Treatment Of CO2 Research Articles

Techno-economic analysis of gasification routes for ammonia production from Victorian brown coal

The environmental, economic, and technical viability of high and low pressure gasification technologies for the production of ammonia from low rank coal was examined. Three cases were developed starting with different gasification technologies (UGI and BGL), leading to different flowsheets, mass and energy balances, and finally heat integration. Environmental and economic analyses were performed on each of the cases. Three further cases were considered for the treatment of CO2 generated in the process: direct emission, use in urea production, and carbon capture and storage.CO2 emissions for the base cases were found to be 2.36–3.15kg CO2-e/kg NH3, with a low pressure, UGI gasifier based process giving the lowest emissions. All values obtained are higher than the range of 1.25–1.80kg CO2-e/kg NH3 for natural gas based ammonia plants in Australia.In comparison with 2013 ammonia prices, the cases were found to be similarly economically unviable. At a discount rate of 15%, the break-even prices achieved are in the order of 2.5 times the current prices, at A$1500/t–A$1600/t in most cases. While no overall benefit for a particular case was clear economically or technically, the use of certain technologies gave notable results. The low-pressure UGI gasifiers, after accounting for compression costs, gave an economic benefit over the high-pressure BGL gasifiers. The liquid nitrogen wash unit, when placed before the ammonia synthesis loop, recovered methane that is suitable for power generation.

Carboxylation of terminal alkynes with CO2 catalyzed by bis(amidate) rare-earth metal amides

Three novel bis(amidate) rare-earth metal amides were prepared and characterized. Treatment of CO2 with terminal alkynes obtained propiolic acids in high to excellent yields using the highest reactive Nd-based catalyst at ambient pressure.

Phishing & VAT Fraud in CO2 Permits: DICE in the EU-ETS Now; DICE in Power Tomorrow

In accordance with Directive 2003/87/EC of October 13, 2003, trade in greenhouse gas emissions commenced in the European Union (EU) on January 1, 2005. The EU-Emissions Trading System (EU-ETS) was born. The EU has a Value Added Tax (VAT). VAT is a transaction-based levy on all trade in goods and services. Each Member State has a VAT as a condition of membership. Until January 3, 2017 transactions in CO2 permits are taxed as services. After this date they are exempt as financial instruments. This change in VAT treatment of CO2 permits is directly attributable to rampant fraud in the market. Fraud has been so severe in CO2 permits that public trust in the EU’s emissions trading scheme has been undermined. Important lessons have been learned about controlling fraud from efforts made in the emissions markets. Unfortunately, time and political patience have run out. This paper considers a particular phishing attack in the CO2 market – the January 18, 2011 attack on the Czech registry. The focus of this paper is not on this very sensational fraud; it is on the ETS/ VAT overlap, and the ability to apply what has been learned here to the trade in gas and electricity. Careful consideration of this overlap demonstrates why the Digital Invoice Customs Exchange (DICE) proposal works as an effective fraud prevention mechanism. The moral of this story is that what we have learned can be directly applied to the commodity energy market. We know how that these markets can be secured. We need: (a) an Independent Transaction Log, and (b) a secure self-verifying digital invoice, and (c) a system of automated invoice cross-checking (the customs exchange). Can this be done? Quite simply, “yes.” A call placed to Kim Mayyasi, SmartCloud’s CEO presented this question. Not surprisingly, the response was: “… implementing a real-time transaction database of all power sales in the EU with advanced reasoning for back room analytics could implement the DICE proposal to eliminate MTIC from the EU power markets, and it could do so for the EU CO2 market right now. This is a typical challenge that our technology was designed to handle.”

A conceptual design by integrating dimethyl ether (DME) production with tri-reforming process for CO2 emission reduction

There has been considerable interest in the development of more efficient processes for conversion and utilization of CO2. Tri-reforming, as a new approach for the treatment of CO2 in flue stack gases, has been studied in this work. Tri-reforming process combines CO2 reforming with steam methane reforming and methane oxidation to produce syngas (H2 and CO) at a suitable ratio. To determine the optimum operating conditions for the production of syngas with a target ratio and maximized CO2 conversion, the effects of various factors including reaction temperature, reactor pressure and CH4 flow rate on the compositions of syngas obtained from tri-reforming process are investigated. Also, the production of dimethyl ether (DME) from syngas has been rigorously simulated. An optimum heat exchange network was obtained with the objective of minimizing utility cost, which was calculated by General algebraic modeling system (GAMS). Results show that tri-reforming coupled to DME synthesis is an economically feasible approach for the treatment and utilization of CO2 in flue stack gases.

