Characterisation of the pyrolysis oil derived from bael shell (aegle marmelos)

Monoj Bardalai,Dimbendra Kumar Mahanta 대한환경공학회 2016 Environmental Engineering Research Vol.21 No.2

In the present work, bael shell (aegle marmelos) is used as the feedstock for pyrolysis, using a fixed bed reactor to investigate the characteristics of the pyrolysis oil. The product yields, e.g., liquid, char and gases are produced from the biomass at different temperatures with the particle size of 0.5-1.0 mm, at the heating rate of 150°C/min. The maximum liquid yield, i.e., 36.23 wt.%, was found at 5500°C. Some physical properties of the pyrolysis oil such as calorific value, viscosity, density, pH, flash point and fire point are evaluated. The calorific value of the bael shell pyrolysis oil was 20.4 MJ/kg, which is slightly higher than the biomass, i.e., 18.24 MJ/kg. The H/C and O/C ratios of the bio-oil were found as 2.3 and 0.56 respectively, which are quite higher than some other bio-oils. Gas Chromatography and Mass Spectroscopy (GC-MS) and Fourier Transform Infra-red (FTIR) analyses showed that the pyrolysis oil of bael shell is mostly composed by phenolic and acidic compounds. The results of the properties of the bael shell pyrolysis oil reveal the potential of the oil as an alternate fuel with the essential upgradation of some properties.

Characterization, isotherm and kinetic study of Phaseolus vulgaris husk as an innovative adsorbent for Cr(VI) removal

Monoj Kumar Mondal,Shalini Srivastava,Shashi Bhushan Agrawal 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.2

Phaseolus vulgaris husk as a novel, very common milling agro waste, showed good performance for mutagenic Cr(VI) removal from chromium enriched aqueous solution. The study involves batch experiments to investigate the effects of influencing parameters, such as pH, temperature, contact time, initial Cr(VI) concentration, and adsorbent dose, on the adsorption process. Results showed a maximum of 99.88% removal of Cr(VI) at pH 1.16, temperature 20 oC and adsorbent dose of 6 g L−1. The adsorption equilibrium data followed the Freundlich model, suggesting a heterogeneous nature of the adsorbent surface and the correlation coefficient for pseudo-second-order kinetic model was found to be very high, showing its applicability during the adsorption process. The maximum Cr(VI) uptake capacity was 3.4317mg g−1. Thermodynamic parameters like standard free energy change (−7.175 kJ mol−1), enthalpy change (−8.29 kJ mol−1) and entropy change (0.005 kJ mol−1 K−1) revealed the spontaneous and exothermic nature of adsorption of Cr(VI) onto P. vulgaris husk. Desorption with 1mol L−1 NaOH followed by 1mol L−1 HCl was effective (92.76%) and, hence, it exhibited the possibility of recycling of used husk.

Removal of Orange G from aqueous solution by hematite: Isotherm and mass transfer studies

Monoj Kumar Mondal,Sudama Singh,Meka Umareddy,Betty Dasgupta 한국화학공학회 2010 Korean Journal of Chemical Engineering Vol.27 No.6

The efficiency of hematite for the removal of Orange G from aqueous solution has been studied at various concentrations as a function of time, temperatures and pH. It was found that the low initial concentration, low temperature and low pH favor the removal process. The maximum adsorption of the dye on hematite has been recorded at 25 mg/l concentration, 303 K temperature and pH 3. The negative values of change in free energy and enthalpy indicate the spontaneous and exothermic nature of the process, respectively. Fixation and immobilization of the dye molecules at the surface of hematite as a result of adsorption are responsible for the negative entropy effect. The effect of pH was described by considering coulombic attraction and aqua complex formation approaches. The applicability of various adsorption isotherms--Langmuir, Freundlich and Jossens--was tested in order to find the most suitable isotherm. The Freundlich isotherm was fitted with the data of the present study.

