Thermodynamic feasibility of shipboard conversion of marine plastics to blue diesel for self-powered ocean cleanup
Thermodynamic feasibility of shipboard conversion of marine plastics to blue diesel for self-powered ocean cleanup
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DOI：
10.1073/pnas.2107250118j1of8
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发表时间：
2021-11-16
影响因子：
11.1
通讯作者：
Herschbach, Dudley R.
中科院分区：
文献类型：
--
作者：
Belden, Elizabeth R.;Kazantzis, Nikolaos K.;Herschbach, Dudley R.
收集和清除海洋塑料可以减轻它们对环境的影响；然而，海洋清理将是一项复杂和能源密集型的工作，尚未得到充分的评估。这项工作考察了水热将这种废物转化为燃料以实现自供电清理的热力学可行性和后续影响。一项全面的概率火用分析表明，水热液化有可能产生足够的能量，为该过程和执行清理的船舶提供动力。自驱动清理减少了满载废物的船只往返港口的次数，消除了对大多数塑料浓度使用化石燃料的需求。对大太平洋垃圾带（GPGP）的几种清理情景进行了模拟，相当于每年清除230吨至11500吨塑料；该范围对应于GPGP中塑料表面浓度的不确定度。估计的清理时间主要取决于在不牺牲收集效率的情况下，GPGP中可以部署的围油栏的数量。自供电清理可能是一种从海洋中清除塑料的可行方法，我们对GPGP特性的理解差距应该得到解决，以减少不确定性。
Collecting and removing ocean plastics can mitigate their environmental impacts; however, ocean cleanup will be a complex and energy-intensive operation that has not been fully evaluated. This work examines the thermodynamic feasibility and subsequent implications of hydrothermally converting this waste into a fuel to enable self-powered cleanup. A comprehensive probabilistic exergy analysis demonstrates that hydrothermal liquefaction has potential to generate sufficient energy to power both the process and the ship performing the cleanup. Self-powered cleanup reduces the number of roundtrips to port of a waste-laden ship, eliminating the need for fossil fuel use for most plastic concentrations. Several cleanup scenarios are modeled for the Great Pacific Garbage Patch (GPGP), corresponding to 230 t to 11,500 t of plastic removed yearly; the range corresponds to uncertainty in the surface concentration of plastics in the GPGP. Estimated cleanup times depends mainly on the number of booms that can be deployed in the GPGP without sacrificing collection efficiency. Self-powered cleanup may be a viable approach for removal of plastics from the ocean, and gaps in our understanding of GPGP characteristics should be addressed to reduce uncertainty.