Refining Blog

Refinery Optimization Strategies

Jim Cahill — Thu, 06 Aug 2020 12:30:25 GMT

Ensuring that a refinery is flexible enough to accommodate a variety of discounted crudes and adjust production to meet critical customer commitments sometimes feels like walking a tightrope with just the right balance between the financial benefit these crudes offer and the increased fouling and corrosion they cause to a refinery’s assets.

In my article, Production levels: Are they all they could be?, in the Refiner’s Guide to Digital Transformation and Top Quartile Performance I explore this balance to optimize refinery operations.

When a refinery takes advantage of the increasing number of discounted opportunity crudes, its assets are at risk for corrosion in unexpected places, and accelerated fouling that can affect production capability for the entire refinery. This makes it challenging to meet production targets.

In addition, personnel at many refineries lack sufficient visibility into equipment health. Without visibility and analysis on the condition of equipment, it is impossible to accurately know the current condition of the refinery. Compounding this issue, many refineries still choose route-based data collection.

Unfortunately, this basic method of manual monitoring is performed infrequently and uses valuable and limited resources that should be eliminating problems rather than hunting for them. And, because this approach results in large gaps in asset health data, the refinery is at greater risk for downtime, which may result in revenue loss and an increased risk for a safety or environmental issues.

In the article, I share information on how refiners can increase asset availability and plant utilization—such as gaining insight into the state of the refinery’s assets, so operators can get the right data and analysis on performance to take corrective action before equipment failure results in a shutdown or slowdown.

This approach worked well for a large Gulf Coast refinery which made an automation upgrade for a coker and hydrocracker, resulting in a 50% reduction in lost availability due to unscheduled shutdowns and slowdowns. The improvement in these two units alone was worth $1–$2 million per year in increased margin.

I also highlight tips for producing more yield and cost-effective and efficient training opportunities available that can rapidly help staff become proficient with taking advantage of complex new technologies.

Download the full guide for more strategies to drive Top Quartile operational performance and visit the Refining industry section on Emerson.com for on the technologies and solutions to execute your digital transformation initiatives.

The post Refinery Optimization Strategies appeared first on the Emerson Automation Experts blog.

Holistic Approach to Top Quartile Reliability Performance

Jim Cahill — Wed, 15 Jul 2020 20:47:50 GMT

Operating reliably is one of the critical success factors in driving business performance for manufacturers and producers in the process industries.

In the Refiner’s Guide to Digital Transformation and Top Quartile Performance, the article, From cultural shifts to tactical strategies: Ensuring refinery reliability takes a holistic approach, highlights an effective path to success.

The opportunity?

By generating dramatic asset performance gains of more than 400 hours of operations per year, they [Top Quartile performers] gain two additional weeks of productivity, allowing them to capture more margin opportunities that go right to the bottom line.

The holistic, top-down approach to Top Quartile reliability performance begins with:

…a top-down vision rather than taking a reactive maintenance approach, while at the same time, empowering their personnel to affect real change at the most tactical, fundamental levels.

Here’s the recommended path forward.

Start by assessing common problems
Utilize data to fix asset issues early
Changing the mindset, one step at a time

Common problem indicators include unplanned downtime, overstocked spare parts, and stranded technology. By assessing these problem areas:

…you can then develop a roadmap and cultivate the organizational cultural shifts necessary to improve reliability, and ultimately, production.

Lower reliability means greater downtime.

Those performing below the Top Quartile will often see 2-to-14 percent more downtime, according to a recent Solomon reliability and maintenance study.

From an economic standpoint, this adds up.

A 250 thousand BPD, lower quartile refinery, for instance, spends an average of $10 to $30 million per year more on maintenance than a Top Quartile refinery.

On using potentially underutilized data, more:

…information can be extracted from these [process management and condition monitoring systems] investments to identify the cause of failures and fix equipment earlier and plan repairs at times when the output of an asset is least valuable. Even more importantly, this information can be used to evaluate when continuing operation of an asset could pose a safety risk.

Read the article on ways to drive Top Quartile performance at your facility. And, register today to download the full Refiner’s Guide to Digital Transformation and Top Quartile Performance.

The post Holistic Approach to Top Quartile Reliability Performance appeared first on the Emerson Automation Experts blog.

