Supercritical CO2 extraction (SCFE) is a safe method of efficient botanical extraction using a clean, non-toxic solvent ideal for cannabis, hops and more. Supercritical CO2 was applied to obtain extracts with high cannabinoids concentration. •. Different operating conditions and regimes were evaluated. Supercritical Fluid Extraction (SFE) is the process of separating one component ( the extractant) Extraction conditions for supercritical carbon dioxide are above the critical temperature of 31 °C and critical pressure of 74 bar. Addition of.
CO2 Extraction Supercritical
Technique Reversed-Phase Liquid Chromat Supercritical CO2 Based Techn Run your small scale chiral purification and analysis in a single, easy-to-use platform. Download the application note. Can't find a course? View the complete course list. View US Courses Schedule. Meet the Experts Webinar Series. Beginners Guide to Preparative LC.
Practical Approaches to Peptide Isolation. Search Waters KnowledgeBase - find answers to your troubleshooting questions. Blogging About What's Possible Read and follow the Waters blog for insights on how to use — and how customers use — our technologies, including Empower SFE Bio-Botanical Extraction System A multi-vessel botanical extraction system that rapidly extracts and fractionates botanical matrices. Large abundances of unsaturated fatty acids as well as phytosterols were detected in the wax Unsaturated fatty acids are also very useful platform molecules generating a wide variety of other chemicals [ 38 ].
The high abundance of these molecules is consistent with previous studies on maize stover wax extraction [ 16 ]. Furthermore, in addition to the extraction of high-value waxes, previous studies have shown that scCO 2 extraction also has a positive effect on the downstream processing of maize stover, enhancing yields for ethanol production [ 16 ].
The cellulose, hemicellulose and lignin content of the stover can be found in supplementary materials Table S2. This highlights the great potential of incorporating scCO 2 extraction as a first-step in a biorefinery, however, this will be meaningless if the extraction process is not economically viable. The extraction time was determined by investigating the SFE extraction kinetics using a laboratory-scale supercritical unit.
The extraction was carried out for 4 h, collecting samples at specific time intervals. It is assumed that the performance of the industrial scale unit should be the same or very similar to that of the laboratory supercritical unit. This should not be a problem if the bed density, particle size and the ratio between the mass of the solid and the CO 2 flow rate are kept constant. Typically, in an SFE process there are three linear regions in the extraction curve profiles; the constant extraction rate CER which corresponds to the extraction of solute molecules that are easily accessible and therefore convection in the solvent film surrounding the biomass particles dominates the mass transport, the falling rate period FER where both convection and diffusion effects play a role in mass transport and the third line which corresponds to a process that is entirely diffusion-controlled in this part of the extraction curve, the extraction rate is very low [ 39 ].
The maximum extraction rates are normally observed at the CER region and it is therefore necessary, from an economical perspective, to identify the CER region for extraction of solutes from maize stover. The total yield extracted after 4 h was found to be 0. The COM of extractives involves three main types of costs; direct Costs DC operational costs which are dependent on the production manufacturing rate and include raw material costs, operational labour, utilities among others , fixed costs FC not dependent on production rate and include territorial taxes, insurance, depreciation etc.
These three components of the COM are estimated in terms of five main costs: The COM of wax extraction with depreciation was calculated using the following equation [ 24 ]:. A typical industrial supercritical extraction unit used in the extraction of spices, natural pigments, nutraceuticals etc.
On a yearly basis, the fraction of investment is calculated by multiplying the total investment by the depreciation rate. Another part of the investment is the initial quantity of CO 2 that is required to fill the CO 2 reservoir; however this cost is generally negligible when comparing it to the extraction unit cost. In terms of man-hour per operation-hour, the total C OL is estimated by using tables which are presented by Ulrich The total time when the extraction columns are under operation was taken to be days per year of continuous 24 h per day shift which corresponds to h of continuous extraction.
This value is solely attributed to the work that the operators will carry out on the SFE of waxes. The operators will have other duties within the biorefinery and their overall wage would therefore be higher. Raw material costs for SFE include the solid substrate containing the solute to be extracted as well as the CO 2 that is lost in the extraction process.
