Here we report over possible optimizations onboard cruise ships in the management of glass, paper and cellulosic waste, ranging from simple rationalization of the materials' use (for glass and paper) to the recovery of some of the energy embedded in paper and other cellulosic waste. This latter option is investigated considering two possibilities: i) the recovery of thermal energy from incinerator's flue gas by means of an absorption plant, ii) the production of syngas to be directly fed to the ship engines. For each option, we calculated the achievable benefits in terms of reduced fuel consumption, avoided CO₂ emissions and cost savings (evaluated on the basis of the avoided fuel consumption). Finally, on the basis of the previously calculated benefits, we defined three different scenarios, each including the rationalization of glass and paper waste management, topped by different combinations of thermal energy recovery/syngas production. We then evaluated these scenarios in terms of environmental and economic benefits. This analysis showed that even trivial approaches, as a simple rationalization of paper consumption, can allow consistent advantages over existing waste management policies; moreover, syngas generators for treating cellulosic waste emerged as very effective tools for lowering the environmental impact of modern cruise ships. Joining these two strategies allows notable savings in terms of fuel, CO₂ emissions and ship operational costs, and could represent a path for sizably reducing the environmental footprint of cruise ships.

在这里，我们报告了游轮在玻璃，纸张和纤维素废料管理方面的可能优化，包括从简单合理化材料（玻璃和纸张）的使用到回收纸张和其他纤维素废料中埋藏的一些能量， 。考虑到两种可能性，对后一种选择进行了研究：i）通过吸收装置从焚化炉的烟气中回收热能； ii）生产直接供入船舶发动机的合成气。对于每种选择，我们都以减少燃油消耗，避免CO _2的方式计算了可实现的收益排放和成本节省（根据避免的油耗进行评估）。最后，在先前计算的收益的基础上，我们定义了三种不同的方案，每种方案包括玻璃和纸张废物管理的合理化，以及热能回收/合成气生产的不同组合。然后，我们根据环境和经济效益评估了这些方案。该分析表明，即使是简单的方法，如纸张消耗的简单合理化，也可以提供与现有废物管理政策相比一致的优势；此外，用于处理纤维素废物的合成气发生器已成为降低现代游轮对环境影响的非常有效的工具。结合这两种策略，可以显着节省燃料，CO ₂ 排放量和船舶运营成本，并可能成为大幅减少游轮环境足迹的途径。