scholarly journals Markedly Different Decomposition Temperature and Products of Biomass Pyrolysis at Low Temperature—Differentiation of Acids in Their Effects on Pretreatment

2021 ◽  
Vol 2 (1) ◽  
pp. 8-23
Author(s):  
Peifang Yan ◽  
Xiumei Liu ◽  
Zhanwei Xu ◽  
Zongchao Conrad Zhang

Pine as a softwood and poplar as a hardwood pretreated with hydrochloric acid (HCl), phosphoric acid (H3PO4), and hypophosphorous acid (H3PO2) are studied for the pyrolytic properties and products in thermogravimetry (TG) and fixed bed reactor. The pyrolysis performances are pronouncedly distinguished due to the compositional and structural changes induced by the acid pretreatments. Reduction in the mineral content in the biomass feedstocks by pretreatment with the acids results in significant changes in the pyrolytic products. The residual P in the H3PO2-pretreated biomass apparently catalyzed the biomass deeper dehydration in pyrolysis compared to the other two mineral acids. TG analysis shows a shift of the temperature of maximum mass loss (Tmax) by more than 40 °C to lower temperature in the decomposition of the H3PO2-pretreated biomass from that of the untreated and the HCl- and H3PO4-pretreated biomass. Inspired by the striking differences in TG profiles of biomass pretreated by the three acids, thermal pyrolysis of pretreated biomass was carried out in a fixed bed reactor aimed at producing biochemicals at low temperatures (330 °C and 400 °C). The liquid products obtained from the fixed bed reactor show remarkably different major anhydrosugars as a result of pretreatment by the three acids. While phenolics dominate in the collected pyrolysis liquid from untreated biomass samples, biomass pretreated with all three acids results in substantially reduced phenolics in the bio-oils. The reduction in phenolic compounds in the bio-oil may be attributed to the reduction in mineral content in the feedstock. Consequently, the yields of anhydrosugars, mainly levoglucosan (LG) and levoglucosenone (LGO) are increased. LG yields of 20.9–28.5% from the cellulose content are obtained from HCl- and H3PO4-pretreated pine/poplar, with very low LGO yield (less than 1.7%). However, H3PO2-pretreated biomass is selective to produce LGO, especially at 330 °C. LGO yields of 7.4% and 6.7% are obtained from H3PO2-pretreated pine and poplar, respectively.

2019 ◽  
Vol 19 (3) ◽  
pp. 703 ◽  
Author(s):  
Siti Jamilatun ◽  
Budhijanto Budhijanto ◽  
Rochmadi Rochmadi ◽  
Avido Yuliestyan ◽  
Arief Budiman

With a motto of preserving nature, the use of renewable resources for the fulfillment of human needs has been seen echoing these days. In response, microalgae, a water-living microorganism, is perceived as an interesting alternative due to its easy-to-cultivate nature. One of the microalgae, which possess the potential for being the future source of energy, food, and health, is Spirulina plantesis. Aiming to identify valuable chemicals possibly derived from it, catalytic and non-catalytic pyrolysis process of the residue of S. plantesis microalgae has been firstly carried out in a fixed-bed reactor over the various temperature of 300, 400, 500, 550 and 600 °C. The resulting vapor was condensed so that the liquid product consisting of the top product (oil phase) and the bottom product (water phase) can be separated. The composition of each product was then analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). In the oil phase yield, the increase of aliphatic and polyaromatic hydrocarbons (PAHs) and the decrease of the oxygenated have been observed along with the increase of pyrolysis temperature, which might be useful for fuel application. Interestingly, their water phase composition also presents some potential chemicals, able to be used as antioxidants, vitamins and food additives.


2010 ◽  
Vol 49 (10) ◽  
pp. 4627-4632 ◽  
Author(s):  
Mohammad Shahed Hasan Khan Tushar ◽  
Nader Mahinpey ◽  
Pulikesi Murugan ◽  
Thilakavathi Mani

2020 ◽  
Vol 12 (2) ◽  
pp. 304-311 ◽  
Author(s):  
Gaofeng Xu ◽  
Chengxinzhuo Jia ◽  
Zhengjun Shi ◽  
Ruijuan Liang ◽  
Chunhua Wu ◽  
...  

The ex-situ catalytic cracking of camelina oil using nickel loaded MCM-41 as catalyst at 450 °C in fixed bed reactor was studied. Results revealed that the yield, selectivity and chemical composition of the liquid products was improved by nickel loaded MCM-41 without affecting the crystalline structure of MCM-41. Moreover, the loaded nickel onto MCM-41 facilitated the cyclization, alkylation, aromatization, deoxygenation, isomerization and cracking reactions.


Author(s):  
Lyubov V. Furda ◽  
Dmitry E. Smalchenko ◽  
Evgeny N. Titov ◽  
Olga E. Lebedeva

The process of thermocatalytic conversion of polypropylene into liquid hydrocarbons using amorphous aluminum silicates with aluminum content of 1.6-12.9 wt.% as catalysts was studied. The aluminum silicates were synthesized by sol-gel method using hydrolysis of tetraethoxysilane in a presence of aluminum salt at pH=9. All samples possessed acidic sites with pKa value of 3.46-5.00 and had a developed surface. Textural properties of the aluminum silicates were determined. Thermocatalytic conversion of polypropylene was carried out in a flow fixed-bed reactor with a fixed layer of the mixture of the catalyst and the reagent at a mass ratio of polymer : catalyst of 3 : 1 in argon atmosphere with a gradual rise of temperature in the range of 300 – 450 ºС. The sample of silica, which did not contain aluminum, was demonstrated to be inactive in polypropylene degradation, while other catalysts provided conversion of polypropylene into liquid products. The highest yield of liquid products was 80% for a catalyst with an aluminum content of 8.1 wt.%. According to the results of GLC saturated hydrocarbons were identified among the products for all samples. The effect of the concentration of acidic centers on the chemical and fractional composition of the target products was shown. For the studied aluminum silicates with the same pKa values, an increase in the aluminum content favored the formation of a lighter hydrocarbon fraction. For the catalyst with the highest aluminum content the n-alkanes of С5-С10 composition were identified. These products were closest to gasoline oil fraction. This provides a possibility to consider secondary polyolefins as an alternative source of motor fuels. An influence of catalyst composition on maximal temperature of polyethylene degradation was determined by differential thermal analysis.


Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5497
Author(s):  
Olga Pleyer ◽  
Dan Vrtiška ◽  
Petr Straka ◽  
Aleš Vráblík ◽  
Jan Jenčík ◽  
...  

Catalytic hydrocracking represents an optimal process for both heavy petroleum fractions and Fischer–Tropsch (FT) wax upgrading because it offers high flexibility regarding the feedstock, reaction conditions and products’ quality. The hydrocracking of a heavy vacuum gas oil with FT wax was carried out in a continuous-flow catalytic unit with a fixed-bed reactor and a co-current flow of the feedstock and hydrogen at the reaction temperatures of 390, 400 and 410 °C and a pressure of 8 MPa. The increasing reaction temperature and content of the FT wax in the feedstock caused an increasing yield in the gaseous products and a decreasing yield in the liquid products. The utilisation of the higher reaction temperatures and feedstocks containing the FT wax showed a positive influence on the conversion of the fraction boiling above 400 °C to lighter fractions. Although the naphtha and middle distillate fractions obtained via atmospheric and vacuum distillations of the liquid products of hydrocracking did not comply with the particular quality standards of automotive gasolines and diesel fuels, the obtained products still present valuable materials which could be utilised within an oil refinery and in the petrochemical industry.


2020 ◽  
Vol 9 (2) ◽  
pp. 113-119
Author(s):  
Hendriyana Hendriyana ◽  
Lulu Nurdini ◽  
Rizqi Ajeng Khusnul Khotimah ◽  
Nur Refianti Sukandi ◽  
Tika Dwi Ainun ◽  
...  

Jatropha oil which is non-edible oil were hydro-crack at atmospheric pressure using an activated wood char catalyst in a fixed bed reactor. The hydro-cracking process was carried out at three temperature variations of 400, 450 and 500oC, and three variations of the oil feed injection rate of 2/2, 2/5 and 2 mL/10 minutes. The catalysts were characterized using SEM and BET. The composition of the liquid product obtained from the hydro-cracking process was analyzed using GC-MS. The effects of operating temperature and oil feed injection rate on oil recovery and conversion have been discussed. The results showed that the feed injection temperature and rate had an effect on the yield and conversion. The highest yield of 59.8% oil liquid products was achieved at a temperature of 450oC with injection rate of 2 mL/10 min. The composition of the oil-liquid product was dominated by heptanal at 32.9% -mass. Alkanes group contain C5 to C20 and alkene compounds consist of C8 until C18.


2013 ◽  
Vol 2013 ◽  
pp. 1-3
Author(s):  
Adnan Bulut ◽  
Selhan Karagöz

Table sugars were pyrolyzed at different temperatures (300, 400, and 500°C) in a fixed-bed reactor. The effect of pyrolysis temperature on yields of liquid, solid, and gaseous products was investigated. As expected the yield of liquid products gradually increased and the yield of solid products gradually decreased when the pyrolysis temperature was raised. The yield of liquid products was greatest (52 wt%) at 500°C. The composition of bio-oils extracted with diethyl ether was identified by means of gas chromatography mass spectrometry (GC-MS), nuclear magnetic resonance (1H-NMR), and Fourier transform infrared spectroscopy (FTIR). The following compounds were observed in bio-oils produced from the pyrolysis of table sugar at 500°C: 1,4:3,6-dianhydro-α-d-glucopyranose, 5-(hydroxymethyl) furfural, 5-acetoxymethyl-2-furaldehyde, and cyclotetradecane liquid product. The relative concentration of 5-(hydroxymethyl) furfural was the highest in bio-oils obtained from pyrolysis of table sugars at 500°C.


Author(s):  
Funda Ates ◽  
Ayse Eren Putun ◽  
Ersan Putun

Terpene hydrocarbons are high energy capacity hydrocarbons. The most known terpenoid biomass is Euphorbiaceae family. Euphorbia rigida, a member of Euphorbiaceae, was used as the biomass feedstock and natural zeolite was used as the catalyst in this study. In the experimental studies, firstly the raw material was analysed for its moisture, ash, volatile matter and fixed carbon. Then experiments were carried out in steam atmosphere in a fixed-bed reactor with a heating rate of 7 K/min, pyrolysis temperature of 823 K and mean particular size of 0.55 mm by mixing the catalyst to feedstock in different percentages. Experiments were performed with the catalyst ratios of 5, 10, 20 and 25 (weight-%) under steam atmosphere with the velocities of 12, 25 and 52 cm3/min to determine the effect of catalyst and steam on the product yields and bio-oil composition. Steam velocities were considered as the average steam velocities in the inlet tube of the reactor. The maximum bio-oil was reached to a value of 39.7% when using catalyst ratio of 20% and steam flow rate of 25 cm3/min. Pyrolysis oils were examined by using elemental analysis, IR and 1H-NMR spectroscopy. The liquid products were also fractionated by column chromatography and the gas chromatographic analysis of n-pentane eluate was performed.


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