Refining Report -- OGJ Special Environmentally advanced refinery nears start-up in Germany

Mitteldeutsche Erdöl-Raffinerie GmbH (Mider) is building a 170,000 b/d refinery in Leuna, Germany. Shown here is the site, in eastern Germany's green belt, before construction began in earnest (bottom center). At the upper right is Leuna Raffineriegesellschaft's antiquated 100,000 b/d refinery, which will shut down when the Mider plant starts up in August.

About this report...

Four international projects show how refiners will cope with unsatisfactory refining margins.

One article describes a grassroots refinery nearing start-up in eastern Germany. The plant will be integrated with nearby power production and petrochemical facilities. Another details a Dutch refinery's upgrade, which includes a hydrocracker and a state-of-the-art gasification unit that will produce electricity and steam from visbreaker tar.

A third article outlines how a low-cost project is enabling a Canadian refinery to produce reformulated gasoline for sale in the U.S. A final article describes an unusual new process that solved a waste water problem at a small Texas refinery.

Mitteldeutsche Erdöl-Raffinerie GmbH (Mider), is building a 170,000 b/d, grassroots refinery in Leuna, Germany. The refinery is scheduled to start up in third quarter of this year.

At the heart of the new refinery is a new technology called progressive distillation. Other major units include: vacuum distillation, catalytic reforming, alkylation, visbreaking, fluid catalytic cracking (FCC), and hydrodesulfurization (HDS). In addition, an existing partial oxidation (POX)/methanol production unit will be integrated with the new refinery.

The refinery was designed to meet European Union (EU) fuel specifications for the year 2005 and EU pollution control requirements that will take effect after 2000.

The decision to build

Before Germany's reunification, the oil business in East Germany was managed by two state concerns: Intrac was responsible for supplies and exports, and Minöl for storage, transportation, and distribution of products. Following the fall of the Berlin Wall, privatization efforts made available the petroleum assets of the former East Germany.

The German government wanted to maintain refining capacity in eastern Germany. Elf Aquitaine took advantage of this opportunity and purchased Minöl and its retail network and proposed building a new refinery rather than revamping the existing ones. (See related articles: OGJ, Oct. 15, 1990, p. 52; OGJ, Dec. 24, 1990, p. 30.)

Elf's bid won the project in 1991. The deal closed in early 1993.

The original plan called for construction of a 10 million metric ton/year (mt/y), or 200,000 b/d, refinery. Following revision of its market estimates, Elf reduced the refinery capacity to 8.7 million mt/y, although it can be expanded to 9.7 million mt/y with limited debottlenecking.

Elf Aquitaine, Paris, is the sole investor in Mider at this time. A consortium of Russian state oil companies led by Rosneft was slated to take a 24% stake in the project, but withdrew due to lack of funds (OGJ, Mar. 3, 1997, Newsletter). When the refinery comes on stream, Elf can sell a 33% stake to Bundes anstalt f?r vereinigungsbedingte Sonderaufgaben, or BVS (the former Turehandanstalt, the office for privatization).

Philippe Armand, Elf's director of German refining and project manager for the Mider refinery, says Elf has the clear intention to exercise this option this summer. If Elf does so, BVS, in return, will have the opportunity to acquire a 33% share in the former distribution company, Minöl (now Elf Oil Deutschland GmbH).

Many of Mider's detractors blame the company for building refining capacity in Europe during a period of low utilization and dismal margins.

"If you read the German press, there have been a lot of attacks against us, not because we are Elf, a newcomer," said Armand. "The argument of the people who are attacking us is based on the fact that there is overcapacity of refining in Europe, and especially in Germany."

Refining capacity in Germany was about 105 million mt/y (2.1 million b/d) at the beginning of this year. Germany's excess capacity, however, is in the Rhine Valley, says Armand.

