Karel Ciahotný - Academia.edu (original) (raw)

Papers by Karel Ciahotný

Paliva

Since the 80s of the 20th century, as a result of the reduction in demand for coke, economic cris... more Since the 80s of the 20th century, as a result of the reduction in demand for coke, economic crises and the availability of coking coal, the operations of coke plants in Europe have been ending. Furthermore, the pressure for using renewable energy sources continues to increase, including the production of fuels. In most cases, the current solution is to add biocomponents to fuels produced in the classical way from oil. There are considerations about reusing these coke batteries, this time for the production of liquid fuels. Therefore, this work is devoted to the processing of biomaterials mixed with brown coal by the pyrolytic process. Extracted rapeseed meal, sunflower seed husks and dry distillery grain with solubles (DDGS) were selected as biomaterials. They are waste material from various productions, but these materials also show good energy potential. The brown coal came from the ČSA quarry, which is characterized by a low content of sulfur and ash and also improves the proper...

Prace Naukowe Instytutu Chemii i Technologii Nafty i Węgla Politechniki Wrocławskiej. Konferencje, 1999

Prace Naukowe Instytutu Chemii i Technologii Nafty i Węgla Politechniki Wrocławskiej. Konferencje, 1999

CRC Press eBooks, May 17, 2010

Paliva, Mar 31, 2022

The use of activated carbon in environmental protection and other separation processes has expand... more The use of activated carbon in environmental protection and other separation processes has expanded considerably in recent years in the technologically advanced countries of the world. World production of this interesting adsorbent material is currently approaching 1 million tons per year and is growing constantly. The largest use of activated carbon is in the field of drinking and wastewater treatment, waste gas treatment, chemical methods of gold mining and refining processes in industrial, pharmaceutical and food processing. The sorbent used needs to be regenerated in order to be able to continue to serve or to dispose of it ecologically if its regeneration or reactivation is not possible. The article deals with the possibilities of the restoration of sorption properties of used by regeneration and reactivation procedures, describes the differences between these processes, and also deals with evaluation of the sorption capacities of carbonaceous sorbents with restored sorption capacity. The technologies that use integrated regeneration of the saturated adsorbent directly in the adsorption plant and technologies that replace the saturated adsorbent with new ones, which show more favorable investment costs, are currently used in the operational practice. The saturated adsorbent used with organic substances is usually not disposed of, but regenerated or reactivated in the regeneration / reactivation plant. Both of these technologies have also been introduced and operated in the Czech Republic in the past. In the Czech Republic, there are currently two industrial facilities in operation designed to regenerate activated carbon saturated with organic substances. In the case of regenerated / reactivated sorbents, it is important to have a suitable sorbent certificate with a restored structure, which determines the degree of restoration of the porous structure of the sorbent. Because of this, it is necessary to adjust the expected adsorption capacity of the sorbent with a restored porous structure for the captured substances, and subsequently also the sorbent exchange interval. Only in this way will the adsorption equipment meet the emission limits determined throughout the operation.

Lecture notes in networks and systems, 2018

Along with prospective fashion of solving the engineering-tasks (if development would allow us a ... more Along with prospective fashion of solving the engineering-tasks (if development would allow us a such approach while answering the technology-questions of some project in future), goes alternatively corrective performance of those engineering tools, used to compensate for needed changes in some already existing technical solution. A unique chance to compare the needs of traffic-intentions (while setting the modern road communications through the southern of Bosnia and Herzegovina) verses natural occurrences in the atmosphere (such is a strong north-wind in this geographic region) offers the high-way-section Pocitelj-Zvirovici. Exactly in such cases (and before the actual construction of an engineering-construction is realized) “for the sake” of prospective—and certainly self-sustainable engineering—the tool of CFD (the tool for performing the Computational Fluid Dynamics) was applied to engaged the problem. Again, in the same moment while solving prospectively (through application of the CFD-based research prospectively in) several technical issues on submarine tidal-turbines in bay-area of Swansea in Wales (UK) for electricity production, a corrective way of engineering is requested to research on both imagined fire-scenarion in road-tunnel of Vranduk, close to Zenica (Bosnia) as as well as in case of investigative observing the (large-scale) combustion of the flare-stack in the refinery in town of Lendava (Slovenia). Coming from the both steady-state (k-epsilon turbulence-treatment) and time-dependent applied CFD-based explorations (Large-Eddy Simulation in Smagorinsky-Lilly mode), the unexpected and unwanted strong gaseous flows were detected and the results coming out of this are explained and discussed.

