Recycling of spent solid CO2 adsorbents via catalytic pyrolysis for the recovery of mesoporous silica and valuable heteroaromatic chemicals

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Comparative study on catalytic and non-catalytic pyrolysis of olive mill solid wastes

In this study, catalytic and non-catalytic fast pyrolysis of dried olive husk and olive kernels was carried out. A bubbling fluidised bed reactor was used for the non-catalytic processing of the solid olive wastes. In-situ catalytic upgrading of biomass fast pyrolysis vapours was performed in a fixed bed bench-scale reactor at 500 °C, for catalyst screening purposes. A maximum bio-oil yield of 47.35 wt.% (on dry biomass) was obtained from non-catalytic fast pyrolysis at a reaction temperature of 450 °C, while the bio-oil yield was decreased at 37.14 wt.% when the temperature was increased to 500 °C. In the case of the fixed bed unit tests, the highest liquid (52.66 wt.%) and organics (30.99 wt.%) yield was achieved with the use of the non-catalytic silica sand. Depending on the catalytic material, the liquid yield ranged from 47.03 to 43.96 wt.% the organic yield from 21.15 to 16.34 wt.% on dry biomass. Solid products were increased from 28.23 wt.% for the non-catalytic run to 32.81 wt.% on dry biomass, when MgO (5% Co) was used

GC-MS analysis of alkylpyrazines in the pyrolysis oils of silica-polyethylenimine CO2 sorbents

Solid sorbents based on silica and polyethyleneimine (PEI) are intensively investigated in the field of carbon capture and storage (CCS). Pyrolysis was proposed as a thermal process to recover the pure silica from exhausted sorbents and convert PEI into potentially useful products, such as alkylated pyrazines. A GC-MS method based on internal standardisation with 2-methoxypyrazine was developed and evaluated to determine the concentration of six pyrazines in the pyrolysis oils of exhausted silica-PEI sorbent pyrolysed at 400, 500, 600 and 650°C. The most abundant pyrazines were 2-ethyl and 2,3-dimethyl, occurring at concentrations of 5-28 mg g−1, followed by pyrazine, 2-methyl, 2-ethyl-3-methyl and 2-propylpyrazine. The GC-MS results were compared to those from a HPLC-DAD method using the Welch's test. The 37 % discrepancy of concentrations was attributed to spectral interference in LC-DAD. GC was slightly less precise than HPLC, calibration errors were lower and enabled the identification of highly alkylated pyrazines. Both methods provided comparable values of total pyrazine yields (around 4-7 % by weight)

The decision rule approach to optimization under uncertainty: methodology and applications

Dynamic decision-making under uncertainty has a long and distinguished history in operations research. Due to the curse of dimensionality, solution schemes that naïvely partition or discretize the support of the random problem parameters are limited to small and medium-sized problems, or they require restrictive modeling assumptions (e.g., absence of recourse actions). In the last few decades, several solution techniques have been proposed that aim to alleviate the curse of dimensionality. Amongst these is the decision rule approach, which faithfully models the random process and instead approximates the feasible region of the decision problem. In this paper, we survey the major theoretical findings relating to this approach, and we investigate its potential in two applications areas

Production and characterization of bio-oil from catalytic biomass pyrolysis

Biomass flash pyrolysis is a very promising thermochemical process for the production of bio-fuels and/or chemicals. However, large-scale applications are still under careful consideration, because of the high bio-liquid upgrading cost. In this paper the production of bio-liquids from biomass flash pyrolysis in a single stage catalytic process is being investigated using a novel once through fluid bed reactor. This biomass pyrolysis unit was constructed in Chemical Process Engineering Research Institute and comprises of a catalyst regenerator, a biomass-vibrating hopper, a fluidization reactor (that consists of an injector and a riser reactor), a product stripper along with a hot cyclone and a filter housing and finally a product condensation/recovery section. The unit can process up to 20 g/min. of biomass (50-800 mm) and can circulate up to 300 g/min. of catalyst or inert material. The experiments performed in the pilot plant showed that the unit operates without problems and with satisfactory mass balances in a wide range of experimental conditions both in the absence and presence of catalyst. With the incorporation of an FCC catalyst in the pyrolysis, the physical properties of the bio-oil produced changed, while more stable bio-oil was produced.