Choosing the Right Gas Analyzer for Nitrogen Oxide (NOx) Emissions Monitoring

Jim Cahill — Fri, 10 Jul 2020 22:02:35 GMT

NO_x is probably the most ubiquitous combustion-created air pollutant since it can be generated by any process burning any fossil fuel, and it is tightly regulated by the U.S. EPA and other regulatory bodies around the world. Plants with relevant combustion processes, including most refineries and chemical processing plants, must monitor NO_x output continuously any time fuel is burning. How plants choose to do this is up to them, provided the chosen method can meet the strict regulatory requirements for accuracy and availability.

In this article in Hydrocarbon Processing, Katherine Williams and I compare and contrast two commonly used NO_x measuring technologies: chemiluminescence detection (CLD) and direct absorption spectroscopy. The former measures just NO_x, while the latter can measure a whole range of pollutants. Here are the mechanics of both.

A CLD analyzer determines the amount of NO_x in a sample by measuring the light given off by excited NO₂ molecules.

The first measurement method depends on a chemical effect called chemiluminescence. As the result of a chemical reaction of the intermediates NO and ozone (O₃), NO₂ is produced in an excited energy state form. By emitting a photon in the excited state, the NO₂ returns to its ground state. The light emission, or chemiluminescence, can be detected and measured, and based on the amount of light emitted, the number of NO molecules can be determined.

QCL/TDL systems include high-resolution lasers to measure both the near- and mid-infrared spectral regions for real-time gas analysis down to sub-ppm concentrations.

This second measurement method uses an entirely different approach. Direct absorption spectroscopy utilizes a given compound’s capability to absorb specific wavelengths of electromagnetic radiation. The absorption at a given wavelength is measured, allowing an analyzer to detect and quantify the presence of various compounds of interest. Using this technology, a single analyzer can monitor a range of pollutants in a gas stream.

Emerson’s Rosemount CLD Continuous Gas Analyzer is a single-purpose solution for NOx, and it has a proven track record for surpassing the EPA’s performance requirements for accuracy and availability. Its very wide user-selectable NOx measurement ranges (from 0-5 parts-per-million (ppm) up to 10,000 ppm) make it a versatile solution. It can be used not only in industrial combustion applications but also in gas purity measurements in medical, industrial, and food and beverage applications. Among the various NOx measurement technology alternatives, CLD technology offers reliable performance at excellent value.

But, if the application calls for monitoring other pollutants in addition to NO_x, Emerson’s Rosemount CT4400 Continuous Gas Analyzer uses hybrid quantum cascade laser and tunable diode laser (QCL/TDL) technology to quantify multiple gases. In years past, this capability would have normally required an assortment of analyzers, but many applications can now be handled by a single analyzer.

Compared to older technologies, these analyzers are more reliable, more stable, easier to operate, and require no consumables. However, a large number of Continuous Emissions Monitoring Systems (CEMS) still run older analyzers with high operating costs and low availability, putting operators at risk of costly fines and shutdowns for failing to meet regulatory requirements.

Enhance your ability to meet changing environmental regulations. Read the article for more information on two different approaches for continuous NO_x measurement. You can also visit the Gas Analysis Solutions pages at Emerson.com for more on the technologies and solutions to help you reduce monitoring costs and avoid fines. To connect and interact with other environmental teams in the Refining and Chemical groups, visit Emerson Exchange 365 community.

The post Choosing the Right Gas Analyzer for Nitrogen Oxide (NOx) Emissions Monitoring appeared first on the Emerson Automation Experts blog.

Moving from Paper and Pencil to Digital Practices

Jim Cahill — Tue, 30 Jun 2020 20:12:02 GMT

One path in digital transformation initiatives is the move from paper & pencil-based data collection on operator rounds to Industrial Internet of Things (IIoT)-based sensors collecting and transmitting the data on a continuous basis.

In a Hydrocarbon Engineering article, Disparate Data (registration required), Emerson’s Jodi Johnson describes how this shift helps create value for manufacturers and producers. She opens noting the challenges inherent in the paper & pencil practice.

Maintenance history may be lacking as it is not typically centralized, which creates a lack of understanding of a plant’s current condition and even the location of the assets.

In addition to the time saved not having to track down information on paper, knowing:

…where assets are located and how they are functioning is important for managing plant budgets and optimizing productivity.

Jodi shares the example of digital positioners on control valves, which have been available since the 1980s. As software and secure communications technology has advanced:

…it is possible for end users to have equipment experts regularly review device data anywhere in the world, ensuring that the plant will have the best possible maintenance strategy regardless of the type of equipment.