Removal of acid red-94 from aqueous solution using sugar cane dust: An agro-industry waste

Monoj Kumar Mondal,Ravi Shankar Singh,Anand Kumar,Brij Mohan Prasad 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.6

The feasibility for the removal of Acid Red-94 by sugar cane dust, an agro-industry waste, has been investigated as an alternative for costly adsorbents. The effect of various experimental parameters (adsorbate concentration, solution pH and temperature) on removal of Acid Red-94 has been studied under batch mode of operation. Maximum removal upto 98.73% was achieved at a pH value of 2.0 and temperature 19±0.5 ℃ in case of 10.0mg/l initial dye concentration. Adsorption kinetics has been described by Lagergren equation and adsorption isotherms by classical Langmuir and Freundlich models. The kinetic studies suggest that the rate of uptake of Acid Red-94 on sugar cane dust was mainly diffusion controlled. Various thermodynamic parameters have been calculated and the temperature dependence indicates exothermic nature of adsorption process. The results indicate that sugar cane dust could be used as an eco-friendly and cost-effective adsorbent in the removal of Acid Red-94 from aqueous solution.

Removal of Pb(II) from aqueous solution by adsorption using activated tea waste

Monoj Kumar Mondal 한국화학공학회 2010 Korean Journal of Chemical Engineering Vol.27 No.1

A basic investigation on the removal of Pb(II) ions from aqueous solutions by using activated tea waste was conducted in batch conditions. An inexpensive and effective adsorbent was developed from waste tea leaves for the uptake of Pb(II) from aqueous solution. The influence of different experimental parameters--shaking time, particle size, adsorbent dose, initial pH, temperature, etc.--on lead uptake was evaluated. Lead is adsorbed by the developed adsorbent up to maximum of 99.7%. The initial Pb(II) concentrations were 5, 10, 15 and 20 mg/l in the experiment. The adsorption was found to be exothermic in nature. The Langmuir, Freundlich and Tempkin isotherm models were tried to represent the equilibrium data of Pb(II) adsorption. The adsorption data was fitted very well to the Langmuir isotherm model in the studied concentration range of Pb(II) adsorption. Isotherms have been used to determine thermodynamic parameters of the process: free energy change (ΔGº), enthalpy change (ΔHº) and entropy change (ΔSº). Column experiments were performed to study the practical applicability of the system. The kinetics and the factors controlling the adsorption process were also discussed. Activated tea waste is a better adsorbent compared to other adsorbents available in literature.

Selection of efficient absorbent for CO2 capture from gases containing low CO2

Shailesh Kumar,Monoj Kumar Mondal 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.2

Amine-based absorption processes are widely used in natural gas processing, but recently they have been considered for CO2 capture from flue gas emitted from thermal power plants. The main issue of amine used in the CO2 capture process is the high cost of solvent regeneration. So, this issue can be solved by using efficient amine absorbent. The amine type absorbents employed in the experimentation were an aqueous blend of 2-(Diethylamino)ethanol (DEEA) with different types of diamine activators such as piperazine (PZ), 2-(2-aminoethylamino)ethanol (AEEA), hexamethylenediamine (HMDA), ethylenediamine (EDA), and 3-(Dimethylamino)-1-propylamine (DMAPA). An absorption experiment was performed to evaluate the CO2 absorption performance in terms of CO2 loading, absorption capacity, and absorption rate. The experiment was performed to assess the CO2 desorption performance in terms of desorption capacity, desorption rate, cyclic capacity, and regeneration efficiency. From the results of absorptiondesorption and comparison with benchmark amine absorbent MEA, the aqueous blend of DEEA and HMDA indicated the best performance for CO2 capture applications among all the tested amine blends.

Equilibrium solubility of CO2 in aqueous binary mixture of 2-(diethylamine)ethanol and 1, 6-hexamethyldiamine

Shailesh Kumar,Monoj Kumar Mondal 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.6