PRODUCTION AND CHARACTERISATION OF BIO-OIL FROM CATALYTIC BIOMASS PYROLYSIS by

Bio mass flash py rol y sis is a very prom is ing thermochemical pro cess for the pro duc tion of bio-fu els and/or chem i cals. How ever, large-scale ap pli ca-tions are still un der care ful con sid er ation, be cause of the high bio-liq uid up grad ing cost. In this pa per the pro duc tion of bio-liq uids from bio mass flash py rol y sis in a sin gle stage cat a lytic pro cess is be ing in ves ti gated us ing a novel once through fluid bed re ac tor. This bio mass py rol y sis unit was con-structed in Chem i cal Pro cess En gi neer ing Re search In sti tute and com-prises of a cat a lyst re gen er a tor, a bio mass-vi brat ing hop per, a fluidization re ac tor (that con sists of an in jec tor and a riser re ac tor), a prod uct strip per along with a hot cy clone and a fil ter hous ing and fi nally a prod uct con den-sa tion/re cov ery sec tion. The unit can pro cess up to 20 g/min. of bio mass (50-800 mm) and can cir cu late up to 300 g/min. of cat a lyst or in ert ma te rial. The ex per i ments per formed in the pi lot plant showed that the unit op er ates with out prob lems and with sat is fac tory mass bal ances in a wide range of ex-per i men tal con di tions both in the ab sence and pres ence of cat a lyst. With the in cor po ra tion of an FCC cat a lyst in the py rol y sis, the phys i cal prop er ties of the bio-oil pro duced changed, while more sta ble bio-oil was pro duced. Key words: biomass, catalytic pyrolysis, bio-oil characterisatio

Aromatics from Beechwood Organosolv Lignin through Thermal and Catalytic Pyrolysis

Biomass fractionation, as an alternative to biomass pretreatment, has gained increasing research attention over the past few years as it provides separate streams of cellulose, hemicellulose, and lignin. These streams can be used separately and can provide a solution for improving the economics of emerging biorefinery technologies. The sugar streams are commonly used in microbial conversions, whereas during recent years lignin has been recognized as a valuable compound as it is the only renewable and abundant source of aromatic chemicals. Successfully converting lignin into valuable chemicals and products is key in achieving both environmental and economic sustainability of future biorefineries. In this work, lignin retrieved from beechwood sawdust delignification pretreatment via an organosolv process was depolymerized with thermal and catalytic pyrolysis. ZSM-5 commercial catalyst was used in situ to upgrade the lignin bio-oil vapors. Lignins retrieved from different modes of organosolv pretreatment were tested in order to evaluate the effect that upstream pretreatment has on the lignin fraction. Both thermal and catalytic pyrolysis yielded oils rich in phenols and aromatic hydrocarbons. Use of ZSM-5 catalyst assisted in overall deoxygenation of the bio-oils and enhanced aromatic hydrocarbons production. The oxygen content of the bio-oils was reduced at the expense of their yield. Organosolv lignins were successfully depolymerized towards phenols and aromatic hydrocarbons via thermal and catalytic pyrolysis. Hence, lignin pyrolysis can be an effective manner for lignin upgrading towards high added value products

Utilisation of poultry industry wastes for liquid biofuel production via thermal and catalytic fast pyrolysis

###EgeUn###The objective of this study was to examine the potential of poultry wastes to be used as feedstock in non-catalytic and catalytic fast pyrolysis processes, which is a continuation of our previous research on their conversion into biofuel via slow pyrolysis and hydrothermal conversion. Both poultry meal and poultry litter were examined, initially in a fixed bed bench-scale reactor using ZSM-5 and MgO as catalysts. Pyrolysis of poultry meal yielded high amounts of bio-oil, while pyrolysis of poultry litter yielded high amounts of solid residue owing to its high ash content. MgO was found to be more effective for the deoxygenation of bio-oil and reduction of undesirable compounds, by converting mainly the acids in the pyrolysis vapours of poultry meal into aliphatic hydrocarbons. ZSM-5 favoured the formation of both aromatic compounds and undesirable nitrogenous compounds. Overall, all bio-oil samples from the pyrolysis of poultry wastes contained relatively high amounts of nitrogen compared with bio-oils from lignocellulosic biomass, ca. 9wt.% in the case of poultry meal and ca. 5-8wt.% in the case of poultry litter. This was attributed to the high nitrogen content of the poultry wastes, unlike that of lignocellulosic biomass. Poultry meal yielded the highest amount of bio-oil and was selected as optimum feedstock to be scaled-up in a semi-pilot scale fluidised bed biomass pyrolysis unit with the ZSM-5 catalyst. Pyrolysis in the fluidised bed reactor was more efficient for deoxygenation of the bio-oil vapours, as evidenced from the lower oxygen content of the bio-oil.European UnionEuropean Union (EU) [284498]The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The financial support of this work by the European Union FP7 project, with the title 'Biofuels Research Infrastructure for Sharing Knowledge (BRISK)', under grant agreement no. 284498 is gratefully acknowledged