One area of IIoT technology is digital nameplates on equipment using RFID communications.

Once an RFID tag is attached, it can be scanned and read into an application to track construction changes and visual health in real time. The output of this data collection can create a worklist based on those findings to prioritise service needs, creating a flow of operating and asset information across an organization.

Jodi cites a Bain & Co. study, Big Data Analytics in Oil and Gas which highlights the value in increased visibility to information.

Having access to service and walkdown histories enables improved decision support, by helping prioritise assets that truly need to be worked on. According to management consultants Bain & Co., this level of visibility can help oil and gas companies improve production by 6-8%.

Visit the Hydrocarbon Engineering site and sign up for a free trial if you’re not already a subscriber, for more examples and putting the IIoT technologies together into a digital ecosystem to flexibly execute your digital transformation strategy.

Explore the Industrial IoT and Lifecycle Services – Valves, Actuators & Regulators sections for more on the technologies and services to advance your digital transformation initiatives. You can also connect and interact with other IIoT and digital transformation experts in the IIoT & Digital Transformation group in the Emerson Exchange 365 community.

The post Moving from Paper and Pencil to Digital Practices appeared first on the Emerson Automation Experts blog.

Technology Modernization for Refinery Digital Transformation

Jim Cahill — Thu, 25 Jun 2020 19:39:34 GMT

Control systems’ lives are measured in decades instead of the short life spans we experience with our consumer electronics and other consumer technologies. Yet even with this long lifespan, control systems need to be modernized to take full advantage of advancing technologies that help to improve safety, efficiency and reliability.

In a Refiner’s Guide to Digital Transformation and Top Quartile Performance article, Emerson’s Duncan Schleiss highlights the importance of technology modernization in driving top performance.

Duncan opens noting the technology enablers all around us in our daily lives.

The connected smart home now offers completely different ways of home management—all enabled by a digitally secure, connected, and often wireless communication infrastructure.

These technology enablers which have transformed our lives have not come as fast for manufacturers and producers. For refiners, adopting some of these enablers opens the ability to:

More easily comply with new safety standards.

Manage asset obsolescence more effectively.

Leverage machine analytics to improve availability.

Increase profitability with embedded advanced control.

Access remote experts who help fill the skills gap in real time.

Successfully modernizing technologies as part a digital transformation initiative requires:

…engaging early with an automation partner that can help you minimize modernization project costs and mitigate risks.

This automation partner should have:

Proven track record as a main automation contractor (MAC) for modernization projects.

Proven experience with hot-cutover migrations to modern secure digital architectures.

The conversion tools needed to ensure seamless integration of existing configurations into the new DCS.

A wide variety of built-for-refining solutions including digital twin technology, plant optimization, dynamic alarm management, and layered, advanced machine learning.

Remote availability to experts who can collaborate and problem solve with plant personnel in real time.

The flexibility to adapt solutions to your specific priorities to maximize your ROI.

Read the article and others in the Refiner’s Guide to Digital Transformation and Top Quartile Performance which provide ways for refiners to drive top quartile performance in safety, reliability, energy efficiency and production.

Visit the Distributed Control System Modernization section on Emerson.com for more on the migration and modernization services and technologies to drive your digital transformation initiatives.

The post Technology Modernization for Refinery Digital Transformation appeared first on the Emerson Automation Experts blog.

Improving Refining Operations with Rich Data and Analytics

Jim Cahill — Wed, 10 Jun 2020 16:36:56 GMT

“While online data from sensors has been available for decades, the low cost and quick installation time of wireless sensors compared to their wired counterparts is driving a new digital transformation in refineries around the world. The data from wireless sensors not only provide real-time measurements and valuable insights into asset health, it can spur new ways to integrate work processes and improve the timeliness and accuracy of decision-making for personnel.”

So Emerson’s Dennis Belanger opens the article, Unlock the rich data in your refinery to achieve Top Quartile performance, in the Refiner’s Guide to Digital Transformation and Top Quartile Performance. Dennis describes how big data helps drive increased productivity, lowered maintenance costs and energy usage, reduced downtime, and lower safety and environmental incidents.

He cites a McKinsey study that:

…has ranked Big Data Analytics as one of the top potential technologies that can increase productivity and GDP over the next few years. Among business sectors, manufacturing was the lead with an estimated overall GDP yearly increase of $125–$250 billion.