수확 후 고농도 CO2단기처리가 '매향' 딸기의 저장에 미치는 영향

This experiment was conducted to examine the effects of a short-term treatment of high pressure CO₂ on shelf-life of strawberry fruit. A short-term treatment (12 hr) of 100% CO₂ resulted in the increase of fruit firmness up to 71.9% compared to that at harvest. The firmness of CO₂ treated fruit remained a significantly higher than that of control (air) up to 15 days. The alteration of pectic polymers was observed by CO₂ treatment such as an increase of EDTA soluble pectins and decrease of water soluble ones. The CO₂ treatment resulted in the increase of total amount of wall bound calcium. Pectate lyase activity, an important agent of strawberry fruit softening, was also significantly reduced by CO₂ treatment. Contents of soluble solids and acids of CO₂ treated fruit were higher than those of control fruit. Short-term treatment of high pressure CO₂ affected shelf-life through firmness increase whereas the visual quality and decay incidence of strawberry fruit were not affected.

Cobalt‐Embedded Nitrogen‐Rich Carbon Nanotubes Efficiently Catalyze Hydrogen Evolution Reaction at All pH Values

AbstractDespite being technically possible, splitting water to generate hydrogen is still practically unfeasible due mainly to the lack of sustainable and efficient catalysts for the half reactions involved. Herein we report the synthesis of cobalt‐embedded nitrogen‐rich carbon nanotubes (NRCNTs) that 1) can efficiently electrocatalyze the hydrogen evolution reaction (HER) with activities close to that of Pt and 2) function well under acidic, neutral or basic media alike, allowing them to be coupled with the best available oxygen‐evolving catalysts—which also play crucial roles in the overall water‐splitting reaction. The materials are synthesized by a simple, easily scalable synthetic route involving thermal treatment of Co2+‐embedded graphitic carbon nitride derived from inexpensive starting materials (dicyandiamide and CoCl2). The materials’ efficient catalytic activity is mainly attributed to their nitrogen dopants and concomitant structural defects.

Process simulation and optimization of methanol production coupled to tri-reforming process

Tri-reforming, as a new approach for the treatment of CO2 in flue stack gases, has been studied in this work. To determine the optimum operating conditions for the production of syngas with target ratio and maximum CO2 conversion, the effects of temperature (400–1200 °C), CH4/Flue gas ratio (0.4–1.0) and pressure (1–5 atm), on the compositions of syngas were investigated. Also, the methanol production from syngas has been rigorously simulated. An optimum heat exchange network was obtained with the objective of minimizing both utility and capital costs, which were calculated by General Algebraic Modeling system (GAMS). Furthermore, an economic analysis was carried out to substantiate the potential profits based on the conceptual results from heat integration. Results showed that the tri-reforming process, when integrated with methanol synthesis, is an economical approach for the treatment and utilization of CO2 in flue gases.

Comparison of a Fractional Microplasma Radio Frequency Technology and Carbon Dioxide Fractional Laser for the Treatment of Atrophic Acne Scars: A Randomized Split-Face Clinical Study

No studies have compared fractional microplasma radio frequency (RF) technology with the carbon dioxide fractional laser system (CO2 FS) in the treatment of atrophic acne scars in the same patient. To compare the efficacy and safety of fractional microplasma RF with CO2 FS in the treatment of atrophic acne scars. Thirty-three Asian patients received three sessions of a randomized split-face treatment of fractional microplasma RF or CO2 FS. Both modalities had a roughly equivalent effect. Échelle d'Évaluation Clinique Des Cicatrices d'Acné scores were significantly lower after fractional microplasma RF (from 51.1±14.2 to 22.3±8.6, 56.4% improvement) and CO2 FS (from 48.8±15.1 to 19.9±7.9, 59.2% improvement) treatments. There was no statistically significant difference between the two therapies. Twelve subjects (36.4%) experienced postinflammatory hyperpigmentation (PIH) after 30 of 99 treatment sessions (30.3%) on the CO2 FS side and no PIH was observed on the fractional microplasma RF sides. Both modalities have good effects on treating atrophic scars. PIH was not seen with the fractional microplasma RF, which might make it a better choice for patients with darker skin.

Carbon dioxide recovery from carbonate solutions using bipolar membrane electrodialysis

Process design and cost estimation were conducted for CO2 recovery by liquid absorption with alkaline solution, coupled with bipolar membrane electrodialysis for CO2 gas separation and alkaline solution regeneration. The electrodialysis performances and power consumption for CO2 recovery and alkaline solution regeneration were examined using laboratory-scale electrodialysis equipment under various conditions; degree of CO2 absorption, CO2 recovery ratio, alkaline concentration, and type of cation exchange membrane. The total cost of CO2 recovery was estimated for the treatment of CO2 emitted from a 400MW coal-fired thermal power plant. The minimum cost for the optimum condition was about US$180 per ton-CO2 removed, which is higher than that for the conventional process using amine absorption and thermal desorption. However, a sensitivity analysis indicates that the overall cost could be significantly reduced if the cost of membranes was reduced.

