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Fluid Catalytic Cracking Flue Gas Pressure Control Background Fluid Catalytic Cracking (FCC) is an essential process in refineries used to convert heavy feedstock oil into valuable gasoline, jet fuel, diesel, and other products. During the FCC reaction coke builds up on the catalyst, limiting its ability to carry out the reaction. The spent catalyst is then transferred to the regenerator to burn off the residual coke. As the spent catalyst is regenerated, flue gas (combustion gas) is created by burning off residual coke. The flue gas must then pass through a valve which diverts it to a power recovery train or through a series of separators and electro-static precipitators before being released into the atmosphere. Flue Gas Valve Purpose: Regulate the rate and direction of flue gas exiting the regenerator Helps maintain proper pressure differential between the regenerator and reactor Used for emergency isolation during upset conditions preventing backflow Flue Gas Valve Configuration: Double disc slide valve to provide inherent redundancy Butterfly valve with additional redundancy applied to the actuator system The key to success in this application is in engineering a Flue Gas Valve and actuator assembly that is capable of modulating with position accuracy, while providing fast signal response to control abnormal pressure disturbances. The Flue Gas exiting the regenerator has high pressure, high temperature, high volume, and will contain catalyst particulates. Tight control is critical in maintaining the FCC pressure balance in the cracking process. These conditions can require the Flue Gas Valve to be large in diameter necessitating the use of a hydraulic actuator often controlled by a Hydraulic Power Unit (HPU). Problem Poor Flue Gas Valve performance can create pressure unbalances, which can lead to an inefficient hydrocarbon cracking process. If this condition worsens, it creates potential for unplanned downtime and lost revenue. Common to all HPU systems is their inherent open loop design. Unlike other currently available hydraulic technologies, this design requires an intense maintenance program with frequent intervals. Atmospheric humidity makes contact with the hydraulic oil and creates acid build-up and premature oxidation. Additionally, dirt and particulate from the surrounding air enters the hydraulic system compounding the contamination issue. This is particularly problematic for servo and proportional valve driven hydraulic systems. These servo and proportional valve systems require very specific fluid cleanliness standards. If the fluid cleanliness comes out of spec, the system cannot perform as designed and will result in undesired inconsistent operation and the need to bring the system down for maintenance. The effect of oil degradation requires an HPU to have several filters in the system that must be replaced frequently to effectively clean the oil. There are also dozens of soft goods within these systems that are subjected to high temperatures and need to be replaced periodically before they wear out and become potential leak paths. The pumps within these systems are constantly running to maintain a certain operating pressure for the hydraulic actuator to operate the valve. These continuously running pumps draw a lot of electricity and they must be maintained at a significant cost to ensure the valve and process stay online. Finally, HPU systems often have several hundred feet of hydraulic tubing and hoses which all represent potential leak paths. In order to prevent unscheduled unit downtime, HPU systems are placed on rigorous preventative maintenance programs which are time consuming and expensive. Solution Eliminate the risk of hydraulic oil breakdown, contamination, and maintenance by upgrading to REXA Electraulic™ Actuation. REXA self-contained actuators combine the simplicity of electric operation, the power of hydraulics, maximum reliability, and the flexibility of user-configured control. The principle behind REXA Electraulic™ Actuation is a unique hydraulic circuitry called the Flow Match Valve (FMV) system. The actuator incorporates a bi-directional gear pump coupled to a motor that provides a highly efficient method of pumping hydraulic fluid from one side of the double acting cylinder to the other. The motor and pump only move when a position change is required. Once the target position is reached, the motor and pump shut off and the FMV system hydraulically locks the actuator in place. Motor operation is not required to maintain actuator position; the motor and pump remain idle until a new command signal is received. This maximizes operation efficiency while minimizing wear and tear of the actuator itself. Additionally, the actuator can be configured with full redundancy of full critical components to provide maximum reliability and availability to get you from turnaround to turnaround (TAR). Results With REXA Electraulic™ Actuation the end-user gets all the performance advantages of a hydraulic actuator without the costly maintenance routine. The system provides immediate response to control signal changes and accurately modulates the position of the Flue Gas Valve to ensure efficient and safe process control.  Eliminate the intense preventative maintenance routine of conventional HPU No more routine oil maintenance or fluid conditioning systems No more continuously running pumps wasting energy Achieve accurate Flue Gas Pressure Control with maximum reliability and operational safety Enable stable regenerator pressure with steady differential pressure between the reactor and regenerator Installing a REXA actuator on your Flue Gas Valve allows you to get better control of your FCC process! Literature Download the full Fluid Catalytic Cracking Flue Gas Pressure Control Application Spotlight here! Download

