How to make “Green Hydrogen” a Viable Solution for Reducing Emissions?

To move forward with plans for development in the face of the volatility of shared natural resources, many industries are taking a closer look at alternative fuels. Hydrogen, in particular, has amassed significant attention. “Green hydrogen” is a fuel created using renewable energy, and it has proven to be a valuable asset in transportation, manufacturing, and other energy-focused industries. From fuel cells to hydrogen burners, green Hydrogen has proven its value time and time again. It caters to eco-conscious companies that seek to reduce their emissions, particularly given the fact that there is a common goal of reducing global CO2 emissions down to 0% by 2050. Many major manufacturers in various industries have started down this road of green hydrogen utilization.

Green Hydrogen is formed purely from electrolysis, where water is “split” into its component molecules, isolating the Hydrogen and leaving only O2 as a byproduct.

photo credit from Yale School of the Environment

Electricity is the only constituent of this process requiring outside assistance, so easily accessible renewable energy sources such as wind turbines are often used. Given its simple production and indefinite sustainability, green Hydrogen contains approximately three times as much energy as fossil fuels.

While there is optimism surrounding the prospects of green Hydrogen, it is not without its drawbacks. Some problems include the cost concerning fossil fuels, material volatility, transportation issues, and expandability. Hydrogen is much less dense than other natural gases, meaning it must be cooled to sub-zero temperatures in liquid form to allow for a remotely safe transit from plant to plant. It is also flammable, requiring high expenditure to ensure no explosive mishaps occur during transit. Because of this, green Hydrogen can cost up to three times as much as fossil fuels and natural gas. Often, plants that make waste hydrogen will recycle it, blended it with natural gas, and burn it to power their industrial plants, such as wastewater or sewage treatment facilities, chemical facilities, and food processing facilities. This waste hydrogen is a byproduct of the reforming or refining process, not made from fossil fuels. Therefore, it is considered “green” as no emissions were spent to create it.

The Problem

Because of its instability, green Hydrogen is “blended” with natural gas and used as fuel, usually in large industrial applications that have excess Hydrogen on hand or are making a targeted move toward lowering of emissions and meeting environmental regulations. The blending process is delicate and yet is essential in keeping steady combustion and avoiding expensive outages.

Many end-users are considering switching to hydrogen firing for their steam generation needs; therefore, it is essential to highlight some of the challenges they would be facing when planning to make the fuel conversion or addition. Most end-users have their boiler/burners plant systems suited for natural gas firing; if we compare the natural gas and hydrogen combustion characteristics, the hydrogen firing speed is significantly higher (~5 times) than natural gas. This requires the burner and gas nozzles to be designed for the new fuel velocity. Hydrogen has a higher stoichiometric adiabatic flame temperature (~450 F degrees higher) than natural gas, making necessary the upgrade of internal burner components to higher grade steel or alloys suited for the elevated temperatures.

Emissions play another curveball into the firing of hydrogen, as hydrogen burns “hotter” than natural gas and have a faster combustion rate than natural gas; hydrogen is prone to thermal NOx generation. Considering few techniques to lower the NOx, such as flue gas recirculation (FGR), steam injection, and Ultra-low NOx burners can effectively reduce the emissions to the required levels.

Our Preferred Special Combustion Engineering (PSCE) division has considered all the above. It has developed and installed our Hydrogen burner system on multiple sites successfully, keeping the end-user boiler systems operating safely and environmentally sound.

See also: Automatic, Variable Ratio, Firing of a Blend of “Free” and Purchased Fuels

PSCE Hydrogen Burner

Preferred’s Solution

Our Hydrogen burner, developed by Preferred’s Special Combustion Engineering (PSCE) division, provides the sustainable, safe reclamation of waste hydrogen with high efficiency and carbon footprint reduction. Chemical plant applications are able to use their green, blue, gray, or white Hydrogen, which significantly reduces their use of fossil fuel for their process steam requirements.

Our expertise in coal to natural gas conversions and other alternate “free fuel” applications comes with a commitment to reliable blending of alternate and traditional fuels and reliable combustion, so the plant is operational, and experiences limited down time.

PSCE handles controls, burner, boiler, fuel handling, blending, and a balance of plant integrated combustion. Specializing in these applications gives plant managers the confidence that their burner will light when they need it to, no matter the fuel blend they are achieving for combustion. 

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