CO2 solubility data are important for the efficient design and operation of the acid gas CO2 capture process using aqueous amine mixture. 2-(Diethylamino)ethanol (DEEA) solvent can be manufactured from renewable sources like agricultural products/residue, and 1,6-hexamethyldiamine (HMDA) solvents have higher absorption capacity as well as reaction rate with CO2 than conventional amine‐based solvents. The equilibrium solubility of CO2 into aqueous binary mixture of DEEA and HMDA was investigated in the temperature range of 303.13-333.13 K and inlet CO2 partial pressure in the range of 10.133-20.265 kPa. Total concentration of aqueous amine mixtures in the range of 1.0-3.0 kmol/m3 and mole fraction of HMDA in total amine mixture in the range of 0.05-0.20 were taken in this work. CO2 absorption experiment was performed using semi-batch operated laboratory scale bubble column to measure equilibrium solubility of CO2 in amine mixture, and CO2 absorbed amount in saturated carbonated amine mixture was analyzed by precipitation-titration method using BaCl2. Maximum equilibrium CO2 solubility in aqueous amine mixture was observed at 0.2 of HMDA mole fraction in total amine mixture with 1.0 kmol/m3 total amine concentration. New solubility data of CO2 in DEEA+HMDA aqueous mixtures in the current study was compared with solubility data available in previous studies conducted by various researchers. The study shows that the new absorbent as a mixture of DEEA+HMDA is feasible for CO2 removal from coal-fired power plant stack gas streams.

Kinetics, thermodynamic and equilibrium study of Cr(VI) adsorption from aqueous solutions by NCL coal dust

Ravi Shankar Singh,Monoj Kumar Mondal 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.12

The waste material NCL coal dust was used as adsorbent for removal of Cr(VI) from aqueous solutions under batch adsorption experiments. The maximum removal of 99.97% was recorded at pH 2. The time required to attain equilibrium was found to be 60 min. Adsorption kinetics was described by the Lagergren equation. The value of the rate constant of adsorption was found to be 0.0615 min−1 at 16 mg dm−3 initial concentration and 298 K. The applicability of the Langmuir and Freundlich equations for the present system was also tested at different temperatures:298, 313, and 328 K. Both thermodynamic parameters and temperature dependence indicated the endothermic nature of Cr(VI) adsorption on coal dust. The results showed that NCL coal dust is a promising adsorbent for the removal of Cr(VI) from aqueous solutions.

Hazardous As(III) removal using nanoporous activated carbon of waste garlic stem as adsorbent: Kinetic and mass transfer mechanisms

Anuj Kumar Prajapati,Monoj Kumar Mondal 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.11

Nanoporous activated garlic stem carbon (AGSC) was prepared from garlic stem waste and used to remove As(III)from synthetic water under complete batch experiments. Characterization studies of AGSC were performed by FTIR, SEM, EDX, BET, XPS and XRD techniques. Batch adsorption experiments were carried out to study the adsorption of As(III) onto AGSC. Maximum removal of 93.3% of As(III) was obtained at optimum condition of pH 6, the adsorbent dose 5 g/L, equilibrium time 150 min, initial As(III) concentration 400 μg/L and temperature 298 K. Both Langmuir and Temkin isotherm model fitted well to the experimental data as compared to Freundlich isotherm. Kinetics indicated that the adsorption of As(III) was more suitable for pseudo-second-order than pseudo-first-order and Elovich model. The mass transfer mechanism could be described by Weber-Morris and Boyd mass transfer model. The maximum adsorption capacity of AGSC for As(III) removal was found to be 192.30 μg/g. The negative enthalpy and free energy change indicated that the adsorption process of As(III) onto AGSC was exothermic and spontaneous. The negative value of entropy change suggested decreasing randomness at the AGSC-aqueous As(III) interface during As(III) adsorption.

Seasonal characterization and present status of municipal solid waste (MSW) management in Varanasi, India

Dasgupta, Betty,Yadav, Vijay Laxmi,Mondal, Monoj Kumar Techno-Press 2013 Advances in environmental research Vol.2 No.1

The paper aims to characterise the waste generated in municipality of Varanasi, the most populated city in the state of Uttar Pradesh, India. MSW is a heterogeneous waste and composition of the waste varied from season to season. The generation, collection and management of waste have become a major environmental problem in most of the developing cities. MSW was collected from open dumping grounds for 2 consecutive years. Each year was classified into 3 seasons of 4 months. On analysis it was found that the biodegradable fraction is always more than other fractions with a minimum of 48.25% in rainy season. With such a high fraction of biodegradable wastes, options such as composting and biomethanation could be tried to convert waste into energy. The average weight of waste generation at present is 0.460 kg per capita per day. The study showed that waste generation and collection were increasing every year, which may be attributed to increase in population.