Last updated on July 3rd, 2023 at 06:52 pm

Propane dehydrogenation (PDH) involves the conversion of propane feedstock into propylene, which currently is in high demand worldwide for various industrial applications. This process is already used for notable projects, such as the Alberta Heartland Project, among others, and it’s due to some distinct advantages PDH has. These advantages aren’t widely touted outside of certain industries—and they should be. There are many advantages of PDH in certain industrial applications.

What is propane dehydrogenation?

Propane dehydrogenation is the process of removing hydrogen from a propane stream to produce propylene. This is done using a platinum or chromium oxide-based catalyst depending on the process used. It could be CATOFIN (chromium) or OLEFLEX (platinum) processes.

Propylene is a raw material used in the production of polypropylene, propylene oxide, acrolein, acetone, acrylonitrile, and other chemicals. Originally, it was produced through steam cracking, fluid catalytic cracking (FCC), and methanol-to-propylene but recent advancements are proving more beneficial and efficient.

Propane dehydrogenation offers advantages other methods don’t, such as high propylene selectivity, low costs, a larger source of feedstock, and higher profits.

Propane dehydrogenation is achieved using one of three methods:

1. Direct dehydrogenation without oxidants (PDH)
2. Oxidative dehydrogenation which uses oxygen (ODH)
3. Dehydrogenation using CO2 as an oxidant or to shift the equilibrium from PDH

Advantages of propane dehydrogenation

1. High propylene selectivity

The higher the propylene selectivity, the better. However much propane is fed into the tank, the goal is to get as much propylene as possible as a result. OLEFLEX catalysts use a continuous catalyst regeneration (CCR) system to regenerate materials and ensure high productivity and selectivity levels due to their high activity. The propylene selectivity is 85 percent.

CATOFIN systems do slightly better with a propylene selectivity rate of 88 percent because of their low reactor inlet temperature.

2. Low costs

To make any petrochemical system sustainable, multiple factors need to be applied simultaneously, one of which is the cost needs to be affordable to industrial settings that have many other expenditures.

OLEFLEX plants use a simple design and focus on performance which makes them less expensive to operate. Because the platinum catalyst is so stable in this design, it’s more efficient to get the same level of propylene production with the propane for the entirety of the catalyst’s life. The higher the stability, the tighter the design parameters can be since OLEFLEX catalyst deactivation is predictable.

The highest expense is allocated to the propane feed to produce a high product yield compared to other PDH systems. These other OLEFLEX features reduce operating costs:

• Reduced compressor stress due to positive reactor pressure
• The ability to function without a nitrogen purge to seal valves
• No need for a steam purge
• The capability to regenerate without the use of large utility air compressors
• Production doesn’t need to pause to change catalysts

CATOFIN is also a cost-efficient method of propane dehydrogenation. CATOFIN doesn’t require high compression energy so compressor costs are lowered. It isn’t necessary to pair it with a catalyst regeneration facility which is a whole segment that is removed from overall operating costs. Costs are further reduced since CATOFIN plants don’t require sulfur injections, and it uses non-precious metals.

3. A plentiful source of feedstock

Due to OLEFLEX’s simple design and high production rates, it has low feedstock consumption without lowering propylene production. 

CATOFIN also has a low feedstock consumption because of low operating pressure and has a high tolerance for feed impurities.

4. Abundant profits

Combining “on-purpose” propylene production with efficient, high-activity designs, low costs, and large sources of feedstock allows for industrial settings to make more products for less. Instead of steam cracking to produce ethane with the byproduct of producing propylene, the “on-purpose” advancement focuses on the production of propylene with more cost-efficient approaches. Demand for propylene has surpassed that of ethane; the propylene production industry is more profitable.

Industrial applications and byproducts

Propane dehydrogenation is essential in industrial settings. Not only can propane be processed into propylene, but it can also be polypropene, a thermoplastic polymer that is second in demand to polythene. Polypropene has high chemical resistance and elasticity making it an asset in packaging, manufacturing, and construction. 

Propene is the middle step between propane and other possible byproducts. One propane is converted into propene, it has the potential to become any of the following:

• Propene oxide to make polyurethane
• Acrylic acid for acrylic polymers and in coatings
• Acrylonitrile is used in acrylic fabric and used to make polypropenonitrile
• Isopropanol used as a solvent and to manufacture phenol and acetone
• Cumene used to make epoxy resins and polycarbonate
• Phenol used in the manufacturing of nylon and other synthetic fabrics

Wattco recommendations on heating for propane dehydrogenation

The advantages the OLEFLEX and CATOFIN systems provide are only available if they’re able to operate at higher temperatures. That change means equipment is more susceptible to obstacles.

The solution to ensuring these plants can operate at their high temperatures is implementing electric petrochemical heaters. These heaters can reach and maintain the needed high temperatures quickly and efficiently. The speed at which the heaters reach their target temperatures enables propane dehydrogenation plants to boost production rates and maintain their lower operating costs.

Similarly to OLEFLEX systems, electric petrochemical heaters use a simple design which makes them easier to maintain and more reliable in the long run. The initial problem of higher temperatures is solved with a product that’s easy to maintain and customizable so the equipment isn’t at risk of failing.

Wattco specializes in manufacturing customizable electric petrochemical and PDH heaters. We have a team of highly skilled engineers that understand which type of heater, and what configuration and materials will match the budget and needs of a project. 

For additional help and guidance in getting the right electric heater, contact us. In the meantime, learn more about the advantages of heaters for the petrochemical industry.