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the viability of existing fossil fuel energy sources and processes. A more recent approach proposes the use of DAC [3] to complement the implementation of renewable energy sources in order to facilitate a reduction in global atmospheric CO 2 concentrations. In addition to new processes reported for CO 2 capture from stationary sources, such as the metal-mediated CO 2regenerative amine-based battery process that directly converts CO 2 reaction enthalpy into electrical energy, [4] DAC offers a practical mitigation of CO 2 emissions from highly distributed or mobile point sources. As an alternative to storage of captured CO 2 in deep saline aquifers suggested for large stationary emitting sources, [5] DACproduced CO 2 could be used as a chemical feedstock for the synthesis of value added products. [6,3b,7] Examples of such demonstrated technologies include the use of CO 2 instead of water to cure concrete leading to permanent sequestration of the CO 2 , [8] efficient growth of plants in greenhouses, and conversion of CO 2 into alcohols by algae. [3b,9] Additionally, the uptake of distributed point-of-use DAC CO 2 could mirror, and even be facilitated by, consumer-driven selection of point-of-use solar photovoltaics (PV) electricity generation and storage. [1a,10] Proposed routes for DAC include the use of aqueous basic solutions [11] and solid adsorbents [12] as capture media. Aqueous basic solutions are used because they offer the opportunity to continuously contact the feed air with the solution in the presence of contaminants and other constituents in the air. [13] From a process engineering perspective, this approach is excellent for large-scale carbon capture in the form of a processing plant permanently located alongside free waste-heat sources, such as a coal or gas power plant. [13c,d,14] Solid adsorbents offer the prospect of DAC with a low energy input, low operating costs, minimal infrastructure, and the potential for application over a broad range of scales. [14a,15] Transitioning to a sustainable carbon cycle will require a suite of technologies from large-scale carbon capture plants to a large number of small and distributed carbon capture units. [16] Inspired by the trend of individual responsibility, small and mobile carbon capture units could enable small business enterprises to play their part in reducing global carbon emissions. Recycling carbon dioxide from the air can be a valuable process in beverage carbonation, food preservation, and dry ice cleaning devices. [17] However, if small mobile DAC units relying solely on It is increasingly apparent that negative emissions technologies, such as direct air capture (DAC), are required as part of the technology mix for limiting global atmospheric temperature increase. For all DAC technologies, the requisite energy for regeneration of the separation media strongly influences the overall cost of the process and therefore directly influences their likely implementation. Herein, the results of a pilot-scale demonstration of a new metal organic framework (...

The low rank coals from Victoria, Australia, and Rhineland, Germany are of interest for use in entrained flow gasification applications. Therefore, a high temperature, electrically heated, entrained flow apparatus has been designed to address the shortage of fundamental data. A Victorian brown coal and a Rhenish lignite were subjected to rapid, entrained flow pyrolysis between 1100 and 14008C to generate high surface area chars, which were subsequently gasified at the same temperatures under CO 2 in N 2 between 10 and 80 vol %. The Victorian coal was more reactive than the Rhenish coal, and peak char reactivity was observed at 12008C. Char conversion and syngas yield increased with increasing temperature and plateaued at high CO 2 concentration. Ammonia and tar species were negligible and HCN and H 2 S were present in parts per million (volume) concentrations in the cooled, filtered syngas.

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