The link between anthropogenic emissions of carbon dioxide, increasing atmospheric CO2 levels, and concomitantly increasing global temperatures is established and accepted. The use of aqueous ammonia, to capture CO2 and produce an inexpensive nitrogen fertilizer, ammonium bicarbonate (ABC), is believed to be a feasible approach to CO2 sequestration. Due to the varying concentrations of reactants and varying reaction conditions, different ammonia-carbon compounds may be produced. ABC is the ideal product for maximizing NH3 utilization in CO2 capture; therefore, identification and quantification of ABC in the reaction products is mandatory. Various analytical techniques were used to distinguish and quantify the ABC. Fourier transform infrared spectroscopy can only be used to distinguish ammonium carbamate, and. X-ray diffraction can be used to qualitatively distinguish ABC from the other possible products of the CO2 capture reaction. Carbon-hydrogen-nitrogen elemental analysis and near-infrared (NIR) spectroscopy were used to quantify ABC, with both techniques giving +/-5% agreement for ABC concentrations for 8 of 13 samples from a bench-scale aqueous ammonia CO2 scrubbing system. An additional 3 of the 13 samples were within +/-12%. Results indicate that NIR will be an ideal tool for real-time, on-line measurements of ABC in a full-scale aqueous ammonia CO2 scrubber. The ABC in 11 samples from the bench-scale scrubber at Western Kentucky University was determined by these techniques and assessed to have very good quality as a fertilizer in accordance with GB-3559-92, the Agricultural Ammonium Bicarbonate National Standard of China.

We have measured the apparent surface pK a values of self-assembled monolayers (SAMs) formed from 3-mercaptopropionic acid (3-MPA) and thioctic acid (TA) on evaporated gold film electrodes with a range of surface roughness (R a from 1.3 to 6.3 nm as measured by AC mode atomic force microscopy). The surface roughness is induced and controlled with electrochemical etching via multiple potential cycles between 0.2 and 1.5 V (versus Ag/AgCl/1.0 M KCl) in 100 mM H2SO4 with KCl concentrations ranging from 0.10 to 10 mM. The pK a's are measured by determining the capacitance of the surface using electrochemical impedance spectroscopy in a range of controlled ionic strength (μ = 0.25 M) buffer solutions. The results for 3-MPA are striking, exhibiting a strong logarithmic correlation (R 2 = 0.988) between the KCl concentration used in the electrochemical etching solutions and the apparent surface pK a. Over the range of KCl concentrations, the surface pK a of 3-MPA shifts from 6.5 to 8.4. However, the relationship between the KCl concentrations in the electrochemical etching solutions and the apparent surface pK a of TA is flat at 7.3 ± 0.2 with an R 2 value of less than 0.3 for both linear and logarithmic relationships.

A photocatalyzed ortho‐alkylation of pyridine N‐oxide with ynamides and arylacetylenes has been developed, which yields a series of α‐(2‐pyridinyl) benzyl amides/ketones. Mechanistic studies, including electrochemical studies, radical‐trapping experiments, and Stern–Volmer fluorescence quenching studies demonstrate that pyridine N‐oxide serves as both a redox auxiliary and radical acceptor to achieve the mild photocatalytic single‐electron oxidation of carbon–carbon triple bonds with the generation of a cationic vinyl radical intermediate.

One of the most important indices for evaluating the combustion efficiencies of boilers, as well as the commercial value of the produced fly ash, is the unburned carbon in fly ash. The most common method currently used by combustion engineers to estimate the amount of unburned carbon in fly ash is to equate it to the dry loss on ignition (LOI) value. There seems to be no reported systematic study linking LOI values with the true carbon content of ashes and combustion residues. In this study, the LOI values for 35 combustion residues were determined at 500, 750, and 950 °C, using a macro thermogravimetric analyzer. The carbon contents of the combustion residues and the residues from the LOI determinations were then measured. For the samples in this study, it was determined that temperatures of >790 °C should be used to achieve complete carbon burnoff. For low-percentage-carbon combustion residues, there is very poor agreement between the unburned carbon contents and the LOI values. This is especially true if the samples are exposed to the atmosphere for extended periods of time, because the combustion residues readily absorb moisture and acidic gases. For high-percentage-carbon combustion residues, there is good agreement between the unburned carbon and the LOI values, especially if the residues are relatively fresh.