Information on a New Field of Knowledge: Metallurgical Econology

Avram Nicolae, Cristian Predescu, Maria Nicolae, Ecaterina Matei and Mirela Sohaciu

Science Material and Engineering Faculty, Politehnica University of Bucharest, Bucharest 040062, Romania

Received: February 10, 2011 / Accepted: June 14, 2011 / Published: February 20, 2012.

Abstract: A new branch of science called econology is being defined and shortly characterized as studying the economics-ecology-energy associations (3E or E3 associations). In the future, this must be transformed into tehnology(T)-economy-energy-ecology, so that the symbol of the econology shall be TE3. Being a new field, it becomes necessary to define and characterize the specific methodological tools. That’s why the paper examines the following indices: (1) specific consumption of primary carbon; (2) specific consumption of primary negentropy; (3) reintegration rate of secondary materials and energy. Also, the following issues are presented: (1) the indirect pollution mechanism in metallurgy; (2) analysis of pollution issues by principle “think globally, act locally”.

Key words: Econology, metallurgy, ecology.

1. Introduction??

The approach of the sustainable development concept can be based on two knowledge methodologies.

On one side, especially in the engineering area, specialization plays an important part. The environment engineering is based more and more on a new subbranch of science called ecometallurgy. Its objective is the theoretical foundation of the knowledge and application of the technologies and techniquies of improvement in the metallic material industry in agreement with the objectives of the durable development concept. Under the same terms, some other branches of knowledge can be brought forward: environment economics and environment energetics.

On the other side, in agreement with the globalization tendency, the inter (trans) disciplinary knowledge becomes more and more a necessity. This instrument allows the analysis of the metallurgical process—industrial ecology—environment economics associations as integralist-type modern methodology[1].

The above-mentioned information has to be explored (with help of study and research) by the interdisciplinary area related to the economics-ecology association under optimization terms of energetic requirements. It is the area of the 3E or, to underline the significance further, the area of E3. This new field of scientific knowledge has been called econology. In the future, this ternary must be transform into the tehnology(T)-economy-energy-ecology associations, so that the symbol of econology shall be TE3. No special arguments are required to accept that econology deals, in particular cases, also with type 2E (or E2) associations: economics—ecology, economics—energetics or ecology—energetics. They mention that, for metallurgy, the third E (energetics) means not only the energetic consumptions, but also all the material resource consumptions.

Econology came into being at the end of the twenty century. The etymology of the word is the result of a combination between the prefix econo (from economics) and the suffix logy (from ecology) [2, 3].

Considering the above, it is difficult to briefly, but wholly define econology. The authors of the present article mean, by econology, the scientific branch of research-development-innovation and the discipline of study regarding the optimization of the pollution prevention and control strategies and of the natural resource consumption strategies under economic effectiveness and energetic requirement minimization terms. If econology approaches a certain sector of industrial activities, it may get specific forms as metallurgical econology. Considering the importance of the environmental conditions to the durable development of the society, for the metallurgical engineer, econology means knowledge with reference to associations in the field of environment economics—ecometallurgy—environment energetics—technological processes [4].

In the metallurgical econology, the 3E correlations have to be studied as interdependences among the following functions:

? Energetic performance: it measures the minimization degree of the energetic consumptions;

? Ecological performance: it refers to the pollution level;

? Economic performance: it is a mixture of: (1) financial performance (minimisation of the fabrication costs of the product); (2) production and productivity performance (maximization of production, maximization of labour & facility productivity); (3) quality performance (social utility degree, whereby the product acquires competitiveness conditions).

The basic principle to govern the econological activities can be expressed as follows: the economic performance should not be restricted (enclosed) by the ecological performance or by the energetic performance. Under metallurgical strict terms, this means that metallic materials need to be produced, even if this process implies a certain level of pollution or of resource consumptions. In the event of econology being the TE3 scientific branch, the governing principle is: the technological performance should not be restricted (enclosed) by the economic performance, the ecological performance or by the energetic performance. Under metallurgical strict terms, this means that the technological performance should be reached, even if this implies financial and natural resources or reaching a particular level of pollution.

In other words, the concerns regarding the minimisation of costs and increase of quality, production and productivity have priority. Therefore, the authors conclude that the extensity’s indexes must be predominantly from the category of intensity indexes.

Hereinafter, the authors are going to present some specific indices and measures necessary for econological analyses in metallurgy.

