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Amine-based carbon dioxide capture is the most mature technology for reducing flue gas CO 2 emissions. It has been postulated and observed during commercialisation of this technology that significant quantities of waste amines are produced. Further industrial implementation of this technology requires adequate disposal or valorisation options for this waste. This review presents an analysis of seven biological and chemical technologies for waste amine amelioration or valorisation. Of these, the biological treatments are identified as being more mature for industrial application with the capacity for marketable product generation. Slow speed is the main drawback of the biological processes but this does not hinder their commercial viability. Using waste amine for NOx reduction in power stations is a secondary option, where it seems probable that the amount of waste amine generated in the CO 2 capture plant is sufficient to fulfil the DeNOx requirements of the flue gas. This route, however, requires investigation into the impact of waste amine impurities on the power station and the CO 2 capture plant operations., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Chemical absorption with aqueous amine solvents is the most advanced technology for postcombustion capture (PCC) of CO(2) from coal-fired power stations and a number of pilot scale programs are evaluating novel solvents, optimizing energy efficiency, and validating engineering models. This review demonstrates that the development of commercial scale PCC also requires effective solvent management guidelines to ensure minimization of potential technical and environmental risks. Furthermore, the review reveals that while solvent degradation has been identified as a key source of solvent consumption in laboratory scale studies, it has not been validated at pilot scale. Yet this is crucial as solvent degradation products, such as organic acids, can increase corrosivity and reduce the CO(2) absorption capacity of the solvent. It also highlights the need for the development of corrosion and solvent reclamation technologies, as well as strategies to minimize emissions of solvent and degradation products, such as ammonia, aldehydes, nitrosamines and nitramines, to the atmosphere from commercial scale PCC. Inevitably, responsible management of aqueous and solid waste will require more serious consideration. This will ultimately require effective waste management practices validated at pilot scale to minimize the likelihood of adverse human and environmental impacts from commercial scale PCC.

A sedimentary bacterial isolate has been shown to contain trans-monounsaturated fatty acids (6% of the total fatty acids). The ratio of trans- to cis-acids in this isolate was in the range 3.2 to 7.6. The identification of trans-monounsaturated acids in a marine bacterium implied that the trans-acids which have been reported in recent sediments could derive, in whole or part, from direct bacterial input.