02556nas a2200289   4500008004100000022001400041245007500055210006900130300001600199490000800215520170000223653002101923653001701944653001701961653001301978653000901991653002002000653002302020653002402043100002602067700002002093700002202113700002102135700002002156700001902176856007102195       2019                        eng d  a1876-610200aMethane hydrate dissociation in the presence of novel benign additives0 aMethane hydrate dissociation in the presence of novel benign add  a5856 - 58650 v1583 a<p>The apparent drawbacks of the classical approaches towards dissociation of natural gas hydrates have resulted in a paradigm shift into the development of new hybrid hydrate dissociation practices combining the various basic hydrate dissociation techniques. Another approach that can be followed to maximize the efficiency of gas production from natural gas hydrate reserves is the identification of benign additives which when used even in sparingly small concentrations may enhance the kinetics of hydrate dissociation. In the present work, a class of such additives, never reported before, have been unveiled and christened as Low Dosage Hydrate Dissociation Promoters (LHDPs). The additives were first short listed from a wide potential pool using a lab scale ( 250 ml) stirred tank reactor setup and then further studied using a bench scale ( 2.35 l) reactor setup where they were injected in the form of a water-additive stream to dissociate hydrates. The dissociation approach followed in the case of the bench scale reactor experiments was a combination of the thermal stimulation and depressurization processes along with the element of injection of additives. For both sets of experiments (lab and bench scale), the newly identified LHDPs were found to enhance the kinetics of methane hydrate dissociation as compared to pure water. It was observed that concentration of additive and its flow rate also affect the kinetics of methane hydrate dissociation. An energy and efficiency analysis for the hydrate dissociation method in the case of bench scale rector revealed that additive presence enhanced the energy ratio and thermal efficiency four fold as compared to pure water.</p>
10aDepressurization10aDissociation10aEnergy Ratio10akinetics10aLHDP10amethane hydrate10aThermal Efficiency10athermal stimulation1 aBhattacharjee, Gaurav1 aBarmecha, Vivek1 aChoudhary, Nilesh1 aPande, Nawal, K.1 aChugh, Parivesh1 aKumar, Rajnish  uhttp://www.sciencedirect.com/science/article/pii/S187661021930564802319nas a2200241   4500008004100000022001400041245013600055210006900191260000800260300001600268490000700284520145400291653002701745653001801772653003201790653001701822653002301839100003001862700002601892700001701918700001901935856012301954       2020                        eng d  a0363-907X00aThermodynamic analysis and experimental validation of multi-composition ammonia liquor absorption engine cycle for power generation0 aThermodynamic analysis and experimental validation of multicompo  cDEC  a12430-124430 v443 a<p>Energy conservation, utilization, and effective integration are of utmost importance for future sustenance. Accordingly, this work focuses on the generation of power from the low-grade temperature below 150 degrees C. A proposed novel multi-composition ammonia liquor absorption engine (MALAE) power cycle can be used toward the above purpose by supplying renewable energy obtained from low concentration type solar collectors. Proposed MALAE power cycle minimizes heal loss due to heat recovery and uses high purity NH3 vapors to expand through the isentropic turbine. MALAE power system is modeled and simulated using NH3-H2O as a working fluid for a reboiler temperature of 115 degrees C. The purpose of this work is to simulate the proposed MALAE power cycle with the distillation column and two solution heat exchanger (SHE). MALAE modeling and simulation is accomplished in SCILAB software. The simulation outcome is validated with the pilot-scale 5 kW experimental setup and validation showed +/- 5% deviation. A comparison of MALAE cycle with published cycles signifies higher efficiency of MALAE cycle toward the utilization of low-grade energy from a temperature range of 100 degrees C to 150 degrees C. Finally, detailed parametric analysis of MALAE cycle efficiency is presented in terms of number of plates, distillation pressure and vapor flowrate, absorber temperature, pressure partial condenser temperature, and heat loads.</p>
10aabsorption power cycle10aammonia water10alow-temperature heat source10asolar energy10aThermal Efficiency1 aSatpute, Satchidanand, R.1 aTakalkar, Gorakshnath1 aMali, Nilesh1 aBhagwat, Sunil  uhttps://library.ncl.res.in/content/thermodynamic-analysis-and-experimental-validation-multi-composition-ammonia-liquor