1 Introduction

Le stockage souterrain de dioxyde de carbone rencontre en Pologne un d'intérêt toujours croissant [9,10]. Le but de cet article est de montrer les secteurs industriels émetteurs de grandes quantités de CO₂ et qui, dans un proche avenir, peuvent faire l'objet d'une séquestration souterraine en Pologne. Les émissions de CO₂ des catégories « énergie » et « procédés industriels », les concentrations dans le flux des gaz de combustion ainsi que la localisation des importantes sources ponctuelles d'émission de CO₂ ont été analysées.

2 Origine des données

3 Catégories d'émission de CO₂

4 Données sur les concentrations de CO₂ dans le flux des gaz de combustion/gaz industriels

5 Les sources industrielles d'émission de CO₂ dans le contexte du stockage souterrain

En Pologne, les émissions annuelles de CO₂ des 28 entreprises répertoriées en 2000 dans les secteurs de l'énergie, de l'industrie chimique, de la métallurgie et du ciment dépassent 1 Mt (Fig. 1). Le CO₂ émis dans l'atmosphère est un composant des gaz de combustion (teneur jusqu'à quelques dizaines de pourcent) et des gaz industriels (de diverses teneurs au CO₂ pur). L'utilisation de ce gaz à des fins de stockage souterrain passe par une séparation (procédés coûteux) des gaz de combustion/industriels [3,5]. Dans le cas d'un flux de CO₂ pur, une fois transporté, ce gaz peut être injecté directement sous terre (Fig. 2). Pour des raisons économiques, l'utilisation d'un flux de CO₂ pur est plus intéressante, plus particulièrement pour des installations pilotes de stockage souterrain.

6 Conclusions

The question of sequestration of CO₂ by underground storage begins to focus remarkable attention in Poland. This is reflected by ongoing attempts to work out premises for studies on possibilities to store this gas in deep-seated geological oil- and gas-reservoirs and aquifers [9,10]. Moreover, studies aimed at drawing out the basis for building a pilot installation for underground storage of CO₂ in an abandoned hydrocarbon deposit are carried out. Poland has experience in underground injection and storage of acid gases and the Central Mining Institute in Katowice participates in the EU RECOPOL Project (5 FP EU), aimed at testing possibilities to inject and store CO₂ in deep non-exploitable coal seams.

The aim of this paper is to identify sectors of the Polish industry and single plants that are responsible for emissions of large amounts of CO₂ and might be good candidates for a future pilot program of sequestration of this gas by underground storage. The paper also presents estimations of emissions coming from individual categories, sub-categories and sectors of industry, and concentrations of CO₂ in combustion gases and those emitted to air by industrial sources, calculated with reference to the methodology of IPCC, and location of the largest point sources of emission of this gas in Poland. Concerning the fact that underground storage of CO₂ refers to large point sources, this article does not develop problems of emission from transport (dispersed source of emission), biomass contribution and other greenhouse gases emission, for example methane. The information presented here may be used as a starting point for further studies on possibilities to intercept and sequestrate CO₂ emissions by underground storage.

The data used in this study include those coming from Polish official statistical analyses of the National Emission Centre affiliated to the Institute of Environmental Protection as well as information provided by agencies of local administration and information provided directly by individual plants of the ‘energy’ and ‘industry’ categories, that are responsible for the major part of the emissions.

A special attention should be paid to a report of the National Emission Centre [4]. The report summarizes emissions of carbon dioxide and other greenhouse gases in Poland. The presented data were processed with reference to structure of emissions and sequestration as given in the methodology recommended by ‘Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories’. Reports of that type, which is based on IPCC methodology, are to be compiled in several countries for the needs of international clearings.

In Poland, the bulk of carbon dioxide emissions has its source in industrial sectors assignable in the IPCC approach to the categories ‘energy’ and ‘industrial processes’, whereas the shares of the remaining categories appear negligible (Table 1). The ‘Energy’ category appears to be responsible for about 96% of the national emissions of CO₂, estimated at 314.8 Mt for the year 2000 and the ‘industrial processes’ category, comprising CO₂ emissions freed in the course of various technological processes not related to production of energy, comprises only about 4% of total emission of this gas.

3.1 Energy category

3.2 Category of industrial processes

Content of carbon dioxide in gases originating in combustion of fossil fuels depends on the type of fuel and content of elementary carbon, and, in industrial gases, on the processes that generate them. CO₂-rich stream is emitted in some technological processes such as those connected with production of ammonia in nitrogen plants, hydrogen, ethylene in petrochemical plants as well as some processes taking place in steelworks [2].

Data on concentration of carbon dioxide in streams of combustion/industrial gases emitted by industry in Poland are given below. The data were obtained directly from plants emitting large quantities of carbon dioxide and were supplemented with those taken from the available literature.

