Economic Evaluation using Aspen HYSYS

Integrated economics is a new feature in Aspen HYSYS® that enables process engineers to rapidly estimate the relative capital and operating costs in their process modeling studies using Aspen HYSYS. This feature brings the benefits of the Aspen Economic Evaluation product family (the ICARUS family) to the process simulation environment. The ICARUS family includes:

Aspen Process Economic Analyzer (formerly known as Icarus Process Evaluator)
Aspen Capital Cost Estimator (ACCS)
Aspen In-Plant Cost Estimator

The new costing module evaluates economics based on Icarus technology. The approach used in the technology doesn’t rely on capacity-factored curves for equipment sizing, nor does it rely on factors to estimate installation quantities and installed cost from bare equipment cost. Instead, it follows industry-standard design codes and procedures to represent equipment with associated plant bulks, and cost modeling and scheduling methods to estimate the cost of project.

The main steps in the integrated economic evaluation are as follows:

Activating the costing engine
Mapping unit operations to equipment
Sizing equipment
Economic evaluation and reviewing results

The Mapping and Sizing steps can be individually performed or can be skipped in favor of an “Auto Evaluation” based on default-assigned mappings and sizing algorithms.

Figure 1. Economic Evaluation Tab in Aspen HYSYS Simulation Environment

Activating the Costing Engine

The costing engine is Aspen Process Economic Analyzer (APEA). By activating the economic module, the Aspen HYSYS simulation results automatically transfer to APEA. The module develops estimates based on a “standard basis file” which includes company-standardized, project-standardized, and the geographic cost basis (US Gulf Coast, Europe, Middle East, UK, and Japan) information.

Mapping Unit Operations to Equipment

A key step in economic evaluation with the new integrated evaluation feature is the mapping of each simulator model (unit operation) to one or more process equipment. For example, a distillation column in Aspen HYSYS might be mapped into several items such as a trayed tower, a kettle-type reboiler, an overhead condenser, a reflux pump, and a horizontal drum (Figure 2). The new workflow has both the ability to automatically establish “default” mappings as well as the capability to over-ride these mappings and substitute the user’s own mappings. The user can change, remove, and add equipment during the mapping process.

Figure 2. Mapping a distillation column in Aspen HYSYS to equipment models for cost estimation

Sizing Equipment

Sizing of the equipment is performed using the available simulation data and the default sizing procedure; missing data is estimated by the system. The default material of construction for all equipment is carbon steel. Users can review the sizing and materials of construction and override estimated sizes, revise material of construction, and enter values for unsized equipment.

Economic evaluation

The Economic Evaluation module develops both capital cost and utility cost. The following costs have been considered for the calculation of the project capital cost:

Direct Costs which refers to material costs and labor costs for:

Equipment and Setting
Piping
Civil
Structural Steel
Instrumentation and controls
Electrical equipment and materials
Insulation
Paint

Indirect Field Costs

Engineering and supervision, Start-up and commissioning
Construction expenses - Fringe benefits, Burdens, Insurance, Scaffolding, Equipment Rental, Field services, temporary constructions, etc.

Indirect Non-Field Costs

Freight
Taxes and permits
Engineering - Basic engineering, Detailed engineering, and Material procurement
Contingency - allowances for unpredictable events
Other project costs - General and Administrative expenses, Contract fees, Home office expenses

The utility cost of a project is determined by the Economic module based on the appropriate process utility fluids selected either by the user or by the Sizing Expert from the list of 21 default utility streams already present in the system. Once the utility resources are selected, the utility cost for every utility resource used in the project is determined during the operating cost evaluation.

The results of the economic evaluation and the equipment summaries can be created in Excel format as a complete project economic report. The summary and detailed results can be reviewed in order to study the feasibility of the design and to compare process alternatives.

Contingency (defined based on specified process description, process complexity, and project type), process control, location, engineering start date, soil conditions, vessel design code, and level of instrumentation are the general specifications affecting capital and operating costs. The costing scenario created by Aspen HYSYS can be opened directly by Aspen Process Economic Analyze (APEA) or by Aspen Capital Cost Estimator (ACCE) for further development, define a custom model for sizing equipment or tuning of the cost estimate.

In general, the new feature will be of interest to many HYSYS users due to its functionality in reasonable cost estimation of a project through a simple system and in providing a way to study process alternatives from an economic point of view early in the process design. However, it should be noted that the sizing and the cost evaluation of a project are performed using default methods and procedures and missing data is estimated by system. So, if the user enters more detailed information in the system based on the design criteria and the scope of the project, the estimated cost of the project would be more accurate.

References

1. “Aspen Process Economic Analyzer V7.0 User Guide”, Aspen Technology Industry (July 2008).

2. D. McCarthy, R. Beck, and G. Dissinger, “Getting Started with Relative Economics in Aspen HYSYS”, Aspen Technology Inc. (2011).

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