The cost of the former includes the price of the biomass itself as well as all the cost of all the pre-processing steps leading to the final biomass product used in the extraction such as drying, comminution and cleaning.
Since wax extraction from maize comes from the waste following harvesting of the grain, i. Since maize stover has significant promise for the production of bioenergy, studies have been carried out on costs of corn stover. It is challenging to estimate an appropriate C RM for stover as an extensive literature search showed a large variation in the stover C RM Table 2.
In order to determine the effect of the price of the biomass three different calculations based on three different C RM values were carried out: In an industrial SFE unit, the CO 2 is recycled and therefore the only waste involved in the process is the CO 2 which leaks from the system and the exhausted solid.
The former is negligible while the exhausted stover biomass can be utilized further downstream as part of a biorefinery process or incorporated back into the soil for the uptake of nutrients. Therefore it can be assumed that little or no waste is generated during the extraction process.
Therefore the C WT can be ignored. Three types of costs are involved in the C UT ; the costs associated with the electric power used in the CO 2 pump, the costs associated with the CO 2 heater and costs associated with refrigeration.
In order to calculate electric power costs for the CO 2 pump the pressure and temperature applied during the extraction process as well as the extraction time were determined. The pressure and temperature utilized in the extraction process give the specific enthalpy, from which the total energy used in the extraction process can be obtained by multiplying the variation of specific enthalpy by the extraction time and the CO 2 mass flow rate.
When analyzing the extraction kinetics together with the cost of raw materials and total wax which could be extracted per day, it was found that it is more profitable to carry out 40 min extractions gives a higher overall wax yield per day and reduces the overall costs significantly when compared to 1 h extractions and therefore 40 min was selected as the time for each extraction.
The experimental bed density of the maize stover was found to be 0. The CO 2 mass flow rate required for the industrial-scale unit would be approximately The mass of carbon dioxide used per hour is Therefore the heat required in MJ , Q, was calculated as follows:. Thus the heat energy required is A number of studies have looked into the calorific content of corn stover. An average value from these studies was taken and it is assumed that the energy that is given off when burning dry maize stover is Therefore the amount of maize stover that is required is Therefore the energy which is required to heat the extractor may be obtained by burning A typical refrigeration cycle comprises of a working fluid circulated around a loop which is made up of a compressor, evaporator, expansion valve or turbine and condenser.
Refrigeration is more expensive than heating since it requires electrical power. In order to determine the refrigeration costs the energy required for refrigeration must be determined by calculating the coefficient of performance, COP. The main cost for the C UT is the electricity that is required to pump the CO 2 at the required pressure and temperature.
Raw material costs and labour costs contribute less to the COM. This value is only an estimate and is based on a number of assumptions. The costs can be improved by varying some of the parameters. First of all the figure for the amount of biomass that can be loaded into the supercritical extractor was based on milled biomass. In industry, biomass is normally received as pellets pelletized and this increases the biomass loading by three times [ 62 ].
Furthermore, in this study maize stover was used in the process, yielding 0. Maize leaves have a greater wax content than maize stover. If the maize leaves were used, then the wax yield is almost 2. This is a four-fold reduction in cost compared to stover wax. Finally, it was assumed in the calculations that the cost of raw materials C RM is solely for the supercritical extraction. As stated previously, the supercritical extraction is only the first step pre-treatment step in a biorefinery and thus the biomass will be passed on within the biorefinery for further processing.
The cost of raw materials must also be shared throughout the entire processes within the biorefinery. Since the supercritical extraction of waxes would be carried out as part of a biorefinery set-up, the maize stover biomass collected after the extraction would be passed on to the next stage of the biorefinery process and hence further lower the COM of the wax.
The least elegant and therefore lowest added value-step, would be to simply burn the waste biomass for energy recovery. Herein, cost estimations for electricity generation were carried out as an example of downstream processing of the biomass. Different technologies have different energy conversion efficiencies from biomass.
