Front-end depropanizer feeds are more likely to contain sulfur, butadiene and metal contaminants that can cause catalyst deactivation. The MAPD and CO concentrations are present in higher concentrations than in deethanizer feed so while reactor thermal stability is less of a concern, FE E-DC3 catalyst has been tailored to provide high activity and tolerance to contaminants, while at the same time maintaining excellent selectivity to ethylene. Other commercial catalysts offer high activity but sacrifice selectivity. This superior selectivity enables E-Series catalyst formulations to also provide much longer acetylene converter run lengths compared to other catalysts.
As a major ethylene producer, Chevron Phillips Chemical Company LP has conducted extensive research and development to improve ethylene cracker operations. One of the results of these efforts had been the commercialization of new selective acetylene hydrogenation catalysts known as E-Series catalyst.
Chevron Phillips Chemical has been a commercial producer of ethylene since the 1950s with six ethylene crackers and several others planned or already under construction. Chevron Phillips Chemical operates more than 30 manufacturing facilities in eight countries and has seven research and technology centers.
Chevron Phillips Chemical’s success with the E-Series catalyst goes far beyond its own acetylene converters. Chevron Phillips Chemical has the ability to custom formulate catalysts based on customer needs and process design, to offer catalysts with higher selectivity, improved stable operations without runaways, longer cycle run lengths and longer overall catalyst life. The fact that Chevron Phillips Chemical is both an ethylene producer and catalyst supplier is a great benefit to our customers since we have personal insight into reactor operations.
Types of Ethylene Plants
Ethylene crackers can be broadly divided into two basic configurations, those with front-end acetylene converters and those with back-end converters. Front-end acetylene conversion involves the hydrogenation of acetylene prior to the removal of methane and lighter components from the cracked gas stream (at the front of an ethylene plant) while in back-end plants, the acetylene conversions occurs in a stream at the back end of the plant where basically only ethane, ethylene, acetylene and possibly some carbon monoxide enters the acetylene converter. The differences in feed compositions require different catalyst formulations in order to provide optimum and stable performance.
Chevron Phillips Chemical markets several formulations under the E-Series catalysts designation by acetylene converter type:
- FE E-DC2-4 and FE E-DC2-5 (for front-end deethanizer converters)
- FE E-DC3 (for front-end depropanizer converters)
- FE E-RG (for front-end raw gas converters)
Customer Service and Support
As a worldwide manufacturer and marketer of specialty chemicals, Chevron Phillips Chemical maintains an experienced staff ready to assist with various order processing and shipping alternatives. Our group of knowledgeable chemists and engineers is also ready to assist customers with technical service issues. With significant experience as a major ethylene producer, Chevron Phillips Chemical is uniquely qualified to understand the customer’s catalyst and processing needs. Laboratory experimentation, pilot plant operations, and advanced modeling techniques are also available to address customer inquiries. Our support extends to our experienced professionals assisting with operator training, plant startups, and acetylene converter kinetic and thermodynamic modeling general troubleshooting.
The high selectivity and stability of E-Series catalyst allow the operator to meet extremely low acetylene levels in the reactor effluent while reducing acetylene converter down-time and off-spec production without sacrificing production stability.
- Excellent Selectivity – E-Series catalyst quantitatively removes acetylene while limiting the amount of over-hydrogenation of ethylene to ethane. This enhanced selectivity results in an increased amount of ethylene production as well as in the reduction of reprocessing cost of the recycle ethane.
- Stable ARU Operations – E-Series catalysts are much more stable when operating at the higher conversions necessary to lower the acetylene to tighter ethylene specifications. Operation of other catalysts at this conversion level can result in temperature excursions that can lead to dangerous temperature “runaway” conditions.
- Resistance to CO Changes – Reactors operated with E-Series catalyst are highly resistant to temperature excursions due to fluctuations in carbon monoxide content in the feed. Changes in carbon monoxide levels with traditional catalysts can often lead to off-spec production and temperature runaway conditions. For example, following the decoking of a furnace, an operator can easily adjust the temperature of the acetylene reactor containing E-Series catalyst to accommodate changes in the carbon monoxide content of the feed. This allows the reactor to be operated with little or no off-spec production.
- Ease of Reactor Startup – Using E-Series catalyst enables a quicker startup while minimizing off-spec production compared to traditional catalysts.
- Ease of Use – E-Series catalysts can easily be regenerated by either ex- or in-situ methods. The high crush strength of the catalyst enables them to maintain their integrity through multiple handlings.
Research and Development
Chevron Phillips Chemical is continuing with focused research and development to improve the applications of our selective hydrogenation technology. Our core expertise in catalyst development is supported by an exceptionally broad range of equipment capabilities to optimize catalyst performance. Our manufacturing expertise is supported by a wide range of analytical and pilot plant scale testing activities.
You can count on Chevron Phillips Chemical to provide excellent quality control, customer service, technical expertise, and responsiveness to your needs. E-mail us with your questions about our products at [email protected].