Oxy-Fuel FAQs

Why do people use oxygen for combustion when air is free?

Air contains almost 80% nitrogen, which doesn’t burn; it heats up and removes heat from the process as it exits in the form of hot flue gases. Combustion with oxygen eliminates this waste and provides faster melting, lower fuel usage, lower carbon dioxide generation, reduced NOx and particulate emissions and higher flame temperatures. Oxygen also efficiently burns lower quality fuels and wastes. The economics of using oxygen depend on the process and the needs of the manufacturer. Oxygen benefits are greatest for manufacturers who need extra production, have higher temperature processes (glass, steel, etc.), lack heat recovery, or have emissions issues or undersized baghouses. Oxygen is generally less attractive for just fuel savings, especially for lower temperature processes like boilers, unless fuel costs are extremely high or there are other drivers. Can your process benefit from oxygen?

Russell Hewertson Americas Commercial Technology Manager

How do I choose the right burner technology if my melting furnace is a bottleneck or I want to increase production?

Your furnace may have heat recovery or conventional cold air-fuel burners. Air Products recognizes that no two furnaces are alike, and that the best solution will match your furnace’s characteristics and situation.

When your furnace was first built, oxy-fuel may not have been appropriate, but now that you need a production increase or your furnace has become a bottleneck, an optimized oxy-fuel retrofit can often be a very cost-effective solution.

Following an assessment of your operation, Air Products’ applications engineers can combine our experience, modeling capabilities and wide range of proven burner technologies to develop a customized oxy-fuel solution for your operation—often increasing production by more than 30% with a payback of as little as 3–6 months. And with our latest patented burner, even increasing yields.

Russell Hewertson Americas Commercial Technology Manager

How can I lower the carbon-monoxide levels in my steelmaking furnace off-gas?

It’s a great idea to measure carbon monoxide (CO) and other combustion products such as carbon dioxide (CO2), oxygen (O2) and hydrogen (H2) in your off-gas system. High CO levels in your ductwork indicate incomplete combustion in your furnace, which means you’re losing usable energy!

Usually, introducing dilution air to the ductwork will complete combustion when the CO combines with the oxygen in the air to form CO2. However, this exothermic reaction (post-combustion) may raise temperatures in the ductwork and off-gas handling system, which can lead to shorter life or higher maintenance costs.

Improperly calibrated flow controls, poorly mixed fuel and oxygen/air in the furnace, or other factors may cause incomplete combustion. Thankfully, by better utilizing oxygen in your furnace, you can use that lost energy to improve efficiencies and production rates and reduce emissions.

How can I optimize melting of contaminated metal scrap?

Metal scrap that's contaminated with combustibles like oil, paint or plastic is difficult to melt with conventional methods. Thermal delacquering systems are often used to pretreat the scrap before it’s melted, but these systems increase operational costs. Processing contaminated scrap in air-fuel furnaces has drawbacks like high combustion gas volumes and fumes. The temperature and particles of the combustible material can overwhelm the baghouse. Often, particle load and contamination of the furnace gases do not allow the operation of regenerative burner systems, making energy-efficient melting hard to achieve. Plus, unburned combustibles can reduce furnace efficiency. Oxy-fuel and air-oxy-fuel combustion technologies can enable in situ burnout of combustible fumes, lowering combustion gas volumes and increasing temperatures. Also, utilizing the energy released by burning the contaminants can help reduce energy costs.

Can I remotely monitor what's happening in my furnaces and other process equipment while I'm away from my plant?

With the proper instrumentation and controls, you can securely monitor and control your heat treating or thermal process from nearly anywhere in the world! This is possible using a variety of hardware and communication methods, including Internet, dial-up, and cell phones. Alarm and warning notifications can also be proactively delivered to you so you can react to upsets, trends, and events before it's "too late." It’s important to identify the key parameters, equipment and instrumentation you want to monitor, and then select the hardware and software that best match your needs.

Chris Ward Engineering Associate, North America

How do I know if I'm wasting gas due to leaks in my gas piping?

Gas piping leaks can result from various conditions, including improper thread sealing, missed brazed joints, defective piping, over pressurization, or even vibration and shocks. A pinhole leak can cost you tens of thousands of dollars per year, depending on the size, number and severity of the leak(s). There are many ways to detect leaks; for instance, using soap tests, pressure drop tests, mass spectrometry or thermal conductivity tests. They all have their place; however, they also often come with limitations in precision, speed, difficulty or cost. Air Products’ leak detection service can identify and repair costly leaks in your piping to help improve your part quality and bottom line.