Effect of Steam Deactivation Severity of ZSM-5 Additives on LPG Olefins Production in the FCC Process

ZSM-5-containing catalytic additives are widely used in oil refineries to boost light olefin production and improve gasoline octanes in the Fluid Catalytic Cracking (FCC) process. Under the hydrothermal conditions present in the FCC regenerator (typically >700 °C and >8% steam), FCC catalysts and additives are subject to deactivation. Zeolites (e.g., Rare Earth USY in the base catalyst and ZSM-5 in Olefins boosting additives) are prone to dealumination and partial structural collapse, thereby losing activity, micropore surface area, and undergoing changes in selectivity. Fresh catalyst and additives are added at appropriate respective levels to the FCC unit on a daily basis to maintain overall targeted steady-state (equilibrated) activity and selectivity. To mimic this process under accelerated laboratory conditions, a commercial P/ZSM-5 additive was hydrothermally equilibrated via a steaming process at two temperatures: 788 °C and 815 °C to simulate moderate and more severe equilibration industrial conditions, respectively. n-Dodecane was used as probe molecule and feed for micro-activity cracking testing at 560 °C to determine the activity and product selectivity of fresh and equilibrated P-doped ZSM-5 additives. The fresh/calcined P/ZSM-5 additive was very active in C12 cracking while steaming limited its activity, i.e., at catalyst-to-feed (C/F) ratio of 1, about 70% and 30% conversion was obtained with the fresh and steamed additives, respectively. A greater activity drop was observed upon increasing the hydrothermal deactivation severity due to gradual decrease of total acidity and microporosity of the additives. However, this change in severity did not result in any selectivity changes for the LPG (liquefied petroleum gas) olefins as the nature (Brønsted-to-Lewis ratio) of the acid/active sites was not significantly altered upon steaming. Steam deactivation of ZSM-5 had also no significant effect on aromatics formation which was enhanced at higher conversion levels. Coke remained low with both fresh and steam-deactivated P/ZSM-5 additives

Acid Assisted Organosolv Delignification of Beechwood and Pulp Conversion towards High Concentrated Cellulosic Ethanol via High Gravity Enzymatic Hydrolysis and Fermentation

Background: Future biorefineries will focus on converting low value waste streams to chemical products that are derived from petroleum or refined sugars. Feedstock pretreatment in a simple, cost effective, agnostic manner is a major challenge. Methods: In this work, beechwood sawdust was delignified via an organosolv process, assisted by homogeneous inorganic acid catalysis. Mixtures of water and several organic solvents were evaluated for their performance. Specifically, ethanol (EtOH), acetone (AC), and methyl- isobutyl- ketone (MIBK) were tested with or without the use of homogeneous acid catalysis employing sulfuric, phosphoric, and oxalic acids under relatively mild temperature of 175 °C for one hour. Results: Delignification degrees (DD) higher than 90% were achieved, where both AC and EtOH proved to be suitable solvents for this process. Both oxalic and especially phosphoric acid proved to be good alternative catalysts for replacing sulfuric acid. High gravity simultaneous saccharification and fermentation with an enzyme loading of 8.4 mg/gsolids at 20 wt.% initial solids content reached an ethanol yield of 8.0 w/v%. Conclusions: Efficient delignification combining common volatile solvents and mild acid catalysis allowed for the production of ethanol at high concentration in an efficient mannerValiderad;2018;Nivå 2;2018-07-19 (inah)</p