Revamping Objectives

With rising feedstock prices and hard competition in the market, many producers have looked for possibilities to revamp or modernize their older, less efficient plants so that they can stay competitive. Most revamp projects have been combined with a moderate capacity increase because some of the original equipment was oversized and only specific bottlenecks had to be eliminated, not entailing excessive cost. As the market possibilities for a company do not increase in steps of 1000 or 1500 t/d but slowly and continuously, such a moderate capacity addition will involve less risk and will often be more economical than building a new plant. 

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Producing a statement of requirement or revamp objectives" document... 

The revamp objectives, constraints, and requirements must be clearly stated in a statement of requirement document transmitted to the engineering contractor. The document should be sufficiently detailed and require minimum interpretation so as to avoid oversights and unnecessary site visits. 

Project/Process Engineering and Management of Revamp Projects 2.4.1 Revamp Objectives and Pre-Feasibility Study... 

Once the calibrated simulation model is available, simulations can be re-run and equipment rating studies can be performed to identify equipment limitations and to generate many options to meet the revamp objectives. Spreadsheet and vendor models are also required to perform conceptual design and options. Heat and material balances, and preliminary equipment sizes, are estimated. Detailed process simulations, block flow diagrams, PFD, pipe and process equipment sizes are generated for each revamp design option these are useful for detailed analysis of benefits/constraints and CAPEX estimation for each option. 

This chapter addresses project management aspects of a revamp. It also provides design guidelines that can be used by a refiner in selecting the revamp components. The original driving force for a project is often a particular mechanical problem or a process bottleneck. The ultimate objective of a revamp should be a safe, reliable, and profitable operation. 

In many cases, a refiner decides to revamp a cat cracker and employ a new technology without first identifying the unit s mechanical and process limitations. Sometimes money is spent to relieve a constraint and the unit hits another constraint almost immediately. Failure to perform a proper constraint analysis of the existing operation can result in focusing on the wrong issues for the revamp. In addition, the revamp goals must match the refinery s overall objectives. 

Depending on the proposed objective - deep HDS or combination deep HDS / aromatics saturation - the developed technology can be applied as a single or two stage process. The revamping offers the refinery a much more lower cost route to meet the new gas oil... 

II. Exploiting Equipment Interactions The designer needs to consider total system interactions before finalizing scope for any equipment. Consider a revamp project with the main objective of increasing the duty of a column s feed pre-heater it will require assessment of the condenser s maximum capacity and top rectifying tray section. Simulation of the whole process is needed to understand system interactions. Lee et al. (2007) and Zhu (2014) described ethylene plant retrofit cases to emphasize the importance of system interactions in revamps. 

Purpose To set the project objectives, basis, assumptions and preliminary economics To generate alternative revamp options and establish the best revamp option To fully develop the revamp option To complete engineering, procurement and construction To measure success of the revamp project and document key highlights and lessons learned... 

Table 2.9 Revamp options for heat exchangers and fin fan (or air) coolers. Equipment - Objective Options...

Table 2.15 Revamp options for deaerators, boilers, steam turbines and steam system. Equipment/system - Objective Options...

Design, Retrofit and Revamp of Industrial Water Networks using Multi-objective Optimization Approach... 

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