The holistic approach to environment, Feb 22, 2016

Studies in Surface Science and Catalysis, 2002

ABSTRACT The contribution deals with ammonia-removal from waste air by adsorption using low-cost ... more ABSTRACT The contribution deals with ammonia-removal from waste air by adsorption using low-cost sorbents. The natural zeolite clinoptilolite from the deposit Nižný Hrabovec, Slovakia was tested for ammonia removal from the waste air. Measurements of breakthrough curves for ammonia were performed using fixed beds of clinoptilolite (i) in its natural form and (ii) on clinoptilolite samples pre-treated with acids. The parameters of the experiments were selected to simulate the conditions ruling in animal breeding farms. The pre-treatment of clinoptilolite with acids increased sorption capacity of clinoptilolite for ammonia.

Paliva

In the Czech Republic, the gas industry is a key sector for ensuring the successful growth of ind... more In the Czech Republic, the gas industry is a key sector for ensuring the successful growth of industrial production and the growth of the standard of living. However, the set of Green Deal agreements recently adopted by the European Union envisages the gradual reduction of natural gas consumption and its replacement by ecologically produced (green) hydrogen. However, the production of green hydrogen in the Czech Republic is not yet industrially established, and its realisation will require considerable financial sums as investments in the relevant infrastructure. This will be reflected in a significant increase in the price of gas containing the prescribed proportion of green hydrogen. The planned addition of a certain proportion of hydrogen to natural gas will bring a number of complications to the gas industry. Production of a sufficient amount of green hydrogen, which should be added to natural gas, is not ensured in the Czech Republic or in the EU and will require considerable i...

Chemicke Listy, 2003

In the framework of the project of ammonia removal from waste gases, its adsorption on a natural ... more In the framework of the project of ammonia removal from waste gases, its adsorption on a natural zeolite, clinoptilolite, was investigated. The material can be simply modified to reach an adsorption capacity comparable with commercial adsorbents for removal of ammonia from the gas phase. The adsorbed ammonia can be utilized as a nitrogen source in plant cultivation. On admixing the ammonia-saturated adsorbent with soil, the yields and quality of plant production were favourably influenced, also by the presence of other nutrients in the adsorbent (K, Ca). The modification of clinoptilolite before ammonia adsorption influences the bonding of ammonia to the adsorbent and, consequently, also the dynamics of its release into soil (soil solutions).

Plyn, 2008

The first part of the article, which appeared in Plyn No. 9, describes the history of the coke an... more The first part of the article, which appeared in Plyn No. 9, describes the history of the coke and gas department of the Institute of Chemical Technology in Prague (VSCHT) and the current organisation of a structured curriculum following the overhaul that was carried out a few years ago. This second part of the article offers a more detailed description of gas research at today's Department of Gas Technology, Coking Chemistry and Air Protection, in which students are involved during their studies.

Karbo, 1994

On a controle la validite de la theorie d'adsorption de Dubinin pour l'intervalle surcrit... more On a controle la validite de la theorie d'adsorption de Dubinin pour l'intervalle surcritique des temperatures. On a determine les isothermes d'adsorption de H 2 , N 2 , CH 4 , Ar et CO 2 dans l'intervalle 20-50° C et sous pression 0-3,0 MPa pour 4 echantillons de charbons actifs commerciaux. Les valeurs mesurees ont ete estimees avec l'emploi du systeme d'equations de Dubinin. Sur la base d'allure des isothermes de N 2 a 20° C, on a calcule a tour les parcours des isothermes pour les gaz restes et on les a compare avec les valeurs determinees. On a releve que dans l'intervalle des pressions plus elevees, des differences importantes entre les valeurs mesurees et valeurs calculees se manifestent

Plyn, 2008

In the year that marks the 55th anniversary of the gas department at the Institute of Chemical Te... more In the year that marks the 55th anniversary of the gas department at the Institute of Chemical Technology in Prague (VSCHT), head of the Department of Gas Technology, Coking Chemistry and Air Protection of VSCHT Prague offers the key information about the history of instruction in gas sciences at the level of higher education institutions, the current status and organisation of this instruction, and the forms of enrolment; he also describes the organisation and orientation of research at today's Industry, Coke Chemistry and Air Quality Control Institute, the successor to the former gas department.