2. Specific Consumption of Primary Carbon

In the iron and steel metallurgy, the CO2 emissions prevailingly depend on the carbonic material consumptions [5, 6]. For approximate but acceptable assessments, CO2 is presumed to be generated especially based on the reactions: Ccoke + O2 CO2 CO2 + C 2CO C + FeO Fe + CO FeO + CO Fe + CO2

The problem of outmost importance that needs to be solved at present is the comparison of the two steel making flows from the CO2 emission point of view. Reference is made to the iron ore-blast furnace hot metal-converter steel integrated flow (flow abbreviated by i.f.) and the scrap-electric arc furnace(EAF) flow (abbreviated by e.f.). In order to carry out such analyses, a new econological index is proposed to be defined and used, Ic.s.c.p, called the primary carbon specific consumption index, required to obtain metallic products.

The primary consumption is the quantity of carbon which has to be provided by the natural deposit (the coal mine) to obtain the metallic product on each of the two flows. The primary carbon is used in analyses globally, act locally” principle, the iron metallurgist must report the CO2 global emission on the whole manufacturing flow, not only for the last location of the flow. This implies assessment to be made depending on the quantity of primary carbon, Cp, expressed in (kg primary carbon) supplied by the coal mine.

2.1 Calculus for Primary Carbon Consumption

Based on the above, the index definition and calculation equation is:(kg primary carbon/kg plate) (1)

The review starts from the structure of the two flows (Fig. 1). As thereinafter the authors talk about an assessment guide, the authors shall appeal to simplified balances.

The mathematical models used in the review shall be presented in the following structures.

(1) Specific consumption of primary carbon for the production and transmission of electricity, Cp.c.e(kg carbon/MWh) (2) Cp.c. = specific consumption of power coal(kgcoal/MWh);

[C]c.p.c = content of carbon in the power coal(kgcarbon/kgcoal); rl.r = loss rate with electricity transmission.

(2) Specific consumption of primary carbon for the steel making on the integrated flow, Cp.c.i.f: Cp.c.i.f = CK.[C]K + Cc.c..[C]c + CO2.c.Ce.eO2.Cp.c.e(kgcarbon/t steel) (3) CK = specific consumption of coke (kg coke/t.pig iron);[C]K = content of carbon in coke (kg carbon/kg coke); Cc.c = specific consumption of coal blown in the blast furnace

(3) Cp.c.e.f = {650 KWh/t steel × 0.403 kg

carbon/KWh + 35 m3N oxygen/t steel × 0.60

KWh/m3N oxygen × 0.403 kg carbon/KWh + 20 kg

graphite/t steel × 1 kg carbon/kg graphite } × (1/1 –

0.35) = (262 + 9 + 20) × 1/0.65 = 449 kg carbon/t

steel

2.2 Comparison between the Manufacturing Flows

Depending on the Indirect Pollution with CO2

The application of the “think globally, act locally”

principle starting from the primary carbon

consumptions in the coal mines entails the necessity to

discuss the CO2 indirect pollution phenomenon for the

e.f. flow. The indirect pollution is assessed by the

indirect emission, which represents the quantity of

pollutant related to an agent produced in a location

separate from the consuming location. For the iron and steel metallurgy, the most important indirect pollution is the quantity of CO2 produced in the thermal station and related to the quantity of electricity consumed in the iron and steel plant. The chart of the CO2 indirect pollution phenomenon in the iron and steel metallurgy has been shown in Fig. 2.

In this condition, the indirect pollution can be forecasted by the equation

An important way to optimize the 3E correlations in metallurgy is the reintegration of secondary materials and energy.

The reintegration means the policy of recovery by reintroduction the secondary materials and energy into the manufacturing cycle.

The secondary materials (waste) are the resulting materials that accompany the primary materials. In metallurgy, such an example is the metallurgical slag that accompanies the primary material (pig-iron or steel) or the mill scale (as mixture of iron oxides) which result from steel rolling.

The secondary energies are the energies that leave the manufacturing process without being used in the plant workspace. An example of such energies is the enthalpy of the flue gas that leaves the metallurgical furnace after fuel burning.

In metallurgy, the reintegration is realized based on the 3E technologies: recirculation, recycling and regeneration.

Recirculation means recovery by reintroducing the secondary materials or energies into the same manufacturing flow. The recirculation scheme is presented in Fig. 3.

Recycling is the secondary material recovery by using the materials in manufacturing cycles, different from those which generated them. The recycling scheme is presented in Fig. 4.

Regeneration represents the recovery process of the initial properties of the secondary materials by physical, chemical, thermal or mechanical processing.

The rate of reintegration of secondary materials and energy is the ratio of the reintegrated quantities and total quantities discharged from metallurgical plants. Reintegration in metallurgy is a broad and complex subject.

Dealing with it in detail is beyond the scope of this paper. The above measure expresses the negentropy required for running the processes in the metallurgic mechanism, including: consumption of natural resourcesprocess of obtaining the metallic productremoval from useconversion of products into waste materialsprocessing for waste reintegration.

4. The Consumption of the Primary Negentropy

The econological analyses regarding the primary negentropy consumptions are based on the aspects which will be presented as follows.

