OKK Koksovny has obtained final approval for its newly-built coke-oven battery No. 10 at Svoboda Coking Plant. The trial operation was concluded successfully at the end of April, with the battery subsequently moving to standard production mode.
From construction to trial operation
The construction of the new battery was accomplished between June 2008 and October 2010. The main contractors were HUTNÍ PROJEKT Frýdek-Místek, a. s., which constructed the buildings and some of the technology, and VÍTKOVICE POWER ENGINEERING, a. s., which supplied technology, service machinery and dust-removal equipment for the battery. It can be said that in excess of 200 workers were on-site when the battery was built, when you also take into account the workforces of other subcontractors.
The trial operation was officially started at the beginning of November last year, ending at the end of April this year. “The standard commissioning procedure for a coking battery can take up to half a year. We have managed it in less than two months. We consider that a great success,” said Petr Mokroš, Deputy Director for Production at OKK Koksovny.
Tests performed during the trial operation were used to fine-tune all operational parameters, and verify the correct functioning and faultless operation of all the equipment. “The goal is to check that all operational parameters, which are guaranteed by the contractors, are maintained over a seven-day period. Put simply, the tests are concerned with the number of coke chambers from which coke is pushed per shift and day,” Mokroš explained.
From the start of its operation, the battery has been producing foundry coke, of which OKK Koksovny is the largest European producer. “It is a type of coke with a higher added-value, compared to blast-furnace or heating coke. And our coke is in considerable demand thanks to its high quality,” Mokroš added.
The battery is designed to produce 220,000 tonnes of coke per year from its 56 chambers. The time for coking in one chamber is up to 32 hours. From the beginning of the trial operation to the end of 2010, the battery produced nearly 48,000 tonnes of foundry coke. The battery is heated with coke-oven gas sourced from its own production.
Trouble-free final approval
The planning department of the Moravská Ostrava a Přívoz district council was asked in mid-March to issue the final approval for the battery. The necessary inspection took place in early April with representatives of the relevant government authorities in attendance. OKK Koksovny then received the required approval, entitling the company to permanently operate the site.
“The final approval process in the Czech Republic is very precise and detailed, and demands that a construction meets strict criteria in terms of occupational safety, environmental impact and other parameters. As many as 15 various national and local authorities take part in the process at one time or another in regard to various aspects of production,” Mokroš said.
Environmental impact? Rigorous testing
The new coke-oven battery meets the most stringent environmental limits stipulated in the relevant legal regulations pertaining to the operation of such facilities. The trial operation included measurements for noise, concentrations of chemical pollutants and dust at all workplaces. “The process for the environmental impact assessment is very thorough in the Czech Republic. Measuring sensors are installed directly by the battery. Emissions are evaluated during the approval process by covering part of the battery, with the emissions measured on filters. Measuring stations installed around the battery continuously measure the quality of air to detect any non-standard situation. This way, we have information which is updated every minute, every five minutes or daily. We are also monitoring and evaluating long term,” Mokroš added.
The new battery is of the Still type, running with lower temperatures due to a different arrangement of the air and gas supply. As a result, the battery has a lower level of mono-nitrogen oxide (NOx) emissions. Thanks to the use of an extensive amount of refractory material, the coking chambers are better sealed.
Coking byproducts include raw coking gas, tar condensate and raw tar. The raw coking gas and tar are processed in associated chemical processes of the coking plant and are further utilised. “Overall, what I can say on behalf of OKK Koksovny is that every year we decrease the volume of waste material produced. This fact is especially important in the case of hazardous waste,” Mokroš noted.
Constructing the new battery is a key component of the Coking Plant Optimisation programme
The construction of the new coke-oven battery No. 10 amounts to the most extensive investment project of NWR within its Coking Plant Optimisation Programme (COP 2010), with total investment reaching EUR 63 million. “At the end of 2010, we shut down the Jan Šverma coking plant and consolidated all production at the modernised Svoboda coking plant. Along with the construction of the No. 10 battery, which makes up the most extensive project, realised at an investment of CZK 1.6 billion, the modernisation at the site also included the reconstruction of battery No. 8, providing us with good prospects for years to come,” Mokroš summed up.
The consolidation of production at Svoboda has resulted in reduced operational costs while it has also enabled greater flexibility in responding to market demand for coke.
Combining the output of reconstructed battery No. 8 and the other two operational batteries at the plant, the total production capacity of OKK Koksovny reaches 800,000 tonnes/year.