02183nas a2200241 4500008004100000022001400041245011100055210006900166260000800235300001000243490000800253520135800261653001901619653001801638653002501656653002201681653001301703100002601716700002101742700002301763700002901786856012601815 2024 eng d a0263-876200aExperimental and kinetic modelling studies for the design of fixed bed methanol reactor over CuZA catalyst0 aExperimental and kinetic modelling studies for the design of fix cMAY a79-900 v2053 a

Direct conversion of CO 2 via hydrogenation to value-added chemicals is a vital approach for utilising CO 2 emitted into the atmosphere. In this paper, a critical analysis of reaction kinetic modelling studies is explored in a fixed bed reactor to improve methanol yield for different H 2 to CO 2 ratios by simulating a lab-scale reactor for adiabatic and isothermal conditions. The feed inlet temperature and pressure variations are applied to study the effect of both configurations on methanol production. The results show that the isothermal configuration yields 2.76% more methanol yield compared to the adiabatic reactor. The effect of H 2 to CO 2 molar ratios of 3, 6 and 9 on the performance of the catalyst and the influence of CO and CO 2 hydrogenation is investigated with model simulations. The overall methanol yield is increased from 19.03% to 36.41% with increase in H 2 to CO 2 molar ratio from 3 to 9. Experiments are performed using commercial copper-based catalyst for different temperatures of 210, 230 and 250 degrees C at a pressure of 40 bar for H 2 /CO 2 of 3 and GHSV of 720 h -1 as well as at optimal temperature of 250 degrees C and 50 bar with varying H 2 /CO 2 of 3, 6, 9 for 3 g and 6 g catalyst. The maximum methanol yield of 2.53% and space time yield of 13.59 mg/g cat .h is obtained at H 2 /CO 2 ratio of 9.

10aCO2 conversion10aCuZA catalyst10aH2 toCO2 molar ratio10aKinetic modelling10aMethanol1 aBagwan, Farahanaz, M.1 aDongapure, Pavan1 aKulkarni, Amol, A.1 aVasireddy, Satyam, Naidu uhttps://library.ncl.res.in/content/experimental-and-kinetic-modelling-studies-design-fixed-bed-methanol-reactor-over-cuza02189nas a2200217 4500008004100000022001400041245013100055210006900186260000800255520140300263653001001666653001501676653002401691653001801715653002701733653001201760653002701772100002901799700002301828856012001851 2024 eng d a1618-954X00aPower generation with negative CO2 emissions through bio-electricity with CCS using dry co-gasification of coal-biomass blends0 aPower generation with negative CO2 emissions through bioelectric cSEP3 a

Among the measures proposed for decarbonization of electricity generation, large reductions in CO2 emissions are possible by the adoption of bio-electricity with carbon dioxide capture and sequestration. In the present study, thermodynamic analysis of a thermal power plant that produces electricity through co-gasification of high-ash coal and Casuarina equisetifola (CE), a crop which grows along the Indian coastline, and which is not in competition with other agricultural crops for land and water use, is considered for integrated gasification combined cycle (IGCC) with CO2 capture via oxyfuel combustion and gasification technology. The integrated power plant layout includes the energy required for CO2 gasification of coal, biomass blended fuel, air separation to produce oxygen for oxyfuel combustion as well as for purification and compression of the flue gas up to 30 bar. Simulation results show that a net efficiency of 37% can be achieved using high-ash Indian coal and CE blends up to 30% of the latter. Synergetic effect of co-gasification components is observed in mass, molar and thermal energy flowrates for biomass blended fuel. With the help of CCS, CO2 emissions are reduced to 69.91 gCO(2)/kWh for 100% coal-based IGCC-CC plant and further to -21.69 gCO(2)/kWh (negative CO2 emissions) for 30% biomass blending, thus paving way for CO2-negative power generation.

