Wyniki wyszukiwania - Biblioteka Nauki

1

Influence of Temperature and Reaction Time on the Efficiency of Alkaline Pretreatment of Hay Biomass

100%

Zdeb M. , Skóra A. , Pawłowska M.

Journal of Ecological Engineering

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2021

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tom Vol. 22, nr 2

120--127

EN

Low biodegradability caused by polymeric structure is the main barrier in the use of lignocellulosic materials in biofuels production by using biological methods. Pretreatment of the biomass is the way to improve the suitability of hardly biodegradable biomass for biogas or bioethanol production. Evaluation of the influence of thermal and thermochemical alkaline pretreatment on the efficiency of hydrolysis of hay (mixture of various grass species) was the aim of the study. The batch scale experiment was carried out with the use of NaOH and distilled water as solvents, and the changes in pretreatment time (2, 4 and 8 hours) and temperature (22 and 80°C) were also considered. The efficiency of biomass solubilisation was assessed based on the results obtained from the measurements of chemical oxygen demand (COD) and volatile fatty acids (VFA) concentration in the hydrolysates. The solubility of the biomass, expressed as a percentage of soluble COD in total COD, was calculated. The experiment showed that the highest solubilisation of hay biomass was observed at 80°C under alkaline conditions. In this case, the solubility of the COD was 3-times higher, and the VFA concentration in hydrolysates was 4-times higher in comparison to the distilled water-based test at 22°C. It was noted that time of the process significantly influenced the efficiency of biomass solubilisation only during the experiment carried out at 22°C. Extension of hydrolysis time from 2 to 8 hours increased the value of soluble COD of 70% and 55% for water and alkaline solvent, respectively. The process conducted at 80°C was not time-dependent over the considered period.

2

Anaerobic Co-Digestion of Sewage Sludge and Waste in High Solid State

75%

Aboulfotoh A. M. , Marie A. I. , El-Hefny R.

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tom Vol. 23, nr 6

1--13

EN

In this study, the effect of thermal pre-treatment (TP) on the physical characteristics and co-digestion of a mixture of food waste and sludge was investigated. The food waste (FW) to sewage sludge (SS) ratio used in this research is 1:2 (VS-based) to form a final concentration of 11.20%. The inoculum to substrate ratio was set at 1:1 (volumebased). Undoubtedly, the results show that TP has changed the physical characteristics of the food waste to sewage sludge mixture. The results show that the pretreatment increased the biogas production from 4385 ml for the untreated reactor to 5685 for the reactor R2(140) at 140 °C and the improvement in biogas production reaches 29.65% in the reactor R2(140) and the removal of volatile solids was 58.90%. Therefore, after the biomethane potential test, the temperature of 140 °C was found to be optimal in the production of biogas. The optimal condition is to use a mixture of pre-treated SS at the temperature of 140 °C and untreated FW, so TP is recommended to be used in anaerobic digestion of the mixture of food waste and sewage sludge.

3

Investigation of PIB-succinimides in engine oils

75%

Sagi R. , Bartha L. , Beck A. , Baladincz J.

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tom Vol. 11, no 3

507-513

EN

Along with the ever stricter economical, technical and mainly environmental regulations new types of low phosphorous, sulphurous and metal containing multifunctional engine oil additives are required. In the greatest volume dispersant additives, mainly polyisobuthylene-succinimides are used in the formulation of engine oils. By structure modification advantageous complementary effects could be achieved along the high detergent-dispersant efficiency. In view of this different modified PIB-polysuccinimides with complementary AF/AW, viscosity-index improver and enhanced detergent-dispersant properties were synthesized and investigated in base oil and engine oils. The potential detergent-dispersant efficiency, spot dispersancy, thermal- and oxidation stability, deposit preventing effect and AF/AW properties were studied in fully formulated engine oils. Based on the results it was found that by using suitable additive concentrations the conventional dispersant can be advantageously combined or replaced with these new additives to enhance the properties of the experimental engine oils.

4

Wpływ wybranych parametrów procesu termicznej obróbki węgla kamiennego na skuteczność usuwania rtęci

75%

Dziok T. , Strugała A. , Rozwadowski A. , Okońska A.

Przemysł Chemiczny

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2014

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tom T. 93, nr 12

2034-2037

PL

Dwa niewzbogacone węgle kamienne poddano obróbce termicznej, analizując wpływ końcowej temperatury procesu, szybkości ogrzewania, czasu wytrzymywania w końcowej temperaturze, uziarnienia węgla oraz rodzaju i natężenia przepływu gazu nośnego na zawartość rtęci w produkcie końcowym. Największy wpływ na skuteczność usunięcia rtęci miała końcowa temperatura procesu, szybkość ogrzewania oraz rodzaj i natężenie przepływu gazu nośnego.

EN

Two Polish bituminous coals were thermally pretreated in stationary bed at 110-330°C in N2, air, C02 or H2 streams to study the Hg removal efficiency. The efficiency was the highest for H2 (quite 80%) and increased with increasing the final temp, of the process and decreasing heating rate.

