Search results for "liquefaction"

Liquefaction and re-liquefaction of sediments induced by uneven loading and glacigenic earthquakes: Implications of results from the Latvian Baltic S…

2021

Abstract Seven internally-deformed layers were recognised in the shallow marine bay sediments deposited during mid Marine Isotope Stage 2 along the Latvian Baltic Sea coast bluff at Baltmuiža. Detailed sedimentological analyses of these deformed layers indicate that liquefaction was responsible for the development of soft-sediment deformation structures (SSDS) including injection structures, load casts, flame structures and pseudonodules. Traces of both initial liquefaction and re-liquefaction were recognised within at least four of the seven layers with SSDS (two different generations of pseudonodules and injection structures, clastic injection pipes, disrupted load casts). This is a uniqu…

Robust Mesoporous CoMo/γ-Al2O3 Catalysts from Cyclodextrin-Based Supramolecular Assemblies for Hydrothermal Processing of Microalgae: Effect of the P…

2018

Hydrothermal liquefaction (HTL) is a promising technology for the production of biocrude oil from microalgae. Although this catalyst-free technology is efficient under high-temperature and high-pressure conditions, the biocrude yield and quality can be further improved by using heterogeneous catalysts. The design of robust catalysts that preserve their performance under hydrothermal conditions will be therefore very important in the development of biorefinery technologies. In this work, we describe two different synthetic routes (i.e., impregnation and cyclodextrin-assisted one-pot colloidal approach), for the preparation in aqueous phase of six high surface area CoMo/γ-Al2O3 catalysts. Cat…

Hydrothermal liquefaction of wood using a modified multistage shrinking-core model

2020

Abstract Wood liquefaction in hot compressed water is modeled using the hydrolysis of Cellulose, Hemicellulose, and Lignin. These three components are reacted under catalyst-free subcritical conditions in a temperature range from 553 K to 640 K, and the heating rate ranges from 2 K/min to 6 K/min. Using a simplified reaction scheme, water-soluble products 1 (WSP), Biocrude, char, and gas are generated through intermediates with each wood component. A modified multistage shrinking core model is employed to simulate biomass particle degradation. The reaction and kinetic regime of the hydrothermal liquefaction 2 (HTL) process are treated separately for each wood component. Although the lack of…

Numerical modeling and validation of hydrothermal liquefaction of a lignin particle for biocrude production

2021

Abstract Lignin liquefaction process under catalyst-free conditions in a temperature range from 573 K to 647 K is investigated with this mathematical model. Based on the theoretical understanding of the physical and chemical processes of the liquefaction process in subcritical temperatures, a comprehensive mathematical model for the decomposition of lignin by hydrolysis reaction pathway is developed on the results of a series of batch experiments. The model consists of four main sections. They are liquefaction of lignin particle, oily film, and inorganic (ash) layer formation behavior during the liquefaction, kinetic model to model further liquefaction process of initial products, and the l…

Petri Net Modelling of the Starch Enzymatic Liquefaction

2012

This paper investigates the use of the Petri Net modelling language for the description and analysis of the enzymatic reactions that are used for the starch liquefaction. The Coloured Petri Net formalism supported by the CPN Tools modelling and simulation environment is used. The pools of substrates and products are represented as the places and the possible reactions as the transition of the net. The concurrent reactions are modelled trough transitions that are enabled at the same time. The occurrence probabilities associated with each of these concurrent transitions are chosen as the model parameters. The analysis of the specific properties of the model is used to fit the model to data fr…

Injection structures and load casts in lagoon sediments (Sārnate outcrop, W Latvia)

2018

HYDROTHERMAL LIQUEFACTION OF WASTE BIOMASS FOR THE PRODUCTION OF FUELS

2021

Characterization and Evaluation of Hydrothermal Liquefaction Char from Alkali Lignin in Subcritical Temperatures.

2021

An evaluation of hydrothermal liquefaction (HTL) char is investigated in this work. Morphological studies, N2 adsorption behavior, FTIR analysis, thermal behavior, and elemental composition are studied. The HTL char yield showed an increase with higher operating temperatures. It increased from 11.02% to 33% when the temperature increased from 573 K to 623 K. At lower temperatures, the residence time showed an impact on the yield, while close to the critical point, residence time became less impactful. Elemental analysis showed that both higher operating temperatures and longer residence times increased the nitrogen content of the chars from 0.32% to 0.51%. FTIR analysis suggested the char b…

Effect of transition metals and homogeneous hydrogen producers in the hydrothermal liquefaction of sewage sludge

2022

Hydrothermal liquefaction (HTL) of sewage sludge (SS) was performed in the presence of metallic Zn, Fe and Ni to investigate their effect on the performances of the process in terms of product yields and quality. Experiments were performed in subcritical water at 350 ◦C for 10 min using each metal individually and in the presence of homogenous hydrogen producers like formic acid (FA) and KOH. Interesting results were obtained with Zn that when used alone or in the presence of KOH, increased the cumulative biocrude (BC) yields and resulted in energy recoveries (ER) higher than 100% with respect to initial energy content of the biomass, thus indicating that HTL of SS is globally endothermic. …

Procédé de Liquéfaction, Saccharification et Fermentation Simultanée à Très Haute Gravité utilisant de la farine de manioc pour la production de l'ét…

2021

A simultaneous liquefaction, saccharification and fermentation (SLSF) process at very high gravity of cassava flour for potable ethanol production was developed at lab (1 L) and pilot scale (15 L and 1000 L). Cassava flour (CF) was mixed with tap water to obtain a concentration of 270 g/L dry matter. Sequentially, the mixture of a native starch hydrolyzing enzyme containing a mixture of alpha–amylase and gluco-amylase (Stargen 002 at 2565 GAU/kg CF), gluco-amylase (Amigase Mega L at 0.105% w/w), active dry yeast Saccharomyces cerevisiae (Red Ethanol at 3,5 × 10^7 cells/ml), KH2PO4 (9,9 mM) and urea (16.0 mM) was added into cassava slurry. The SLSF-VHG process including three steps of liquef…