Humair Ahmed Baloch

Parametric study of co-gasification of ternary blends of rice straw, polyethylene and polyvinylchloride

Parametric study of co-gasification of rice straw (RS), high-density polyethylene (PE) and Polyvinylchloride (PVC) was carried out to investigate the effect of temperature, flow rate of steam, typical plasticsxa0and their blends on the quality and volume of synthetic gas. The additions of plastic enhance H2 content in the synthetic gas. The study found that increase in temperature increases the yield of synthetic gas, H2 and CO content and lower heating value (LHV) of synthetic gas. The steam to biomass ratio seems to have a very small effect on gas composition. Likewise the increase in PE content in the feed blend increases the hydrogen content and gas yield. Similar results were obtained by increasing PVC content. Co-gasification experiments of ternary blends of RS, PE and PVC were also conducted. The ternary blends of 20xa0% RS, 40xa0% PE, 40xa0% PVC produced synthetic gas with higher H2 content, higher synthetic gas production rate and higher LHV of synthetic gas. This work confirms that synergistic interactive effect takes place during the co-gasification of ternary blends of PE, PVC and RS due to volatile-char interaction and mineral catalytic effects. This work also suggests that carefully designed co-gasification unit can handle waste with varying composition of biomass and plastic to produce improved quantity as well as quality of synthetic gas.

Parametric study of pyrolysis and steam gasification of rice straw in presence of K2CO3

A parametric study of pyrolysis and steam gasification of rice straw (RS) was performed to investigate the effect of the presence of K2CO3 on the behavior of gas evolution, gas component distribution, pyrolysis/gasification reactivity, the quality and volume of synthetic gas. During pyrolysis, with the increase in K2CO3 content in RS (i) the instantaneous CO2 concentration was increased while CO concentration was relatively stable; (ii) the yield of CO2 and H2 increased on the cost of CH4. During steam gasification of RS, with the increase in K2CO3 content in RS (i) the instantaneous concentration of CO2 and H2 increased while instantaneous concentration of CO and CH4 decreased; (ii) the yield of CO2 and H2 production and total yield increased; and (iii) yield of CO and CH4 production followed the order: 9% K2CO3 RS<6% K2CO3 RS<raw RS<3% K2CO3 RS<water-leached RS. Water-leached RS showed the highest pyrolysis reactivity, while stream gasification reactivity was proportional to K2CO3 content in RS. The results of this study reveal that the presence of K2CO3 during pyrolysis and steam gasification of RS effectively improves production of H2 rich gas.

Synthesis of magnetic carbon nanocomposites by hydrothermal carbonization and pyrolysis

The fabrication of magnetic carbon nanostructures is emerging to develop composites with unique properties. Consolidating magnetic nanoparticles with carbon materials can be used in nanoelectronics, catalysis, optical application, biosensors, environmental remediation, energy, hydrogen storage, drug transport, magnetic resonance imaging and cancer diagnosis. In addition, thermochemical methods such as hydrothermal carbonization and pyrolysis are low energy processes that offer an efficient synthesis of the controlled morphology of magnetic carbon nanocomposite. These methods provide chemical and morphological improvements of the structure, such as high surface area, ordered nanosizes, crystal matrix, material stability, electrical conductivity, magnetic saturation and coercivity. This paper reviews the fabrication and properties of magnetic carbon nanocomposites.

Upgradation of chemical, fuel, thermal, and structural properties of rice husk through microwave-assisted hydrothermal carbonization

The process parameters of microwave hydrothermal carbonization (MHTC) have significant effect on yield of hydrochar. This study discusses the effect of process parameters on hydrochar yield produced from MHTC of rice husk. Results revealed that, over the ranges tested, a lower temperature, lower reaction time, lower biomass to water ratio, and higher particle size produce more hydrochar. Maximum hydrochar yield of 62.8% was obtained at 1000xa0W, 220xa0°C, and 5xa0min. The higher heating value (HHV) was improved significantly from 6.80xa0MJ/kg of rice husk to 16.10xa0MJ/kg of hydrochar. Elemental analysis results showed that the carbon content increased and oxygen content decreased in hydrochar from 25.9 to 47.2% and 68.5 to 47.0%, respectively, improving the energy and combustion properties. SEM analysis exhibited modification in structure of rice husk and improvement in porosity after MHTC, which was further confirmed from BET surface analysis. The BET surface area increased from 25.0656xa0m2/g (rice husk) to 92.6832xa0m2/g (hydrochar). Thermal stability of hydrochar was improved from 340xa0°C for rice husk to 370xa0°C for hydrochar.

An overview of microwave hydrothermal carbonization and microwave pyrolysis of biomass

Biomass utilization has received much attention for production of high density solid fuels. Utilization of cheap and naturally available precursors through environmentally friendly and effective processes is an attractive and emerging research area. Pyrolysis and hydrothermal carbonization (HTC) are well-known technologies available for production of solid biofuel using conventional or microwave heating. Microwave heating is a simpler and more efficient heating method than conventional heating. This study presents a critical review on microwave pyrolysis and microwave HTC for solid fuel production in terms of yield and quality of products. Moreover, a brief summary of parameters of microwave pyrolysis and microwave HTC are discussed. The fuel, chemical, structural and thermal weight loss characteristics of solid fuels produced from different biomass are discussed and compared.

Advanced nanomaterials synthesis from pyrolysis and hydrothermal carbonization: A review

Background: Carbon-based structural materials are widely studied in the field of renewable energy and environmental sciences. Utilization of abundant, natural, renewable energy precursors together with simple and low energy processes can contribute to reduced emissions of greenhouse gas so is considered as fundamental for manufacturing of sustainable nanostructured materials. Description: Among different resources available for generation of nanostructured materials, plant biomass is superior in terms of economic, environmental and social issues. In addition, transformation of low-value biomass to emerging renewable materials is advantageous compared to dumping and incinerating the biomass. There are a number of techniques and processes for production of nanostructured materials from biomass. Pyrolysis and hydrothermal carbonization (HTC) may be used to convert biomass into nanostructured materials. Objective: This study reviews and compares the production of nanostructured materials from pyrolysis and HTC. Furthermore, the latest developments in pyrolysis and HTC for nanomaterials production are assessed and comparative characteristics are studied for nanomaterials obtained.