In-situ catalytic upgrading of biomass pyrolysis vapor: Co-feeding with methanol in a multi-zone fixed bed reactor

The in-situ catalytic upgrading of the biomass pyrolysis vapor and its mixture with methanol were conducted in a fixed bed multi-zone reactor. The steps were comprised; thermally converting the biomass in the pyrolysis reactor, passing its vapor in contact with the HZSM-5 zeolite catalyst in the presence of methanol vapor, and transformation of the resulting upgraded pyrolysis vapor into the liquid product. The biomass pyrolysis and catalytic pyrolysis vapor upgrading were performed at 500 degrees C. The highly valuable chemicals production was a function of the hydrogen to carbon effective ratio (H/C-eff) of the feed. This ratio was regulated by changing the relative amount of biomass and methanol. More aromatic hydrocarbons (50.02 wt.) and less coke deposition on the catalyst (1.3 wt.) were yielded from the biomass, when methanol was co-fed to the catalytic pyrolysis process (H/C-eff = 1.35). In this contribution, the deposited coke on the catalyst was profoundly investigated. The coke, with high contents of oxo-aromatics and aromatic compounds, was generated by polymerization of biomass lignin derived components activated by catalyst acid sites. (C) 2015 Elsevier Ltd. All rights reserved

Effects of pretreatments of Napier Grass with deionized water, sulfuric acid and sodium hydroxide on pyrolysis oil characteristics

The depletion of fossil fuel reserves has led to increasing interest in liquid bio-fuel from renewable biomass. Biomass is a complex organic material consisting of different degrees of cellulose, hemicellulose, lignin, extractives and minerals. Some of the mineral elements tend to retard conversions, yield and selectivity during pyrolysis processing. This study is focused on the extraction of mineral retardants from Napier grass using deionized water, dilute sodium hydroxide and sulfuric acid and subsequent pyrolysis in a fixed bed reactor. The raw biomass was characterized before and after each pretreatment following standard procedure. Pyrolysis study was conducted in a fixed bed reactor at 600 o�C, 30 �C/min and 30 mL/min N2 flow. Pyrolysis oil (bio-oil) collected was analyzed using standard analytic techniques. The bio-oil yield and characteristics from each pretreated sample were compared with oil from the non-pretreated sample. Bio-oil yield from the raw sample was 32.06 wt% compared to 38.71, 33.28 and 29.27 wt% oil yield recorded from the sample pretreated with sulfuric acid, deionized water and sodium hydroxide respectively. GC–MS analysis of the oil samples revealed that the oil from all the pretreated biomass had more value added chemicals and less ketones and aldehydes. Pretreatment with neutral solvent generated valuable leachate, showed significant impact on the ash extraction, pyrolysis oil yield, and its composition and therefore can be regarded as more appropriate for thermochemical conversion of Napier grass

Solvothermal Liquefaction of Corn Stalk: Physico-Chemical Properties of Bio-oil and Biochar

This study investigated the conversion of corn stalk to bio-oil by solvothermal liquefaction using ethanol as a solvent. Effect of reaction temperature, time and solvent to biomass ratio on the yield and the properties of bio-oil and biochar was studied. Analysis of corn stalk and bio-oil were done to determine the surface functional groups, existing bonds and molecular structure of specified compounds. Investigations were done to identify different compounds in bio-oil, the thermal stability, and weight loss kinetics of biochar. Study shows that percentage yield of bio-oil increases with increase in temperature and time, up to a specific level, and then starts declining. Further, the heating value, carbon content, and fixed carbon content of both bio-oil and biochar increased to 30.52, 22.8 MJ/kg, and 66.42 and 61.25%, 26.10 and 27.97% respectively from those (19.55 MJ/kg, 51.12 and 6.36%) of the corn stalk. This study suggests that the bio-oil contained mostly phenolic compounds and its derivatives. Two major DTG peaks were observed at 380 and 620 °C indicating the improvement in thermal stability of the biochar after solvolysis liquefaction process. Investigation results can be very useful in optimizing process parameters for solvothermal liquefaction

Upgradation of chemical, fuel, thermal, and structural properties of rice husk through microwave-assisted hydrothermal carbonization

The process parameters of microwave hydrothermal carbonization (MHTC) have significant effect on yield of hydrochar. This study discusses the effect of process parameters on hydrochar yield produced from MHTC of rice husk. Results revealed that, over the ranges tested, a lower temperature, lower reaction time, lower biomass to water ratio, and higher particle size produce more hydrochar. Maximum hydrochar yield of 62.8% was obtained at 1000 W, 220 °C, and 5 min. The higher heating value (HHV) was improved significantly from 6.80 MJ/kg of rice husk to 16.10 MJ/kg of hydrochar. Elemental analysis results showed that the carbon content increased and oxygen content decreased in hydrochar from 25.9 to 47.2% and 68.5 to 47.0%, respectively, improving the energy and combustion properties. SEM analysis exhibited modification in structure of rice husk and improvement in porosity after MHTC, which was further confirmed from BET surface analysis. The BET surface area increased from 25.0656 m 2 /g (rice husk) to 92.6832 m 2 /g (hydrochar). Thermal stability of hydrochar was improved from 340 °C for rice husk to 370 °C for hydrochar