10aBECCS10aCombustion10aDry co-gasification10aIGCC-CC plant10aNegative CO2 emissions10aOxyfuel10aThermodynamic analysis1 aVasireddy, Satyam, Naidu1 aJayanti, Sreenivas uhttps://library.ncl.res.in/content/power-generation-negative-co2-emissions-through-bio-electricity-ccs-using-dry-co02098nas a2200241 4500008004100000022001400041245012000055210006900175260000800244300001200252490000700264520120300271653002901474653002001503653004301523653004701566653003301613653000901646100002601655700002101681700002901702856012501731 2024 eng d a0360-319900aReaction kinetics for catalytic hydrogenation of quinoline to decahydroquinoline as liquid organic hydrogen carrier0 aReaction kinetics for catalytic hydrogenation of quinoline to de cNOV a102-1120 v923 a

The catalytic hydrogenation of quinoline to decahydroquinoline (DHQ) formation is studied for various parameters such as temperature, hydrogen pressure, reaction time, solvents, reactant-to-solvent ratio, and catalyst loading over 5%Pd loaded on alumina (Pd/Al2O3) to obtain optimal reaction conditions. The hydrogen uptake of quinoline in the liquid phase reaction using isopropylalcohol (IPA) is studied in an autoclave reactor. The optimum reaction parameters of 50 bar H2 pressure and 175oC with reactant to solvent ratio of 1:9 for reaction time of 5 h are observed. The effect of IPA solvent showed that hydrogen uptake of 6.91 wt% with complete hydrogenation of quinoline and DHQ yield of more than 99% is observed. The reaction kinetic model is developed for a simplified reaction mechanism and is simulated using the Markov Chain Monte Carlo (MCMC) simulation tool to predict the rate constants and the experimental observations are validated with the model predictions. The activation energy for quinoline hydrogenation to py-THQ formation is estimated to be 136.57 kJ/mol. It is envisaged that quinoline hydrogenation to pz-THQ is the rate-limiting step in the DHQ formation.

10aDecahydroquinoline (DHQ)10aHydrogen uptake10aLiquid organic hydrogen carrier (LOHC)10aMarkov chain Monte Carlo (MCMC) simulation10aThermal screening unit (TSU)10atool1 aBagwan, Farahanaz, M.1 aKinage, Anil, K.1 aVasireddy, Satyam, Naidu uhttps://library.ncl.res.in/content/reaction-kinetics-catalytic-hydrogenation-quinoline-decahydroquinoline-liquid-organic02758nas a2200145 4500008004100000245015200041210006900193260000800262490000700270520213700277100002102414700002102435700002902456856012702485 2025 eng d00aEvaluation of reaction kinetics for chemoselective hydrogenation of citral for intensification of citral intermediates using copper-based catalysts0 aEvaluation of reaction kinetics for chemoselective hydrogenation cMAR0 v673 a

Citral intermediates’ formation kinetics is studied using non-noble metal catalyst (Cu/SiO2) to evaluate catalyst performance characteristics via chemoselective hydrogenation of citral. The catalyst is synthesised by the precipitation method and characterised using XRD, FESEM and BET surface area analyser. Hydrogenation experiments are carried out using an Autoclave reactor in the temperature range of 80–120°C, pressure range of 10–50 bar and for catalyst loadings of 0.5, 1 and 1.5 g. The intermediates product distribution comprises aldehyde and alcohol formation such as citronellal, nerol and citronellol formation. The performance of the Cu/SiO2 catalyst is evaluated using the parameters such as citral conversion, citronellol selectivity and yield as 96.96%, 95.30% and 92.30%, respectively under optimal conditions of 50 bar, 120°C and 1 g catalyst for the reaction time of 100 min. The absence of internal and external mass transfer limitations is verified using the Carberry number and Weisz-Prater modulus criterion. The intrinsic kinetics of the gas–liquid phase hydrogenation of citral is determined using the Langmuir–Hinshelwood-Hougen-Watson (LHHW) model for citral intermediates formation. The reaction kinetic parameters show that citronellol formation favours by the nerol route compared to citronellal conversion.

