question: Why is it so hard to capture co2?
comment: CO2 is a low energy molecule. Gasoline, for example, is a very high energy molecule. You can light it on fire and it produces a lot of heat energy. There is a lot of energy store in gasoline. There is also a lot of energy in oxygen, O2 molecules. Capturing CO2 isn't super hard, but if you want to convert it into something else, like carbon and O2, that take energy. We have this ability. We can use energy to break CO2 into Carbon and Oxygen. The problem is, we get almost all our energy from burning carbons. Burning carbons produces CO2. To get the energy we need to capture CO2, we first need to release CO2. its a catch 22. We can't even produce all the energy we need today without burning carbons. So producing extra energy to recapture the carbon we already release, is a very tall order.
passages: Many man-made chemicals are derived from fossil fuels (such as petroleum or coal) in which C is greatly depleted. CO--or rather, its relative absence—is therefore used to determine the relative contribution (or mixing ratio) of fossil fuel oxidation to the total carbon dioxide in a given region of the Earth's atmosphere.
   In subsurface monitoring, there are direct and indirect methods to determine the amount of in the reservoir. A direct method would be drilling deep enough to collect a fluid sample. This drilling can be difficult and expensive due to the physical properties of the rock. It also only provides data at a specific location. Indirect methods would be to send sound or electromagnetic waves down to the reservoir where it is then reflected back up to be interpreted. This approach is also expensive but it provides data over a much larger region; it does however lack precision. Both direct and indirect monitoring can be done intermittently or continuously.
   Section::::Artificial sequestration.:Carbon capture.
  
  Currently, capture of carbon dioxide is performed on a large scale by absorption of carbon dioxide onto various amine-based solvents. Other techniques are currently being investigated, such as pressure swing adsorption, temperature swing adsorption, gas separation membranes, cryogenics and flue capture.
   There are multiple classifications of amines, each of which has different characteristics relevant to CO capture. For example, Monoethanolamine (MEA) reacts strongly with acid gases like CO and has a fast reaction time and an ability to remove high percentages of CO, even at the low CO concentrations. Typically, Monoethanolamine (MEA) can capture 85% to 90% of the CO from the flue gas of a coal-fired plant, which is one of the most effective solvent to capture CO.
  
  Challenges of carbon capture using amine include:
  
  BULLET::::- Low pressure gas increases difficulty of transferring CO from the gas into amine
   As of 2012, Hatton worked on electrochemically mediated methods of carbon capture and conversion which could be used to reduce emissions from power plants and industry and decrease greenhouse gases. The researchers are studying magnesium oxide-based materials, coating particles of MgO with alkali metal nitrates. The resulting materials can capture more than ten times as much carbon dioxide (CO2) as other materials being investigated, at lower temperatures.
   The top-down, atmospheric measurement approach involves satellite data and in-situ measurements of carbon dioxide concentrations, as well as atmospheric models that model atmospheric transport of carbon dioxide. These have limited ability to determine carbon dioxide emissions at highly resolved spatial scales and can typically not represent finer scales than a 1 km grid. The models also must resolve the fluxes of carbon dioxide from anthropogenic sources like fossil fuel burning, and from natural interactions like terrestrial ecosystems and the ocean. Due to the complexities and limitations of the top-down approach, the EU combines this method with a bottom-up approach.
   The calculation of the annual net difference between carbon release and carbon storage constitutes the annual global atmospheric carbon accumulation rate. Using this method, the annual carbon flux ratio has been calculated to be approaching zero. This means the carbon respiration rate and carbon storage rate are in balance when generating a global estimate of this figure.
   CO is typically captured from fixed point sources such as power plants and factories. CO captured from these exhaust stream itself varies in concentration. A typical coal power plant will have 10-12% CO concentration in its flue gas exhaust stream. A biofuel refinery produces a high purity (99%) of CO with small amount of impurities such as water and ethanol. The separation process itself can be performed through separation processes such as absorption, adsorption, or membranes.
   During the last two decades, a new form of electrode was developed based on the luminescence emission of a photo-active chemical compound and the quenching of that emission by oxygen. This quenching photophysics mechanism is described by the Stern–Volmer equation for dissolved oxygen in a solution:
  
