Many operating facilities struggle with improperly tuned control loops, noisy instrument measurements, and oversized control elements. As a result, critical process control loops are often operated in manual mode for years, compromising process stability, efficiency, and operational flexibility.

One of P&T's clients operated its oil separation and crude stabilization units in manual control for nearly a decade after commissioning. The root causes included an inefficient control strategy, poorly tuned control loops, and excessive noise from a steam flow measurement system.

‍P&T conducted a comprehensive review of the control philosophy, reduced measurement noise, optimized control loop tuning, and implemented advanced control strategies. These improvements successfully restored automatic operation, ensured effective stripping performance during feed fluctuations, minimized reboiler fouling during rapid feed rate reductions, and significantly improved overall process stability.

‍If your facility is experiencing controllability challenges on distillation columns or other process equipment, and operators are forced to run critical control loops in manual mode, contact P&T at info@peng-tech.com. Our specialists can help identify the root causes and implement sustainable solutions that restore process stability, improve performance, and enhance operational reliability.

Operating critical control loops in manual mode can introduce significant process safety and operational risks. Following equipment modifications, debottlenecking projects, or control valve replacements, improperly tuned control loops can result in process instability, production losses, and plant upsets.

‍One of P&T's clients experienced significant operational challenges after debottlenecking its oil processing facilities. The upgraded plant suffered from instability in the flow and level control loops of multiple three-phase separators and induced gas flotation (IGF) vessels. These control issues led to repeated process upsets and flare liquid carryover (flare rainout), adversely affecting plant reliability and performance.

P&T performed a comprehensive assessment of the process equipment, control system, and equipment sizing. A rigorous process simulation model was developed, followed by dynamic simulations of startup, shutdown, and upset scenarios to identify the root causes of the controllability issues. Based on these studies, optimized control strategies and tuning parameters were developed and implemented, resulting in significantly improved process stability, enhanced operability, and increased plant reliability.

If your facility is experiencing controllability challenges and operators are forced to maintain critical control loops in manual mode, contact P&T at info@peng-tech.com. Our specialists can identify the root causes, evaluate control system performance through advanced process and dynamic simulation, and implement sustainable solutions that improve safety, stability, and plant performance.

In many operating facilities, control strategies that follow the original design intent may not always deliver optimal performance under actual operating conditions. In some cases, they can contribute to process instability, hydrocarbon carryover, liquid carryover, equipment upsets, or reduced operational reliability.

For example, one of P&T's clients experienced intermittent hydrocarbon carryover from the coalescing section of an AGRU inlet separator to the absorber. The separator level was controlled using a gap-control strategy, which resulted in fluctuating liquid inventory and periodic carryover events that triggered absorber foaming. P&T reviewed the control philosophy, identified the root cause, and implemented an improved control strategy by replacing the gap-control scheme with a properly tuned PID controller. The modification eliminated the carryover incidents and significantly improved process stability.

If you are uncertain whether your current control strategy is delivering the desired performance, P&T can help assess, optimize, and troubleshoot your control systems to improve safety, stability, and operational efficiency.

Contact P&T at info@peng-tech.com to discuss your challenges and explore potential solutions.

During a process safety review conducted for one of P&T’s clients, a gap was identified in meeting ALARP requirements for a process separator. The existing control philosophy relied on a single pressure controller using split-range control for vessel pressurization from a high-pressure source, discharge to a downstream compressor, and relief to flare. This configuration introduced a potential vulnerability, as a common instrument failure could lead to loss of pressure control and potential vessel overpressure in high-H₂S service.

Following a detailed evaluation of the system, supported by dynamic simulation studies, P&T recommended segregating these functions into independent pressure control loops with dedicated setpoints. This redesign reduces the risk of common-cause failure and significantly enhances overall process safety and operational reliability.

If you would like to evaluate your system for process safety performance and control strategy robustness, contact P&T at info@peng-tech.com

Step regeneration is an effective approach for extending the service life of molecular sieve dehydration beds by providing controlled temperature ramping, which minimizes thermal shock, improves water desorption efficiency, and reduces thermal and mechanical degradation of the adsorbent.

Successful implementation of this method requires carefully controlled heating during the initial stage of the regeneration cycle to avoid rapid temperature shocks to the dehydration bed.

At one of P&T’s client facilities, an optimized control scheme was implemented based on existing equipment constraints to enable a gradual and controlled ramp-up of regenerant heating. This improvement was one of the contributing factors that significantly enhanced regeneration performance and helped extend the molecular sieve bed life from 3 years to 4 years.

If you would like to assess opportunities to improve the performance, reliability, and lifecycle of your dehydration or adsorption systems, contact P&T at info@peng-tech.com.

Advanced Process Control (APC) performance is highly dependent on properly defined engineering limits for manipulated variables (MV) and controlled variables (CV). In many operating facilities, conservative or outdated constraints can restrict controller performance and limit economic optimization opportunities.

P&T specializes in reviewing and optimizing APC constraint settings to enable selective product recovery aligned with real-time market export value. By systematically refining MV and CV limits, control systems can safely operate closer to true process constraints, improving product yield, maximizing value, and enhancing overall plant profitability.

If you would like to evaluate opportunities to unlock additional economic value from your APC systems, contact P&T at info@peng-tech.com.