PBL Proses Industri Kimia | Kelompok 2 Pembuatan Amonia Dari Nitrogen dan Hidrogen

Summary

This video presentation discusses the ammonia production process from natural gas and nitrogen, focusing on a plant with a capacity of 250,000 tons per year. The process includes several key stages: feed treatment, desulfurization, primary and secondary reforming, purification, methanation, and ammonia synthesis. The gas is first cleaned to remove sulfur, then reformed to produce hydrogen and carbon dioxide, which is purified and separated. The ammonia synthesis occurs in the ammonia converter under high pressure and temperature, with waste gases managed through a specialized unit. The overall process ensures efficient and safe ammonia production while minimizing environmental impact.

Takeaways

• 😀 The ammonia plant design is based on producing 250,000 tons per year using nitrogen and hydrogen.
• 😀 The feed gas, primarily natural gas, must be cleaned to remove impurities like H2S to avoid poisoning the catalyst in the reformer unit.
• 😀 The desulfurization process separates H2S from natural gas using iron sponge and water as an absorption medium.
• 😀 The cleaned natural gas is mixed with steam and heated before being sent to the primary reformer for further processing.
• 😀 The primary reformer (R1) operates at 37 ATM and 137°C, using nickel-based catalysts to convert feed gas into hydrogen (H2) and carbon dioxide (CO2).
• 😀 The secondary reformer (R2) converts residual carbon compounds into hydrogen at 787°C and 31 ATM, with air added to provide nitrogen (N2) for ammonia synthesis.
• 😀 The purification and methanation steps involve removing CO2, ensuring it does not degrade the ammonia converter catalyst or pose a risk.
• 😀 The high-temperature shift (HTS) process converts CO into CO2 using a catalyst, followed by a low-temperature shift (LTS) process to further refine CO2 removal.
• 😀 CO2 is removed from the process using an absorber unit (AB01) at 120°C and 31 ATM, utilizing K2CO3 and water as absorbents.
• 😀 Methanation takes place in a separate unit (metanator), where any residual CO and methane (CH4) are converted into methane at 288°C and 25 ATM.
• 😀 The ammonia synthesis process occurs in the ammonia converter (R06), using an Fe2O3 catalyst and a 3:1 ratio of H2 to N2 at 400°C and 139.5 ATM to form NH3.
• 😀 The excess gas that doesn't react is treated as pure gas (CH4, H2, N2), which is managed in a waste treatment unit to prevent environmental damage.

Q & A

What is the primary purpose of the desulfurization process in ammonia production?

The desulfurization process is used to remove sulfur compounds, specifically H2S, from the natural gas feed before it enters the reforming unit. This prevents catalyst poisoning in the primary reformer.

What are the key stages of the reforming process in ammonia production?

The reforming process consists of two stages: the primary reformer (R1), where natural gas is combined with steam to produce hydrogen and carbon dioxide, and the secondary reformer (R2), where the mixture reacts with air to produce nitrogen, hydrogen, and carbon dioxide.

Why is steam added to the natural gas in the reforming units?

Steam is added to natural gas to facilitate the production of hydrogen (H2) during the reforming reaction. The steam reacts with methane in the feed gas to generate hydrogen and carbon monoxide.

What role does the secondary reformer (R2) play in the ammonia production process?

The secondary reformer (R2) is used to further react the products from the primary reformer with air. This step is essential for generating the nitrogen (N2) needed for ammonia synthesis, while also producing hydrogen (H2) and CO2.

What is the purpose of the High-Temperature Shift (HTS) and Low-Temperature Shift (LTS) processes?

The HTS process is used to convert carbon monoxide (CO) into carbon dioxide (CO2) at high temperatures, while the LTS process further refines this conversion at lower temperatures to improve the reaction and increase CO2 yield.

What is the role of the CO2 removal process in the ammonia plant?

The CO2 removal process separates CO2 from the process gas to prevent it from degrading the catalyst in the ammonia converter. This ensures the efficiency and longevity of the catalytic reaction in the synthesis of ammonia.

Why is the CO2 removal step critical for catalyst protection?

CO2 is toxic to the ammonia converter catalyst, which is why it must be removed before the gas enters the ammonia synthesis unit. If CO2 is present, it could lead to catalyst deactivation and a reduction in the overall efficiency of the ammonia production process.

How is the methanation process used in ammonia production?

The methanation process is used to convert any residual carbon monoxide (CO) and methane (CH4) into methane (CH4) in a methanator. This ensures that the gas mixture entering the ammonia converter is free from these impurities.

What are the optimal temperature and pressure conditions for the ammonia synthesis in the converter?

The optimal conditions for ammonia synthesis are a temperature of 400°C and a pressure of 139.5 atm. These conditions help facilitate the reaction of nitrogen (N2) and hydrogen (H2) to form ammonia (NH3) using an iron oxide (Fe2O3) catalyst.

What happens to the unreacted gases after the ammonia synthesis?

The unreacted gases, which include methane, hydrogen, and nitrogen, are managed in a waste handling unit (UCL). This unit ensures that these gases do not harm the environment by capturing and managing them properly.