IIoT analytics in the Plantweb digital ecosystem helps refiners address the wealth of raw data from additional sensors and:

…validate and analyze using the appropriate parameters and alerts to uncover the trends—and account for the anomalies—that will help predict equipment or process failures.

Get your copy of the Refiner’s Guide for more using operational analytics and other technologies to drive your digital transformation initiatives.

Visit the Refining section on Emerson.com for ways to improve operational flexibility and reduce operating costs, unplanned slowdowns and shutdowns, and be more adaptive to new clean fuels regulations.

The post Improving Refining Operations with Rich Data and Analytics appeared first on the Emerson Automation Experts blog.

Coriolis Flow Meters for High Accuracy Refining Applications

Jim Cahill — Thu, 04 Jun 2020 14:27:33 GMT

Measuring flow rates with differential pressure (DP) instruments has been a time-tested practice for decades. While still the most widely used flow measurement technology, other technologies have unique advantages for some applications.

In a Processing article, Controlling critical refining applications with Coriolis meters, Emerson’s Julie Valentine and Meha Jha share specific applications where Coriolis flow measurement provides opportunities for better control and more reliable operations.

Julie and Meha open the article noting that

…while dP flow meters have great application flexibility and repeatability, their accuracy can easily be impacted by changes in the composition or flow profile of the fluid flowing through them, or by changing process conditions such as pressure or temperature.

Also:

…dP flow meters require very regular maintenance as these technologies have impulse lines that can be prone to plugging depending on climate conditions and fluid properties. Like many mechanical meters, the accuracy of the device also degrades over time due to wear and tear on the orifice plate.

Coriolis flow meters, such as Emerson’s Micro Motion Coriolis flow meters, are well-suited for applications requiring greater accuracy and robustness. These meters:

…are multi-variable devices that provide a direct measurement of mass flow, density and temperature for liquids, slurries and gases. The technology is based on the Coriolis effect in which the inertia created by the fluid flow causes the meter’s tubes to twist proportional to the mass flow rate.

Julie and Meha highlight these refinery applications as a great fit for Coriolis flow measurements.

Tank dewatering
Crude blending
Fuel blending
Acid control in alkylation units
Combustion control

I’ve touched on some of the blending applications in earlier posts so let me highlight the acid control application and invite you to read the article for the rest.

Coriolis meters can be used to reduce acid consumption by online measurement and control of acid strength in sulfuric acid alkylation units. Density measurements from Coriolis meters can be measured and correlated to acid concentration at the interstage settlers, as well as the final spent acid settler. Monitoring the spent acid strength online allows for better optimization and control of fresh acid. Coriolis meters are also used to determine the acid-to-hydrocarbon ratio in the contactor, replacing high maintenance, low reliability sight gases.

Visit the Coriolis Flow Meters for Mass, Volume, & Density section on Emerson.com for more on how this flow measurement technology can be applied for your most critical flow measurement needs. You can also connect and interact with other flow measurement experts in the Measurement Instrumentation group in the Emerson Exchange 365 community.

Coriolis Flow Meters for High Accuracy Refining Applications

Jim Cahill — Thu, 04 Jun 2020 14:27:33 GMT

Julie and Meha open the article noting that

…while dP flow meters have great application flexibility and repeatability, their accuracy can easily be impacted by changes in the composition or flow profile of the fluid flowing through them, or by changing process conditions such as pressure or temperature.

Also:

…dP flow meters require very regular maintenance as these technologies have impulse lines that can be prone to plugging depending on climate conditions and fluid properties. Like many mechanical meters, the accuracy of the device also degrades over time due to wear and tear on the orifice plate.

Coriolis flow meters, such as Emerson’s Micro Motion Coriolis flow meters, are well-suited for applications requiring greater accuracy and robustness. These meters:

…are multi-variable devices that provide a direct measurement of mass flow, density and temperature for liquids, slurries and gases. The technology is based on the Coriolis effect in which the inertia created by the fluid flow causes the meter’s tubes to twist proportional to the mass flow rate.

Julie and Meha highlight these refinery applications as a great fit for Coriolis flow measurements.

Tank dewatering
Crude blending
Fuel blending
Acid control in alkylation units
Combustion control

I’ve touched on some of the blending applications in earlier posts so let me highlight the acid control application and invite you to read the article for the rest.

