AGO

Current issue

VOL. 4 (2006)

Full text of each article is available in PDF format. CD with full texts could be ordered on our web site.
All articles have been reviewed by the members of Scientific Board.

Geothermal Heat Pumps with Two-Phase Condensing Ejector
(in english)
Bergander M. J.
Abstract
The paper describes the development of a novel vapor compression cycle for refrigeration with regenerative use of the potential energy of two-phase flow expansion, which in traditional systems is lost in expansion valves. The new cycle includes a second step compression by an ejector device, which combines the compression with simultaneous throttling of the liquid. The compressor compresses the vapor to approximately 2/3 of the final pressure and additional compression is provided in an ejector, thus the amount of mechanical energy required by a compressor is reduced and the efficiency is increased. Investigations described here were performed under the funding from the US Department of Energy. The thermodynamic model was developed for R22 refrigerant, showing a possible efficiency improvement of 38% as compared to the traditional vapor compression cycle. The theoretical work was followed by building a 10 kW prototype and practical demonstration of 16% energy savings in the first attempt.

Decision support systems based on the Life Cycle Inventory (LCI) – part of a Life Cycle Assessment (LCA) for Municipal Solid Waste (MSW)
Management Case Study
(in english)
Bieda B.
Abstract
The LCIs for pyrolysis method was based on the pyrolysis facility designs for City of Konin, in Poland. Two different scenarios of the economic feasibility were studied for the municipal solid waste process via incineration based on the pyrolysis. First scenario used the American technology of the pyrolysis-based process, and the other the Australian pyrolysis process equipment. The economic analysis methods used to study the operational total costs of the actually, and new equipments, was discounted cash flow rate of return (IRR) and net present value (NPV) of the new and actually investments.In this paper, the Monte Carlo (MC) simulation method was used for the sensitivity analysis. The Monte Carlo sampling was done using an Excel spreadsheet modified to develop scenarios for inputs given the probability distributions, means values, etc. and Crystal Ball®, a software package offered by Decisionnering, generates random numbers for a probability distribution over the entire range of possible values, based on the assumption variables.

Mass transport on the mechanical grate of waste thermal treatment devices
(in polish)
Jaworski T.
Abstract
Combustion process – especially waste combustion – seems to be very easy to organize. In fact, it is very complex and could be carried out in different ways to obtain highest possible ecological, energetic and economic efficiency. Calculation method of real time of waste residence in combustion chamber – elaborated as computer program is described in this paper. Quoted above computer program combines link measurement data and mathematical formulae; tests carried out by author in Silesian University of Technology, Chair of Technologies and Installations for Waste Management in year 2006 on laboratory stand for testing advancing and reciprocating grates and compare it with theoretical equations. Regression model and method of calculation of average time of residence on the grate is described. Difference between time of residence in ideal and real reactor is the result of stochastic character of the second one. Because in the model mechanical grate is treated as real reactor flow it is adequate to the real conditions and can be intermediate compared to ideal flow models. Quoted above flow model described in the paper includes mixing phenomenon (longitudinal dispersion). Mixing intensity - which is linked with time of residence on the grate - depends on: type of grate, angle of inclination, grate speed, grate length and sort of transported material.

Analysis of mobility polycyclic aromatic hydrocarbons in soil
(in polish)
Wandrasz J. W., Czop M.
Abstract
Laboratory research were carried out to learn the distribution process of PAH in soils with different physical and chemical properties. In research three mixtures of PAH were used (fluorence, anthracene, pyrene) as a water solution. Vertical movement of substances down the ground was taken into consideration. Soil was mounded loosely and in non-saturated state (porous structure with water and gas inside). Time of experiment was established for 30 days to avoid and limit biodegradation of substances introduced into soil. Concentration of particular substances in specified points in soil profile were measured to obtain their changes in time. Some of those results are presented in this paper.

Hazardous waste incineration – case study
(in polish)
Pikoń K, Grabski T.
Abstract
Special waste utilization could cause serious environmental impact – mainly because of its compositions and inhomogeneous structure. The most widespread method of special waste utilization is incineration. Installation created for waste combustion should be constructed in way that ensure the highest possible level of environmental protection. In the article case study of waste incineration installation SARPI has been quoted. Eco-energetic balance has been made. Under consideration has been taken all available data about compounds causing environmental impact. Environmental impact indicators for installation under analyze has been made.

WWW system - Waste works on waste system
(in polish)
Pilawski M., Pabjan. Z., Bartczak M.
Abstract
Waste transformation system works as a system of alternative fuels production. One can use that alternative fuels to transformation of other kinds of wastes. In technological line is created idea : „ WWW System - Waste Works on Waste System „.In consistency WWW System works as a „ all waste liquidation system”. In the paper is described one of possible of WWW System with tires transformation process into gas fuel using to transformation of waste plastic materials into liquid fuel components, etc. Excess of fuel or energy production is sold on the market.

Economics aspects of industrial waste management
(in polish)
Alwaeli M., Langosz K.
Abstract
Industrial wastes proclaims more of hazard source for environment. Utilization as secondary materials wastes assure many economic effects as: enlargement the raw material base, decrease capital-absorptivity and energy- absorptivity, materials expenditure and costs of production. An article gives an description of industrial wastes management economics aspects. Differences between wastes and primary raw materials properties are not substantial. Many times these changes overcome only obverse manufactory form. The reason is that primary raw materials often have not undergo fundamentally changes during production process. (Scarp metal stay metal and rubbish stay paper). An article gives an description of connected costs of use industrial wastes as substitute of raw materials.

Mathematical modelling of biomass combustion process on mechanical stoker
(in english)
Nadziakiewicz J., Czekalski R.
Abstract
The paper presents model of biomass combustion process on a mechanical stoker. Continuous two-dimensional process (which is simplification of real, three-dimensional one) was substituted with one-dimensional unsteady process of combustion of separated bed segment. The model considers drying, devolatilization, combustion of particles and reactions in gaseous phase. Results of the computation process are changes of temperatures of solid and gaseous phase, as well as gas composition in time, which corresponds to the values of those parameters in different places on mechanical stoker. The further part of investigation are laboratory measurements of the process.

Tests of granulated adsorbents production on the basis of chars from used car tyres
(in polish)
Stelmach S., Wasielewski R., Figa J.
Abstract
The results of investigations of granulated (extruded) active carbon production from fluffy char obtained from the thermolysis of used car tyres as a feedstock were presented. The forming tests of the char mixtures with chosen binders were carried out. The composition of forming mixture was optimized in order to obtain maximum mechanical strength of the product. Next, the recarbonization as well as steam activation of the product were carried out. The obtained adsorbent had weak adsorptional properties and low mechanical strenghth. From binders chosen to investigations the best binder for dusty char agglomeration was molasses.