No abstract

No abstract

Hydrothermal co-liquefaction of mixed (wet and dry) biomass residue streams would greatly enhance the viability and scale up potential of the technology as platform in bioenergy and biorefinery applications. This study aims to identify possible interaction effects between three different feeds (protein-rich microalgae, lignocellulosic wood, and carbohydrate-rich sugar beet pulp) and to broaden the data set for evaluating this concept. Co-liquefaction was evaluated at 250 and 350°C at 10 min of holding time, using 10 wt%( in water) binary mixtures (1:1 wt basis) and a (1:1:1 wt basis) ternary mixture. Results show that interaction during co-liquefaction does play a role and especially reduced the amount of biocrude produced. The biocrude yields obtained are around 15 and 40% below the estimated values for binary and ternary mixtures, on basis of linear averaging the results for the single feeds. For mixtures including algal biomass, a more than proportional nitrogen content and fraction of high molecular mass components was found in the biocrude. For the predictability of biocrude yield and composition in case of biomass mixtures, more work is needed to unravel these interactions.

No abstract

One of the most efficient among the methods of managing waste tire rubber is the pyrolysis process which allows for obtaining pyrolysis oil. The as-received, raw tire pyrolysis oil (rTPO) is a complex mixture whose components exhibit a wide boiling temperature range, reflected in the physicochemical properties influencing injection, combustion, performance, and emission. The present contribution is aimed at producing TPO via steam-assisted pyrolysis followed by its fractionation by vacuum distillation. The resultant TPO fractions were analyzed in terms of composition as well as physicochemical parameters. The products are liquids with a relatively high density, poor volatility, and satisfactory low-temperature properties. They exhibit a mutually similar chemical composition reflected in a roughly the same Watson factor. The dominant components are cyclic and aromatic compounds, as was proven by gas chromatography coupled to mass spectrometry analysis and mid-infrared Fourier transform spectroscopy. Such a characteristic of the TPO fractions opens the way to utilize them either as additives to conventional automotive fuels or for heat and power generation. In particular, the two lightest fractions demonstrate high potential as fuel additives. Among the advantages of the fractionation of rTPO, one of the most important is the effect of the accumulation of sulfur-containing compounds in the highest boiling fractions, namely, vacuum fractionation allowed for reduction of the S content by 69.6 and 43.5 wt % (with regard to the rTPO) for the fractions boiling up to 180 and 180–250 °C, respectively. Thus, fractionation of pyrolysis oils could be used also as an ingenious and effective pretreatment method prior to exact desulfurization.

Hydrothermal liquefaction of biomass in near-/supercritical water has attracted great attention in recent years. Although this technology seems to be promising for transformation of microalgal biomass, the information on the impact of feedstock and processing variables of continuous hydrothermal liquefaction on the properties of bio-oil provided in previous literature is scarce. Herein, the low-lipid Scenedesmus sp. biomass has been transformed to bio-oils through continuous hydrothermal liquefaction under various process conditions. The influence of temperature and residence time on bio-oil characteristic was discussed based on characterization by IR, GC-MS and gel permeation chromatography. The relative degree of branching of carbon chain of bio-oils components was estimated based on deconvolution of methyl and methylene IR absorption bands. The presumptive pathways of the reactions have been postulated. Finally, it was found that the parameters of bio-oil may be tailored by adjustment of processing variables, however, possible subsequent/parallel effects must be considered while designing the process.

No abstract

No abstract