Plyn, 2010

Ten years ago, the Institute of Chemical Technology in Prague developed special technology for H ... more Ten years ago, the Institute of Chemical Technology in Prague developed special technology for H 2 S removal from biogas using impregnated activated carbon. This technology has been brought to an industrial scale by KS Klima-Service a.s., based in the town of Dobřis, and is currently used for H 2 S removal from biogas at four wastewater treatment plants in the Czech Republic. The article summarises industrial experience with this technology over more than ten years of its successful application under industrial conditions.

Chemicke Listy, 2005

Removal of volatile organic compounds (VOC) using adsorption was investigated. Four organic compo... more Removal of volatile organic compounds (VOC) using adsorption was investigated. Four organic compounds (acetone, toluene, decane and cyclohexanone) and eight commercial adsorbents were used for determination of adsorption isotherms. A flow laboratory apparatus working on gravimetric principle was used for the measurement of adsorption isotherms at 20 °C or 25 °C. Subsequently, thermal desorption for three adsorbents and two organic compounds was tested. Desorption processes were carried out by heating a saturated adsorbent in an electric oven. For evaluation of experimental data, the Langmuir and Dubinin adsorption theories were used. The highest adsorption capacities were obtained for activated carbon adsorbents produced by Silcarbon Co. Natural zeolites show very low adsorption capacities. The best desorption efficiency was observed for Envisorb B+.

New Perspectives in Fluid Dynamics, 2015

Applied Computational Fluid Dynamics, 2012

Paliva

Since the 80s of the 20th century, as a result of the reduction in demand for coke, economic cris... more Since the 80s of the 20th century, as a result of the reduction in demand for coke, economic crises and the availability of coking coal, the operations of coke plants in Europe have been ending. Furthermore, the pressure for using renewable energy sources continues to increase, including the production of fuels. In most cases, the current solution is to add biocomponents to fuels produced in the classical way from oil. There are considerations about reusing these coke batteries, this time for the production of liquid fuels. Therefore, this work is devoted to the processing of biomaterials mixed with brown coal by the pyrolytic process. Extracted rapeseed meal, sunflower seed husks and dry distillery grain with solubles (DDGS) were selected as biomaterials. They are waste material from various productions, but these materials also show good energy potential. The brown coal came from the ČSA quarry, which is characterized by a low content of sulfur and ash and also improves the proper...

Prace Naukowe Instytutu Chemii i Technologii Nafty i Węgla Politechniki Wrocławskiej. Konferencje, 1999

Prace Naukowe Instytutu Chemii i Technologii Nafty i Węgla Politechniki Wrocławskiej. Konferencje, 1999

