Upgrading Pyrolysis Oil to Produce Liquid Transportation Fuels

The effects of stabilizing fast pyrolysis oil via catalytic alcohol pretreatment on upgrading via hydrodeoxygenation or thermal treatment was studied by comparing the properties of upgraded-stabilized oils with those of upgraded-non-stabilized oils (benchmarks). The major expected effect was reduction in molar mass of upgraded oils, as stabilization was expected to reduce the reactivity of fast pyrolysis oil, thereby reducing polymerization. It was observed that molar mass reduction was induced by dilution effect of the alcohol rather than reactivity reduction due to stabilization. Also, the effects of different alcohols on stabilization and subsequent upgrading were examined at minimized dilution effect conditions. Stabilization did not significantly affect the molar mass distribution of upgraded oils. However, other properties (e.g. CO2 production and H2 consumption) were significantly affected by stabilization

Recovery of Volatile Fatty Acids from Fermented Wastewater by Adsorption

Separation of volatile fatty acids (VFAs) from fermented wastewater is challenging, due to low VFA concentrations in mineral-rich streams. As a result, separation capacity and selectivity with traditional solvents and adsorbents are both compromised. In this study, using a complex artificial model solution mimicking real fermented wastewaters, it is shown that a simple and robust adsorption-based separation technique can retain a remarkable capacity and selectivity for VFAs. Four types of polystyrene-divinylbenzene-based resins (primary, secondary, and tertiary amine-functionalized, and nonfunctionalized) were examined as the adsorbents. The presence of chloride, sulfate, and phosphate salts resulted in coadsorption of their acidic forms HCl, H2SO4, and H3PO4 on amine-functionalized adsorbents, and severely reduced the VFA capacity. With the nonfunctionalized adsorbent, almost no mineral acid coadsorption was observed. This together with a high total VFA capacity of up to 76 g/kg in equilibrium with the model solution containing a total VFA concentration of 1 wt % resulted in a very high selectivity for the VFAs. Nitrogen-stripping with various temperature profiles was applied to regenerate the adsorbent, and study the potential for fractionation of the VFAs during regeneration. Butyric acid (HBu) was obtained in mole fractions of up to 0.8 using a stepwise increase in the stripping temperature from 25 °C via 120 to 200 °C. During four successive adsorption-regeneration cycles, no reduction in the adsorption capacity was observed

Extraction of volatile fatty acids from fermented wastewater

Valorization of wastewater streams can be done by fermentation to produce volatile fatty acids (VFAs) which are applied as platform chemicals for synthesis of value-added chemicals. Since VFA concentration in fermented wastewater is very low (∼1 wt%) and fermented wastewater contains considerable amounts of dissolved salts, recovery of VFAs from fermented wastewater is challenging. To study the potential of some ionic liquids compared to traditional solvents for extraction of VFAs from fermented wastewater, a detailed study on the effects of various salt-originating ions on VFA extraction was performed. Ion exchange and intermolecular interactions (e.g. hydrogen bonding) were found to be responsible for extraction of VFAs. The presence of salts (e.g. KCl) resulted in extraction of acidic forms of salt-originating anions (e.g. H+ + Cl−). 20 wt% trioctylamine (TOA) in n-octanol (representing conventional solvents) and [P666,14][Phos] (an ionic liquid) were found to be the most promising VFA-extracting solvents. Their maximum VFA loadings while being in equilibrium with an artificial fermented wastewater were determined by performing cross-current extractions. [P666,14][Phos] achieved a higher maximum VFA loading which enables it to deliver a much more concentrated VFA stream at a lower solvent to feed ratio (S/F)

Liquid-liquid extraction-based process concepts for recovery of carboxylic acids from aqueous streams evaluated for dilute streams

In this manuscript carboxylic acid extraction processes are reviewed and compared on energy efficiency, especially in situations with very low carboxylic acid concentrations. Production of carboxylic acids by fermentation rather than petrochemical routes aims at reducing dependency on petroleum resources. Wastewater streams are potential carbon sources for fermentation. However, their limited carbon content results in low carboxylic acid concentrations (∼1 wt%) that render separation of waste-derived carboxylic acids challenging. This necessitates implementation of cost-effective separation concepts. The incentive to review liquid–liquid extraction (LLX)-based processes for carboxylic acids was to evaluate their applicability to low carboxylic acid concentrations. Although a thorough study of recent solvent developments was beyond the scope of this work, a brief discussion on their families supported the LLX-based process developments that were assessed in terms of energy demand by simulating their thermal unit operations with Aspen Plus. They were simulated both under their reported conditions and with their initial concentration set to 1 wt%. A process proposed by Urbas (1983) that makes use of CO2, CO2-switchable solvents and low-boiling organic solvents outperformed the others for low carboxylic acid feed concentrations. With a heating duty of about 36 MJ/kgproduct, it could recover both volatile and non-volatile carboxylic acids from fermentation broths with 1 wt% initial carboxylic acid loading. Future developments in the field may be based on this process design, but with more environmentally friendly solvents such as the bio-based furan derivatives

