Study of adsorption characteristics of Au(III) onto coal particles and their application as radiotracer in a coal gasifier.
This paper describes a systematic study carried out to investigate adsorption characteristics of198Au onto the surface of coal particles using a radiotracer technique. The main objective of the study was to optimize labeling conditions and utilize the labeled coal particles as a radiotracer for tracing coal particles in fluidized bed coal gasifiers. The effect of various experimental factors such as pH, amount of adsorbent, initial gold concentration, temperature and contact time between adsorbate and adsorbent were studied to obtain optimum conditions for maximum adsorption of198Au on coal particles from an aqueous solution. Analysis of the data showed that the Langmuir model was found most suitable to describe the adsorption phenomena. The thermodynamic analysis showed that the adsorption process is feasible, spontaneous and endothermic in nature. The results of the kinetics suggested that the adsorption presumably follows second order kinetics and chemisorption in nature. Based on the optimized conditions, the amount of coal particles and activity to be used for tracing the coal phase in pilot-scale gasifiers was estimated. Accordingly, the radiotracer was prepared and successfully used for measurement of residence time distribution (RTD) in a pilot-scale coal gasifier.
Isotope Production and Applications Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India.
Sunil
S
Goswami
Isotope Production and Applications Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India. Electronic address: hjpant@barc.gov.in.
Harish Jagat
HJ
Pant
Isotope Production and Applications Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India.
Rajwardhan Nandram
RN
Ambade
Material Processing Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India.
Bhasakar
B
Paul
Radiation Technology Development Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India.
Lalit
L
Varshney
Isotope Production and Applications Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India.
Ashutosh
A
Dash
Adsorbate; Adsorbent; Adsorption capacity; Coal particles; Gasifier; Gold(III); Gold-198; Radiotracer; Residence time distribution