Coriolis meters can be used to reduce acid consumption by online measurement and control of acid strength in sulfuric acid alkylation units. Density measurements from Coriolis meters can be measured and correlated to acid concentration at the interstage settlers, as well as the final spent acid settler. Monitoring the spent acid strength online allows for better optimization and control of fresh acid. Coriolis meters are also used to determine the acid-to-hydrocarbon ratio in the contactor, replacing high maintenance, low reliability sight gases.

The post Coriolis Flow Meters for High Accuracy Refining Applications appeared first on the Emerson Automation Experts blog.

Driving Refinery Safety Performance Improvement

Jim Cahill — Fri, 29 May 2020 16:49:34 GMT

Refining crude oil into gasoline, jet fuel and other petrochemical products requires constant vigilance in safety. And although the refining industry has always been focused on safety—and overall rate incidence reports have been decreasing—there are still opportunities for improvement.

According to the American Fuel and Petrochemical Manufacturers (AFPM), the top three leading causes of Tier 1 and Tier 2 incidents between 2012 and 2016 were due to issues with piping, atmospheric tanks, and pumps.

In an article from the Refiner’s Guide to Digital Transformation and Top Quartile Performance, Emerson’s Tim Olsen shares ways for refiners to embrace new strategies and technologies that reduce their personnel’s exposure to hazardous environments and materials—and integrate more accurate, reliable, and regulatory-compliant process equipment to enhance personnel and site safety.

When it comes to personnel safety, Tim notes that for refiner’s staff members:

…who make the rounds to enable your refinery to operate smoothly, safety is everything. Even though a typical refinery spends less than 10 percent of its time in transient operation—those hours surrounding a plant shutdown or startup—it’s also the time when 20-to-30 percent of process safety incidents occur.

Ways modern technologies can help include:

…better methods of flame and gas detection in the most hard-to-reach and dangerous refinery environments, the ability to use more wireless sensing and analytics to eliminate the need for personnel to do manual data collection in dangerous areas, and more accurate, reliable methods of toxic gas detection that further keep your personnel out of harm’s way.

Process equipment failures also affect safety performance.

According to the National Response Center Database, approximately 40 percent of process safety incidents can be tied to mechanical integrity across all processing industries.

Read the article and others in the Refiner’s Guide for more on ways to drive improved performance in safety and digitally transform your refining operations.

Visit the Downstream Hydrocarbons section on Emerson.com for more on the technologies and solutions to help you drive top quartile business performance. You can also connect and interact with other downstream hydrocarbon industry experts in the Refining group in the Emerson Exchange 365 community.

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Digital Transformation Actionable Roadmap

Jim Cahill — Fri, 15 May 2020 17:20:15 GMT

Because the refining industry is constantly changing, with new regulations and opportunities with discounted crude oils, changing distribution patterns, and new competitors on the scene—refiners are challenged to adapt to a complex and dynamic environment.

Not only must they optimize process operations, train and upskill staff, and be flexible enough to capture favorable market conditions, they need to maintain compliance and meet safety standards, while improving efficiency. Digital transformation provides a path to Top Quartile performance in safety, efficiency, and reliability.

In an article from the Refiner’s Guide to Digital Transformation and Top Quartile Performance, Emerson’s Marcelo Carugo shares avenues for starting the digital transformation process. Three essential conditions for refiners include:

Operational agility—which involves being able to efficiently process different feedstocks while avoiding asset degradation, becoming more flexible to accommodate changing demands for different products, and producing more products for markets not traditionally served.
Achieving Top Quartile performance-level availability—which is related to operational and mechanical availability, asset reliability at the site, and best-in-class strategies and technologies.
Implementing shared intelligence—where sophisticated new technologies deliver the right information to the right person who can take the right action when needed. It’s about bringing the data to the expert, instead of the expert to the data.

In Marcelo’s article, Creating a clear and actionable roadmap for digital transformation, he describes critical elements for successful digital transformation initiatives. These include:

Developing a clear and focused business case for investment.
Creating a scalable methodology that lets refiners transform operations at their pace, based on the value you achieve.
Incorporating a flexible technology platform that allows refiners to effectively start anywhere.
Choosing a strategy that includes people and work practice.

Read the article as well as other on ways to drive Top Quartile performance in the Refiner’s Guide to Digital Transformation and Top Quartile Performance. Also, visit the Refining section on Emerson.com for more on the technologies and solutions to help you drive business performance improvements during these challenging times.

