Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 8

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  thermohydrolysis
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
EN
The main problem occurring during poultry and animal production is the management of waste generated in slaughterhouses and poultry processing plants. These wastes, due to the bacteriological threat and the difficulty in storage, adversely affect all elements of the environment and thus require quick neutralization. The prospective method of liquidation of this type of waste is thermohydrolysis in near-critical water. The aim of the work was to examine the decomposition of poultry waste, i.e. waste blood, soft tissues, chicken heads, feathers, subjected to the process of thermohydrolysis in near-critical water. The decomposition process was carried out at a pressure of 10 MPa in the temperature range of 120°C - 250°C and with a variable residence time in the reactor. Detailed analysis of the results allowed us to state that the longer the residence time in the reactor, the higher the content of soluble organic compounds in the liquid phase. The beneficial effect of applying the thermohydrolysis process on the increased reduction of organic substances present in the investigated wastes was also demonstrated.
EN
The long-term use of plant protection products in agriculture, including pentachlorophenol (PCP), has contributed to their widespread distribution in the natural environment. So far, no cheap and effective techniques for removing chlorophenols by physicochemical or biological methods have been developed. Therefore, alternative methods of neutralizing them are currently being sought. The aim of the study was to investigate the possibility of pentachlorophenol decomposition by high temperature thermohydrolysis. The decomposition process was carried out at a constant pressure of 25 MPa, in the temperature range of 20°C to 500°C and at various volumetric flows of PCP through the reactor. Detailed analysis of the results showed that the process and degree of pentachlorophenol reduction depended on residence time in the reactor and the process temperature. The obtained results indicate that thermohydrolysis in supercritical water is not an effective method to neutralize pentachlorophenol. The high costs of conducting this process together with an average degree of PCP conversion (the conversion of pentachlorophenol at the lowest volumetric flow rate through the reactor reached about 45%) cause that thermohydrolysis at high temperature is not a costeffective method of neutralizing pentachlorophenol.
3
Content available Methane fermentation of poultry slaughterhouse waste
EN
One of the alternative methods for the treatment of animal by-products is their utilization in biological processes with a simultaneous production of energy-rich biogas. The results of the investigations of methane fermentation of animal waste are discussed in the study. The methane fermentation was carried out at 35°C. The substrates used in the experiments included poultry heads and muscle tissue. Furthermore, the fermentation residues subjected previously to hydrothermal processing were used as a substrate. The suspension of those substrates in the initial concentration range from 1 g TOC/dm3 to 11 g TOC/dm3 was used in the process. Additionally, the effect of the preliminary stage of hydrothermal substrate processing on methane fermentation efficiency was assessed. Poultry waste was subjected to thermohydrolysis at the temperature from 100°C to 300°C and pressure up to 9.0 MPa. The efficiency of the methane fermentation was estimated on the basis of biogas generated in the process. The biogas production was between 0.17 Ndm3/g TOC and 1.53 Ndm3/g TOC. In the case of poultry heads, a beneficial impact of hydrothermal processing at the temperatures from 100°C to 175°C was confirmed. For poultry meat the preliminary thermohydrolysis brought about a decrease of methane fraction in the biogas evolved. The preliminary hydrothermal processing made it possible to meet the requirements of legal regulations for the hygienization of by-products of animal origin. The obtained results allowed us to identify conditions under which the methane fermentation was carried out and which ensured a high level of methanization.
PL
W latach osiemdziesiątych ubiegłego wieku pojawiło się zainteresowanie płynem nadkrytycznym jako medium do prowadzenia różnych procesów chemicznych. Szczególnie interesującym okazała się woda w warunkach nadkrytycznych (374°C, 22,1 MPa). W pracy przedstawiono biologiczne aspekty utleniania i termohy-drolizy związków organicznych prowadzonych w warunkach wody nadkrytycznej w reaktorze rurowym.
EN
In the eighties of last century interests in supercritical fluids treated as media for different chemical processes aroused. Supercritical water (374°C, 22.1 MPa) appeared to be an especially interesting medium. Biological aspects of oxidation and thermohydrolysis of organic compounds in the presence of supercritical water in a tube flow reactor were studied.