The Mider refinery will replace outdated capacity that is being idled. Leuna Raffineriegesellschaft's antiquated 100,000 b/d refinery, adjacent to the Mider plant, will shut down when the new refinery starts up. And Hydrierwerk Zeitz GmbH's nearby 73,700 b/d refinery in Zeitz, Germany, closed in 1995.

While it is true Mider is not increasing Germany's net refining capacity, few European refiners would have fretted over the loss of 173,700 b/d of refining capacity in Western Europe.

Driving forces

The driving forces for a decision to build a refinery fall into three categories, says Armand. They are:

The new Leuna refinery will process Russian Export Blend. The crude will be shipped through the Friendship pipeline from the Urals region. In case of a supply interruption, Mider has negotiated an alternative supply route via harbors at Gdansk, Poland, and Rostock, Germany (see map). Products from the refinery will supply local markets.

Before Elf won the bidding for the refinery, a group led by Royal Dutch/Shell was planning to build a pipeline from the Hamburg refining center to Dresden in eastern Germany. The German government, however, wanted the region to be self-sufficient in petroleum products.

• Market characteristics-(supply and demand, taking into account both quantities and specifications)

  The products market in Central Europe comprises mostly middle distillate and gasoline. The German oil industry's trade association, Mineralölwirtschaftsverband, predicted product demand in the year 2000 for the Leuna region to be 2.6 million mt/y (63,600 b/d) gasoline and 5.2 million mt/y (99,700 b/d) middle distillate. Elf sized the new refinery to produce slightly less than the demand for these products: 2.1 million mt/y gasoline and 4.9 million mt/y middle distillate.

• Synergy

• Potential links with petrochemicals production can increase margins and secure a future market for products. Mider will sell as much as 700,000 mt/y naphtha to Dow Chemical as feed for Dow's ethylene unit in Böhlen, Germany, formerly owned by S?chsiche Olefinwerke AG (see map).

In addition to the ethylene integration, a portion of the heavy fuel oil produced by the refinery will be converted via partial oxidation to methanol in a unit operating at the existing Leuna refinery. The methanol unit capacity is 600,000 mt/y. A flow diagram of the process is shown in Fig. 1 [44203 bytes].

The unit was built in 1988 based on a process licensed by Shell International Petroleum Mij. and Lurgi GmbH. Of the output, 30% will be sold locally as feedstock.

Mider had to make only minimal changes to adapt the unit to meet current environmental regulations. The unit also will produce feedstock for hydrogen production.

Mider will use the remainder of the heavy fuel oil to produce power. The refinery also will sell propane, propylene, and other by-products to local users. For example, Mider will swap 80,000 mt/y sulfur for sulfuric acid to feed the refinery's alkylation unit.

Construction

Elf awarded a lump-sum contract to a consortium of Thyssen Rheinstahl Technik GmbH, Lurgi, and Technip (Cie. Française et de Construction). This group was responsible for the core of the refinery-the process units and tank farm. Mider is managing ancillary construction, which includes nontechnical buildings, interfaces, new pipelines, and reuse of equipment from the existing Leuna refinery.

Mider started detailed engineering and procurement in May 1994. After 1 year of searching for bombs from World War II and moving earth, construction began in May 1995. Mider found 10 tons of bomb remnants during this period.

Although there was no snow on the ground at the time of groundbreaking, the earth was frozen solid. Mider had to use pneumatic hammers, which slowed progress. Construction has since caught up to schedule, however, and there has been little variation from the plan.

Construction of the refinery is nearly complete. The units will start up sequentially beginning in August. The refinery should be completely on line in October.

The expected construction costs have remained at slightly less than DM 5 billion ($3 billion) since 1994.

The refinery

Except for the progressive distillation unit, all other units are based on off-the-shelf designs. The main processing units are detailed in Table 1 [43219 bytes]. A flow diagram is given in Fig. 2 [24297 bytes].

