CO₂ Capture from Cement Plants Using Oxyfired Precalcination and/or Calcium Looping

This paper compares two alternatives to capture CO₂ from cement plants: the first is designed to exploit the material and energy synergies with calcium looping technologies, CaL, and the second implements an oxyfired circulating fluidized bed precalcination step. The necessary mass and heat integration balances for these two options are solved and compared with a common reference cement plant and a cost analysis exercise is carried out. The CaL process applied to the flue gases of a clinker kiln oven is substantially identical to those proposed for similar applications to power plants flue gases. It translates into avoided cost of of 23 $/tCO₂ capturing up to 99the total CO₂ emitted in the plant. The avoided cost of an equivalent system with an oxyfired CFBC precalcination only, goes down to 16$/tCO₂ but only captures 89% of the CO₂ emitted in the plant. Both cases reveal that the application of CaL or oxyfired CFBC for precalcination of CaCO₃ in a cement plant, at scales in the order of 50 MWth (referred to the oxyfired CFB calciner) is an important early opportunity for the development of CaL processes in large scale industrial applications as well as for the development of zero emissions cement plants

Palladium-Catalyzed Carbonylative Cyclization of Amines via γ‑C(sp³)–H Activation: Late-Stage Diversification of Amino Acids and Peptides

The selective γ-C­(sp³)–H carbonylation of <i>N</i>-(2-pyridyl)­sulfonyl (<i>N</i>-SO₂Py)-protected amines has been accomplished by using palladium catalysis and Mo­(CO)₆ as carbonyl source. The reaction provides a powerful approach for derivatization of amine-based moieties, including amino acids, into richly functionalized γ-lactams. Not only methyl groups, but also methylene C–H bonds of cyclopropanes and conformationally biased molecules can be activated to provide ring-fused γ-lactam derivatives. This carbonylation protocol is also amenable to the late-stage diversification of more-complex multifunctional molecules such as dipeptides and tripeptides, demonstrating the key role of the <i>N</i>-SO₂Py as directing group and its capacity to override other inherent substrate coordinating elements. In addition to providing an attractive solution to the difficulties in handling hazardous CO gas, the use of Mo­(CO)₆ as an air-stable solid source of CO in substoichiometric amount (0.33 equiv) ensures Pd^II-catalytic activity by preventing its decomposition or deactivation under excess of CO via reduction of Pd^II to Pd⁰ or saturation of the metal coordination sphere. Indeed, significantly lower efficiency is observed when the reactions are carried out under CO atmosphere (1 atm), or in the presence of increased amounts of Mo­(CO)₆. A series of experimental and DFT mechanistic studies provide important insights about the reaction mechanism

Toward Liquid Biopsy: Determination of the Humoral Immune Response in Cancer Patients Using HaloTag Fusion Protein-Modified Electrochemical Bioplatforms

Autoantibodies raised against tumor-associated antigens have shown high promise as clinical biomarkers for reliable diagnosis, prognosis, and therapy monitoring of cancer. An electrochemical disposable biosensor for the specific and sensitive determination of p53-specific autoantibodies has been developed for the first time in this work. This biosensor involves the use of magnetic microcarriers (MBs) modified with covalently immobilized HaloTag fusion p53 protein as solid supports for the selective capture of specific autoantibodies. After magnetic capture of the modified MBs onto screen-printed carbon working electrodes, the amperometric signal using the system hydroquinone/H₂O₂ was related to the levels of p53-autoantibodies in the sample. The biosensor was applied for the analysis of sera from 24 patients with high-risk of developing colorectal cancer and 6 from patients already diagnosed with colorectal (4) and ovarian (2) cancer. The developed biosensor was able to determine p53 autoantibodies with a sensitivity higher than that of a commercial standard ELISA using a just-in-time produced protein in a simpler protocol with less sample volume and easily miniaturized and cost-effective instrumentation