With rising energy costs and mounting pressure to reduce emissions, the petroleum refining and petrochemicals industries are focused on optimising plant performance to increase energy efficiency. Engineering and Construction (E&C) companies are faced with generating process designs optimised for capital and operating expenditures with quick turn-around times. Owner operators are pressed to increase product yields while maintaining product quality and strict safety standards. The challenges faced by both parties force them to evaluate and study heat exchange equipment in the context of the process because heat exchangers are critical to the overall process performance. 

Heat exchangers are associated with up to 80% of the primary energy consumed in a process and make up almost 30% of the capital investment. Essentially, the heat exchanger is the backbone in chemical plants, requiring regular assessment of mechanical integrity to optimise plant production needs. Therefore, processors downstream of the ‘cheap’ refinery energy will view energy cost with greater scrutiny. To achieve optimal process design and performance, E&Cs are forced to take a holistic approach to process optimisation using high fidelity simulations – an approach only achievable with the incorporation of rigorous exchanger designs in simulation to accurately model thermal and hydraulic performance in the context of the entire process. 

Empowering engineers 

Increasing throughput brings economies of scale and improves return on investment. Overall, it is predominantly financial pressures that drive the need for process engineers to upgrade existing equipment or modify the process for a major upgrade. Changing demand from refineries in terms of product output is another key factor. The simplest energy reduction strategy involves recovering heat and then recycling it to provide a greater throughput per unit of energy consumed, thus increasing operational profit and reducing emissions. The traditional workflow for designing heat exchangers, however, is slow, involves several iterations and is prone to data transcription errors. All of these limitations inhibit the evaluation of additional design scenarios.

The challenges with the existing workflow can be resolved by providing process engineers with engineering software, which creates a seamless, integrated engineering workflow. These software applications help optimise design and operational performance and create a powerful and collaborative environment across departments within the organisation. For example, many leading global refineries and petrochemical companies use the Aspen Exchanger Design and Rating (EDR) product family. AspenTech’s process simulators change the workflow by integrating simulation, economic evaluation, basic engineering, energy optimisation and Aspen EDR tools into a single environment for the process engineer. This enables process engineers, thermal equipment specialists and mechanical engineers to collaborate in producing cost effective process designs for minimum capital and operating cost in fewer engineering man hours. 

AspenTech recently introduced Activated Analysis in Aspen HYSYS and Aspen Plus, which displays energy efficiency, heat exchanger details and capital and operating economics while modelling is being performed. Activated Energy helps process engineers quickly identify ways to improve designs to reduce energy costs, saving design time and future operating costs. This intuitive feature allows engineers with minimal heat transfer experience to produce rigorous exchanger models easily and efficiently. 

Integrated solutions

Innovations in the integration of process simulation models with Activation energy analysis and Heat Exchanger Design and Rating have provided engineers with the tools to achieve millions of dollars of benefit through increased capacity and energy savings. Integration reduces project errors and re-works, makes effective use of specialist engineering manpower and reduces project timescales. Many leading global E&Cs and refining, chemical and petrochemical owner operators have achieved benefits from rigorous exchanger modelling in simulation, including: 

•  Reduced exchanger costs by up to 30%

•  Improved reliability and increased process uptime

•  Improved engineering efficiency by up to 30%

Bringing together best-in-class EDR and process simulation software provides companies designing and operating processes with an advanced, integrated lifecycle solution. This encompasses conceptual design, detailed design and plant start-up through to operations decision support. Essentially, fully integrated process simulation empowers engineers to build and operate safer, more efficient and more competitive process plants.