By means of its components, natural resources represent the ranking states of the matter. Thus, it can be asserted that the environment is a storage megasystem of negentropy. In such context, it is valid the if the statement regarding that the nature storages a primary negentropy, nSp, where the negentropy of the natural resources, nSn.r, is a part of this. The existence of living organisms consists of efforts made in order to constantly maintain the level of the quality of life, that is of the own entropy (or negentropy). These efforts require large demands of negentropy from outside.

The economic-productive process through which goods required by social needs are produced is a matter-ranking process, a proven fact that the negentropy of the steel plate is bigger than that of the iron ore taken from nature. According to the first principle of thermodynamics, this transformation cannot be performed unless there is consumption of nSp from outside the outline of the operating process.

As a whole, the human activity means:

? the consumption of natural resources’ negentropy, nSn. r.;

? the production of negentropy, Sn, within operating processes, So.p;

? the release of specific secondary materials (toxic wastes) in the environment is made together with the release of the entropy, Sw, because the alteration states of the ranking matter is increased;

? the transformation of the negentropy of the initial good, resulted from the operating process in entropy of the wastes, is accompanied by wastage, which can be both physical and moral;

? recovering negentropy, Sr.n., based on activities of reintegrating wastes (recirculation, recycling, regeneration).

The history of human production shows that the positive reserve )(.drnnSnS? does not cover the quantum in absolute values. Thus, the human activity based on a social purpose has to appeal to nSp, which therefore will decrease.

A diagram representing the variation of the(neg)entropy in megasystem may be the one described in Fig. 5.

The above finding is sustained by an assertion according to which what comes in the economic process consists of valuable natural resources, and what goes out represent useless wastes. Thermodynamically speaking, this means that both matter and energy absorbed by the economic-productive process are in a state of negentropy, and what is discharged is in a state of entropy.

To conclude, the following aspects are notable:

? the development of some activities regarding the social needs which maintain the entropic level so this causes a decrease of negentropy somewhere else;

? the operationalization of the concept of sustainable development has to consider first of all the reduction of rates (speeds) of decreasing nSp.

The deficit of primary negentropy )(pnS? is:

(6)

In these terms, it can be stated that the technology-sociology connection, in the sense that the first factor influences the other one, should be analyzed considering the reserves of negentropy. As it is known, the quality of life, as social object, may be improved through modern technological means, as mechanization, automation, etc.. However, it should also be taken into account that the mechanization of agriculture, for example, by replacing the ox as an instrument of gaulage for the plough with the tractor, causes an increase in the consumption of initial negentropy due to the manufacture of the tractor and due to the necessary resources for its operation and workers’ social needs.

5. Conclusions

The Ic.s.p.p index is an important econological tool for:

? Calculating the supply consumptions with raw materials of the metallurgical plants;

? Assessing the depletion degree of the raw material deposits.

The same index can be used upon assessing the industry dematerialization strategies, characterized by minimising the primary substance specific consumptions. With regards to the primary carbon consumptions, the i.f. flow is superior to the e.f. flow. Consequently, the report remains the same also as far as the CO2 emission is concerned. The primary carbon reduced consumption technologies have formed the basis of the iron and steel metallurgy decarbonisation strategies, also called iron and steel metallurgy without coke, which lead to minimising the CO2 pollution due to the iron and steel metallurgy. Such technologies can be applied by:

? Replacing the iron and steel metallurgy on coke by the one on hydrogen, where the processes shall be based on the reaction:

FeO + H2 Fe + H2O

? Replacing the electricity produced in thermal stations by electricity produced in hydroelectric power stations;

? Recovery of energetic secondary resources advanced within the iron and steel metallurgical plant.

Applying the “think globally, act locally” principle at the e.f. flow implies the fact that, although locally, the CO2 pollution in the EAF area is unimportant, however, globally, the iron metallurgist ought to assume responsibility for the CO2 pollution generated in the thermal station and carried by the quantity of electricity consumed in the iron and steel plant.

References

[1] A. Nicoale, C. Predescu, M. Nicolae, P. Vizureanu, A. Vasiliu, A.A. Minea, Operationalization of the SD-Concept in Siderurgy, Printech Printhouse, Bucharest, 2006, pp. 123-125.省略.省略.

[4] A. Nicolae, I. Bor?, C. Predescu, M. Nicolae, V. ?erban, A. Predescu, et al., Metalurgical Econology, Printech Printhouse, Bucharest, 2009, pp. 43-50. (in Romanian)

[5] P. Vizureanu, The analysis of the melting process of the materials in the solar furnaces, Metalurgia International 14 (2009) 5-10.

[6] N.M. Mihaiescu, A. Dima, I. Rusu, Research concerning materials for filters, Metalurgia International 14 (2009) 55-60.