5 Reasons Why Performance Evaluations are Essential for Your Processing Units
Annual health checks for Sulfur Recovery Units (SRU) and Amine Units have become an industry standard, ensuring operational performance and reliability form ongoing operations and before scheduled turnarounds.
1-Establishing Baseline Performance
Baseline performance data is crucial for assessing the current state of SRUs and Amine Units. This data acts as a reference point, allowing operators to detect deviations from normal operations. Without a baseline, identifying specific issues becomes challenging, leading to extended downtime and increased maintenance costs.
2-Early Detection of Issues
Regular health checks enable early identification of operational inefficiencies, potential corrosion, contamination, fouling, and other issues. Catching these problems early helps prevent them from escalating into costly shutdowns or safety incidents.
3-Optimization Opportunities
By regularly analyzing system performance, SRE’s health checks reveal optimization opportunities. This could involve setting new operating parameters, fine-tuning the amine circulation rates, or adjusting the temperatures within the SRU. These improvements can lead to better recovery rates, lower emissions, and reduced energy consumption.
4-Supporting Turnaround Planning
Comprehensive health checks provide valuable data for planning turnarounds. Knowing the condition of equipment and potential trouble areas allows for precise scheduling and resource allocation, minimizing downtime and optimizing repair efforts.
5-Ensuring Compliance and Safety
In industries dealing with hazardous materials like H2S, safety is paramount. SRE’s rigorous safety protocols, including the use of SCBAs and trained engineers for sample collection, ensure that all health checks comply with the highest safety standards, protecting personnel and the environment.
Sulfur Recovery Engineering (SRE) offers comprehensive health check services that go beyond routine maintenance, establishing baseline performance, pinpointing optimization opportunities, and identifying potential issues early to avoid costly unscheduled and emergency shutdowns.
Book your Performance Evaluation with SRE today
From Fuel to Fines: Key Operating Costs in Sulfur Recovery Units
Managing a Sulfur Recovery Unit (SRU) involves more than just initial setup costs; it encompasses a spectrum of ongoing expenses that can significantly impact operational efficiency and regulatory compliance. Let's delve into the breakdown of these costs based on a recent YouTube transcript, categorizing them into three main areas: operating costs, maintenance costs, and emergency costs.
1. Operating Costs
Operating costs are fundamental to day-to-day SRU functionality and include:
Fuel Gas: Used in incinerators, thermal oxidizers, and other processes to convert sulfur compounds into SO2. Costs can vary based on the type and availability of gas.
Hydrogen: Essential for hydrogenation reactors and other units. While using on-site hydrogen can save on procurement costs, it may contain contaminants that reduce catalyst lifespan.
CO2 Emissions: Many jurisdictions impose costs per ton of carbon emitted, impacting overall operational expenses.
2. Maintenance Costs
Maintenance ensures the longevity and efficiency of SRU components:
Catalysts: Crucial for sulfur conversion, with costs varying by type (e.g., Illumina, Titania) and lifespan (typically 4-6 years).
Condenser Tube Sheet Failures: Result from improper thermal management during startups and shutdowns, potentially costing upwards of five figures to repair.
Refractory Damage: Repair costs can escalate dramatically if damaged during a runaway fire.
Plugged Rundown Lines: Costs can arise from unplugging lines, especially if external assistance is required.
Performance Evaluations: Conducted periodically to optimize SRU operations, typically costing around $35,000 per evaluation for comprehensive assessments.
3. Emergency Costs
Emergencies can lead to severe financial repercussions and regulatory penalties:
Regulatory Fines: Non-compliance fines can be substantial, sometimes reaching millions, depending on the severity of emissions violations.
Production Losses: SRU downtime can incur significant daily losses, ranging from $100,000 to over $1 million, highlighting the criticality of swift troubleshooting and repair.
Consent Decrees: Regulatory mandates may require frequent performance evaluations, increasing operational costs.
The operation of SRUs involves meticulous cost management across various fronts. From daily operational expenditures to mitigating potential emergencies and regulatory fines, understanding and planning for these costs are critical for maintaining operational reliability and compliance. By proactively addressing these cost factors, refineries and gas plants can optimize their SRU operations and ensure sustainable performance in the face of regulatory scrutiny and operational challenges.
Understanding these nuances not only helps in budgeting effectively but also in strategizing long-term operational excellence and compliance within the dynamic landscape of sulfur recovery management.
The Importance of High Quality SRU Feed Streams
The SRU is only as good as the feed streams it receives – this is a common statement in the sulfur recovery industry. Before testing
The SRU is only as good as the feed streams it receives – this is a common statement in the sulfur recovery industry. Before testing an SRU, one of the first questions we ask is “how stable is the acid gas flow”? And after analyzing the samples, one of the first things we check is the acid gas quality, i.e., the H2S content, as well as the concentrations of contaminants in the feed stream(s).
The reaction furnace (RF) is the first vessel and considered the ‘heart’ of the SRU. Its performance is based largely on the quality of feed stream(s) it is processing, whether it be only Amine Acid Gas (AAG), or the additional Sour Water Stripper Acid Gas (SWS AG) often processed in refineries. The H2S content affects how hot the RF can run, and the higher the better; it also dictates which configuration can be utilized, whether it be straight through, split-flow, or direct oxidization.
