User:Maudesquad/sandbox

Maude Hoffmann

Project topic: Metal-organic frameworks.

We choose this topic because we found there isn't a lot of information on Wikipedia about the carbon capture application of MOFs. Also, we felt like there's a lot of room to improvement in articles related to this topic, especially in the Zeolitic imidazolate framework (a class of MOFs) one, which is a very short article. UC Berkeley conducts research about MOFs in relation to carbon capture, so we are in close proximity to many sources of information on this topic. To help general understanding the importance of carbon capture and sequestration, we can improve the readily available information about carbon capture technologies like MOFs.

Related articles to edit: Carbon capture and storage, Metal-organic framework, Carbon dioxide removal, Carbon dioxide scrubber and Zeolitic imidazolate framework.

Sources: http://www.osti.gov/scitech/servlets/purl/1091874, http://digitalassets.lib.berkeley.edu/etd/ucb/text/Swisher_berkeley_0028E_12933.pdf, http://www.osti.gov/scitech/servlets/purl/1003992-YRfi3u/, http://digitalassets.lib.berkeley.edu/etd/ucb/text/Sumida_berkeley_0028E_12601.pdf, http://www.chem.tamu.edu/rgroup/zhou/PDF/095.pdf and the Carbon Capture and Sequestration Textbook used in class.

lead section for Carbon Capture and Storage (CCS) article
Capturing CO2 is most effective at point sources, such as large fossil fuel or biomass energy facilities, industries with major CO2 emissions, natural gas processing, synthetic fuel plants and fossil fuel-based hydrogen production plants. Extracting CO2 from air is also possible, but not very practical because the CO2 is not concentrated.[9] Concentrated CO2 from the combustion of coal in oxygen is relatively pure, and could be directly processed. Impurities in CO2 streams could have a significant effect on their phase behaviour and could pose a significant threat of increased corrosion of pipeline and well materials.[10] In instances where CO2 impurities exist and especially with air capture, a scrubbing separation process would be needed.[11] According to the Wallula Energy Resource Center in Washington state, by gasifying coal, it is possible to capture approximately 65% of carbon dioxide embedded in it and sequester it in a solid form.[12] CO2 can be separated, or captured, out of flue gas post-combustion with various technologies, namely absorption (or scrubbing), adsorption, or membrane separation processes. Currently, amine scrubbing is the dominant technology for capture capture. Metal-organic frameworks (MOFs) are a novel, promising carbon capture technology alternative to amine scrubbing. They can be use pre-combustion, post-combustion, or in oxy-fuel combustion in the process of burning fossil fuels to reduce carbon dioxide emissions. Organisms that produce ethanol by fermentation generate cool, essentially pure CO2 that can be pumped underground.[13] Fermentation produces slightly less CO2 than ethanol by weight. Broadly, three different types of technologies for scrubbing exist: post-combustion, pre-combustion, and oxyfuel combustion:

An alternate method under development is chemical looping combustion (CLC). Chemical looping uses a metal oxide as a solid oxygen carrier. Metal oxide particles react with a solid, liquid or gaseous fuel in a fluidized bed combustor, producing solid metal particles and a mixture of carbon dioxide and water vapor. The water vapor is condensed, leaving pure carbon dioxide, which can then be sequestered. The solid metal particles are circulated to another fluidized bed where they react with air, producing heat and regenerating metal oxide particles that are recirculated to the fluidized bed combustor. A variant of chemical looping is calcium looping, which uses the alternating carbonation and then calcination of a calcium oxide based carrier as a means of capturing CO2.[20] A few engineering proposals have been made for the more difficult task of removing CO2 from the atmosphere – a form of climate engineering – but work in this area is still in its infancy. Capture costs are estimated to be higher than from point sources, but may be feasible for dealing with emissions from diffuse sources such as automobiles and aircraft.[21] The theoretically required energy for air capture is only slightly more than for capture from point sources. The additional costs come from the devices that use the natural air flow. Global Research Technologies demonstrated a pre-prototype of air capture technology in 2007.[22]

