World Coal Cover Feature

WORLD COAL OCTOBER 2013

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OCTOBER 2013 - VOLUME 22 NUMBER 10

Supplier selection

After carefully evaluating the various technologies and bids, the project builder, PT Inti Karya Persada Technics (IKPT), selected Geometrica as the dome supplier. “The contractor also received bids from manufacturers of concrete domes and aluminium domes,” said Zalba. “But the Geometrica solution offered more than 25% savings.” Geometrica immediately set to work on construction drawings, once it learned it had been chosen by IKPT and Pupuk-Kaltim.

“This project was very similar to domed bulk storage facilities we have built worldwide,” said Jorge Parada, Geometrica’s site consultant. “Our galvanised-steel dome technology has proved itself in many environments and applications. This one, along the coast of Indonesia in a tropical rainforest, is another great example.” The galvanised-steel dome structure is clad with aluminium sheeting, combining the strength of steel with the corrosion resistance of aluminium. It also meets National Fire Protection Association guidelines for control of confined dust.

Construction Inside the 80 m dia. storage facility, highlighting the stacker and the skylights.

Francisco Castaño, Geometrica Inc., US, and Ahmad Mardiani, PT Pupuk Kalimantan Timur, Indonesia, discuss the installation of a coal storage dome at an Indonesian fertiliser plant.

I

ndonesia’s largest fertiliser producer, PT Pupuk Kalimantan Timur (Pupuk-Kaltim), in looking to balance the use of coal-fired boilers with environmental concerns, sought to use modern technology in clean coal storage facilities.

Due to the fluctuations of natural gas markets in recent years, Pupuk-Kaltim launched a project to diversify the fuel used at its Bontang facility, east Kalimantan, with a new coal-fired boiler.

Indonesian Government policies encourage the use of coal as a substitute for natural gas. In opting to use coal, Pupuk-Kaltim would thus be able to remain in line with state policy, while also benefitting from the potentially substantial economic benefits associated with such a move.

One possible problem, of course, is that of environmental impact. To address such concerns, Pupuk-Kaltim chose to use only clean coal technologies: a circulating fluidised bed boiler, a Geometrica coal storage dome and a continuous barge unloader. The successful use of these technologies earned recognition at the JEA Northside power plant in Jacksonville, US, because of their assistance in keeping the environment around the facility as pristine as possible.

Specifications via the internet

After initial research on dome storage for coal, Mr Supriono, a mechanical engineer with Pupuk-Kaltim, made contact with Geometrica in 2009. The dome was to be supported by a 10 m high, reinforced concrete perimeter-ring wall. It would cover 40,000 short t of coal, as well as a coal stacker and a portal reclaimer.

Within a few days, Cecilio Zalba, Geometrica’s sales manager, emailed Supriono a proposal with preliminary drawings and a guide specification for a circular, galvanised-steel dome with aluminium cladding and an 80 m dia..

Pupuk-Kaltim wrote a functional specification for the dome. The specification allowed the consideration of different dome-construction technologies, including concrete, aluminium and steel. The dome was required to resist the specified environmental loads, withstand corrosion from the humid Kalimantan environment and help control explosion hazards. It was also a requirement that the dome use technology that permitted fast construction by local crews, without special equipment.

By early 2011, the design had been approved in Indonesia and Geometrica had manufactured the components for the dome at its plant in Monterrey, Mexico.

Geometrica labelled, pre-sorted and packaged the components in the order required for assembly. Crates of these materials were then loaded into containers for shipment to the Port of Jakarta, Indonesia. From there, IKPT transported the containers to the job site in Tanjung Harapan.

Construction of the dome and stacker/reclaimer began simultaneously in June 2011. Assembly began at the top of the concrete wall and progressed toward the apex. The assembly, by 20 workers assisted by two Geometrica consultants, took two months. The aluminium cladding was complete after another two months.

Conclusion Domed structure sits next to the water, protecting the pile inside from the environment.

Coal boiler plant, Pupuk Kaltim, Bontang, Kalimantan Timur, Indonesia.

Geometrica met all of the expectations for this project and Pupuk-Kaltim is pleased with the operation of the storage facility.

The first coal drop into the new storage facility was on 21 May 2012. The dome is protecting the coal from rain and protects the environment from coal dust.

Today, Pupuk-Kaltim’s coal boiler project is humming along, producing the steam required to help the company deliver its production rate of 3 million short tpa of urea to its customers in Indonesia and beyond.

The new Geometrica dome at Bontang keeps the coal spotless.

October 2013 | Reprinted from World Coal