Fluid Catalytic Cracking Catalyst Slide Valve Control Background Fluid Catalytic Cracking (FCC) is a refining process used to convert heavier crude oil fractions into usable products such as gasoline, jet fuel, and diesel. In the reactor vessel feed oil is mixed with catalyst particles at high temperatures 900°F (482°C) to 1000°F (538°C), breaking the hydrocarbons into smaller particles. During the FCC reaction coke builds up on the catalyst, limiting its ability to carry out the reaction. The spent catalyst in the reactor chamber is then transferred to the regenerator to burn off the residual coke. Then the regenerated catalyst is transferred back to the base of the reactor riser to be used again. The key to success of this application is Spent and Regenerated Catalyst Slide Valve actuators that provide both reliable positioning accuracy and fast response to the abnormal pressure disturbances that may occur. The valve stroke lengths are typically 8in (20cm) to 24 in (61cm). The Regenerated Catalyst Slide Valve regulates the flow of the regenerated catalyst to the riser, maintaining the pressure head in the standpipe and protecting the reactor from a flow reversal. Maintaining a proper differential pressure is critical for smooth operation. Too high of a pressure difference can lead to excessive catalyst carryover, while too low of a pressure difference can result in poor catalyst circulation. The Spent Catalyst Slide Valve controls the stripper catalyst level, regulates flow of spent catalyst to the regenerator and protects the reactor and main fractionator from a flow reversal. The Spent Catalyst Slide Valve plays a crucial role in maintaining a catalyst barrier, which stops hydrocarbons within the reactor from entering the regenerator. If mixed with oxygen, these hydrocarbons in the regenerator or flue gas train are a safety risk of an explosion. Poor valve performance can create pressure unbalances, which can lead to an inefficient hydrocarbon cracking process. If this condition worsens, it creates potential for unit shutdown and expensive downtime. Problem Traditional Hydraulic Power Units (HPU) are commonly used for positioning in critical FCC applications including the spent and regenerated actuators requiring position accuracy, speed, and response time. However, HPU systems have numerous drawbacks associated with them. Common to all is an “open loop” design. This design characteristic requires an intense and frequent maintenance program. Atmospheric humidity comes in contact with the hydraulic oil and creates acid build-up and premature oxidation. Dirt and particulate from the surrounding air enters the hydraulic system compounding the contamination issue. This is particularly problematic for servo and proportional valve driven hydraulic systems. These servo and proportional valve systems require very specific fluid cleanliness standards. If the fluid cleanliness is not kept within spec, the system cannot perform as designed and will result in undesired inconsistent operation and/or the need to bring the system down for maintenance. These oil cleanliness requirements necessitate the use of filters that must be replaced frequently. There are also dozens of soft goods within these systems that are subjected to high temperatures and need to be replaced periodically before they wear out and become potential leak paths. The pumps within these systems are constantly running to maintain a certain operating pressure for the hydraulic actuator to operate the valve. These continuously running pumps draw a lot of electricity (up to ~$23,000 per year) and they must be maintained at a significant cost to ensure the valve and process stay online. Finally, HPU systems often have several hundred feet of hydraulic tubing and hoses which all represent potential leak paths. In order to prevent unscheduled unit downtime, HPU systems are placed on rigorous preventative maintenance programs which are time consuming and expensive. Solution Eliminate the risk of hydraulic oil breakdown, contamination, and maintenance by upgrading to REXA Electraulic™ Actuation. REXA self-contained actuators combine the simplicity of electric operation, the power of hydraulics, maximum reliability, and the flexibility of user-configured control. The principle behind REXA Electraulic™ Actuation is a unique hydraulic circuitry called the Flow Match Valve (FMV) system. The actuator incorporates a bi-directional gear pump coupled to a motor that provides a highly efficient method of pumping hydraulic fluid from one side of the double acting cylinder to the other. The motor and pump only move when a position change is required. Once the target position is reached, the motor and pump shut off