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Distillation Column Automation Control and Optimization

Jim Cahill — Fri, 13 Mar 2020 05:00:00 GMT

Pete Sharpe

James Beall

The cold section of an ethylene plant is responsible for cooling and purifying the product-grade ethylene, propylene and other bi-products from the cracking furnaces. Cracked gas is cooled in transfer-line exchangers which produce steam from the effluent gas energy. Gas is further cooled with water in the quench column, scrubbed and dried before being compressed in the cracked gas compressor and fed to the cold box.

Ethylene Cold Box

The cold box is a complicated, multi-stream heat exchanger which cools the cracked gas. A methane/hydrogen stream is pulled off the cold box which also acts as the condenser for the demethanizer, the first column in the purification train. The demethanizer bottoms feeds a series of distillation columns which separate high-purity ethylene and propylene products from recycle ethane and propane, C4s and higher.

Doug White

Since most columns operate under cryogenic conditions that can condense light gases, the refrigeration bill for these plants is substantial. While modern ethylene plants are quite heat integrated, they still need two large refrigeration compressors to provide cooling to the distillation column condensers and cold box. As Emerson’s Dr. Douglas White has explained, energy costs for the cold side of an ethylene plant represents roughly 20% of the total energy bill.

Operating the distillation train in an ethylene plant can be challenging because of constant feed rate and composition changes as furnaces are brought on- and off-line. High purity columns like the ethylene and propylene splitters exhibit very long time constants and deadtime which is difficult for most PID controllers to handle well.

These columns also have sections of flat temperature profiles which give little indication when product compositions are changing. Since the final product comes from these columns, the tendency is to operate conservatively, leading to increased product giveaway (greater purity than required) and higher energy consumed per ton of product.

Distillation Control Best Practices

Best practice for distillation control starts with the proper instruments and robust, stable control loop performance. From an instrumentation perspective, it is important to have tray temperatures located in the proper section of the column with a steep temperature profile and mounted in such a way as to measure true equilibrium vapor/liquid temperatures—and not splashed by a down-comer or return reflux. Key control valves such as the reflux, reboiler, column pressure and feed valves should have high-performing valves with smart positioners tuned for stable, responsive position control and monitored for good performance.

Columns that operate close to flooding can use patented & innovative digital techniques to identify incipient flooding characteristics.

Finally, it is important to select the optimum regulatory control scheme based on the column’s characteristics (reflux/distillate ratio, product purity, etc.)

Modern loop tuning techniques such as Lambda Tuning should be used to stabilize the overall column control and tools such as DeltaV InSight should be used to monitor loop variability, mode, limits, oscillation, tuning and performance indices.

The next best practice for distillation columns is to utilize advanced control techniques to simultaneously control the composition of both ends of the column. Embedded model predictive control (MPC) algorithms such as DeltaV PredictPro can be used to address the long time constants and decouple the interactions inherent in distillation column controls.

Inferential predictions such as DeltaV Neural can be used for control between lab samples or gas chromatograph (GC) cycles. To make implementation and support even easier, Emerson has a pre-engineered library of distillation-specific APC functions and calculations in the SmartProcess Distillation application. These libraries calculate control and constraint parameters such as internal reflux, jet flood, reboiler and condenser duty, product recovery and energy per ton.

The APC will automatically stabilize the column and maintain on-spec production at minimum energy during changes in feed rates and composition. Furthermore, it is common for one or more of the distillation columns and/or the refrigeration system to be the plant bottleneck, limiting the total plant throughput. With APC monitoring and controlling constraint limits while minimizing energy and refrigeration load, it is possible to increase the total plant throughput.

Optimizing Energy versus Recovery

Finally, for ethylene and propylene splitters, there is further opportunity to optimize energy vs. recovery. Essentially, a two-product distillation column is controlled using two basic handles—material balance (e.g. distillate-to-feed (D/F) ratio) and energy balance (e.g. reflux-to-feed (R/F) ratio). The column control strategy will define which handle is tied to which product quality.

If the final product purity, ethylene in this case, is controlled using the D/F ratio, then the recovery of ethylene from the bottoms stream is controlled using energy (figure 1). Because of the non-linearity of energy vs. recovery, there is always a tradeoff of how much ethylene and propylene should be removed from the recycle feed to the furnaces. The optimum point is where the cost of the incremental energy used to recover an additional lb. of product is equal to the incremental value of that lb. recovered as product vs recycled (figure 2).

