Discovering the journey of Nitrogen: From Manufacturing to Everyday Uses

Nitrogen, being one of the most abundant elements found in earth’s atmosphere accounting for approximately 78% of the total volume, is an essential component in the current world economy and technology. Although not visually perceptive and non-odorous, this gas is indispensable for a vast number of uses ranging from the agricultural sector to the medical field and the food and beverage industry. It is regretful that many people are not aware of the different uses of Nitrogen and the process of manufacturing it, but knowing these facts can help people appreciate the importance of Nitrogen in their lives.

Welcome to the world of Nitrogen, where we will be discussing the methods of Nitrogen production, the importance of Nitrogen in different industries and how Nitrogen is used to propel technological advancements around the world.

Introduction

Nitrogen is a powerhouse in various industries, essential for numerous industrial processes. Nitrogen's versatility and inert properties make it an indispensable asset, boosting efficiency, safety, and quality across multiple fields. In manufacturing processes, it's used for blanketing and purging to create inert atmospheres, preventing oxidation, and ensuring product integrity. The food and beverage sector relies on Nitrogen for packaging, keeping products fresh and extending their shelf life by displacing oxygen. Electronics manufacturers use Nitrogen to prevent oxidation and maintain the quality of sensitive components. In the oil and gas industry, Nitrogen is key for pressure testing, purging pipelines, and enhancing oil recovery. Healthcare depends on Nitrogen for medical gas applications, including cryopreservation of biological samples. The pharmaceutical sector also uses Nitrogen for purging, blanketing, and cryopreservation. In automotive services, Nitrogen inflation improves tire performance and safety. Laser cutting and metal fabrication industries leverage Nitrogen for clean, oxide-free cutting environments.

Manufacturing Process

The manufacturing of substantial quantities of relatively pure Nitrogen primarily involves cryogenic distillation. Conversely, moderate volumes of Nitrogen with lower purity levels are typically generated using pressure swing adsorption and membrane permeation techniques.

Cryogenic Nitrogen Process

The procedure for extracting Nitrogen from air involves three primary stages: (1) Purification, (2) Refrigeration, and (3) Rectification, as illustrated in the following Fig.

Purification

To begin the process, the air undergoes purification to eliminate dust particles, carbon dioxide, and water vapor. This purification process involves several steps. Initially, the air is compressed to concentrate its contents. Next, the compressed air is directed through a heat exchanger where it is cooled, causing water vapor to condense and separate from the air stream. Subsequently, the air passes through an adsorbent bed consisting of a molecular sieve. This adsorbent bed effectively removes residual water, carbon dioxide, and any traces of other impurities present in the air. The molecular sieve acts as a highly selective filter, capturing these unwanted components while allowing Nitrogen to pass through. By meticulously purifying the air in this manner, the subsequent stages of the Nitrogen extraction process can proceed with optimal efficiency and purity.

Refrigeration

Once the air is purified, the next crucial step involves cooling it down or liquefying it to prepare for the subsequent rectification stages downstream. This cooling process is essential for creating the conditions necessary for effective separation of the constituent gases. To achieve this, a plate-fin heat exchanger is employed, utilizing the refrigeration values inherent in both the product streams (oxygen and Nitrogen) and the waste stream (Nitrogen). By leveraging the temperature differences between these streams, the purified air is efficiently cooled and liquefied, readying it for further processing in the subsequent rectification stages. This strategic use of refrigeration values ensures optimal energy efficiency and enables precise control over the cooling process, facilitating the seamless progression of the Nitrogen extraction process.

Rectification

The final stage of the process involves subjecting the cooled and liquefied air to fractional distillation, which occurs in two separate columns designed for Nitrogen-oxygen separation. These columns operate at different pressures, facilitating the separation process. During fractional distillation, Nitrogen is distilled as a vapor, while oxygen is obtained in liquid form. Additionally, due to the closely similar boiling points of oxygen and argon, a third column is dedicated exclusively to removing argon as a contaminant. This column serves to vent the argon to the atmosphere, ensuring that the Nitrogen and oxygen streams remain pure and uncontaminated. By employing this meticulous fractional distillation process, the desired separation of Nitrogen and oxygen is achieved with precision and efficiency, meeting the stringent purity requirements of the end products.

Processes used by Major Players

Process: Pressure Swing Adsorption (PSA) Process

The Linde Nitrogen PSA generators are specifically engineered for continuous use in various applications, providing a consistent supply of high-purity Nitrogen for inerting, blanketing, and purging processes that require clean and dry Nitrogen. The PSA process is used by Linde Group in order to manufacture Nitrogen. The PSA process cycle consists of two key mechanisms:

• Pressurisation/adsorption
• Depressurisation/desorption

The Pressure Swing Adsorption (PSA) method entails alternating pressurizing and depressurizing two identical adsorber beds, labeled as A and B. The sequence initiates with bed A undergoing pressurization while bed B is in the process of depressurization.

• During the pressurization of bed A, compressed air is introduced, leading to the adsorption of moisture, oxygen, and carbon dioxide. Once the target pressure is reached, the Nitrogen product is transferred from bed A to a receiver before entering the product piping. Meanwhile, bed B is depressurized to atmospheric pressure.

