Further development of the mill sludge valorization process

工厂污泥增值工艺的进一步发展

• 批准号: 515765-2017
• 负责人: Christopher, Lew
• 金额: $ 0.91万
• 依托单位: Lakehead University
• 依托单位国家: 加拿大
• 项目类别: Engage Plus Grants Program
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=639912
• 关键词: Further; development; mill; sludge; valorization

The Canadian pulp and paper industry generates about 1.5 million tons of primary and secondary sludge everyyear, which requires disposal and presents a major environmental challenge. On average, 60% of the totalwastewater treatment costs of pulp and paper mills account for sludge disposal. For this reason, Domtar Inc., aglobal pulp and paper company, is interested in minimizing their waste sludge and converting it into avalue-added stream that can reduce the carbon footprint, diversify their product range, create additionalrevenues, and enhance their competitiveness on the international market. For example, the Domtar Windsormill, with annual pulp and paper production capacity of 447,000 and 642,000 tons, respectively, generates 75tons of sludge per day. The mill disposes of their waste sludge by landfilling, a process that is neithereconomically attractive nor environmentally friendly. This is a follow-up Engage Plus proposal that aims tofurther advance the positive outcomes from the original Engage project. The Engage Plus proposal will furtherinvestigate opportunities to valorize the mill sludge from Domtar through a novel recycling process that couldincrease the efficiency of the proposed enzymatic hydrolysis and fermentation process, and reduce the overallproduction costs. Domtar mills will directly benefit from the outcomes of this project by upgrading a wastesludge stream to value-added products such as sugars and lactic acid. The Engage Plus project will addressimportant milestones such as optimization of enzyme and surfactant dose, enzyme and substrate recycling,fermentation of primary sludge-derived sugars utilizing low nitrogen sources such as secondary sludge, processintegration and optimization. The following steps are essential to accomplish the project goals: 1)Compositional analysis of sludge; 2) Analysis of enzyme activity/loss conversion yields; 3) Optimization ofenzyme dose for maximal release of fermentable sugars; 4) Protein solubilization from secondary sludge andprotein characterization; 5) Bioconversion of primary sludge-derived fermentable sugars using solubilizedprotein from secondary sludge as nitrogen source.

加拿大纸浆和造纸工业每年产生约150万吨初级和二级污泥，这需要处理，并提出了一个重大的环境挑战。平均而言，纸浆和造纸厂废水处理总成本的60%用于污泥处理。因此，全球纸浆和造纸公司Domtar Inc.对最大限度地减少其废污泥并将其转化为增值流感兴趣，这可以减少碳足迹，使其产品范围多样化，创造额外收入，并提高其在国际市场上的竞争力。例如，Domtar Windsormill的年产纸浆和造纸能力分别为44.7万吨和64.2万吨，每天产生75吨污泥。工厂通过填埋处理他们的废污泥，这一过程既不经济也不环保。这是“参与+”的后续提案，旨在进一步推动“参与+”项目的积极成果。Engage Plus的提案将进一步研究通过一种新的回收工艺对Domtar工厂污泥进行增值的机会，该工艺可以提高所提议的酶解和发酵过程的效率，并降低总体生产成本。Domtar工厂将直接受益于该项目的成果，将废渣流升级为糖和乳酸等增值产品。Engage Plus项目将解决一些重要的里程碑问题，如酶和表面活性剂剂量的优化、酶和底物的循环利用、利用低氮源（如二次污泥）发酵初级污泥衍生糖、工艺整合和优化。为了实现项目目标，以下步骤是必不可少的：1)污泥成分分析；2)酶活性/损失转化率分析；3)优化酶用量，使可发酵糖得到最大释放；4)二次污泥的蛋白质增溶及蛋白质表征；5)利用二次污泥中溶解的蛋白质作为氮源，对初级污泥衍生的可发酵糖进行生物转化。