1 aDebtirtha, Banik1 aKinage, Anil, K.1 aVasireddy, Satyam, Naidu uhttps://library.ncl.res.in/content/evaluation-reaction-kinetics-chemoselective-hydrogenation-citral-intensification-citral02620nas a2200253 4500008004100000022001400041245009600055210006900151260000800220300001100228490000800239520172800247653002801975653002202003653001902025653002202044653003302066653004802099100002202147700002202169700002202191700002902213856012402242 2025 eng d a0019-452200aExperimental investigation and lumped kinetic modeling studies for upcycling of polyolefins0 aExperimental investigation and lumped kinetic modeling studies f cNOV a1021270 v1023 a

The present work discusses on comparative kinetic analysis of the pyrolysis of polypropylene (PP), high-density polyethylene (HDPE), and low-density polyethylene (LDPE) using sophisticated lumped models. Unlike many previous studies that focused on single-polymer kinetic models or employed simplified reaction schemes, this study develops an enhanced multistep reaction network that explicitly considers both primary decomposition and secondary cracking pathways, thereby improving the accuracy of product distribution predictions. By integrating this detailed reaction framework with a robust nonlinear regression approach using LSQNONLIN and ODE45 solvers in MATLAB, the study achieved greater accuracy in estimating kinetic parameters than traditional curve-fitting methods. The findings reveal that HDPE exhibits the highest activation energy (222.97 kJ mol(-1)), indicating it is more thermally stable than LDPE (193.44 kJ mol(-1)) and PP (62.16 kJ mol(-1)). One of the highlights of the present work is that lower pyrolysis temperature (400 degrees C) is found to be optimum for liquid yield by reducing secondary cracking, which aligns with the sustainable fuel production principles. The study also emphasizes on the limitations of previous lumped models that overlooked wax decomposition pathways, which are crucial for optimizing the hydrocarbon distribution. Future research should investigate catalytic interventions and reactor design modifications to enhance the product selectivity and scalability. This study offers a more comprehensive kinetic framework for advancing the valorization of plastic waste through pyrolysis, aiding the development of efficient waste-to-fuel conversion strategies.

10aLumped kinetic modeling10aPlastic pyrolysis10aRate constants10aReaction pathways10aSecondary cracking reactions10aTemperature-dependent product distributions1 aKavade, Omkar, G.1 aDhepe, Paresh, L.1 aDevi, Nandini, R.1 aVasireddy, Satyam, Naidu uhttps://library.ncl.res.in/content/experimental-investigation-and-lumped-kinetic-modeling-studies-upcycling-polyolefins01883nas a2200253 4500008004100000022001400041245010100055210006900156260000800225300001100233490000700244520100500251653002901256653003001285653002001315653002301335653002201358653002701380100002601407700002401433700002101457700002901478856012201507 2026 eng d a0930-751600aReaction kinetics for dehydrogenation of decahydroquinoline to quinoline for hydrogen generation0 aReaction kinetics for dehydrogenation of decahydroquinoline to q cFEB ae701770 v493 a

Catalytic dehydrogenation of decahydroquinoline (DHQ) to quinoline is a promising pathway for hydrogen release in liquid organic hydrogen carrier systems. In this work, solvent-free DHQ dehydrogenation over Pd/Al2O3 is systematically investigated to evaluate hydrogen release performance and reaction kinetics. High DHQ conversion (83.9%) and degree of dehydrogenation (82.7%) are achieved at optimal reaction conditions. A power-law kinetic model based on a simplified reaction mechanism is developed and simulated using a Markov Chain Monte Carlo (MCMC) approach for estimation of rate constants and validation of concentration profiles with experimental data. The apparent activation energies are determined to be 45.85 kJ/mol for DHQ to 5,6,7,8-tetrahydroquinoline (bz-THQ) and 185.43 kJ/mol for bz-THQ to quinoline formation, identifying latter as the rate-limiting step. This framework provides mechanistic insight and supports the potential of DHQ as an efficient hydrogen carrier.

10aDecahydroquinoline (DHQ)10adegree of dehydrogenation10aDehydrogenation10arate-limiting step10aReaction kinetics10aWeisz-Prater criterion1 aBagwan, Farahanaz, M.1 aDadkar, Sarthak, S.1 aKinage, Anil, K.1 aVasireddy, Satyam, Naidu uhttps://library.ncl.res.in/content/reaction-kinetics-dehydrogenation-decahydroquinoline-quinoline-hydrogen-generation