Added new section to Carbon Dioxide Scrubber article
Metal-organic framework is one of the most promising technology for carbon dioxide capture and separation inadsorption processes. Although no large-scale commercial technology exists nowadays, several researches have indicated the great potential that MOFs have as a CO2 scrubber. It's characteristics, such as pore structure and surface functions can be easily tuned to improve CO2 selectivity over other gases. [1] A MOF could be specifically designed to act like a CO2 removal agent in post-combustion power plants. In this scenario, the flue gas would pass through a bed packed with a MOF material, where CO2 would be stripped. After saturation is reached, CO2 could be desorbed by doing a pressure or temperature swing. Carbon dioxide could then be compressed to supercritical conditions in order to be stored underground or utilized in enhanced oil recovery processes. However, this is not possible in large scale yet due to several difficulties, one of those being the production of MOFs in great quantities.[2] In a project sponsored by the DOE and operated by UOP LLC in collaboration with faculty of four different universities, MOFs were tested as possible carbon dioxide removal agents in post-combustion flue gas. They were able to separate 90% of the CO2 from the flue gas stream using a vacuum pressure swing process. From extensive investigation, they found out that the best MOF to be used was a Mg/DOBDC one, which has a 21.7 wt% CO2 loading capacity. Estimations showed that, if a similar system would be applied to a large scale power plant, the cost of energy would increase by 65%, while a NETL baseline amine based system would cause an increase of 81% (the DOE goal is 35%). Also, each ton of CO2 avoided would cost $57, while for the amine system this cost is estimated to be $72. The project ended in 2010,estimating that the total capital required to implement such project in a 580 MW power plant was 354 million dollars.[3]

lead section for metal-organic framework article
Metal-organic frameworks (MOFs) are compounds consisting of metal ions or clusters coordinated to organic molecules to form one-, two-, or three-dimensional structures that can be porous. The organic molecules included are sometimes referred to as "struts", and include such examples as 1,4-benzenedicarboxylic acid (BDC). More formally, a metal–organic framework is a coordination network with organic ligands containing potential voids. A coordination network is a coordination compound extending, through repeating coordination entities, in one dimension, but with cross-links between two or more individual chains, loops, or spiro-links, or a coordination compound extending through repeating coordination entities in two or three dimensions; and finally a coordination polymer is a coordination compound with repeating coordination entities extending in one, two, or three dimensions.[1] In some cases, the pores are stable during elimination of the guest molecules (often solvents) and could be used for the storage of gases such as hydrogen, carbon dioxide, and methane. For example, MOFs could offer a way to filter carbon dioxide out of a power plant’s flue gas emissions. Other possible applications of MOFs are in gas purification, in gas separation, in catalysis and as sensors.[2]

Maude's Carbon Capture and Storage (CCS) MOF rough drafts
Carbon dioxide (CO2) has been a large contributor to global warming thus many technologies are being explored to CO2 capture out of power plant flue gases in order to reduce emissions into the atmosphere. Metal-organic frameworks (MOFs) are a novel, promising carbon capture technology alternative to amine scrubbing. CO2 can be separated, or captured, out of flue gas post-combustion with various technologies, namely absorption (or scrubbing), adsorption, or membrane separation processes. Currently, amine scrubbing is the dominant technology for capture capture. MOFs are used to adsorb out carbon dioxide. They can be use pre-combustion, post-combustion, or in oxy-fuel combustion in the process of burning fossil fuels to reduce carbon dioxide emissions. Metal ion clusters collected onto an organic molecule framework. They form a crystalline porous separation material for carbon dioxide(CO2) out of flue gas from burning fossil fuels. The material selectively traps CO2 with a high working capacity. MOFs can operate as langmuir isotherms or stepwise adsorbents. They can be very tunable for different adsorption processes with the flexibility of the frameworks and different metal ions.