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Yard waste is either dumped or is being openly burned to get rid of it, instead of using it as a valuable renewable energy source. In this study, hydrothermal carbonization of yard waste was conducted to valorize it as a solid bio fuel, using a batch reactor. The effect of process parameter on yield, energy and physicochemical properties of the valorized solid bio fuel (hydrochar) was examined in this study by varying reaction temperature (160-200 °C for 2 h) and reaction time (2-24 h at 200 °C). The calorific value of hydrochar was within a range of 17.72-24.59 MJ/kg as compared to 15.37 MJ/kg for untreated yard waste. Hydrochar mass yield decreased from 78.6% at operating temperature - time of 160 °C -2 h to 45.6% at 200 °C -24 h. The plot of atomic ratios (H/C and O/C) demonstrates improvement in the coalification process which was mainly governed by decarboxylation and dehydration reactions. The grindability of the prepared hydrochar was comparable to that of coal. Hydrochar produced at lower reaction condition (160-200 °C at 2 h) have better flowability as compared to that produced at higher reaction condition (4-24 h at 200 °C). The reaction time longer than 12 h has a minimal effect on the yield, energy and physicochemical properties of hydrochar. Increasing reaction time and temperature improved the ignition and burnt temperature of hydrochar. All reaction condition has an energy ratio (energy output to energy input) of more than one making HTC process a net energy producer.

Abstract In many visions and roadmaps, there is a broad agreement that fuel cells – both for stationary and mobile applications – are the key technology to allow the development of a hydrogen infrastructure. Furthermore, this development is generally thought to be based on a gradual, decentralised evolution. Nevertheless, in this paper it is argued that, taking into account the entire hydrogen chain (production, transport, storage, distribution and end-use), this decentralised fuel-cell based philosophy shows some serious flaws. Therefore, a new hydrogen-transition approach was pushed forward: mixing in of hydrogen into the natural-gas bulk. Using Flanders – the Northern part of Belgium – as a case study, the development of a transitory hydrogen infrastructure has been studied, taking into account the entire hydrogen chain and its dynamics, from production to end use. In a next step, this transition is being quantified. An optimisation model has been developed using Matlab and the commercial solvers GAMS and CPLEX. Following a mixed-integer linear-programming approach, this model is able to determine the economically optimal hydrogen-production mix and operational behaviour of each hydrogen-production plant separately. The model then allows gaining valuable insights in the importance of storage and the influence of fuel prices and carbon taxes with regard to the development of an early hydrogen economy.

Abstract In this communication, a mathematical model is presented to predict the thermal performance of a spherical solar still. The analysis is based on the heat and mass transfer relationships by Dunkle (1961) which have been modified empirically so as to validate the experimental results of Menguy et al. (1980). Numerical calculations have also been made to study the effect of the absorptivity of the basin liner on the distillate yield of the still

The present work aimed at the standardization of transesterification process parameters for the production of methyl ester of filtered neem oil and fuel characterization for engine performance. The effect of process parameters such as molar ratio, preheating temperature, catalyst concentration and reaction time was studied to standardize the transesterification process for estimating the highest recovery of ester with lowest possible viscosity. Based on the observations of the ester recovery and kinematic viscosity, it was found that filtered neem oil at 6:1 M ratio (methanol to oil) preheated at 55 °C temperature and maintaining 60 °C reaction temperature for 60 min in the presence of 2 percent KOH and then allowed to settle for 24 h in order to get lowest kinematic viscosity (2.7 cSt) with ester recovery (83.36%). Different fuel properties of the neem methyl ester and neem oil were also measured. Results show that the methyl ester of neem obtained under the optimum condition is an excellent substitute for fossil fuels.

Abstract Brown and Ladner's parameters have been compared with those of Williams for the same conditions. The combination of experimental data from 1H n.m.r. and 13C n.m.r. spectra gives the value of the Brown and Ladner's parameter H aru C ar . A comparison of the H aru C ar values was performed on a group of different coal oil samples.

Solid concentration is considered as one of the most important parameters governing the anaerobic digestion process. In this present study, four solid concentration levels (10%, 15%, 20% and 25% of...

This paper presents the performance analysis of different types of energy-efficient lamps used in indoor lighting applications. The objectives of this paper is to investigate and compare the electrical power quality and different photometrical parameters of few energy efficient lamps widely used in indoor applications now-a-days i.e. Fluorescent Tube Lights (FTLs), Compact Fluorescent Lamps (CFLs) and white Light Emitting Diodes (LEDs). These energy efficient lamps produce high total harmonic distortion but operate at high power factor. Few samples of commercial energy saving lamps are tested with different combinations of control gears and their performances are compared. The electrical and photometrical parameters are presented to verify the effectiveness of the lamp-ballast combinations. The result shows that although these lamps provide higher luminous efficacy, higher illumination but also high level of THD. The result also shows that the performance of these lamps do not change significantly with the change of normal commercial available control gears.