Analysis of composition of combustion gases from two power plants run on natural gas showed that they mainly consist of nitrogen (from 76.3 to 81.7%), oxygen (14 do 15%), water vapour (6.5%), carbon dioxide (3.2 to 3.3%), with small concentrations of other gases. In turn, data from five power plants run on lignite show clearly a higher content of carbon dioxide in combustion gases, ranging from 8.5 to 13.5%. In gases from combustion of hard coal (data from 13 power and power and heat plants), nitrogen clearly predominates (71.6 to 80.8%) over carbon dioxide (9.5 to 15.2%), oxygen (6 to 10%), water vapour (4.8 to 10.1%) and other gases occurring in negligible concentrations (CO, SO₂, NO_x).

Data from the chemical industry show that air emissions from ammonia plants include: pure carbon dioxide and combustion gases yielding nitrogen, carbon dioxide, oxygen, water vapour and some other gases. In production of urea, installations for methane decomposition, absorption and condensation of NH₃ steadily emit gas with the following composition: NH₃, 28 kg h⁻¹, CO₂, 27 kg h⁻¹, and H₂O, 1045 kg h⁻¹ [6]. One of Polish plants that produce calcinated soda is emitting gases with carbon dioxide content equal to 37% of their volume. Strongly concentrated stream of carbon dioxide is also emitted by ethylene-producing petrochemical plants.

In production of iron and steel, concentrations of carbon dioxide in converter gas before CO is burned up over stock hole range from 7 to 14%, and those of CO from 75 to 90%, and O₂ from 2.5 to 20% [7]. Concentrations of carbon dioxide in emissions coming from arc (electric) furnaces used for the production of steel is small, ranging from 0.2 do 4.6% of volume of gases, depending on a given phase of this process [8]. In the sintering section of one of Polish iron and steel works, concentration of carbon oxide equals 17% of volume of off-gases (flue-gases), whereas it drops to 1 to 3.5% in such gases from converter processes, that is to similar values as given by Jędrzejowski [7]. Converter gas above metal in converter (before burning it up) yields about 90% of CO and 10% of CO₂. Combustion gases from open-hearth furnaces of Polish iron and steel works yield 14–18% of CO₂ and 2–5% of O₂, whereas contents of CO and SO₂ is up to 0.5% and water vapour – up to 25% [8].

In year 2000, there were in Poland 28 power and chemical plants and cement kilns, which were responsible for emitting over 1 Mt of CO₂ (Fig. 1) [11]. Estimations show that total emission from these plants was equal to 165.6 Mt, which corresponds to 52.6% of the total emission of CO₂ in Poland in that year. Energy plants have here the largest share in total emissions of CO₂, with the Bełchatów power plant as the largest source of emission on the country scale (over 10% of total emissions). Eight plants are emitting from 5 to 10 Mt of CO₂ and 19 from 1 to 5 Mt.

Appropriate geological structures for underground storage of CO₂ should be found for these plants. From the three basic elements of underground storage of this gas: capturing, transporting and storing, the first is the one that generates the highest costs. The costs of transport depend on the distance from the source of emission to the storage place. The costs of injection are the lowest and depend on the depth of reservoir and the volume of CO₂ injected [3,5].

The high costs of CO₂ capture are the main reason why underground storage is not in common use. Industrial examples of underground storage of CO₂ (EOR installations, Sleipner installation in the North Sea) show that this operation is technically feasible and can bring economical profit.

CO₂ that is emitted to the atmosphere is the component of gases that are produced during fuel combustion (concentration up to tens per cent) and industrial gases (diversified concentration up to pure gas). Using combustion/industrial gases with low concentration CO₂ for underground storage purposes needs its separation, which is an expensive process. In case of pure stream of CO₂, it is ready for injection underground immediately after transport (Fig. 2). Using pure stream of CO₂ is also more interesting, because of economical reasons, especially for pilot installations of underground storage of this gas in order to avoid the emission toward the environment.

Analysis of data on the magnitude of CO₂ emissions, processed in accordance with the IPCC methodology, provided interesting and comparable results. The results, especially those concerning emissions of the categories ‘energy’ and ‘industrial processes’, along with data on the concentration of CO₂ in combustion and industrial gases and location of major point sources of emissions give a good starting point for discussion on the possibilities of sequestration of this gas by underground storage methods on the scale of a specific country, both in industrial (EOR installations) and in environmental purposes.

Chosen industrial branches (e.g., ammonia production, hydrogen production) from industrial sector (Industrial Processes category) that emit significant concentrated streams of CO₂ may become the first source of carbon dioxide for sequestration by underground storage in the near future, especially in pilot installations.