CRC Press eBooks, May 17, 2010

Paliva, Mar 31, 2022

The use of activated carbon in environmental protection and other separation processes has expand... more The use of activated carbon in environmental protection and other separation processes has expanded considerably in recent years in the technologically advanced countries of the world. World production of this interesting adsorbent material is currently approaching 1 million tons per year and is growing constantly. The largest use of activated carbon is in the field of drinking and wastewater treatment, waste gas treatment, chemical methods of gold mining and refining processes in industrial, pharmaceutical and food processing. The sorbent used needs to be regenerated in order to be able to continue to serve or to dispose of it ecologically if its regeneration or reactivation is not possible. The article deals with the possibilities of the restoration of sorption properties of used by regeneration and reactivation procedures, describes the differences between these processes, and also deals with evaluation of the sorption capacities of carbonaceous sorbents with restored sorption capacity. The technologies that use integrated regeneration of the saturated adsorbent directly in the adsorption plant and technologies that replace the saturated adsorbent with new ones, which show more favorable investment costs, are currently used in the operational practice. The saturated adsorbent used with organic substances is usually not disposed of, but regenerated or reactivated in the regeneration / reactivation plant. Both of these technologies have also been introduced and operated in the Czech Republic in the past. In the Czech Republic, there are currently two industrial facilities in operation designed to regenerate activated carbon saturated with organic substances. In the case of regenerated / reactivated sorbents, it is important to have a suitable sorbent certificate with a restored structure, which determines the degree of restoration of the porous structure of the sorbent. Because of this, it is necessary to adjust the expected adsorption capacity of the sorbent with a restored porous structure for the captured substances, and subsequently also the sorbent exchange interval. Only in this way will the adsorption equipment meet the emission limits determined throughout the operation.

Lecture notes in networks and systems, 2018

Along with prospective fashion of solving the engineering-tasks (if development would allow us a ... more Along with prospective fashion of solving the engineering-tasks (if development would allow us a such approach while answering the technology-questions of some project in future), goes alternatively corrective performance of those engineering tools, used to compensate for needed changes in some already existing technical solution. A unique chance to compare the needs of traffic-intentions (while setting the modern road communications through the southern of Bosnia and Herzegovina) verses natural occurrences in the atmosphere (such is a strong north-wind in this geographic region) offers the high-way-section Pocitelj-Zvirovici. Exactly in such cases (and before the actual construction of an engineering-construction is realized) “for the sake” of prospective—and certainly self-sustainable engineering—the tool of CFD (the tool for performing the Computational Fluid Dynamics) was applied to engaged the problem. Again, in the same moment while solving prospectively (through application of the CFD-based research prospectively in) several technical issues on submarine tidal-turbines in bay-area of Swansea in Wales (UK) for electricity production, a corrective way of engineering is requested to research on both imagined fire-scenarion in road-tunnel of Vranduk, close to Zenica (Bosnia) as as well as in case of investigative observing the (large-scale) combustion of the flare-stack in the refinery in town of Lendava (Slovenia). Coming from the both steady-state (k-epsilon turbulence-treatment) and time-dependent applied CFD-based explorations (Large-Eddy Simulation in Smagorinsky-Lilly mode), the unexpected and unwanted strong gaseous flows were detected and the results coming out of this are explained and discussed.

The holistic approach to environment, Feb 22, 2016

Studies in Surface Science and Catalysis, 2002

ABSTRACT The contribution deals with ammonia-removal from waste air by adsorption using low-cost ... more ABSTRACT The contribution deals with ammonia-removal from waste air by adsorption using low-cost sorbents. The natural zeolite clinoptilolite from the deposit Nižný Hrabovec, Slovakia was tested for ammonia removal from the waste air. Measurements of breakthrough curves for ammonia were performed using fixed beds of clinoptilolite (i) in its natural form and (ii) on clinoptilolite samples pre-treated with acids. The parameters of the experiments were selected to simulate the conditions ruling in animal breeding farms. The pre-treatment of clinoptilolite with acids increased sorption capacity of clinoptilolite for ammonia.

Paliva

In the Czech Republic, the gas industry is a key sector for ensuring the successful growth of ind... more In the Czech Republic, the gas industry is a key sector for ensuring the successful growth of industrial production and the growth of the standard of living. However, the set of Green Deal agreements recently adopted by the European Union envisages the gradual reduction of natural gas consumption and its replacement by ecologically produced (green) hydrogen. However, the production of green hydrogen in the Czech Republic is not yet industrially established, and its realisation will require considerable financial sums as investments in the relevant infrastructure. This will be reflected in a significant increase in the price of gas containing the prescribed proportion of green hydrogen. The planned addition of a certain proportion of hydrogen to natural gas will bring a number of complications to the gas industry. Production of a sufficient amount of green hydrogen, which should be added to natural gas, is not ensured in the Czech Republic or in the EU and will require considerable i...