Hydrotreatment of fast pyrolysis oil: Effects of esterification pre-treatment of the oil using alcohol at a small loading

Aiming to retard the self-polymerization of the reaction intermediates during bio-oil upgrading process, a large amount of alcohol (e.g., 50 wt% with respect to bio-oil) was used in the stabilization of fast pyrolysis oil by esterification before hydrotreatment by the authors in a previous work. In order to reduce the amount of alcohol use and hence improve the process economy, effects of stabilizing fast pyrolysis oil by esterification with methanol, ethanol or glycerol at a small loading (5 wt% w.r.t. bio-oil) in the presence of Amberlyst-35 DRY - A solid acid catalyst on the subsequent hydrotreatment of the oil were investigated. The bio-oil hydrotreatment experiments were carried out at 300 and 350 °C in a combined batch and semi-batch operation mode with Ru/C catalyst. The results demonstrated that, although stabilization of the pyrolysis oil by esterification with a small alcohol loading had least effects on the mass and carbon distribution in the hydrotreatment products and the elemental composition of the hydrotreated oil products, it could effectively reduce the molecular weight of the feed, prevent self-polymerization and decrease the overall molecular weight of the hydrotreated oil products

Recovery and conversion of acetic acid from a phosphonium phosphinate ionic liquid to enable valorization of fermented wastewater

Production of volatile fatty acids (VFAs) by fermentation is a potential sustainable alternative for conventional petrochemical routes to VFAs. Due to the low VFA content of fermentation broths, robust and economical separation technology has to be devised to recover the VFA. Liquid-liquid extraction of VFAs with the phosphonium phosphinate ionic liquid (IL) [P 666,14 ][Phos] allows good VFA extractability. For an extraction process using [P 666,14 ][Phos] to be green, it is essential to efficiently regenerate the solvent and recover the VFA. To obtain insight into the (strong) intermolecular interactions between [P 666,14 ][Phos] and acetic acid, selected as a model VFA, 1 H NMR, 31 P NMR, FT-IR and isothermal titration calorimetry (ITC) were applied. The observations were used to interpret operations to recover acetic acid from the IL, which included evaporation at elevated temperature under vacuum, possibly assisted by nitrogen stripping, in situ esterification and back-extraction with volatile bases. Through evaporative regeneration with nitrogen stripping, HAc could be removed, but only down to an HAc/IL molar ratio of 1. The remaining molar equivalent of HAc-IL interacts tightly with the IL by partial proton transfer and strong hydrogen bonding interactions with the phosphinate anion. Back-extraction of HAc with trimethylamine (TMA) and subsequent decomposition of the HAc-TMA complexes allowed for successful IL regeneration. This process uses ten times less amine (TMA) than conventional amine-based extraction processes (e.g. tri-n-octyl amine), and provides a sustainable process route to obtain pure carboxylic acids from highly diluted aqueous solutions without generating large streams of byproducts. Further valorization via in-line vaporization/catalytic ketonization or via in-line thermal decomposition and ketonization of the TMA-HAc salt was also demonstrated, showing the potential of the VFAs as a green platform for bio-based chemicals

Geothermal exploration in Indonesia based on Mineralogy and Hydrothermal Alteration

Indonesia with its large, but partially unexplored geothermal potential is one of the most interesting and suitable places in the world to conduct geothermal exploration research. This study focuses on geothermal exploration based on fluid-rock geochemistry/geomechanics and aims to compile an overview on geochemical data-rock properties from important geothermal fields in Indonesia. The research carried out in the field and in the laboratory is performed in the framework of the GEOCAP cooperation (Geothermal Capacity Building program Indonesia-the Netherlands). The application of petrology and geochemistry accounts to a better understanding of areas where operating power plants exist but also helps in the initial exploration stage of green areas. Because of their relevance and geological setting geothermal fields in Java (Wayang Windu, Tanguban Perahu) have been visited so far. Mount Salak, Gunung Slamet (Java) and Flores surveys are planned in the near future. Operators, universities and governmental agencies will benefit from this approach as it will be applied also to new green-field terrains. By comparing the characteristics of the fluids, the alteration petrology and the rock geochemistry we also aim to compile an overview of the geochemistry of several geothermal fields in Indonesia. The gathering of this information is the base for the geomechanical experiments on-going at TUD. At the same time the rock petrology and fluid geochemistry will be used as input data to model the reservoir fluid composition along with T-P parameters with the geochemical workbench PHREEQC. The field and laboratory data are mandatory for both the implementation and validation of the model results. If successful, this approach can be applied in many geothermal fields characterized by steep terrain and tropical vegetation, which hampers the classical seismic-geophysical exploration methods.Petroleum EngineeringApplied Geophysics and Petrophysic