It is a fact for all APC vendors and consultants that many of the success stories have to remain unpublished to respect client confidentiality. It is with great thanks to our clients that some good news can be expressed in these pages.
AMT and BayernOil achieve €4.2 million p.a. in benefits to Neustadt Hydrocracker Unit
Using AspenTech's DMCplus and GCC inferential calculations, a middle distillate hydrocracker unit has been optimized. The controller significantly reduces variations in the cut-points of kerosene and diesel, allowing the unit to maximise production closer to the product specifications. With a utilization factor of 95%, this project provided a consistent benefit of €4.2 million per annum, giving a project payback period of less than 6 months. The project was presented at the Hydrogen Processing International Refining and Petrochemicals Conference in 2016.
Advanced process control improves operation of a polypropylene unit
Saudi Polyolefins Co. (TASNEE Petrochemicals) operates two world-scale polypropylene (PP) units in Jubail, Saudi Arabia. The units include polymerization and extrusion sections. The polymerization section for each line has two reactors operating in parallel mode for homopolymer production. Hydrogen is added continuously in a fixed ratio to the propylene feed to control the PP's molecular weight. The molecular weight is expressed as the melt flowrate (MFR). Each reactor train has its own degassing section, intermediate product storage and extruder. The total capacity of the plant is 720,000 tpy. In early 2009, TASNEE decided to deploy an advanced process control (APC) solution for its recently debottlenecked PP plant in Jubail. Selected APC vendors were supplied with an extensive set of plant operating data, allowing them to perform a preliminary benefits analysis. The project scope included a reactor composition controller and virtual online analyzer for MFR and xylene solubility (XS). Quality control information and automated transition records for the four reactors were also included. The project was completed seven months after the formal kickoff meeting. The total benefits achieved shows that the ROI was less than three months. As of 09/01/2013, the installed APC solution has been online for over 24 months, with an average utilization of over 93%. Hydrocarbon Processing, September 2013.
Alkylation Unit Acid Strength Control at LyondellBasell
Using AspenTech's DMCplus, advanced control of the acid side of a Stratco Sulfuric Acid Alkylation Unit at LyondellBasell's Channelview, Texas petrochemical complex was deployed. The controller minimized fresh acid consumption by driving the spent acid strength continuously to the low spent acid strength limit. The overall acid balance was maintained by controlling the acid to hydrocarbon interface levels in each of a series of contactor/settler pairs. The main challenges of this process were extremely long response times of acid strength through each of the contactor/settler pairs, inconsistent level responses, and the accuracy of the acid strength measurement. These all had to be addressed successfully in order to control the final acid strength. The controller achieved a significant reduction in acid consumption, as well as stabilizing the settler levels and overall acid material balance. A presentation for this application was made at the AIChE Topical Conference on Refinery Processing in 2010.
Alkylation Unit Optimization at Samsung Total Chemicals
Using AspenTech's DMCplus, a multivariable controller was developed to optimize the alkylation unit at Samsung Total Chemicals in 2009. The controller greatly improved product quality control, and resulted in energy savings in the range of approximately $2 million per annum. The details of this application were presented in the 5th Internationational Symposium on Design, Operation and Control of Chemical Processes.
Coker Advanced Control at BP Gelsenkirchen
Using AspenTech's DMCplus, advanced control of a delayed coker was deployed at BP Gelsenkirchen Horst site in Germany, with commissioning completed early in 2005. The project achieved significant increases in throughput, product yields and improved product qualities. The project payback was less than 6 months. The performance reported in the paper is a summary of a BP internal report carried out to post audit the results one year after commissioning. The paper appeared in Hydrocarbon Processing, June 2007.
FCCU Advanced Control at Chevron Pembroke Refinery
Using Honeywell's RMPCT advanced controller, a residue FCC reactor and main fractionator has been implemented at Chevron's Pembroke Refinery. Inferential properties on the main fractionator and gas plant are implemented using first principles models which provide accurate inferences without analyser or lab biasing. This project was a revamp of older applications, involving restructuring of the applications, re-testing and commissioning. Since commissioning in July 2005 the application now has high operator acceptance and high up-time. Payback was achieved within a month. A presentation on this application was made at the ERTC Asset Maximisation Conference 2006 (ERTC Computing & ERTC Reliability), May 8-10, 2006, Vienna, Austria.
Simplified Optimizer For Ethylene Unit
Rigorous closed-loop optimization for ethylene plants can be configured for significantly lower cost than previously considered possible. A breakthrough furnace optimizer application at Maruzen Petrochemical's Keiyo naphtha cracker has shown that it is possible to achieve great benefits using a rigorous optimization model for the furnace to achieve the desired ethylene/propylene production, while a simplified optimization model can be used to predict back end constraints such as charge gas compressor power and the ethylene/propylene recovery trains. A presentation on this application was made at the AIChE 16th Annual Ethylene Producers Conference, 25-29 April 2004 in New Orleans (Paper 65c).
FCCU Revamp at BP Gelsenkirchen
Our first application using Cutler Technology Corporation's [UPID]™ modelling technology was to revamp an FCCU multivariable controller at BP's Gelsenkirchen refinery. Details of the application have been presented at the 2003 NPRA 'Plant Automation and Decision Support' conference and in Petroleum Technology Quarterly Winter 2004 issue.