewinding, where it is cut into smaller rolls. The final stages involve cutting, finishing (smoothing and polishing), and packaging the paper for distribution to customers.