The Unibon vacuum gas oil (VGO) desulfurization unit gives Mider the flexibility to maximize either gasoline or middle distillate production to meet market demands. The unit will use a hydrotreating catalyst in the first bed and a hydrocracking catalyst in the last bed. The cracking catalyst will enable the Unibon unit to achieve 12-20% conversion, depending on demand, says Mider process engineer Jacques Pradier.

Fig. 3 [27009 bytes] shows a breakdown of the expected refinery yields.

The quality of the Russian Export Blend fed to the refinery is very similar to that of Arab Light. It contains 1.2-1.3 wt % sulfur and has an API gravity of about 32°.

Mider will process this crude about 95% of the time. For a brief period each summer, however, the refinery will process Arab Heavy (Safaniya) to produce bitumen.

About one third of the refinery's products will be shipped via pipeline-most of it through a 130-km line to a tank farm at Chemnitz and the remainder through a 40-km line to Dow's naphtha cracker at Böhlen (see map). Another third will be shipped by road, and the remaining third, including the methanol output, will leave the refinery in rail cars.

Steam and electricity will be supplied by a power plant built especially for the refinery. The power production is basically integrated with the refinery process, says Armand. Mider will provide feedstock to fuel the power plant and will take the steam and electricity produced.

The power plant comprises four boilers and three turbo generators. Three boilers will be fed by heavy fuel oil and one by excess synthesis gas from the partial oxidation unit. Output will be 90 mw of electricity, and an average of 160 tons/hr of steam at 40 bars. The plant can produce as much as 300 tons/hr of steam when needed during unit start-ups.

The power station also will supply process and cooling water. Mider will purchase additional oxygen (0.5 million t/y) from Linde AG for use in the partial oxidation process.

Given the refinery's expected environmental performance-in terms of both fuels and emissions-and its integration with power and petrochemical production, it should be an exemplary, modern facility.

Fuel specifications

Tables 2 [75675 bytes] and 3 [49445 bytes] show the expected specifications of, respectively, gasoline and diesel output from the refinery. In addition to the unleaded, regular German-specification gasoline shown in Table 2, Mider will be able to produce a 98-RON premium grade with essentially no sulfur, and a 95-RON Eurosuper with 70 ppm sulfur.

Mider will meet gasoline benzene specifications through fractionation of hydrotreated naphtha. The naphtha will be split into three cuts:

• The lightest portion will be sent to the refinery's gasoline pool.

• The middle cut will be sold as ethylene feedstock.

• The bottom portion will be fed to the reformer.

The reformer, licensed by Institut Français du Petrole, is guaranteed to produce a 102-RON reformate. Pradier says it is one of the lowest-pressure units in the world. (The reactor's average operating pressure is 3.5 bars or 51 psi.) It will produce high-purity hydrogen (almost 95 vol %) at a rate of 3.6-3.7 wt % on feed.

The hydrogen is not pure enough to be used in the Unibon unit, so it will be used in the two distillate hydrotreaters. These units will enable the refinery to easily beat the 500 ppm maximum sulfur specification for diesel fuel. Mider will even be able to produce a product with as little sulfur as 200 ppm. And, with a small additional investment attributable to a catalyst change-out in the second Unibon reactor-a high-pressure (80 bar or 1,160 psi) hydrotreater-Mider would be able to meet a 50 ppm limit.

About half the refinery's hydrogen supply will come from syngas conversion in a unit owned and operated by Linde. The syngas is produced in the POX unit. The conversion unit is located inside the refinery fence. The high-purity hydrogen produced by this unit will be used in the Unibon unit.

A third hydrogen source is a steam methane reformer (SMR), also owned and operated by Linde. This unit also will provide nitrogen and oxygen for the refinery and other local users.

About 60,000 mt/y of MTBE will be purchased on the open market and used to adjust gasoline specifications.

Progressive distillation

The Mider refinery will include the first-ever application of progressive distillation technology, according to Pradier. The process uses successive preflashes in three towers (Fig. 4 [53649 bytes]).