• After completing Nitrogen production from bed A, an equalization step occurs. Bed B, now at atmospheric pressure, is pressurized to an intermediate level while the gas remaining in bed A, still at operating pressure, flows into bed B. This step maintains a constant flow, purity, and pressure of the Nitrogen product throughout the PSA cycle, facilitated by a Nitrogen receiver, without consuming air or generating product gas.

• Subsequently, bed A undergoes depressurization, releasing oxygen-enriched waste gas into the atmosphere. This depressurization allows the discharge of previously adsorbed oxygen, carbon dioxide, and water vapor. At the same time, bed B is brought to operating pressure to begin its Nitrogen production phase. After Nitrogen production, bed B goes through equalization and subsequent depressurization.

• The cycle repeats with bed A being pressurized and bed B being depressurized. This repetitive process ensures continuous Nitrogen production, with each bed alternating between pressurization, production, equalization, and depressurization stages. The use of Nitrogen receivers is crucial for maintaining the desired flow, purity, and pressure of the Nitrogen product throughout the PSA cycle.

Applications of Nitrogen

• Fertilizers

Nitrogen is a critical macronutrient for plants, functioning as a key component of proteins, chlorophyll (essential for photosynthesis), and nucleic acids (DNA and RNA).  Insufficient Nitrogen availability in native soils hinders plant growth, reproduction, and disease resistance.  Modern agricultural practices, aiming for high crop yields to meet global food security demands, necessitate N levels exceeding those naturally present.  Therefore, the application of Nitrogen fertilizers provides a readily available source of Nitrogen to crops, promoting optimal growth and maximizing yield potential.  This targeted nutrient management strategy enhances agricultural productivity and contributes significantly to global food security.

• Chemical

The chemical and resin industry relies heavily on Nitrogen, a gas with exceptional inert properties. Nitrogen acts as a multi-faceted guardian in these processes: it displaces oxygen to prevent degradation of chemicals, shields raw materials from unwanted reactions, creates an oxygen-depleted environment to minimize fire risk during storage, and even purges machinery for a clean and safe production line.

• Food & Beverage

The food and beverage industry is a prime example where Nitrogen gas plays a critical role in ensuring safe and fresh products for consumers. By replacing oxygen in the packaging, Nitrogen gas acts as a multi-pronged shield. Firstly, it prevents unwanted oxidation, a process that can spoil fats and oils in foods, leading to rancidity and off-flavors. Secondly, by displacing oxygen, Nitrogen inhibits the growth of aerobic bacteria, those that require oxygen to survive. This significantly slows down spoilage, extending the shelf life of perishable items like fruits, vegetables, and meats. Consequently, Nitrogen gas packaging helps maintain the freshness, flavor, and quality of food and beverages for a longer period, minimizing waste and ensuring a more enjoyable consumer experience.

• Fire Extinguishers

Nitrogen gas extinguishers offer a unique approach to fire suppression. Unlike traditional water or chemical extinguishers, they combat flames by displacing oxygen, a critical element for combustion. By flooding the burning area with Nitrogen, these extinguishers create an inert atmosphere that suffocates the fire. This method is particularly advantageous in environments containing sensitive equipment or valuable materials that could be damaged by water or chemical fire retardants. However, it's crucial to note that the Nitrogen concentration must be carefully controlled.

Market Outlook

The surge in demand for Nitrogen across diverse industries and consumer applications is propelled by its low cost. Nitrogen gas has become an indispensable product in industrial processes worldwide, revered for its affordability compared to alternative options. Simultaneously, Nitrogen's importance extends beyond industrial settings to meet the burgeoning needs of everyday consumer needs. From preserving food freshness through packaging to enhancing tire performance via inflation services, Nitrogen plays an indispensable role in numerous aspects of daily life. Industrial Nitrogen's influence extends well beyond its cornerstone application in fertilizer production. While traditional sectors like petrochemicals and manufacturing remain the demand backbone, the market flourishes due to continuous innovation.  Emerging applications within the rapidly expanding food and beverage industry, coupled with escalating Nitrogen utilization in healthcare and pharmaceutical manufacturing across both developed and developing regions, are significant growth drivers.  Furthermore, the anticipated surge in Nitrogen demand within the chemical industry, fueled by advancements in cryogenic fraction distillation technology, presents promising opportunities for the future of the industrial Nitrogen market.

Nitrogen Major Global Manufacturers

Significant players in the Global Nitrogen market are Yingde Gases Group Company, Linde Group, Praxair Inc., nexAir, CanAir Nitrogen, Chengdu Taiyu Industrial Gases, Universal Industrial Gases, Air Products and Chemicals, Messer Group, Air Liquide, and Others.

Conclusion:

To sum up, Nitrogen is one of the most intriguing elements that remain almost invisible but are indispensable in many aspects of our existence. From fertilizers that help in food production to gas used in packing to ensure that our favorite drink does not go bad, Nitrogen is very relevant. Its non-reactivity makes it a perfect protector during chemical production, it protects products and processes. As the world becomes high-tech, it becomes even more apparent that Nitrogen is a versatile element with more uses than one, making it a fundamental component in our industrial processes, food sector, and even in the chemical sector. The next time you enjoy a drink that has been kept fresh by a liquid Nitrogen vaporizer or gaze at a bouquet of flowers that have been kept fresh by Nitrogen, take a moment to think about this gas!