and the FMV system hydraulically locks the actuator in place. Motor operation is not required to maintain actuator position; the motor and pump remain idle until a new command signal is received. This maximizes operation efficiency while minimizing wear and tear of the actuator itself. These slide valve applications can require additional reliability to maximize plant uptime, prevent potential safety issues, and reduce the risk of unplanned shutdown (>$1.7M per day in gasoline production alone). The actuator can be configured with full redundancy of critical components to provide maximum reliability and availability to get you from turnaround to turnaround (TAR). Choosing a redundant REXA system will increase actuator reliability to a value over 99.9%. Results With REXA Electraulic™ Actuation, the end-user gets all the advantages of a hydraulic actuator. The system responds immediately to control signal changes and accurately modulates the position of the Catalyst Slide Valve to ensure efficient and safe process control. Reliability is increased and maintenance requirements are reduced and simplified. Utilizing REXA actuators for Spent and Regenerated Catalyst Slide Valves eliminates the intense preventative maintenance routine of a conventional HPU. This means no more routine oil maintenance, no more fluid conditioning systems with filters, and no more constantly running pumps wasting electricity. Installing REXA Actuators on your Catalyst Slide Valves allows you to reduce and simplify your preventative maintenance list. Catalyst Slide Valves require accurate positioning and immediate response to control signal change. With REXA, end-users gain accurate control with maximum reliability and operational safety enabling stable regenerator pressure and steady differential pressure between the reactor and the regenerator in the FCC. This reassures end-users to have confidence to position their Spent and Regenerated Catalyst Slide Valves and

Background on Fluid Catalytic Cracking (FCC) Fluid catalytic cracking (FCC) is an essential process in refineries, used to convert heavy feedstock oil into valuable gasoline, jet fuel, and diesel, amongst other products. During the FCC reaction coke builds up on the catalyst, limiting the catalyst’s ability to carry out the reaction. The spent catalyst transfers over to the regenerator to burn off the residual coke. As the spent catalyst is regenerated, flue gas (combustion gas) is created by burning off residual coke. The flue gas must then pass through a flue gas slide valve which diverts the flue gas to a power recovery train or through a series of separators and electro-static precipitators before it is released into the atmosphere.  The Importance The flue gas slide valve provides accurate pressure control of the regenerator, and in turn, control the differential pressure between the reactor and the regenerator. Tight control is critical in maintaining the FCC pressure balance in the cracking process, allowing smooth flow of the catalyst and feedstock oil between the reactor and the regenerator.  Why REXA? With REXA Electraulic™ Actuation, the end-user gets all the advantages of a hydraulic actuator, such as fast response to signal command and precise modulation of the Flue Gas Slide valve, which are essential for tight control, an efficient process and safe operation.  Literature Download the full FCC Flue Gas Application Spotlight!  Download

Furnace and Heater Stack Dampers Background Furnaces help refineries and petrochemical plants break down and convert hydrocarbon fluids into fuels or chemicals such as gasoline, diesel, ethylene and propylene. As furnaces sometimes account for more than 50% of total plant energy consumption, small improvements in efficiency equate to large financial returns. Refineries and petrochemical plants tend to overlook draft control when making process improvements.  Optimizing the draft in a process heater is easy as there are many types of processes and instruments to choose from. The challenge is safely elevating process fluid temperature to a target level while maximizing thermal efficiency, throughput and reducing O2, CO and NOx emissions. Fast-acting, repeatable and accurate damper positioning enables fine-tuning of modern damper control systems.  Problem Despite the high-level automatic control of instruments running complex loops in refineries and petrochemical plants, many dampers are controlled manually via cable and winch. This type of damper arrangement complicates accurate positioning, leading to poor furnace draft control. More importantly, manual operation of dampers creates a potential safety hazard to personnel – especially during emergency situations.  In an inexpensive attempt to automate a damper, a lot of plants select pneumatically-operated drives. Prone to hysteresis, static friction (stiction), overshoot and instability, pneumatic actuators face increased difficulty making small and controlled position changes. This inability to achieve stiff control limits the combustion process efficiency. Solution Upgrading or automating existing dampers with REXA Electraulic™ damper drives provides immediate benefits – enhancing furnace draft control.  Literature Download the full Furnace and Heater Stack Dampers Application Spotlight! Download