The first preflash is dry, and takes place at 2 bars(g) or 29 psig. This separation produces light gasoline with a true boiling point (TBP) cut point of 80-90° C. (176-194° F.).

The bottoms from Column 1 flow to the second preflash tower, which is a wet column. In the presence of steam and at 1 bar(g) or 15 psig, this column produces medium naphtha (TBP = 90-120° C. or 194-248° F.).

The bottoms from Column 2 are heat-exchanged and sent to the main atmospheric column. This column produces a variety of streams, including heavy naphtha, kerosine, and light and heavy atmospheric gas oils.

Bottoms from the main column are heated, then sent to the vacuum column. Light gas oil is drawn from the top of this column; medium and heavy gas oils are fed to the Unibon and FCC units.

The process will produce a deep-cut vacuum resid (585+° C. or 1,085+° F.), which will be processed in the visbreaker.

"The POX unit capacity is limited," said Pradier, "and it is the reason Mider chose a deep cut point for its vacuum resid and a vacuum flasher for visbreaking."

The progressive distillation scheme is more energy efficient than traditional atmospheric distillation. According to Pradier, the energy consumption of a good, conventional distillation unit will be slightly less than 2% of its feed, in fuel-oil-equivalents. The progressive distillation unit will consume only about 1.35%, taking into account fuel burning, power, and steam.

"The process will use a lot of low-pressure steam," said Pradier, "which reduces the partial pressure in the vacuum tower and increases vaporization."

NOx, SOx, VOC emissions

One factor that makes operating in Germany difficult is that the "bubble" emissions concept does not apply. The administration does not view the plant as a whole, says Armand, but rather dictates that each exhaust point must comply with applicable regulations.

In other words, a refinery, or other industrial facility, cannot compensate for excessive emissions from one source by using low-emissions equipment elsewhere. As a result, Mider has equipped almost all exhaust points in the refinery and power plant with de-NOx and de-SOx technologies.

To Mider, an important consequence of this regulatory tack was that each heater had to comply. As a result, the refinery's heaters will burn no fuel oil-just fuel gas or syngas. In addition, the heaters are equipped with low-NOx burners.

The power plant will produce 60 tons/day gypsum (calcium sulfate) as a result of de-SOx exhaust treatment.

Current national limits for SO2 emissions are 0.9 kg/ton of product treated. Part of Mider's strategy to reduce sulfur emissions involves the inclusion of the Elf/Lurgi Sulfreen process for treatment of sulfur plant tail gas. With this, Mider should achieve sulfur recovery as high as 99.5%.

"The objective of the German government is to reach [SO2 emissions] of 0.6 kg/ton," said Armand, "and the new Leuna plant is designed for 0.45 kg/ton. So our emissions are already half of other German refineries, which are on the order of 0.9 kg/ton."

To reduce emissions of volatile organic compounds (VOCs), the storage tanks will have either floating roofs or internal floating screens. Vapor recovery facilities have been installed on each loading facility and on the bitumen storage facility.

In addition to these emissions-reduction measures, the FCC unit will be equipped with an electrostatic precipitator to reduce emissions of fine particles. The UOP-designed FCC unit has several other state-of-the-art features, including: suspended cyclones, an open-end riser, and Optimix feed nozzles.

Regarding Germany's strict emissions policies, Armand said: "On the whole, there was no room for any deviation from these concepts. That is definitely an advantage for us. We consider it an investment, not just spending, because in the future it will give us an advantage."

This large Unibon reactor was shipped by barge on the Saale River and then trucked to the refinery construction site.

Other regulations

To protect the soil from contamination, all storage tanks have double shells and double bottoms. In addition, all process units sit on foundations made of a special, less-porous mixture, and the slabs are twice as thick as normal.

"The requirements for foundations in Germany are very heavy," said Armand. "It's not just a matter of money-it takes a lot of time. Each foundation has to be approved by the authorities."

