Physical and Chemical Properties and Accelerated Aging Test of Bio-oil Produced from in Situ Catalytic Pyrolysis in a Bench-Scale Fluidized-Bed Reactor

Abstract

In situ catalytic upgrading is a promising technique to improve the properties of bio-oil because the bio-oil produced from the conventional method has several negative attributes, such as low heating value and highly acidic nature, and is also unstable during storage. In this study, the catalytic effect of CaO, MgO, and ZSM-5 as in situ upgrading catalysts during biomass pyrolysis was studied in a fluidized-bed reactor. Southern pine sawdust was subjected to pyrolysis with inert bed material (quartz sand) and subsequently with the catalysts. The quality of bio-oil obtained was compared to the baseline values (i.e., with the use of sand as bed material without any catalyst) in terms of its chemical composition, heating value, viscosity, pH, total acid number (TAN), and oxygen and water contents. The use of CaO resulted in an improvement in pH (2.39−3.98) and TAN (88.9−46.6) of the bio-oil when compared to the results when using only sand. In comparison, MgO was a mild catalyst because it altered the bio-oil quality slightly, while ZSM-5 had no effect on the acid content in bio-oil, although it produced bio-oil with the least oxygen content at a significantly lower yield and higher water content (38.5%). In terms of chemical composition, the catalysts exhibited different behaviors to various groups of compounds. Anhydrosugars were reduced by all of the catalysts tested to different extents, but CaO significantly altered the quality of bio-oil by reducing organic acids, while CaO and ZSM-5 reduced the abundance of phenolic compounds with a higher oxygen content. An accelerated aging test was performed to compare the efficacy of these in situ catalysts on improving the stability of bio-oil, and it was observed that the bio-oil produced using CaO was the most stable when compared to the baseline and other catalytic bio-oils tested in this study.

Characterization of bamboo species at different ages and bio-oil production

“…1), which was modified from Mahadevan's study [27]. A screw feeder was driven by a motor to transfer biomass from a biomass feeder to fluidized bed reactor.…”

Aspen plus simulation to predict steady state performance of biomass‐CO2 gasification in a fluidized bed gasifier

“…cellulosic ethanol) or thermochemical (e.g. gasification, combustion, pyrolysis, and hydrothermal liquefaction) routes . Gasification is the process of partial combustion of biomass to produce a high calorific value gas, syngas, which is a combination of CO, H 2 , CH 4 , and CO 2 along with tar (condensable organic compounds) and other contaminants (NH 3 , H 2 S, HCN, etc.)…”

“…The main aim of this current study was to develop a model that is able simulate the steady‐state output of the bench scale atmospheric fluidized bed gasifier that was experimentally studied in the earlier parts of this research. Experimental studies were conducted earlier in the course of this research to investigate the effects of temperature and CO 2 flow rate on biomass‐CO 2 gasification, and understand the chemistry of the process in a fluidized bed gasifier (reactor volume: 97 in; fluidized bed volume: 71 in) . This study identified the reactions dominating the process throughout the gasification temperature range.…”

Graudkopības atlikumu vidēji ātrā pirolīze

“…Lai novērotu katalītisko efektu zinātniskos pētījumos parasti izmanto katalizatoru daudzumu, kas pēc masas ir līdzīgs [121,122,123] vai pat pārsniedz biomasas daudzumu [124].…”

“…Veses ar līdzautoriem[131] novēroja, ka CaO klātbūtnē notiek intensīva policiklisko aromātisko ogļūdeņražu veidošanās, līdzīgu tendenci termiski apstrādāta dolomīta klātbūtnē novēro arī Zhang ar līdzautoriem[227]. Autori secina, ka lignocelulozes pirolīzes , formaldehīds, acetaldehīds un acetons, tādēļ arī kviešu salmu pirolīzes procesā novēro ketonu un aldehīdu relatīvā iznākuma palielināšanos.Taču ketonu un aldehīdu veidošanās katalītiskajā kviešu salmu pirolīzē nav tik intensīva, cik ir organisko skābju daudzuma samazinājums CaO, Ca(OH)2 un 850 °C termiski apstrādāta dolomīta Kā jau iepriekš minēts, CaO, Ca(OH)2 un 850 °C termiski apstrādāta dolomīta (CaO•MgO) ietekmē novēro olefīnu relatīvā iznākuma palielināšanos, olefīnu veidošanās lignocelulozes procesā ir saistīta ar spirtu dehidratācijas reakcijām.Līdzīgu tendenci, ka kalciju saturošie katalizatori spēj samazināt anhidrocukuru un spirtu veidošanos, novēro arī citu autoru darbos[122,123,142], Patwardhan ar līdzautoriem[142] apgalvo, ka atšķirībā no ceolītiem, kas veicina furāna atvasinājumu veidošanos no anhidrocukuriem,…”