  BULLET::::- formula_2: Luminescence in the presence of oxygen
  
  BULLET::::- formula_3: Luminescence in the absence of oxygen
  
  BULLET::::- formula_4: Stern-Volmer constant for oxygen quenching
  
  BULLET::::- [O2]: Dissolved oxygen concentration
  
  The determination of oxygen concentration by luminescence quenching has a linear response over a broad range of oxygen concentrations and has excellent accuracy and reproducibility. 
   Different calculation methods can lead to different results. The results can largely vary also for different geographic regions and timeframes (see, in example, how C.I. of electricity varies, for different European countries, and how varied in a few years: from 2009 to 2013 the C.I. of electricity in the European Union fell on average by 20%, So while comparing different values of Carbon Intensity it is important to correctly consider all the boundary conditions (or initial hypotheses) considered for the calculations. For example, Chinese oil fields emit between 1.5 to more than 40 g of COeq per MJ with about 90% of all fields emitting 1.5–13.5 g COeq. Such highly skewed carbon intensity patterns necessitate disaggregation of seemingly homogenous emission activities and proper consideration of many factors for understanding.
   The difference between intracellular and extracellular CO concentrations reflects the CO demand of a phytoplankton cell, which is dependent on its growth rate. The ratio of carbon demand to supply governs the diffusion of CO into the cell, and is negatively correlated with the magnitude of the carbon fractionation by phytoplankton. Combined, these relationships allow the fractionation between CO and phytoplankton biomass to be used to estimate the phytoplankton growth rates.
   About two thirds of the total cost of CCS is attributed to capture, making it limit the wide-scale deployment of CCS technologies. To optimize a capture process would significantly increase the feasibility of CCS since the transport and storage steps of CCS are rather mature technologies.
   In EOR, the captured CO is injected into depleted oil fields with the goal to increase the amount of oil to be extracted by the wells. This method is proven to increase oil output by 5-40%. The scale of CO utilization through this technologies ranges from 30-300 MtCO/yr. It is a permanent and mature technology in CCU. The biggest market driver for EOR is the heavy reliance on oil. In United States, some of the additional market drivers include: tax revenue for foreign oil as well as the presence of carbon tax credits.
  
  Section::::Examples of technology and application.:Carbon mineralization.
   Carbon respiration
  
  Carbon respiration (also called carbon emissions and carbon releases) is used in combination with carbon fixation to gauge carbon  flux (as CO) between atmospheric carbon and the global carbon cycle
  
  Section::::Basic process.
   Section::::Cost.
  
  The IPCC states that estimations for BECCS cost range from $60-$250 per ton of CO.
  
  Section::::Technology.
  
  The main technology for CO capture from biotic sources generally employs the same technology as carbon dioxide capture from conventional fossil fuel sources. Broadly, three different types of technologies exist: post-combustion, pre-combustion, and oxy-fuel combustion.
  
  Section::::Technology.:Oxy-Combustion.
   Analyzers
  
  BULLET::::- Carbon dioxide analyzer: CO analyzers typically use infrared-based detection methods to take advantage of the fact that CO will absorb infra-red light and re-emit light at slightly longer wavelengths. The panel meter on the analyzer displays over the entire 0.01 - 10% CO range and a voltage output proportional to CO concentration is also generated for data recording.
   Section::::Applications.
  
  Section::::Applications.:Environmental monitoring and cleanup.
  
  GC-MS is becoming the tool of choice for tracking organic pollutants in the environment. The cost of GC-MS equipment has decreased significantly, and the reliability has increased at the same time, which has contributed to its increased adoption in environmental studies.
  