Retention basins have been installed at all pipe interconnections.

"This may seem a bit petty," said Armand, "but, when you make these additions, it can cost a lot of money."

All drain systems are closed. The recovered streams are treated in a covered, API separator.

The refinery will use the existing water treatment facility from the refinery that is shutting down. The plant will be revamped with the addition of a biological treatment facility. Treated water from the plant will flow into the Saale River.

The facility will produce about 10,000 t/y sludge. The sludge will be centrifuged, compacted, and sent to a cement factory for recycling.

German noise restrictions also are quite strict.

"Inside the units, we are limited to 85 db," said Armand. "Externally, the regulatory bodies force us to have two points of measurement, which are not far from the plant. Basically, we are required to have less than normal electrical appliances-42 db. This is less than a dishwasher," he added.

Because the refinery lies in Germany's "green belt," it also must meet certain requirements for "sight protection." On approach, one can see only the tallest towers because the plant is surrounded by a large, grassy berm.

Land excavated during construction was used to make the berms, on which trees will be planted. The government has even prescribed which types of trees Mider must plant.

A unique characteristic of Germany's strict requirements is that sight protection applies not only from ground level, but also from the air. For this reason, Mider was asked to plant loam on the roofs of the nontechnical buildings and control rooms, as compensation for land that was used for industrial purposes.

"That's a law that applies now everywhere in Germany when you build something new," said Armand. "The problem is that our buildings were not at all designed for that. Not only did we not know how to plant the loam on the roofs, but the foundations and the strengths of the nontechnical buildings were inadequate."

After a long discussion with the authorities, Mider compensated for its inability to comply with this requirement by planting additional trees around the refinery.

Safety

Mider encountered further challenges with the safety certification authorities. In the area of fire protection, for example, the applicable regulations dictated that trained fire fighters be standing by at all times.

Mider proposed training its operators to be firemen, using the argument that the operators know their units better than anyone. This method also is more efficient because the refinery is not paying trained people to stand by, waiting for an accident.

This concept was new to the regulatory authorities, who found it difficult to accept. After Elf arranged a trip to one of its French refineries to observe how the process worked, the authorities eventually accepted the plan.

Also for purposes of fire protection, all pipe racks in the refinery are made of concrete. Had Mider used metal racks, expensive flocking would have been required.

Storage, shipping

The refinery's tank farm will have a capacity of 1 million tons. Of this, there will be 300,000 tons of crude storage, 250,000 tons for end products, and 450,000 tons of intermediates storage.

A typical refinery of this size has 50% more storage capacity, says Armand. But because of the single crude supply source and the refinery's in-line blending capabilities, Mider was able to reduce the amount of storage needed.

Each pumping station in the storage facility is equipped with a drum to recover hydrocarbons. An alarm sounds in the control room if a leak is detected.

The refinery also has 22,400 cu m of LPG storage capacity. For safety reasons, the bullets are "buried" behind 10-ft-high berms.

The new refinery will use the truck-loading racks from the old Leuna plant. Two new racks were added, however, as was a rail-loading facility.

Operation

The refinery will be controlled using a Foxboro distributed control system. There will be one main control room and several unmanned satellite control rooms. Each operator will control 20-25% more control loops, compared to Elf's French refineries, says Armand.

At start-up, the Mider refinery will employ 550 people. This number may seem high for a refinery of this size, but the partial oxidation plant alone employs 140 people.

Armand expects gross operating costs to be $4/bbl. This figure includes the investment in the power plant, which, technically, is not part of the refinery.

On a comparative basis, operating costs will be about $3/bbl for the refinery and $1/bbl for the partial oxidation plant. This equates to a net cost of about $2/bbl.

"We hope to be in the best tenth of European refineries," said Armand.

Given the current status of the European refining industry, this will be an impressive feat.

Copyright 1997 Oil & Gas Journal. All Rights Reserved.