5

Effect of Thermal Pretreatment on the Kinetic Parameters of Anaerobic Digestion from Recycled Pulp and Paper Sludge

63%

Habchi S. , Lahboubi N. , Karouach F. , Naim I. , Lahlou Y. , Bakraoui M. , Sallek B. , El Bari H.

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tom Vol. 23, iss. 1

192--201

EN

This paper investigates the influence of thermal pretreatment on kinetic parameters based on four kinetic models: Modified Gompertz, transference and logistic functions and first order equation. The kinetic modeling was applied on experimental results of previous study on producing methane from anaerobic digestion of Recycled Pulp and Paper Sludge (RPPS) under mesophilic conditions. We observed that the thermal pretreatment improve considerably improved the kinetic parameters mainly the methane production rate and the lag phase. Indeed, it can be noted that methane production rate μ increases significantly from a value of 4.72 to 16.27 ml/h using logistic function for 1 g VS/L added load. Then the lag phase parameter λ has dramatically decreased from 5.46 to 1.04 h using logistic function for 1.5 g VS/L added load. This means that the thermal pretreatment of RPPS accelerates the methane production process and saves time.

6

A concept of the hybrid mercury removal process from hard coal

51%

Dziok T. , Strugała A. , Chmielniak T. , Baic I. , Blaschke W. , Dziok T. , Strugała A. , Chmielniak T. , Baic I. , Blaschke W.

Zeszyty Naukowe Instytutu Gospodarki Surowcami Mineralnymi Polskiej Akademii Nauk

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2017

7

Koncepcja hybrydowego procesu usuwania rtęci z węgla kamiennego

51%

Dziok T. , Strugała A. , Chmielniak T. , Baic I. , Blaschke W.

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tom nr 98

125--135

PL

W powadzonych aktualnie pracach mających na celu obniżenie antropogenicznej emisji rtęci duży nacisk kładzie się na obniżenie emisji rtęci z procesów energochemicznego przetwórstwa węgla, głównie z procesów spalania. Jednym ze sposobów pozwalających na obniżenie antropogenicznej emisji rtęci jest jej usuwanie z węgla przed jego konwersją. Należy zaznaczyć, że rtęć w węglu kamiennym może być obecna zarówno w substancji organicznej jak i mineralnej, stąd też uniwersalna metoda powinna pozwalać na usuwanie rtęci z obu tych składowych substancji węglowej. W pracy przedstawiono koncepcję hybrydowego procesu usuwania rtęci z węgla kamiennego. Idea procesu polega na połączeniu procesów wzbogacania metodami mokrymi bądź suchymi (etap pierwszy) oraz wstępnej termicznej preparacji w temperaturze 200–400°C (etap drugi). W etapie pierwszym w procesie wzbogacania/ /odkamieniania z węgla usuwana jest część rtęci występującej w substancji mineralnej. Natomiast w etapie drugim z węgla usuwana jest rtęć występująca w substancji organicznej oraz rtęć w obecnych jeszcze w węglu składnikach mineralnych o relatywnie niskiej temperaturze uwalniania rtęci. Na podstawie wyników wstępnych badań, skuteczność obniżenia zawartości rtęci w węglu w takim procesie hybrydowym została oszacowana w przedziale od 36 do 75% (ze średnią wartością 58%). Efekt obniżenia zawartości rtęci w węglu jest jeszcze bardziej zauważalny w przypadku odniesienia jej zawartości do wartości opałowej węgla. Tak określona skuteczność obniżenia zawartości rtęci w węglu mieściła się w przedziale od 53 do 92% (przy średniej wartości wynoszącej 71%).

EN

Nowadays, actions allowing for a reduction of anthropogenic mercury emission are taken worldwide. Great emphasis is placed on reducing mercury emission from the processes of energochemical coal conversion, mainly from the coal combustion processes. One of the methods which enable a reduction of anthropogenic mercury emission is the removal of mercury from coal before its conversion. It should be pointed out that mercury in hard coal may occur both in the organic and mineral matter. Therefore, a universal method should allow for the removal of mercury, combined in both ways, from coal. In the paper, a concept of the hybrid mercury removal process from hard coal was presented. The idea of the process is based on the combination of the coal cleaning process using wet or dry methods (first stage) and the thermal pretreatment process at a temperature in the range from 200 to 400°C (second stage). In the first stage, a part of mercury occurring in the mineral matter is removed. In the second stage, a part of mercury occurring in the organic matter as well as in some inorganic constituents characterized by a relatively low temperature of mercury release is removed. Based on the results of the preliminary research, the effectiveness of the decrease in mercury content in coal in the hybrid process was estimated in the range from 36 to 75% with the average at the level of 58%. The effect of the decrease in mercury content in coal is much more significant when mercury content is referred to a low heating value of coal. So determined, the effectiveness was estimated in the range from 36 to 75% with the average at the level of 58%.