In the current energy environment, where prices are low and risk is high, companies need to ensure they can maintain profitability. Better understanding of operations, faster troubleshooting and more options for improvement projects can enable engineers to enhance the performance of existing natural gas processing and LNG plants.

With new business slowing, the midstream industry is currently experiencing a shift from greenfield projects to revamps to make existing plants more profitable when operational improvements are limited. Revamp projects are aimed at increasing capacity and lowering manufacturing costs and, for engineering teams, there is a pressing need to consider and minimize capex.

Additionally, the midstream industry is seeing stricter quality specifications and more complex environmental health and safety compliance requirements.

A single integrated software platform can provide companies with the tools to manage and mitigate risk, reduce operational costs, enable gas plant optimization and redesign. Simultaneously, they can meet safety directives and environmental standards for emissions of flared gas and wastewater. Equipped with a depth of modeling accuracy, engineers can also work more efficiently with integrated workflows and the ability to look at the process as a whole when considering changes to the feed compositions and flowrates, configuration or the solvents used.

Current challenges

In addition to the industry shifts from greenfield projects to revamping existing plants, engineers are facing additional challenges and complexities in the current market environment, including:

• Ever-increasing complexity of product specifications—Fungible product specifications for products entering a sale gas pipeline need to be met in order to ensure customer satisfaction. These tight specifications must be evaluated amid changing feed conditions, compositions and capacities.

• Managing products to maximize margins—LPG mixtures have become more important sales products for gas producers as gas liquids have increased in value for chemical feedstocks and liquid fuels, while the incremental value added to the heating value of natural gas has decreased. Additionally, when left in sales gas, CO2, helium or nitrogen all decrease the heating value of the product. To maximize profits, the value of the products and the cost of recovering the NGL and removing the additional gases must be considered periodically. For these reasons, accurately predicting NGL, CO2, helium or nitrogen content along each step of the processing is essential.

• New workforce realities—The complexities of a multigenerational staff mean that employers must embrace a range of tools and technologies to ensure that employees are regularly trained and fully equipped with the appropriate tools. As a wave of experienced engineers retires, a younger generation is being put into more challenging roles. As a result, organizations are looking for opportunities to supplement lack of experience and enable more confident decision-making. Simulation tools are not only enabling decision-making where manual troubleshooting knowhow was once required, but are also creating a bridge between retiring veterans and the new generation of engineers.

• More stringent environmental and safety regulations—Meeting environmental and safety standards is crucial for avoiding fines and penalties and ensuring maximum plant uptime. If high concentrations of H2S or CO2 are present, the product will not meet environmental standards and damage may be incurred on downstream equipment.

• Inevitable equipment limitations—Prematurely failing equipment, difficult-to-operate units and insufficiently sized safety systems can lead to operational issues, such as reduced product quality or even shutdowns. Heat exchangers, columns, compressors, pumps, and relief and flare systems must be properly sized for all scenarios to avoid operational risks.

Obstacles and opportunities

While all of these challenges represent obstacles to overcome, they also present opportunities for advancement with long-term benefits.

Advanced process simulation tools provide organizations the solutions needed to grow stronger and become more efficient, allowing new heights to be gained and hurdles to be overcome. To address the challenges faced in the design and operation of gas processing facilities, process simulation solutions empower engineers to more deeply understand the process, how the process responds to changes, how to optimize operations, and prevent and manage potentially damaging scenarios.

In every part of the gas plant, simulation is needed. A gas plant, with its many sections, has many interconnections with downstream dependencies, recycle streams, heat exchanger networks and flare systems. As the feed changes with varying flowrates and compositions, a plant can either handle the new feed or will need to be adjusted within plant limitations. In order to handle a different range of feeds, it may need to be modified. This is why a full plant model that utilizes the most accurate modeling technology for each section is very important. With this type of solution, companies can provide a quick evaluation of where a constraint is violated and how to accommodate the change.

There are advanced process simulation tools available today that offer property packages and unit operations specifically designed and tested for difficult-to-model processes, such as acid gas removal, sulfur recovery, dehydration, NGL recovery and liquefaction. To gain these benefits and more, companies have also implemented a fully integrated simulation solution offering seamless workflows to automatically incorporate equipment sizing, costing, energy networks and safety systems right in the process model. As a result, users can make the right decisions when changing feed conditions, compositions, capacities and aging equipment-impact economic objectives. Additionally, by integrating these types of solutions, organizations can model the entire gas process without having to compromise separate simulation tools that require manual data transfer, saving time and avoiding errors.

Accuracy and efficiency

For example, Bilfinger, an engineering, procurement and construction firm based in Mannheim, Germany, used an integrated platform of engineering solutions to help the company evaluate more design alternatives faster, taking into account various factors—such as changing operating conditions and feedstock composition, as well as environmental regulations in different geographies of the world.

Being able to easily transfer data between a variety of products and product features has not only sped up the time it took to evaluate a design alternative, it has also helped to eliminate errors associated with data transfer. The ability to model an entire gas plant with one simulator has improved the understanding of the behaviour of the plant and how all processes are interconnected.

By using this advanced solution, Bilfinger reported spending 40% less engineering hours on evaluating design, screening two to three times more design alternatives per project and expanding the range of services they offer. Additionally, the company has continued to provide designs optimized for profitability with maximized product yield and consistent quality.

Another company, Process Ecology Inc., an oil and gas consulting firm based in Calgary, Alberta, has been able to save clients $60,000 per day by reducing emissions and avoiding shutdowns due to noncompliance. By implementing an advanced engineering platform, Process Ecology developed an automated process to generate documentation required to meet environmental regulations.

Through several successful projects, the company confirmed that the advanced tools it had been using had the ability to accurately predict air emissions in glycol dehydration facilities. As a result, Process Ecology has shown savings up to $30,000 a year for a single dehydrator in energy costs, often through reductions in the glycol circulation rate.

Future success

Navigating uncertainty is essential in today’s market. Those companies that will thrive must be leaner, efficient and able to adapt quickly to market dynamics. As engineers continue to drive improvement in plant operations, it is imperative they have the right simulation tools in place to help make informed decisions and remain competitive.

Plant issues arise all too frequently and in order for organizations to ensure the best action is taken, operators need access to an integrated software platform. With the right technology, engineers can make the right decisions for their plants to ensure profits outweigh costs. Additionally with these solutions, organizations can minimize risk against unplanned events, as they will have the tools to adjust day-to-day actives to find the most effective and efficient way to run the business.

Jennifer Dyment is an engineering product marketing specialist for Aspen Technology Inc.