Using these best practices in an ethylene plant’s distillation columns, ethylene producers can expect improvements on the order of:

5-10% increased capacity
20-50% reduction in product quality variation
3-5% reduction in energy per ton
5-10% reduction in product inventories by reducing off-spec and re-work

In the next series of blog posts, our Downstream Hydrocarbons industries team will cover some of the other key value improvement practices (VIPs) for ethylene complexes to improve production, reliability, safety, energy and emissions.

From Jim: Visit the Operational Certainty and Ethylene sections on Emerson.com for more on the technologies, methodologies and solutions to help you drive business performance improvements.

The post Distillation Column Automation Control and Optimization appeared first on the Emerson Automation Experts blog.

Refinery Flare Regulatory Compliance

Jim Cahill — Fri, 21 Feb 2020 16:18:30 GMT

At the 2020 4C Health, Safety & Environment conference, Emerson’s Jamie Marsden presented, New Refinery Flare Regulations 40 CFR Part 63. The rule, 40 CFR 63 Subparts CC and UUU, affects any refinery with a flare used as a control device for an emission point, and those refineries must have been in compliance by January 30, 2019.

These regulations set flare operating limits, require a flare management plan (FMP), and require a continuous parameter monitoring system (CPMS) plan. The regulations also cover pilot flame monitoring, visible emissions and flare tip velocity—requirements previously found in earlier versions of the rule.

Jamie explained that the FMP rule specifically states:

For each flare, the owner or operator shall operate the flare to maintain the net heating value of flare combustion zone gas (NHVcz) at or above 270 British thermal units per standard cubic feet (Btu/scf) determined on a 15-minute block period basis when regulated material is routed to the flare for at least 15 minutes.

And:

For each flare actively receiving perimeter assist air, the owner or operator shall operate the flare to maintain the net heating value dilution parameter (NHVdil) at or above 22 British thermal units per square foot (Btu/ft2) determined on a 15-minute block period basis when regulated material is being routed to the flare for at least 15 minutes.

It allows the (EPA) Administrator to confirm that the selected site-specific operating limit(s) adequately ensures that the flare destruction efficiency is 98 percent or greater or that the flare combustion efficiency is 96.5 percent or greater at all times. Combustion efficiency, net heating value in the combustion zone, and net heating value dilution parameter are calculated as defined in rule CFR 63.670.

The gas chromatograph performing these measurements average continuous emissions monitoring system (CEMS) calibration response must not differ by more than 10 percent of calibration gas value at each level after each 24-hour period. Any one injection shall not deviate more than 5 percent from the average concentration measured at that level. The linear regression curve for each organic compound shall have an r 2 ≥0.995.

The sample to be analyzed shall flow continuously through the sampling system. The sampling system time constant shall be ≤5 minutes or the sampling frequency specified in the applicable regulation, whichever is less.

Here’s a typical flare system to meet the 40 CFR 63.670 controls:

Jamie shared the basics of a gas chromatograph system:

There are two standard Rosemount gas chromatograph solutions to meet the flare vent gas composition monitoring requirement of 40 CFR Part 36. The first solution, a Rosemount 1500XA process gas chromatograph measures hydrocarbons, H2S, H2, CO and CO2. The second 1500XA option measures hydrocarbons, H2S, H2, CO, CO2 and Benzene.

Jamie also noted that custom solutions are also available since the downstream hydrocarbon producer is responsible for confirming the components that are in the flare that need to be measured.

Visit the Gas Chromatography for Environmental Monitoring section on Emerson.com for more on solutions to comply with flare regulatory reporting. You can also connect and interact with other gas chromatograph experts in the Measurement Instrumentation group in the Emerson Exchange 365 community.

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Driving Safer and More Secure Refining and Chemical Operations

Jim Cahill — Tue, 28 Jan 2020 20:15:05 GMT

According to the United States Energy Information Administration, the Texas and Louisiana Gulf Coast refiners and petrochemical producers accounted for 50.5% of the U.S. total finished petroleum products as of October 2019. So with over half of America’s refining and petrochemical production, running these facilities as safely, efficiently and reliably as possible is critical.

For refiners and chemical producers in the Corpus Christi and Houston, Texas regions, Emerson and Emerson Impact Partner Puffer-Sweiven industry experts will team up to conduct two Digital Transformation Innovations for Process and Personnel Safety in Refineries and Chemical Plants seminars.

