Department of Chemical Engineering, Indian Institute of Technology Guwahati, Assam, 781039, India.
Department of Chemical Engineering, Indian Institute of Technology Guwahati, Assam, 781039, India.
J Environ Manage. 2019 Feb 1;231:1241-1256. doi: 10.1016/j.jenvman.2018.10.092. Epub 2018 Nov 21.
The utilization of fossil fuels leads to the emission of greenhouse gases into the environment. As a consequence, ozone layer depletion, global warming, acid rain, etc. are caused. Thus, alternate ways have to be planned to eradicate the detrimental effects of the usage of fossil fuels. As biomass is a renewable energy source, co-utilization of coal with biomass could significantly reduce carbon emission. In addition, chemical looping combustion (CLC) is a promising technology for the inherent capture of CO without any post-treatment of flue gas. Hence, the integration of co-combustion of solid fuel with CLC technology can produce clean energy in the context of carbon negative system. The present study addresses the issues and prospects of the co-CLC process of solid fuels such as coal and biomass. Low-cost oxygen carriers, which are suitable for the solid-CLC process, are elucidated. The effect of solid fuel based inherent constituents such as ash, volatile matter and tar on the performance of the CLC process is discussed. Furthermore, the beneficial and inhibitory effects of the co-combustion of solid fuels are elaborated. The formation and reduction mechanism of NO and SO pollutants during the CLC process are investigated. In addition, the effect of gasifying medium (CO and steam) during the co-CLC technology is also discussed. The performance of the CLC based thermal power plants is analyzed, and the results show a gain of 5-6% in net thermal efficiency, compared to a power system operating under conventional technology. The effect of the process parameters on gas conversion, char conversion, overall solid fuel conversion, combustion efficiency and CO yield is investigated. The investigation shows that the co-combustion based CLC is a potential technology for the implementation of carbon capture and storage (CCS) with a low energy penalty.
化石燃料的利用导致温室气体排放到环境中。因此，造成了臭氧层破坏、全球变暖、酸雨等问题。因此，必须计划替代方法来消除使用化石燃料的不利影响。由于生物质是一种可再生能源，因此煤与生物质的共利用可以显著减少碳排放。此外，化学循环燃烧（CLC）是一种有前途的技术，可以在不进行烟道气后处理的情况下固有地捕获 CO。因此，将固体燃料的共燃烧与 CLC 技术集成可以在碳负系统的背景下产生清洁能源。本研究解决了煤和生物质等固体燃料的共 CLC 过程的问题和前景。阐明了适合固体-CLC 过程的低成本氧载体。讨论了基于固体燃料的固有成分（如灰分、挥发分和焦油）对 CLC 过程性能的影响。此外，还阐述了固体燃料共燃烧的有利和不利影响。研究了 CLC 过程中 NO 和 SO 污染物的形成和还原机制。此外，还讨论了共 CLC 技术中气化介质（CO 和蒸汽）的影响。分析了基于 CLC 的火力发电厂的性能，结果表明，与采用传统技术的发电系统相比，净热效率提高了 5-6%。研究了工艺参数对气体转化率、炭转化率、总固体燃料转化率、燃烧效率和 CO 产率的影响。研究表明，基于共燃烧的 CLC 是一种具有低能量损失的碳捕获和储存（CCS）实施的潜在技术。