Biodiversity, Nitrogen Deposition, and CO2 Affect Grassland Soil Carbon Cycling but not Storage

Grasslands are globally widespread and capable of storing large amounts of carbon (C) in soils, and are generally experiencing increasing atmospheric CO2, nitrogen (N) deposition, and biodiversity losses. To better understand whether grasslands will act as C sources or sinks in the future we measured microbial respiration in long-term laboratory incubations of soils collected from a grassland field experiment after 9 years of factorial treatment of atmospheric CO2, N deposition, and plant species richness on a deep and uniformly sandy soil. We fit microbial soil respiration rates to three-pool models of soil C cycling to separate treatment effects on decomposition and pool sizes of fast, slow, and resistant C pools. Elevated CO2 decreased the mean residence time (MRT) of slow C pools without affecting their pool size. Decreasing diversity reduced the size and MRT of fast C pools (comparing monocultures to plots planted with 16 species), but increased the slow pool MRT. N additions increased the size of the resistant pool. These effects of CO2, N, and species-richness treatments were largely due to plant biomass differences between the treatments. We found no significant interactions among treatments. These results suggest that C sequestration in sandy grassland soils may not be strongly influenced by elevated CO2 or species losses. However, high N deposition may increase the amount of resistant C in these grasslands, which could contribute to increased C sequestration.

ChemInform Abstract: Enantiocontrolled Synthesis of Trialkyl-Substituted Stereogenic Carbons. A General Route to cis-3,5-Dialkyl γ-Lactones.

Lewis acid treatment of tertiary Co2(CO)6-propargylic alcohols having a stereochemically defined benzyloxy group at the γ-benzyl position yielded after cobalt demetalation sec-dialkyl bishomopropargylic alcohols in good yields. The reaction is highly stereoselective and predictable, providing pure stereoisomers. The use of benzyl-α,α‘-d2 ethers permitted the stereoselective d-labeling of methines and methylenes. Very simple chemical manipulations provided a general methodology to obtain the enantiomers of 3,5-dialkyl-γ-lactones.

Evaluation for Attractiveness of Four Chemicals to the Biting Midge, Forcipomyia taiwana (Diptera: Ceratopogonidae)

Four chemicals (1-octen-3-ol [octenol], lactic acid, acetone, and carbon dioxide) were evaluated for their attractiveness to the biting midge, Forcipomyia taiwana. The attractiveness was based on the number of adult biting midges attracted to each chemical. Results showed that the attractiveness of each chemical changed with different release rates. The optimal attractive release rates for octenol, lactic acid, and acetone fell in the range 0.5-0.9 mg/h, 0.2-1.4 mg/h, and 3.4-10.9 mg/h, respectively. The most attractive release rates were 0.7 mg/h, 0.2 mg/h, and 4.8 mg/h, respectively. Octenol, lactic acid, and acetone were evaluated simultaneously but in separate traps, at the best attractive release rate mentioned above to compare their attractiveness efficacies. Octenol was the most attractive to F. taiwana, followed by lactic acid and acetone; however, there was no significant difference between the mean numbers of adults attracted by the 3 attractants. Carbon dioxide (CO2) with release rates of 100, 250, and 500 ml/min showed no differences in attractiveness. When combinations of CO2, octenol, and blue light (BL, lamda max = 405 nm) were evaluated, the number of adults attracted by the treatment of CO2 + BL was the lowest, and that of the CO2 + octenol + BL was the highest.

Cobalt-Complexed Propargyl Cations: Generation under Neutral Conditions and Spontaneous, High-Temperature Conversion to Propargyl Radicals

A novel method for the generation of Co2(CO)6-complexed propargyl cations under neutral conditions is developed. The optimized experimental protocol involves treatment of the respective Co2(CO)6-co...

