Therefore, the rate of H2S production is influenced by thermodynamics, the carbon gasification rate, gasification product distribution, and the mass transfer coefficient between the char bed and the surrounding gas phase.
In the slow heating rate gasification, the coal particles were fed into the quartz reactor at ambient temperature and the reactor was then heated up at a pre-set heating rate (approximately 15 K/min) to the target temperature (700 900 °C).
In the middle and late stage of the reaction, between 30 and 60 min of the reaction time, SDI oil yield improves by 7.63 %, reaching nearly 59%%, while rate of gasification increases only by 1.25 %; meanwhile, SDV oil yield increases only by 0.89 %, while rate of gasification is up 3.94 %, much higher than that of SDI.
Carbon conversion rate and gasification efficiency are increased by increasing temperature and H2 production at 870°C reaches the highest rate.
The maximum rate of gasification under the conditions studied of 53 g/L s is much higher than previously reported.
At the initial stage of the reaction, when the reaction is at its 30 min, SDI oil yield improves by 8.29 %, rate of gasification by 2.09 %; while for SDV within the same amount of time, the oil yield increases by 11.61 %, and rate of gasification is equal to that of SDI.
We studied the cavity growth, fracturing mechanism, and the effects of various design and operational variables, such as linking-hole type, gas feed rate, and gasification agent.
It was also found that CAHR char reactivity decreased with pyrolysis temperature, but increased with pyrolysis heating rate and gasification temperature at 850 950 °C.
It is important that a high temperature in the combustion zone be maintained in the actual UCG process by adjusting the flow rate of gasification agents and the H2O/O2 ratio (Perkins and Sahajwalla 2005; Prabu and Jayanti 2011).
On the other hand, SDV pyrolysis products have small molecular weights; the target products will have secondary pyrolysis and rate of gasification increases as reaction time and severity increases.
The effect of temperature (°C), heating rate (°C/min), gasification medium (steam or air), air ratio, steam to biomass ratio (S/B) as well as the catalytic effect of Fe naturally dispersed in the biomass char were studied.
