Investigation of thermochemical process of coal particle packed bed reactions for the development of UCG

In this study,a packed bed reactor was developed to investigate the gasification process of coal particles.The effects of coal particle size and heater temperature of reactor were examined to identify the thermochemical processes through the packed bed.Three different coal samples with varying size,named as A,B,and C,are used,and the experimental results show that the packed bed with smaller coal size has higher temperature,reaching 624°C,582°C,and 569°C for coal A,B,and C,respectively.In the case of CO formation,the smaller particle size has greater products in the unit of mole fraction over the area of generation.However,the variation in the porosity of the packed bed due to different coal particle sizes affects the reactions through the oxygen access.Consequently,the CO formation is least from the coal packed bed formed by the smallest particle size A.A second test with the temperature variations shows that the higher heater temperature promotes the chemical reactions,resulting in the increased gas products.The findings indicate the important role of coal seam porosity in underground coal gasification application,as well as temperature to promote the syngas productions.

Thermochemical co-conversion of biomass-plastic waste to biochar:a review

Biomass and plastics are two of the most common municipal solid wastes globally that have continuously placed a burden on the environment.It is therefore important that they are properly recycled.Thermochemical coconversion offers a valuable opportunity to recycle biomass and plastics simultaneously into biochar,which reduces the time and cost of recycling them individually while producing a material with a wide range of applications.This study is a review of published literature that discusses the thermochemical co-processing of biomass and plastic wastes into biochar.It was observed that co-pyrolysis and co-hydrothermal carbonization are the most commonly utilized technologies for this process.The characteristics of different biomass and plastics that have been thermochemically converted into biochar were compared.The properties of the resulting biochar are affected by the feedstock composition,pre-treatment and blending ratio,the reactor’s configuration,reaction temperature,and the presence of a catalyst.Most studies found that treating the feedstocks separately resulted in a lower yield of biochar than processing them together.The biochar created by this procedure has been used as a soil additive and as an adsorbent for water treatment.Future perspectives and suggestions,such as the necessity for some technical advancement,biochar’s economic benefits,improved government participation,and raised social awareness,were also made.These factors have the potential to propel this field of study to great horizons.

Current technology development for CO2 utilization into solar fuels and chemicals:A review

The continuous consumption of fossil fuels causes two important impediments including emission of large concentrations of CO2 resulting in global warming and alarming utilization of energy assets.The conversion of greenhouse gas CO2 into solar fuels can be an expedient accomplishment for the solution of both problems,all together.CO2 reutilization into valuable fuels and chemicals is a great challenge of the current century.Owing to limitations in traditional approaches,there have been developed many novel technologies such as photochemical,biochemical,electrochemical,plasma-chemical and solar thermochemical.They are currently being used for CO2 capture,sequestration,and utilization to transform CO2 into valuable products such as syngas,methane,methanol,formic acid,as well as fossil fuel consumption reduction.This review summarizes different traditional and novel thermal technologies used in CO2 conversion with detailed information about their working principle,types,currently adopted methods,developments,conversion rates,products formed,catalysts and operating conditions.Moreover,a comparison of these novel technologies in terms of distinctive key features such as conversion rate,yield,use of earth metals,renewable energy,investment,and operating cost has been provided in order to have a useful review for future research direction.

IMPROVEMENT IN TENSILE PROPERTIES OF α+β TYPE Ti ALLOYS BY HYDROGEN TREATMENT

A new process to refine the microstructure of α+βtvpe Ti alloys was developed by using hydrogen as a temporary alloying element.It involves hydrogenating the alloys below the hydrogenated β transus temperature about 0-40 K,air cooling to room temperature and then dehydrogenating at 948 K.Ti-6AI-4V and Ti-5AI-2.5Fe alloys treated hy this new process show much refined microstructures,and the yield strength,ultimate strength as well as the elongation increase 8—15,5—13 and 7—14% respectively

Pyrolysis technologies for biochar production in waste management:a review

Pyrolysis is a thermal conversion process in the absence of air to derive energy components from the residues.Renewable-energy technologies will play a major role in addressing future challenges related to environmental safety and energy security.One of the many easily available renewable energy sources is biomass-an organic material that is thought to be carbon-neutral.Pyrolysis technology is a thermochemical process that can be used to produce useful products from biomass,such as biochar,bio-oil and combustible pyrolysis gases.The structure and relative product yield are impacted by the pyrolysis method employed.This article evaluates different approaches for biomass pyrolysis.Fast,slow and advanced pyrolysis methods using various pyrolyser reactors have been studied in the literature and are provided to increase the variety and use of these methods in upcoming studies and research.Slow pyrolysis can lead to increased ecological well-being,as it increases the amount of biochar produced using auger and rotary-kiln reactors.Rapid pyrolysis,mainly in fluidized-bed reactors with bubbling and rotating circulation,can be used to obtain bio-oil.Advanced pyrolysis methods offer a good probability of yielding great prosperity for specific applications.The selection of a pyrolysis process is based on the required output in terms of solid,liquid and gaseous fuels,and the parameter plays a crucial role in the pyrolysis performance.

Revolutions in algal biochar for different applications:State-of-the-art techniques and future scenarios

Algae are potential feedstock for the production of bioenergy and valuable chemicals.After the extraction of specific value-added products,algal residues can be further conve rted into biogas,biofuel,and biochar through various thermochemical treatments such as conventional pyrolysis,microwave pyrolysis,hydrothermal conversion,and torrefaction.The compositions and physicochemical characteristics of algal biochar that dete rmine the subsequent applications are compre hensively discussed.Algal biochar carbonized at high-temperature showed remarkable performance for use as supercapacitors,CO_(2) adsorbents,and persulfate activation,due to its graphitic carbon structure,high electron transport,and specific surface area.The algal biochar produced by pyrolysis at mode rate-temperature exhibits high performance for adsorption of pollutants due to combination of miscellaneous functional groups and po rous structures,whereas coal fuel can be obtained fro m algae via torrefaction by pyrolysis at relatively low-tempe rature.The aim of this review is to study the production of algal biochar in a cost-effective and environmental-friendly method and to reduce the environmental pollution associated with bioenergy generation.achieving zero emission enerev production.