However, intense development is occurring within this area and a number of highly efficient technologies are emerging. Therefore two calculations were carried out: The inclusion of a more high value step within the biorefinery such as microwave pyrolysis of the biomass prior to energy recovery or fermentation of the stover for production of ethanol and surfactants, would further reduce the COM [ 15 , 16 ]. A detailed spreadsheet entitled Economics COM calculations containing all of the calculations may be found in supplementary materials Table S3.
Figure 3 is a schematic that summarizes the key results and highlights all the relevant material and energy inputs. In order to highlight the most relevant parameters, a simple one-at-a-time sensitivity analysis was carried out, whereby different parameter values were varied in order to identify the most relevant parameters. The maize stover was harvested after R6 stage silage from plants cultivated under field conditions near York UK.
The cobs were removed and the stover samples were milled to 0. The biomass was removed, weighed and placed in the convection oven once more. At specific intervals the biomass was weighed until a constant weight was achieved. Supercritical fluid grade carbon dioxide The required temperature and pressure were applied. An internal pump was used in order to obtain the required pressure bar. The system was run in dynamic mode, in which the carbon dioxide which contained the epicuticular lipids, was allowed to flow into the collection vessel.
Despite the promise of substantially higher efficiency and lower capital costs, the use of s CO 2 presents material selection and design issues. Materials in power generation components must display resistance to damage caused by high-temperature , oxidation and creep. Candidate materials that meet these property and performance goals include incumbent alloys in power generation, such as nickel-based superalloys for turbomachinery components and austenitic stainless steels for piping.
Components within s CO 2 Brayton loops suffer from corrosion and erosion, specifically erosion in turbomachinery and recuperative heat exchanger components and intergranular corrosion and pitting in the piping. Testing has been conducted on candidate Ni-based alloys, austenitic steels, ferritic steels and ceramics for corrosion resistance in s CO 2 cycles.
Given the volume of carbon fuels used in producing electricity, the environmental impact of cycle efficiency increases would be significant. Supercritical CO 2 is an emerging natural refrigerant, used in new, low carbon solutions for domestic heat pumps.
Supercritical CO 2 heat pumps are commercially marketed in Asia. EcoCute systems from Japan, developed by Mayekawa, develop high temperature domestic water with small inputs of electric power by moving heat into the system from the surroundings. Supercritical CO 2 has been used since the s to enhance recovery in mature oil fields.
Using gasifiers instead of conventional furnaces, coal and water is reduced to hydrogen gas, carbon dioxide and ash.
This hydrogen gas can be used to produce electrical power In combined cycle gas turbines, CO 2 is captured, compressed to the supercritical state and injected into geological storage, possibly into existing oil fields to improve yields. The unique properties of s CO 2 ensure that it remains out of the atmosphere. Supercritical CO 2 could be used as a working fluid in enhanced geothermal systems.
Possible advantages compared to water include higher energy yield resulting from its lower viscosity, better chemical interaction, CO 2 storage through fluid loss and higher temperature limit.
As of , the concept had not been tested in the field. Supercritical carbon dioxide is used in the production of silica, carbon and metal based aerogels. For example, silicon dioxide gel is formed and then exposed to s CO 2. When the CO 2 goes supercritical, all surface tension is removed, allowing the liquid to leave the aerogel and produce nanometer sized pores. Supercritical CO 2 is an alternative for terminal sterilization of biological materials and medical devices with combination of the additive peracetic acid PAA.
Supercritical CO 2 does not sterilize the media, because it does not kill the spores of microorganisms. Moreover, this process is gentle, as the morphology, ultrastructure and protein profiles of inactivated microbes are preserved.
Supercritical CO 2 is used in certain industrial cleaning processes. Natural extracts using supercritical carbon dioxide. From Wikipedia, the free encyclopedia. DeSimone and William Tumas, eds.
Supercritical fluid extraction
Supercritical carbon dioxide (sCO 2) is a fluid state of carbon dioxide where it is held at or Supercritical carbon dioxide is used as the extraction solvent for creation of essential oils and other herbal distillates. Its main advantages over. Supercritical CO2 extraction is an efficient and clean way of obtaining extracts that prevent plants' natural properties. This is currently the best method to produce. Many reactions, extractions, separations and other operations in the chemical process industries (CPI) involve the use of organic solvents.