A novel approach for treatment of CO2 from fossil fired power plants, Part A: The integrated systems ITRPP

Abstract The environmental issues, due to the global warming caused by the rising concentration of greenhouse gases in the atmosphere, require new strategies aimed to increase power plants efficiencies and to reduce CO2 emissions. This two-paper work focuses on a different approach for capture and reduction of CO2 from flue gases of fossil fired power plant, with respect to conventional post-combustion technologies. This approach consists of flue gases utilization as co-reactants in a catalytic process, the tri-reforming process, to generate a synthesis gas suitable in chemical and energy industries (methanol, DME, etc.). In fact, the further conversion of syngas to a transportation fuel, such as methanol, is an attractive solution to introduce near zero-emission technologies (i.e. fuel cells) in vehicular applications. In this Part A, integrated systems for co-generation of electrical power and synthesis gas useful for methanol production have been defined and their performance has been investigated considering different flue gases compositions. In Part B, in order to verify the environmental advantages and energy suitability of these systems, their comparison with conventional technology for methanol production is carried out. The integrated systems (ITRPP, Integrated Tri-Reforming Power Plant) consist of a power island, based on a thermal power plant, and a methane tri-reforming island in which the power plants' exhausts react with methane to produce a synthesis gas used for methanol synthesis. As power island, a steam turbine power plant fuelled with coal and a gas turbine combined cycle fuelled with natural gas have been considered. The energy and environmental analysis of ITRPP systems (ITRPP-SC and ITRPP-CC) has been carried out by using thermochemical and thermodynamic models which have allowed to calculate the syngas composition, to define the energy and mass balances and to estimate the CO2 emissions for each ITRPP configuration. The repowering of the base power plants (steam turbine power plant and gas turbine combine cycle) is very high because of the large amount of steam produced in the tri-reforming island (in the ITRPP-SC is about of 64%, while in the ITRPP-CC is about of 105%). The reduction in the CO2 emissions has been estimated in 83% (15.4 vs. 93.4 kg/GJFuelinput) and 84% (8.9 vs. 56.2 kg/GJFuelinput) for the ITRPP-SC and ITRPP-CC respectively.

Ring‐banded spherulites in PCL and PCL/MWCNT solution‐casting films and effect of compressed CO2 on them

AbstractThe ring‐banded spherulites in poly(ε‐caprolactone) (PCL) solution‐casting films in the absence and presence of multi‐walled carbon nanotube (MWCNT) are studied by atomic force microscopy (AFM), polarized optical microscopy (POM), transmission electron microscopy (TEM), and scanning electronic microscopy (SEM). The results indicate that birefringent ring‐banded spherulites of PCL can grow from solution below 50 °C, and the temperature is much lower than that from pure PCL melt. We also find out that the presence of MWCNT apparently widen the temperature range of forming ring‐banded structure. Furthermore, the mechanism for the ring‐banded structure forming is studied, and it is attributed to the twisting of lamellae crystals, and the driving force is suggested including the deflexion of lamellae bundles. In addition, effect of compressed CO2 on the morphology of PCL and PCL/MWCNT solution‐casting film is also investigated, and the results reveal that both PCL and PCL/MWCNT films undergo recrystallization with the treatment of compressed CO2 and accordingly, the related properties can be adjusted. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 784–792, 2009

Reaction of the dicobalt alkyne compound Co2(CO)6( -dmad) with the diphosphine ligand 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd). Spectroscopic properties, X-ray diffraction data, and thermal reactivity of the chelating isomer of Co2(CO)4(bpcd)( -dmad)

Treatment of Co2(CO)6(μ-dmad) (where dmad = dimethyl acetylenedicarboxylate) with the bidentate ligand 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) in the presence of added Me3NO affords the new alkyne compound Co2(CO)4(bpcd)(μ-dmad) in good yield. Both IR and 31P NMR spectroscopies indicate that the bpcd ligand is coordinated to a single cobalt center in a chelating fashion in solution. The solid-state structure of Co2(CO)4(bpcd)(μ-dmad) is identical to the solution structure Co2(CO)4(bpcd)(μ-dmad), as determined by X-ray diffraction analysis. Co2(CO)4(bpcd)(μ-dmad) crystallizes in the triclinic space group P-1, a = 10.7460(8) A, b = 11.628(2) A, c = 15.077(1) A, α = 95.831(9)°, β = 91.205(7)°, γ = 101.526(9)°, V = 1834.7(3) A3, Z = 2, and d calc = 1.514 g/cm3; R = 0.0489, R w = 0.0528 for 2854 reflections with I > 3σ(I). The thermal reactivity of Co2(CO)4(bpcd)(μ-dmad) has been briefly explored by spectroscopic methods, and evidence is presented for the attack of one of the PPh2 groups on an alkyne carbon atom in Co2(CO)4(bpcd)(μ-dmad) to from the zwitterionic hydrocarbyl compound Co2(CO)4(μ-η2:η2:η1:η1-(MeO2C)=C(CO2Me)PPh2C=C(PPh2)C(O)CH2C(O)] upon thermolysis. The redox chemistry of both Co2(CO)4(bpcd)(μ-dmad) and Co2(CO)4[μ-η2:η2:η1:η1-(MeO2C) C=C(CO2Me)PPh2C=C(PPh2)C(O)CH2C(O)] has been explored by cyclic voltammetery.