The concentrations of contaminants, mainly hydrocarbons and BTEX, is also important for the RF performance. For their complete oxidization, hydrocarbons require much more oxygen than H2S does; this negatively impacts the smooth operation of the Air Demand signal. Hydrocarbons and BTEX also cause various issues downstream if they are not completely oxidized, therefore keeping their levels at a minimum is vital. Maintaining stable and consistent feed stream flows is also crucial for the smooth operation of the Air Demand control loop.
Optimizing the operation of upstream Amine and Sour Water units is vital for providing the SRU with the highest possible quality feed streams, and for minimizing the levels of contaminants. SRE now offers full Amine Unit Performance Evaluations, along with the SRU testing we’re known for. Our highly trained team of engineers can safely obtain these hazardous samples, and our optimization programs make the sour units achieve the highest efficiencies they were designed for.
Solids Contamination
Problem Definition European Refinery Client requested assistance with solids contamination in their DEA system. Corrosion issues in the regenerator bottom section and reboiler were reported.
Problem Definition
European Refinery Client requested assistance with solids contamination in their DEA system. Corrosion issues in the regenerator bottom section and reboiler were reported. Amine analysis results were sent to SRE for review.
SRE’s Response – Solids contamination
Within one hour of receiving the request, SRE provided review of DEA analysis results and reported to the client that Heat Stable Amine Salt (HSAS) levels were considerably higher than maximum guideline level of 2 weight percent and were the probable cause of corrosion in the regenerator and reboiler.
The contamination in the system was the result of high corrosion rates found in the unit. A report on HSAS management was sent to the client. Additional guidance was provided to the client on short-term mitigation of HSAS using neutralization to immediately reduce the corrosion problem.
RESULTS
Using SRE’s guidelines, the client was able to reduce HSAS to an acceptable level. Solids contamination and corrosion rates were reduced.
SRE continues to provide assistance to this client to maintain the unit within guidelines for HSAS, solids and corrosion.
Trace Oxygen in Raw Gas To Determine Corrosion Source
Q4 2017 saw SRE complete a number of interesting projects. For one gas plant in Canada, SRE was involved with determining the source of corrosion with our client’s gas sweetening unit.
Q4 2017 saw SRE complete a number of interesting projects. For one gas plant in Canada, SRE was involved with determining the source of corrosion with our client’s gas sweetening unit. In an amine system, corrosion problems can easily be identified by the color of the amine: pale green indicating light corrosion; brown indicating corrosion greater than the filtration capabilities; and black indicating dangerous levels. Although there are many sources for corrosion, our client had already identified that their corrosion was most likely cause by an increased amount of Bicine.
There are several mechanisms for producing bicine in amine gas treating facilities which include (1) reaction of diethanolamine (DEA) with glyoxal – a common hydrogen sulfide (H2S) scavenger – and (2) exposure of the heated gas treating solution to an oxidizer. Bicine impacts gas treating amine solutions in two ways. First, it forms heat stable amine salts (HSAS) and second, it increases the corrosivity of the amine solution. Here, it was thought that the oxidizer was Oxygen (O2) ingress from the field raw gas.
As such, SRE’s scope of work was to complete trace O2 analyses at various points through the gas plant, including the raw gas from each field and throughout the inlet lines to the Amine contactors. In one day, SRE conducted 22 trace O2 measurements from 10 different locations. Sampling was extensive as a 3-minutes sample time and portable equipment allowed the site Engineer to be able to request extra measurements for due diligence. These capabilities are in stark contrast to a trailer full of equipment and a 2-hour run time – 1 hour to mobilize, 30 minutes to warm up line and 30 minutes to conduct analysis – used by other testing companies, where 22 samples could take a few days & cost 3 times more.
Results ranged from 20 ppm to 250 ppm with all raw gas inlets having a measurable amount of O2. The site Engineer planned to use the data to conduct their own material balance and to continue to mitigate the amine system corrosion.
The Benefits of Baseline SRU Evaluation
The typical lifecycle of a new unit is to go from design basis to simulations and data sheets and then from construction and commissioning to startup
The typical lifecycle of a new unit is to go from design basis to simulations and data sheets and then from construction and commissioning to startup. In the case of the Sulfur Recovery Unit (SRU), an additional step may be taken after startup in the Performance Guarantee of the unit where the Operating Company ensures the Licensor has designed and built a unit which meets the BoD. Most of the time, though, Operators choose to forego the Performance Guarantee (budget, timing, incapable of meeting testing conditions, etc.). Beyond the money-back aspect, what Operators are foregoing is the crucial sample set illustrating how the unit truly performs: an operating baseline.
Real analytical results are better than a simulated material balance.
Long after the unit is operational and just about when problems start to arise, recently SRE was brought in by an SRU Operator to determine the problems with their SRU. As we’ve mentioned in our webinars, SRE starts any troubleshooting with analytical results of the unit’s current performance. However, this snapshot in time is meaningless without something to which to compare it. Once the current performance was determined and the BTEX breakthrough was obvious, we asked “has the unit always been like this?” And that’s when the Operator will bring out the material balance in the SRU’s As Built drawings – we’re now trying to compare apples with oranges – and better yet, the simulation never took into consideration any aromatics in the whole design.
Although troubleshooting exercises can be solved without reference data, having something to compare to always helps. Solving a problem fast means less downtime and more production. Even better is data on a regular basis. Trends can provide leading indicators to potential problems and to future catastrophes, saving big money down the road.
Having a baseline set of analytical results, benchmarks the performance of the SRU. It’s an invaluable reference which will be far more accurate than the material balance provided by the Licensor. Further, if you’re lucky, the test results will show areas for improvements or at the least, confirm that your unit is healthy.