  Section::::Applications.:Criminal forensics.
   For many years, the strong oxidizing agent potassium permanganate (KMnO) was used for measuring chemical oxygen demand. Measurements were called "oxygen consumed" from permanganate, rather than the "oxygen demand" of organic substances. Potassium permanganate's effectiveness at oxidizing organic compounds varied widely, and in many cases biochemical oxygen demand (BOD) measurements were often much greater than results from COD measurements. This indicated that potassium permanganate was not able to effectively oxidize all organic compounds in water, rendering it a relatively poor oxidizing agent for determining COD.
   The concentration of CO in the upper layer of the world's oceans is higher than is found in air, and thus it is the most concentrated "mine" from which zero-net carbon fuels can be produced. The U.S. Navy estimates that a typical nuclear propelled aircraft carrier which generates 100 megawatts of electricity can produce 41,000 US gallons(155,202 litres) of jet fuel per day and production from the onboard nuclear reactor would cost about $6 per gallon($1.58 per liter). While that was about twice the petroleum fuel cost in 2010, it is expected to be much less than the market price in less than five years if recent trends continue. Moreover, since the delivery of fuel to a carrier battle group costs about $8 per gallon, shipboard production is already much less expensive. Heather Willauer of the United States Naval Research Laboratory proof-tested the technology in 2013, fueling an internal combustion engine equipped model airplane with the synthetic fuel.
   Section::::Capture.:separation technologies.
  
  Carbon dioxide can be separated out of air or flue gas with absorption, adsorption, or membrane gas separation technologies. Absorption, or carbon scrubbing, with amines is currently the dominant capture technology. Membrane and adsorption technologies are still in the developmental research stages, initiating primary pilot plants in the near future. Metal–organic frameworks (MOFs) are a novel class of materials that offer promise for carbon capture using adsorption technologies.
   In addition to the IL-CCS project, there are about three more projects that capture CO from the ethanol plant at smaller scales. For example, Arkalon at Kansas, USA can capture 0.18-0.29 MtCO/yr, OCAP at Netherlands can capture about 0.1-0.3 MtCO/yr, and Husky Energy at Canada can capture 0.09-0.1 MtCO/yr.
  
  Section::::Current Project.:At MSW recycling centers.
   In contrast to terrestrial plants, where CO diffusion in air is relatively fast and typically not limiting, diffusion of dissolved CO in water is considerably slower and can often limit carbon fixation in phytoplankton. As gaseous CO is dissolved into aqueous CO, it is fractionated by both kinetic and equilibrium effects that are temperature-dependent. Relative to plants, the dissolved CO source for phytoplankton can be enriched in C by about 8‰ from atmospheric CO.
   The liability of potential leak(s) is one of the largest barriers to large-scale CCS. To assess and reduce such liability, the leakage of stored gasses, particularly carbon dioxide, into the atmosphere may be detected via atmospheric gas monitoring, and can be quantified directly via the eddy covariance flux measurements.
  
  Section::::Monitoring geological sequestration sites.
   There are two recognized EPA methods for the measurement of dissolved oxygen for CBOD:
  
  BULLET::::- Standard Methods for the Examination of Water and Wastewater, Method 4500 O
  
  BULLET::::- In-Situ Inc. Method 1002-8-2009 Dissolved Oxygen Measurement by Optical Probe.
  
  Section::::Method summary.
   In the most common and pertinent case of GHG data from countries with a "medium carbon" intensity electric grid and input ores of about 0.01%. The median value of GHG emissions was determined to be about 9 grams, as depicted in figure 4 of the Yale paper, when the now world-standard "centrifuge" enrichment approach alone, is assessed. In 2013 the other less economic approach of "diffusion" enrichment, that is similarly depicted in figure 4 was retired worldwide. When it operated the median GHG value that the Yale analyst's depict for this old technology was about 15 grams under the same "medium carbon" grid conditions.
  