Chemicke Listy, 2003

In the framework of the project of ammonia removal from waste gases, its adsorption on a natural ... more In the framework of the project of ammonia removal from waste gases, its adsorption on a natural zeolite, clinoptilolite, was investigated. The material can be simply modified to reach an adsorption capacity comparable with commercial adsorbents for removal of ammonia from the gas phase. The adsorbed ammonia can be utilized as a nitrogen source in plant cultivation. On admixing the ammonia-saturated adsorbent with soil, the yields and quality of plant production were favourably influenced, also by the presence of other nutrients in the adsorbent (K, Ca). The modification of clinoptilolite before ammonia adsorption influences the bonding of ammonia to the adsorbent and, consequently, also the dynamics of its release into soil (soil solutions).

Plyn, 2008

The first part of the article, which appeared in Plyn No. 9, describes the history of the coke an... more The first part of the article, which appeared in Plyn No. 9, describes the history of the coke and gas department of the Institute of Chemical Technology in Prague (VSCHT) and the current organisation of a structured curriculum following the overhaul that was carried out a few years ago. This second part of the article offers a more detailed description of gas research at today's Department of Gas Technology, Coking Chemistry and Air Protection, in which students are involved during their studies.

Karbo, 1994

On a controle la validite de la theorie d'adsorption de Dubinin pour l'intervalle surcrit... more On a controle la validite de la theorie d'adsorption de Dubinin pour l'intervalle surcritique des temperatures. On a determine les isothermes d'adsorption de H 2 , N 2 , CH 4 , Ar et CO 2 dans l'intervalle 20-50° C et sous pression 0-3,0 MPa pour 4 echantillons de charbons actifs commerciaux. Les valeurs mesurees ont ete estimees avec l'emploi du systeme d'equations de Dubinin. Sur la base d'allure des isothermes de N 2 a 20° C, on a calcule a tour les parcours des isothermes pour les gaz restes et on les a compare avec les valeurs determinees. On a releve que dans l'intervalle des pressions plus elevees, des differences importantes entre les valeurs mesurees et valeurs calculees se manifestent

Plyn, 2008

In the year that marks the 55th anniversary of the gas department at the Institute of Chemical Te... more In the year that marks the 55th anniversary of the gas department at the Institute of Chemical Technology in Prague (VSCHT), head of the Department of Gas Technology, Coking Chemistry and Air Protection of VSCHT Prague offers the key information about the history of instruction in gas sciences at the level of higher education institutions, the current status and organisation of this instruction, and the forms of enrolment; he also describes the organisation and orientation of research at today's Industry, Coke Chemistry and Air Quality Control Institute, the successor to the former gas department.

Plyn, 2010

Ten years ago, the Institute of Chemical Technology in Prague developed special technology for H ... more Ten years ago, the Institute of Chemical Technology in Prague developed special technology for H 2 S removal from biogas using impregnated activated carbon. This technology has been brought to an industrial scale by KS Klima-Service a.s., based in the town of Dobřis, and is currently used for H 2 S removal from biogas at four wastewater treatment plants in the Czech Republic. The article summarises industrial experience with this technology over more than ten years of its successful application under industrial conditions.

Chemicke Listy, 2005

Removal of volatile organic compounds (VOC) using adsorption was investigated. Four organic compo... more Removal of volatile organic compounds (VOC) using adsorption was investigated. Four organic compounds (acetone, toluene, decane and cyclohexanone) and eight commercial adsorbents were used for determination of adsorption isotherms. A flow laboratory apparatus working on gravimetric principle was used for the measurement of adsorption isotherms at 20 °C or 25 °C. Subsequently, thermal desorption for three adsorbents and two organic compounds was tested. Desorption processes were carried out by heating a saturated adsorbent in an electric oven. For evaluation of experimental data, the Langmuir and Dubinin adsorption theories were used. The highest adsorption capacities were obtained for activated carbon adsorbents produced by Silcarbon Co. Natural zeolites show very low adsorption capacities. The best desorption efficiency was observed for Envisorb B+.

New Perspectives in Fluid Dynamics, 2015

Applied Computational Fluid Dynamics, 2012