There is growing interest in the novel concept of operating Enhanced Geothermal Systems (EGS) with CO2 instead of water as heat transmission fluid. Initial studies have suggested that CO2 will achieve larger rates of heat extraction, and can offer geologic storage of carbon as an ancillary benefit. Fluid-rock interactions in EGS operated with CO2 are expected to be vastly different in zones wit...

Engineered geothermal systems (EGS) present an opportunity to expand the implementation of geothermal power. There has been some interest in the possible application of CO2 as a heat extraction fluid in these systems instead of water, due to a variety of inherent benefits, including being a nonpolar fluid, low viscosity at the temperatures and pressures within the reservoir and a large buoyancy...

Supercritical fluid and ultrasound assisted extractions were applied as a first step in a complex processing of spruce bark in order to recover polyphenols compounds. The aim of the study was to compare the efficiency of these "green" processes with a conventional extraction technique (ethanolic extraction). Supercritical fluid extraction was carried out in two steps: (i) static extraction for ...

Highest yield of eugenol-rich fractions from Cinnamomum tamala (bay leaf) leaves were obtained by supercritical carbon dioxide (SC-CO2), compared to hydro-distillation, organic solvents, liquid CO2 and subcritical CO2 extractions. Optimization of SC-CO2 extraction parameters was carried out to obtain an extract with maximum eugenol content. This was achieved using a sample size of 10g at 55°C, ...

Emission metrics aggregate climate impacts of greenhouse gases to common units such as CO2-equivalents (CO2-eq.). Examples include the global warming potential (GWP), the global temperature change potential (GTP) and the absolute sustained emission temperature (aSET). Despite the importance of biomass as a primary energy supplier in existing and future scenarios, emission metrics for CO2 from f...

Preliminary communication The interest in high pressure technology during last decades increased intensively. Supercritical Fluid Extraction (SFE) is a process that is growing in importance as an alternative to conventional separation processes. SFE uses environmentally friendly CO2 as the extracting agent in the process because of its relatively low critical pressure (7,38 MPa), its low critic...

Carotenoids are well known for their nutritional properties and health promoting effects representing attractive ingredients to develop innovative functional foods, nutraceutical and pharmaceutical preparations. Pumpkin (Cucurbita spp.) flesh has an intense yellow/orange color owing to the high level of carotenoids, mainly α-carotene, β-carotene, β-cryptoxanthin, lutein and zeaxanthin. There is...

Extraction of compounds from microalgae requires cell disruption as a pretreatment to increase extraction yield. Botryococcus braunii is a microalga with a significant content of carotenoids and other antioxidant compounds, such as chlorophylls. Cell disruption of B. braunii using CO2 rapid depressurization was studied as a pretreatment for the extraction of carotenoid and chlorophyll pigments....