Cobalt‐Mediated Cyclooligomerization Reactions of Borylacetylenes

AbstractReaction of bis(diethylamino)acetylene (1) with lithium and chlorobis(dimethylamino)borane yields 1‐[bis(dimethylamino)boryl]‐2‐(diethylamino)acetylene (2). Treatment of 1‐aryl‐2‐(trimethylstannyl)acetylenes 3 with chlorobis(diisopropylamino)borane results in the quantitative formation of 1‐aryl‐2‐[bis(diisopropylamino)boryl]acetylene compounds 4. The 1‐aryl‐2‐borylacetylene derivatives 5, 6, and 7 are obtained by the reaction of 3 with the appropriate haloborane, or by reacting 4 with two equivalents of HCl and one equivalent of catechol, dithiocatechol and 2‐hydroxythiophenol. The catalytic cyclotrimerizations of 5a−d with [CpCo(CO)2] or [Co2(CO)8] lead to isomeric mixtures of the triborylbenzene derivatives 8a−d and 8a′−d′, whereas 6a−d and 7a−b undergo cyclotrimerization only with catalytic amount of [Co2(CO)8], to give isomeric mixtures of the triborylbenzene derivatives 12a−d/12a′−d′ and 13a−b/13a′−b′, respectively. The reaction of 2 with a stoichiometric amount of (η5‐cyclopentadienyl)bis(ethene)cobalt leads to (η5‐cyclopentadienyl)(η4‐cyclobutadiene)cobalt complexes 9. The analogous complexes 10 and 11 are obtained by the reactions of 6 and 7 with a stoichiometric amount of (η5‐cyclopentadienyl)dicarbonylcobalt. Treatment of Co2(CO)8 with 5a, 6a, and 7a yields the dicobaltatetrahedranes 14a, 15a and 16a. Compound 15a reacts with two equivalents of diphenylacetylene and 1‐(1,3,2‐benzodioxaborolyl)‐2‐phenylacetylene (5a), to furnish (1,3,2‐benzodithiaborolyl)pentaphenylbenzene (17) and bis(1,3,2‐benzodioxaborolyl)(1,3,2‐benzodithiaborolyl)triphenylbenzene (18), respectively. The new compounds have been characterized by NMR spectroscopy and mass spectrometry, as well as by X‐ray structural analyses for 4a, 5a, 6a, and 10a. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Asymmetric synthesis of the (2S,4S,6S)‐2,4,6‐trimethylnonyl subunit of siphonarienes

AbstractThe paper describes an asymmetric approach to the synthesis of the (2S,4S,6S)‐2,4,6‐trimethylnonyl segment of siphonarienes. The key step used is a newly developed methodology to obtain sec‐dialkyl acetylenes based on the intramolecular hydride transfer from a secondary γ‐benzyloxy group with well‐defined absolute stereochemistry, ensured by a Sharpless asymmetric epoxidation reaction, to a cation generated by Lewis acid treatment of a tertiary Co2(CO)6‐complexed propargylic alcohol.

Linking two alkyne-bridged dicobalt complexes via a urea-based ligand: synthesis and spectroscopic and structural characterization of [[Co(2)(CO)(6)(mu-HC identical with C-)]-CH(2)NH](2)C=O.

Treatment of Co2(CO)8 with HC⋮CCH2NH2 under mild reaction conditions yielded an unusual complex of {[Co2(CO)6(μ-HC⋮C-)]-CH2NH}2CO, 1. The structure of 1 was established by X-ray diffraction analysis. The compound 1 can be viewed as two propargylamine-bridged dicobalt complexes coupled by a carbonyl group. Obviously, carbonylation of a primary amine took place during this reaction.

Enantiocontrolled synthesis of trialkyl-substituted stereogenic carbons. A general route to cis-3,5-dialkyl gamma-lactones

[reaction: see text] Lewis acid treatment of tertiary Co2(CO)6-propargylic alcohols having a stereochemically defined benzyloxy group at the gamma-benzyl position yielded after cobalt demetalation sec-dialkyl bishomopropargylic alcohols in good yields. The reaction is highly stereoselective and predictable, providing pure stereoisomers. The use of benzyl-alpha,alpha'-d2 ethers permitted the stereoselective d-labeling of methines and methylenes. Very simple chemical manipulations provided a general methodology to obtain the enantiomers of 3,5-dialkyl-gamma-lactones.