A state of the art of required techniques for employing activated carbon in renewable energy powered adsorption applications

This paper reviews, for the first time, the measurement adsorption characteristics techniques to facilitate optimal testing of the validity of adsorbent materials in adsorption applications. Thermo-physical properties, adsorption characteristics and modelling techniques are presented. The characterisation of material thermo-physical properties includes true and bulk densities, specific heat capacity, surface area, pore volume distribution and thermal conductivity. The adsorption characteristics were categorized into adsorption isotherms and kinetics including experimental and theoretical equations. A range of models used in the simulation of adsorption cooling systems is presented and discussed. The paper highlights the conditions for which each measurement technique is most suitable and the limitations of modelling techniques, which is a vital element in the robust assessment of the performance of adsorption cooling units

Adsorption Cooling System Employing Activated Carbon/R32 Adsorption Pair

This paper reports the performance of an adsorption cooling system employing activated carbon powder (Maxsorb III)/R32 adsorption pair. The system has been modeled and simulated numerically and the effect of changing the operating conditions has been studied. The system has been simulated to driven by a low-grade heat source temperature below 90ºC and effectively employs solar heat and/or waste sources to drive the system

A state of the art of required techniques for employing activated carbon in renewable energy powered adsorption applications

This paper reviews, for the first time, the measurement adsorption characteristics techniques to facilitate optimal testing of the validity of adsorbent materials in adsorption applications. Thermo-physical properties, adsorption characteristics and modelling techniques are presented. The characterisation of material thermo-physical properties includes true and bulk densities, specific heat capacity, surface area, pore volume distribution and thermal conductivity. The adsorption characteristics were categorized into adsorption isotherms and kinetics including experimental and theoretical equations. A range of models used in the simulation of adsorption cooling systems is presented and discussed. The paper highlights the conditions for which each measurement technique is most suitable and the limitations of modelling techniques, which is a vital element in the robust assessment of the performance of adsorption cooling units.</p

Experimental study on Egyptian biomass combustion in circulating fluidized bed

The present study investigates the combustion of four kinds of biomass in a circulating fluidized bed. The combustion chamber is a steel cylinder with 145 mm inner diameter and 2 m height. Tests were conducted on wheat straw, sawdust-wood, cottonseed burs, and corncobs. Excess air was varied for each fuel. Temperature, heat flux and gas emissions were measured along the combustion chamber and at the chimney inlet. Results showed that sawdust-wood produces the highest values of CO emissions (about 3000 mg/Nm3). On the other hand, cottonseed burs produce the lowest values of CO emissions (about 250 mg/Nm3). The SO2 emissions were very low in all tests (less than 20 mg/Nm3). The lowest emission value occurred at an excess air ratio (EA) of 1.24 except for cottonseed burs where it was 1.4.Biomass Fluidized bed combustion Pollutant emissions Renewable energy

Experimental investigation of porous carbon for cooling and desalination applications

Abstract Adsorption cooling and desalination (ACD) system presents a solution for water, energy, and environmental dilemma. This study expresses an enhancement of adsorption system performance in terms of cooling and desalination effects by improving an activated carbon Maxsorb III (Max) as an adsorbent. Max has been initially treated with HCl. Then, it has been activated by impregnating it in salt hydrates ((NH4)2CO3). Characterization methods, including XRD, N2 and water adsorption isotherm, and water adsorption kinetics have been conducted for raw Max, treated Max, and activated Max with (NH4)2CO3. The experimental values have been fitted with the Dubinin & Astakhov equilibrium model for isotherm and the model of linear driving force for kinetics. These fitted parameters have been utilized in a previously validated model to estimate adsorption cooling-desalination system performance with and without heat recovery. Max/(NH4)2CO3 achieves a water uptake of 0.53 kgH2O.kg-1. Max/(NH4)2CO3 produces 13.2 m3.ton-1 of freshwater per day with a specific cooling power of 373 W.kg-1 and 0.63 COP. Also, the freshwater reaches 22.5 m3.ton-1 of Max/(NH4)2CO3 per day with condenser-evaporator heat recovery. These results indicate the potential of utilizing the Max material in dual cooling and desalination applications to achieve double what silica gel can offer