EN
In the eighties interests in the supercritical fIuids treated as media for different chemical processes had aroused. Specially interesting media is supercritical water (3740C, 22,1 MPa). Above that point water changes its parameters, for instance water solvation mode changes from jonic to non-jonic. In this study thermohydrolysis of the p-nitrotoluenosulfonic acid (PNTS), 4,4'-dinitrostilbene-2,2'-disulfonic acid (DNSDS), and 4,4'-diaminostilbene-2,2'-disulfonic acid (DASDS) in the presence of the supercritical water in the tube flow reactor bas been studied. The influence of some process parameters was investigated. Kinetics of the chemical reactions, which took place in the system, was identified. The models were also compared with experimental data.
PL
Lata osiemdziesiąte ubiegłego wieku to czas szczególnego zainteresowania płynami nadkrytycznymi do prowadzenia różnych procesów chemicznych. Szczególnie interesującym medium jest woda w warunkach nadkrytycznych (374°C, 22,1 MPa). Powyżej tego punktu zmieniają się właściwości solwatacyjne wody z typu jonowego na niejonowy. Utrata polarności powoduje, że typowe związki jonowe, takie jak np. sole stają się praktycznie w niej nierozpuszczalne, natomiast stają się rozpuszczalne typowe niepolarne związki organiczne z rozpuszczalnika dla substancji jonowych. W pracy przedstawiono wyniki badań procesu termohydrolizy 3 wybranych substancji organicznych pochodnych stilbenu: kwasu -nitrotoluenosulfonowego (PNTS), kwasu 4,4'-dinitrostilbenodisulfonowego-2,2' (DNSDS) i kwasu 4,4'-diaminostilbenodisulfonowego-2,2' (DASDS) w rurowym reaktorze przepływowym. Przebadano wpływ różnych parametrów na przebieg procesu. Dla wszystkich przeprowadzonych eksperymentów reakcji termohydrolizy wyznaczono wartości rzędu reakcji rozkładu oraz stałej szybkości reakcji. Uzyskane wyniki porównano z wynikami eksperymentalnymi.
PL
Związki stilbenu poddano procesowi termohydrolizy w warunkach wody pod- i nadkrytycznej w zakresie temp. 20-600°C i pod ciśnieniem 250 bar. Doświadczenia prowadzono w laboratoryjnym reaktorze przepływowym. Przebadano zakres stężeń tych związków 16-2000 mg/dm3. Uzyskane wyniki posłużyły do opracowania modelu matematycznego tego procesu.
EN
Stilbene compounds hydrolysis in sub- and supercritical water were examined in the range 20-600°C and at 250 bar in a tubular laboratory-scale reactor. Stilbene compounds feed concentrations were between 16 and 2000 mg/dm3. Obtained results were basis for elaboration of mathematical model of the process.
8
Content available remote Badanie mechanizmu mokrego utleniania nadmiernego osadu czynnego
PL
Zaprezentowano wyniki badania procesu termohydrolizy nadmiernego osadu czynnego. Badania prowadzono w zakresie temperatur 50 ÷ 200°C i pod cisnieniem do 4,0 MPa, oceniając wpływ temperatury i stężenia początkowego substratu na szybkość roztwarzania węgla organicznego tworzącego fazę stałą. Stwierdzono, że w temperaturze 200°C ok. 50% węgla organicznego tworzącego fazę stałą prowadzi do roztworu, a szybkość procesu roztwarzania nie zależy od początkowego stężenia osadu.
EN
A series of experiments on thermohydrolysis of excess activated sludge are described in the paper. The rate of sludge digestion at temperature range from 50 to 200°C and under pressure up to 4.0 MPa was investigated. The effect of initial concentration on the rate of activated sludge particle digestion was also studied. On the basis of the investigations it was found that the process temperature growth enhanced the degree of activated sludge conversion which at 200°C reached 50%.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.