scholarly journals Physical chemical analysis of polymeric substances synthesized from monomers in heavy pyrolysis oil

2021 ◽  
Vol 2131 (4) ◽  
pp. 042045
Author(s):  
F Burkhev ◽  
H Kushiev ◽  
T Juraev

Abstract Our article describes in the results of the research the polymerization of the residual (brown tint) after the separation of useful cabocylic compounds (indene) from the composition of one of the important fractions of heavy pyrolysis oil (indene and its homologues), which are considered to be a brownish product formed on the basis of natural gas pyrolysis, and the molecular mass and physical chemical. As a result of the analysis of the infrared (IR), it was known that the product contains functional groups (-C=C-) with a polymerizing property, along with an aromatic ring, and the polymer is made up of a mixture of isomers of polyvinyl toluene. The molecular mass of the polymer (MM) in the viscometric method was determined as the best solvent of benzene in the process of maturation, the macromolecular mass and the degree of polymerization (p) were determined as a result of the studies conducted.

Author(s):  
EMERSON RENATO MACIEL DA-SILVA ◽  
ANDREY NILDO DE JESUS DA LUZ SOUZA-JUNIOR ◽  
SAMYA UCHÔA-BORDALLO ◽  
REGINA CELI SARKIS-MULLER ◽  
EWERTON CARVALHO DE-SOUZA ◽  
...  

Author(s):  
Chengxue Ma ◽  
Chang Zhao ◽  
Patteson Chula Mwagona ◽  
Ziyu Li ◽  
Zixuan Liu ◽  
...  

The debates about the extent to which phytoplankton in freshwater ecosystems are regulated by top-down or bottom-up forces have been ongoing for decades. This study examines the effects of bottom-up and top-down factors on the phytoplankton functional groups in a eutrophic lake. Phytoplankton and zooplankton were sampled and physical-chemical variables measured from May 2019 to October 2019 in Lake Hulun, China. Approximately 43 phytoplankton species were observed and grouped into 23 functional groups. For the zooplankton, about 27 species were observed and classified into 8 functional groups. The study revealed that the bottom-up effects of physical-chemical variables on some phytoplankton functional groups was stronger than the top-down effects of zooplankton. Water temperature (WT), total phosphorus (TP), total nitrogen (TN), conductivity (Cond), water transparency (SD), and dissolved oxygen (DO) significant influence the biomass of the phytoplankton functional groups. The biomass of phytoplankton functional groups was influenced positively by nutrient availability likely because nutrients influence the growth and reproduction of phytoplankton in freshwater. WT and DO had a positive influence on biomass of phytoplankton functional groups. Conversely, phytoplankton biomass revealed a decreasing trend when SD and Cond significantly increased. This study showed that zooplankton functional groups were positively correlated with phytoplankton biomass implying that the top-down control of phytoplankton by the zooplankton in the lake is not strong enough to produce a negative effect. It is evident that the zooplankton functional groups in Lake Hulun are controlled more by bottom-up force than top-down.


Cellulose ◽  
2020 ◽  
Vol 27 (12) ◽  
pp. 6811-6829 ◽  
Author(s):  
Mátyás Báder ◽  
Róbert Németh ◽  
Jakub Sandak ◽  
Anna Sandak

Abstract Pleating is an optimal way to increase bendability of wood used in diverse industrial applications. It results in the excessive buckling of cell walls and modifications of constitutive polymers. However, thoughtful understanding of the physical–chemical mechanisms of that modification process is very limited. The main purpose of the present study was to identify changes in functional groups of wood polymers induced by longitudinal compression. Four types of wood samples prepared from beech and sessile oak (untreated, steamed, longitudinally compressed and fixated for 1 min as well as longitudinally compressed and fixated for 18 h) were assessed by infrared spectroscopy. The spectra interpretation revealed that changes can be observed in hydroxyl as well as in carbon–oxygen single and carbon-hydrogen functional groups of polysaccharides and lignin. Beech wood seems to be more susceptible to investigated modification processes as compared to oak. Detailed interpretation of infrared spectra allows identification of changes in the hygroscopicity of wood as well as alterations in the linkage between structural elements in the polymer matrix of wood induced by the applied treatments. Graphic Abstract


Author(s):  
David Chiaramonti ◽  
Anja Oasmaa ◽  
Yrjo¨ Solantausta

Biomass fast-pyrolysis oil (PO) is a liquid biofuel derived from lignocellulosic biomass: it offers several advantages compared to the direct us of solid bio fuels, such as high energy density, storability and transportability typical of liquid fuels, possibility to use the fuel in engines and turbines, easier downscaling of plants (which is a very important aspect for decentralized energy generation schemes). In addition, PO is the lowest cost biofuel, thus offering the possibility to penetrate also the large scale power generation market. Biomass POs have been studied and applications tested for many years, either for heat generation in medium-scale boilers or power generation. The present works reviews and analyses the most relevant experiences carried out so far and published results in power production from biomass PO. Power generation systems (PGS) which are here examined are gas turbines, diesel engines, stirling engines, as well as co-firing applications in large scale power plants (coal or natural gas plants). The main techniques for upgrading this biofuel and their impact on technologies are also shortly introduced and considered. The current status of development for each PO-based power generation option is discussed. This review work showed that long term demonstration (either technical or economical) is however still needed, even for the most developed technologies (use of PO in modified gas turbines and cofiring in natural gas stations): projects are on going to achieve long term demonstration.


2014 ◽  
Vol 798-799 ◽  
pp. 3-8 ◽  
Author(s):  
Jonas Alexandre ◽  
Afonso Rangel Garcez de Azevedo ◽  
Gustavo de Castro Xavier ◽  
Leonardo Gonçalves Pedroti ◽  
Carlos Maurício Fontes Vieira ◽  
...  

The mining and processing of limestone in the state of Rio de Janeiro, southeast of Brazil, generates a considerable amount of small particles, like a powder ,which is commercialized as a by product. In principle, this inert limestone powder could be recycled as part of another civil construction material. Thus, the objective of this work was to characterize a limestone powder by its physical properties, chemical analysis and microstructural aspects. The results were compared with the characteristics of a common cement and a conventional sand to be possibly applied in the fabrication of limestone incorporated concrete blocks. It was found that the limestone powder has physical, chemical and microstructural characteristics satisfactory for concrete blocks incorporation.


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