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Concluding our coverage of the ARTC 15th Annual Meeting, GTForm takes a look at the petrochemical and operability and reliabilty streams.
The second day of the ARTC 15th Annual Meeting featured two technical streams, one focusing on the latest petrochemical technologies and the other on the latest techniques and options for improving reliability and reducing maintenance costs in refineries.
Stream A – Petrochemicals
Didier Lambert, Topnir, opened the petrochemical stream with a presentation on steam cracker optimisation through the use of an online measurement process, along with a general overview of Topnir’s offerings. He explained that the Topnir system is a turnkey system for the measurement of hydrocarbon properties in less than one minute and can operate on an offline and/or online basis. The 740,000tpa ethylene steam cracker at the Naphtachimie Total/Ineos joint venture was used as a case study for Topnir’s online analyser/pattern recognition technologies and its advanced process control/real-time optimisation systems. The former allowed much greater monitoring of potential ethylene content. Lambert also discussed how such systems can be used in the petrochemical industry to improve both furnace control and severity optimisation, potentially generating US$3–5 million in benefits a year, through greater yields, energy savings, tighter product quality and other factors, based on the results of a PetroChina case study.
Christian Dupraz, Axens, followed with a look at (R)FCC options for high propylene yield. According to Axens’ projections, an additional 4Mta of propylene production from refineries is expected to come online. He made the point that incremental fuel demand growth for all oil products is expected to be strong in the Asia-Pacific region, making product flexibility desired and that while options such as the recycling of light naphtha or a C4 cut appear attractive due to their simplicity, they are not selective for added propylene and have no impact on distillate yields, while Axens’ Flexene solution, which features a separate polynaphtha oligomerisation unit, allows an FCC to be optimised for production of either propylene, gasoline, jet fuel or diesel, creating significant flexibility.
Nicholas Kim, SK-KBR, spoke about Ole-SIV, a new paraffin/olefin separation via absorption process. After drawing attention to a CMAI forecast that predicts global butadiene use will grow at a CAGR of 3.7% from 2011 to 2015, with global capacity lagging behind (with a CAGR of 2.7% over the same period), Kim explained that Ole-SIV, does not require vacuum operation, can work in the vapour phase, is a constant pressure operation and a continuous process. It also features high olefin selectivity, and the process consists of three steps: adsorption, rinsing and deabsorption. Quoting a case study in South Korea, Kim said the process can result in a total investment saving of up to 21% (new) and 30% in the case of a revamp, while reducing energy consumption by up to 40%. He also explained that SK-KBR is in the final stages of researching and developing ethylene recovery from FCC off-gas and propylene splitting.
Stream B – Operability and reliability
Eva Andersson, Alfa Laval, began the stream with a look at the benefits of welded compact heat exchangers. She said heat recovery is currently often performed using outdated shell-and-tubes and a switch to welded compact heat exchangers can pay back in potentially less than six months, given the fact that their efficiency is up to 50% greater. Andersson also said the fouling rates are at least three times lower than with shell-and-tubes heat exchangers. In the case of a 50,000bpd refinery, replacement of shell-and-tube heat exchangers with Alfa Laval’s Compabloc solution resulted in fuel savings of US$850,000 a year, a reduction in CO2 emissions of 5,000tpa and a payback time of six months, while the time from initiation to commission was 20 months. Andersson also gave an example of a 150,000bpd refinery where the installation of Compabloc in a hydrogen production unit allowed the cooling water requirement to be reduced by 60%, and explained that spiral heat exchangers are well suited for heavy fouling applications by virtue of their self-cleaning design and allow longer service intervals and less downtime. She gave the example of the Nynäs bitumen refinery in Sweden where the replacement of shell-and-tube heat exchangers with 14 Compabloc units, resulted in a 96% reduction in associated maintenance costs.
Chanchana Payungwong, Thaioil, discussed the open-loop real-time optimisation of a Thaoil refinery’s utility system. The project was awarded at the end of 2009 and was a joint effort between Thaoil Group and Invensys. It made use of rigorous online modelling and equation-based optimisation (ROMeo). In 2011, the convergence of utility optimisation averaged 88%, and Payungwong explained that much of the benefits from optimisation have arised from minimisation of boiler fuel oil use through greater use of fuel gas, increased GTF power generation and WHR steam generation and a reduction in STG power production to maintain the steam and power balance. She finished by explaining that the next step will be a study to implement closed-loop real-time optimisation to fully capture the benefits of online optimisation.
Herman Lee, KBC, continued the theme of optimisation with a look at how plant reliability can be improved via an energy reduction and optimisation programme. He noted that typically energy efficiency programmes reduce energy costs by 15–20% and a 15% reduction typically translates into savings of US$21 million a year. Giving a case study of an Asian petrochemical plant, Lee said that while large cost savings were identified, partly from importing steam from a refinery, they were constrained by minimum turndown on the boiler and concerns over steam supply reliability from boiler shutdown, creating a need for further projects. He made the point that when considering investment aimed at overcoming energy efficiency constraints, it is important to consider how these may tie in with future plans for the site. Lee followed up with a look at an energy study performed for an Asian refinery, which resulted in a substantial drop in steam demand and increased operating flexibility. In addition, it changed the steam generation system from one that was unsafe when one main utility generator was offline to one that was unsafe only when two were offline.Concluding our coverage of the ARTC 15th Annual Meeting, GTForm takes a look at the... more
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Recent engineering evidence suggests that the unsinkable ship experienced a hull failure at the surface and broke into pieces before it went down.
By Dan Deitz, Executive Editor
When our boat had rowed about half a mile from the vessel, the Titanic—which was illuminated from stem to stern—was perfectly stationary, like some fantastic piece of stage scenery,"recalled Pierre Marechal, a French aviator and a surviving first-class passenger of the ill-fated liner. "Presently, the gigantic ship began to sink by the bows ... suddenly the lights went out, and an immense clamor filled the air. Little by little, the Titanic settled down ... and sank without noise ... In the final spasm the stern of the leviathan stood in the air and then the vessel finally disappeared."
British and U.S. investigations of the Titanic tragedy have resulted in greater lifeboat capacity, improved subdivision of ships, and the creation of an ice patrol.
Elmer Z. Taylor, who watched from Lifeboat No. 5, close enough to the Titanic to observe its final demise, would later write, "The cracking sound, quite audible a quarter of a mile away, was due, in my opinion, to tearing of the ship's plates apart, or that part of the hull below the expansion joints, thus breaking the back at a point almost midway the length of the ship."
"At that time the band was playing a ragtime tune, "remembered Harold Sydney Bride, the surviving wireless operator of the Titanic. "I saw a collapsible boat on deck ... I went to help when a big wave swept it off, carrying me with it. The boat was overturned and I was beneath it, but I managed to get clear. I swam with all my might and I suppose I was 150 feet away when the Titanic, with her aft quarter sticking straight up, began to settle."Recent engineering evidence suggests that the unsinkable ship experienced a hull... more
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