Elliott Allan, Mahmood Talat
FPInnovations-Paprican, 570 boul. St. Jean, Pointe-Claire, QC, Canada H9R 3J9.
Water Res. 2007 Nov;41(19):4273-86. doi: 10.1016/j.watres.2007.06.017. Epub 2007 Jun 15.
While anaerobic digestion is commonly practiced in the municipal sector, it has not gained popularity in the pulp and paper industry mainly because of its long sludge residence time requirement of 20-30 days. The construction of large digesters to provide such extended residence times is capital-intensive and thus the implementation of anaerobic digestion has remained economically prohibitive. A review of the literature suggests that recent developments in sludge preconditioning technologies have substantially reduced the sludge residence time requirement to the order of 7 days. Also, the preconditioned sludges have been reported to hold potential for higher methane recovery with reduced excess sludge production requiring disposal. Such advantages, coupled with escalating fuel prices and the introduction of carbon credits under the Kyoto Accord, have significantly improved the economics of anaerobic digestion. As the cost of sludge management varies from one mill to another, mill-specific economic assessment of anaerobic digestion could identify cost-saving opportunities.
虽然厌氧消化在市政领域普遍应用，但在制浆造纸行业却未得到广泛采用，主要原因是其对污泥停留时间的要求长达20至30天。建造大型消化器以提供如此长的停留时间成本高昂，因此厌氧消化的实施在经济上仍然难以承受。文献综述表明，污泥预处理技术的最新进展已将污泥停留时间要求大幅降低至约7天。此外，据报道，经过预处理的污泥具有更高的甲烷回收潜力，同时减少了需要处置的剩余污泥产量。这些优势，再加上燃料价格不断上涨以及《京都议定书》下碳信用额度的引入，显著改善了厌氧消化的经济性。由于不同工厂的污泥管理成本各不相同，针对特定工厂进行厌氧消化的经济评估可以发现节省成本的机会。