The seminars will run from 8am to 1pm on February 10 in Corpus Christi and February 12 in Houston. I’ll update the post as additional locations are announced.

The focus for the seminars will be on the technologies and solutions in control and asset management to help drive safer and more secure operations. Key discussion areas will include:

Safety First: Digital transformation solutions for safety
Process Safety – focus on safer operations
Achieve Top Quartile- Operational Availability, Net Cash, Margin while maintaining Safety and Environmental
Compliance
Occupational Safety
Cyber threats
Actionable next steps

Several Emerson experts you may recognize from earlier posts will share their experience including Marcelo Carugo, Ed Schodowski, Dr. Doug White, Christiane Lederer, Marcio Donnangelo, Marcelo Dultra, Dave Macedonia, Scott Pettigrew, and Pete Sharpe.

Register today if you’ll be in the Corpus Christi area on February 10 or Houston on February 12, or contact our refining & chemical industry experts to discuss ways to drive safer and more secure operational performance.

The post Driving Safer and More Secure Refining and Chemical Operations appeared first on the Emerson Automation Experts blog.

Driving Safer and More Secure Refining and Chemical Operations

Jim Cahill — Tue, 28 Jan 2020 20:15:05 GMT

The seminars will run from 8am to 1pm on February 10 in Corpus Christi and February 12 in Houston. I’ll update the post as additional locations are announced.

The focus for the seminars will be on the technologies and solutions in control and asset management to help drive safer and more secure operations. Key discussion areas will include:

Safety First: Digital transformation solutions for safety
Process Safety – focus on safer operations
Achieve Top Quartile- Operational Availability, Net Cash, Margin while maintaining Safety and Environmental
Compliance
Occupational Safety
Cyber threats
Actionable next steps

The post Driving Safer and More Secure Refining and Chemical Operations appeared first on the Emerson Automation Experts blog.

Optimizing Opportunity Crude Usage while Minimizing Operational Risks

Jim Cahill — Wed, 04 Dec 2019 15:24:07 GMT

Meha Jha

Julie Valentine

For refiners, opportunity crude is crude oil available on the spot market that are typically much lower cost than crude oil received under long-term contracts.

In a Hydrocarbon Engineering article, Finding the Sweet Spot, Emerson’s Meha Jha and Julie Valentine collaborated with Topnir Systems‘ Didier Lambert, to highlight the processing challenges for opportunity crudes and solutions to address these challenges.

They open describing the challenge in processing opportunity crudes.

As using expensive crudes can limit the profit margins of a refiner, there is a trade-off between the cost of crudes and the risk of operational impacts they can have on the process.

If the opportunity crudes are not blended to the right ratios for which the refining process has been designed, these operational impacts can include:

…risks such as corrosion, fouling, bottlenecks and slowdowns.

They provide an example of what the use of operating crudes can financially deliver.

An increased usage of just 1% of opportunity crudes could save US$5 million for a 250 000 bpd refinery at a differential of US$6/bbl…

Even the composition of long-term suppliers of crude can change.

Furthermore, crude assays from known suppliers are not always consistent as changes in the conditions at the source can affect the crude over time.

Crude assays, lab analysis and tank blending are the traditional ways to find and change the characteristics of the crude oil, such as its API gravity, acidity, sulfur content, etc. To avoid some of the operational impacts, refiners are looking to more automated and continuous ways characterize and blend the crude oil.

These changes include adopting technology to provide online crude characterization and inline blending to accurately measure each component according to a target recipe, enabling real time blend adjustments based on the online crude analysis.

Instrumentation such as [hyperlinks added for more information]:

Flow, density and viscosity meters can confirm simple characterisations. Topology and near-infrared (TopNIR) analysers and models can be used for full characterisation.

Simple characterizations include crude oil density, viscosity and water cut. Full characterization includes:

…API gravity, sulfur, temperature boiling point curve, TAN [total acid number], carbon-hydrogen ratio, asphaltenes, and yields.

Models help to allow fewer samples to be required to interpolate compatible crudes by providing:

…a library of crude clusters grouped by chemical characteristics and properties.

Read the article for more on how the simple and full characterizations combined with advanced process control can help maximize the use of opportunity crudes and avoid the operational impacts of non-compatible crude blends.

Visit the Refining section on Emerson.com for more on the technologies and solutions to drive top quartile performance. You can also connect and interact with other refining industry experts in the Refining group in the Emerson Exchange 365 community.

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