다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Lignocellulosic biomass pyrolysis mechanism: A state-of-the-art review

Climate change and fossil fuel depletion are the main reasons leading to hydrogen technology. There are many processes for hydrogen production from both conventional and alternative energy resources such as natural gas, coal, nuclear, biomass, solar and wind. In this work, a comparative overview of the major hydrogen production methods is carried out. The process descriptions along with the technical and economic aspects of 14 different production methods are discussed. An overall comparison is carried out, and the results regarding both the conventional and renewable methods are presented. The thermochemical pyrolysis and gasification are economically viable approaches providing the highest potential to become competitive on a large scale in the near future while conventional methods retain their dominant role in H2 production with costs in the range of 1.34–2.27 $/kg. Biological methods appear to be a promising pathway but further research studies are needed to improve their production rates, while the low conversion efficiencies in combination with the high investment costs are the key restrictions for water-splitting technologies to compete with conventional methods. However, further development of these technologies along with significant innovations concerning H2 storage, transportation and utilization, implies the decrease of the national dependence on fossil fuel imports and green hydrogen will dominate over the traditional energy resources.

A comparative overview of hydrogen production processes

Pyrolysis is one of the thermochemical technologies for converting biomass into energy and chemical products consisting of liquid bio-oil, solid biochar, and pyrolytic gas. Depending on the heating rate and residence time, biomass pyrolysis can be divided into three main categories slow (conventional), fast and flash pyrolysis mainly aiming at maximising either the bio-oil or biochar yields. Synthesis gas or hydrogen-rich gas can also be the target of biomass pyrolysis. Maximised gas rates can be achieved through the catalytic pyrolysis process, which is now increasingly being developed. Biomass pyrolysis generally follows a three-step mechanism comprising of dehydration, primary and secondary reactions. Dehydrogenation, depolymerisation, and fragmentation are the main competitive reactions during the primary decomposition of biomass. A number of parameters affect the biomass pyrolysis process, yields and properties of products. These include the biomass type, biomass pretreatment (physical, chemical, and biological), reaction atmosphere, temperature, heating rate and vapour residence time. This manuscript gives a general summary of the properties of the pyrolytic products and their analysis methods. Also provided are a review of the parameters that affect biomass pyrolysis and a summary of the state of industrial pyrolysis technologies.

Lignocellulosic biomass pyrolysis: A review of product properties and effects of pyrolysis parameters

Slow-pyrolysis of biomass for the production of biochar, a stable carbon-rich solid by-product, has gained considerable interest due to its proven role and application in the multidisciplinary areas of science and engineering. An alternative to slow-pyrolysis is a relatively new process called hydrothermal carbonization (HTC) of biomass, where the biomass is treated with hot compressed water instead of drying, has shown promising results. The HTC process offers several advantages over conventional dry-thermal pre-treatments like slow-pyrolysis in terms of improvements in the process performances and economic efficiency, especially its ability to process wet feedstock without pre-drying requirement. Char produced from both the processes exhibits significantly different physiochemical properties that affect their potential applications, which includes but is not limited to carbon sequestration, soil amelioration, bioenergy production, and wastewater pollution remediation. This paper provides an updated review on the fundamentals and reaction mechanisms of the slow-pyrolysis and HTC processes, identifies research gaps, and summarizes the physicochemical characteristics of chars for different applications in the industry. The literature reviewed in this study suggests that hydrochar (HTC char) is a valuable resource and is superior to biochar in certain ways. For example, it contains a reduced alkali and alkaline earth and heavy metal content, and an increased higher heating value compared to the biochar produced at the same operating process temperature. However, its effective utilization would require further experimental research and investigations in terms of feeding of biomass against pressure; effects and relationships among feedstocks compositions, hydrochar characteristics and process conditions; advancement in the production technique(s) for improvement in the physicochemical behavior of hydrochar; and development of a diverse range of processing options to produce hydrochar with characteristics required for various industry applications.

A comparative review of biochar and hydrochar in terms of production, physico-chemical properties and applications

Co-pyrolysis of pine cone with synthetic polymers

The slow and fast pyrolysis of cherry seed

http://www.adktroutguide.com/files/2006_Characterisation_of_products_from_pyrolysis_of_waste_sludges.pdf

Jale Yanik

Papers

Co-pyrolysis of pine cone with synthetic polymers

The slow and fast pyrolysis of cherry seed

Characterisation of products from pyrolysis of waste sludges

Effects of feedstock type and pyrolysis temperature on potential applications of biochar

Evaluation of two different scrap tires as hydrocarbon source by pyrolysis