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Gasification reactions of Thar coal chars with CO2 and H2O have been investigated, using pressurized thermo-gravimetric analyzer (PTGA). A quartz fixed-bed reactor was used to prepare coal char at 900 °C with a nitrogen environment. Dynamic heating segments were maintained with a constant heating rate during all experiments. The temperature was raised from room temperature to 1000 °C, at different pressures 1 atm., 5 atm., and 10 atm. using pure reacting gases (CO2 and H2O). The weight loss data obtained from PTGA results were used to study the kinetic behavior of Thar lignite char for gasification reactions with CO2 and H2O as gasifying reacting species. It was observed that gasification reactions of char with reacting gas CO2 and char with reacting gas steam (H2O) initiated at 750 °C and completed after reaching 950 °C, at atmospheric pressure, but the occurrence of reactions was slightly delayed at high pressures. Volumetric Model and Grain Model were used to develop a kinetic model for Thar lignite. The direct plot and integral methods were used to calculate Arrhenius parameters such as the pre-exponential factor (A) and activation energy (E). An increase of A and E was also observed in increasing pressures. The activation energy (E) was investigated from 244.64 to 317.6 kJ/mol at atmospheric pressure; whereas, it is lying in the range of 286.13–356.67 kJ/mol at a pressure of 10 atm.

Thermochemical characterization of four different biomasses sawdust (SD), rice husk (RH), cotton stalk (CS) and sugarcane bagasse (SB) was investigated to understand their kinetic characteristics. The TGA experiments were done using inert and oxidative atmospheres to understand the reaction kinetics of selected biomasses. The temperature was enlarged from room temperature to 900 °C at a heating rate of 10 °C min−1 under non-isothermal conditions. The weight loss of all the four biomass materials under an inert and oxygen environments showed alike weight loss trend occurring in three main stages. It was observed that all four biomass materials degraded in three identical regions. In the first region of weight loss, moisture evaporation was observed, in second region cellulose and hemicellulose degradation was achieved, whereas in third region lignin degradation was achieved under both an inert and oxy-combustion atmospheres at different temperature ranges. The activation energy, pre-exponential factors were evaluated through Arrhenius correlation equations. The values of E calculated during pyrolysis for CS, SB, SD and RH were 79.10, 68.32, 53.46, 52.9 (kJ mol−1) during oxy-combustion atmospheres 122.6, 106.31, 123.28 and 118 (kJ mol−1), respectively.

Biomass materials such as CS (Cotton Stalks) and RH (Rice Husk) are a renewable source of energy. As biomass resources have potential to offer a uninterpted supply of biofuels through thermal decomposition processes. Nevertheless, an appropriate understanding of reaction kinetics and thermal properties of biomasses play a vital role in designing of the commercial plants using biomass as a raw material for energy generation. The kinetic characteristics of the CS and RH samples under pure nitrogen 99.9% and pure oxygen 99.9% was performed. The temperature was raised from ambient to 900oC maintaining the heating rate of 10oC/min. CS and RH decomposition was noticed in three dissimilar regions. The kinetic characteristics such as (pre-exponential factor, the order of reaction and activation energy) were calculated for both selected materials. The activation energies calculated under nitrogen environment for CS and RH was 68.77 and 72.31 kJ/mole, whereas the regression coefficient (R2) was 0.9877 and 0.9731 respectively. The activation energies under oxygen environment were higher, it was 106 and 118 kJ/mole. The regression coefficient (R2) under oxygen environment was 0.9987 and 0.99883 for above sample sequence.

In this study 2D numerical simulation for two-stage entrained flow dry feed coal gasification performance was developed. The detailed operational characteristics of O/C distribution between the two stages of the gasifier were examined in standard CFD software FLUENT®14 to analyze their effects on the gasification performance. Furthermore the different reaction mechanisms were investigated for validation of the model with experimental results. The results show that H 2 and CO composition at the exit of gasifier are increased at O/C ratio 0.8 as compared to other simulation cases, and the temperature gradually decreases from 2nd injection level because of water-shift reaction. Maximum CO% was observed when 40% of oxygen injected at the lower level, overall range of H 2 % at the exit of gasifier was 10–45% but maximum H 2 % was found when 50% O 2 % and 30% of coal injected at a lower level. The maximum temperature about 2300 K when 40% O 2 and 40% of coal was injected at a lower level. Overall optimized results for CO, H 2 , and minimum CO 2 formation was observed when 60% O 2 and 40% of coal was injected at a lower level of the gasifier. The gasification performance can be controlled with the optimized coal/oxidant distribution between the stages.

As (Arsenic) is one of the lethal element present at the various locations of the world, putting human beings in danger by polluting the water. Arsenic Kit and atomic absorption spectrometer were used to determine As in ground water of Sindh province, Pakistan. Twenty-Four (24) districts both on the left and right bank of RI (River Indus) were analyzed. It was observed from the results that highest As concentration 200 ppb (parts per billion) i.e. above the WHO (World Health Organization) limit (10 ppb) was observed in Sakrand, district Shaheed Benazirabad followed by Hala, Matairi, TMK (Tando Mohammad Khan) and Nasarpur regions. It was further found that ground water of regions on the left bank of RIwas more contaminated than the right bank. Contour map was created using OriginPro and coordinate systems to highlight the elevated arsenic in the studied area. HRA (Health Risk Assessment) of these areas was carried out to calculate EDI (Estimated Daily Intake), TQH (Target Hazard Quotient) and CR (Cancer Risk). 45% of the total ground water samples analyzed were above the permissible limit for As in water and mostly these are located on the left bank of RI. The local wells in Sindh have never been tested for metal concentration former to use. These results provide baselines for researchers, NGO's (Non-Governmental Organizations) and government to apply arsenic treatment technologies in those areas.

During process of fermentation a variety of parameters effect on ethanol production, current work focusses to investigate the effect of different carbon sources on ethanol production using numerical simulation. The fermentation process was carried out using microprocessor-controlled fermenter in which different types of carbon sources were studied like glucose, sucrose and molasses from 10 % to 15% of range. The model proposed by Monod was found to be more appropriate for describing the batch growth and ethanol production using kluyveromyces marxianus. The maximum yield of ethanol production took place using 15 % molasses as carbon source. The maximum ethanol production (76 g/l) was observed at 15% molasses, as for sucrose and glucose are concerned it gives lower value of ethanol production up to 73g/l by keeping other operational parameter under optimized condition such are 35oC, 300rpm, 0.2vvm/l and pH5.5. Approximately same results were achieved by using experimental data and model execution.