Implementation of biorefining technologies in Kraft mills: impact assessment and feasibility

卡夫工艺生产的木浆用于制造高质量的印刷纸、薄纸和包装材料。它是一个有吸引力的候选部分转化为生物炼制，同时保持其传统核心产品的制造。森林生物炼制的前提是，在废液中溶解的一些化学制浆步骤的副产品的木材有机成分可以比在现场燃烧以恢复其目前所做的更有利；它们可以用作制造各种具有重要市场价值的产品的原料。然而，卡夫工厂向生物精炼厂的转变将深刻地改变其可持续能源生产的能力。该项目建议制定一种方法和标准，以评估加拿大卡夫工厂生物炼制方案的技术经济可行性。从高度集成和节能的卡夫工厂的基本案例开始，我们将应用最先进的模拟技术和系统工程工具来检查关键生物炼制技术对该过程的能量平衡和运营成本的影响。它们是木质素沉淀、半纤维素提取和生物质气化。一种新的先进的能源效率分析方法将被开发并应用于研究。它将个别地和综合地考虑到影响能源消耗的因素：内部能源回收、使用蒸汽注入和混合、水系统关闭、热电生产和结合能源升级技术（联产和三产、吸收式热泵）。经济可行性将通过一种新的热经济分析方法进行评估。将确定生物精炼技术对工艺废气排放的影响。该项目的主要成果将是指导方针，可用于审查拟议的生物炼制概念的可行性，指导对这些技术的投资，并帮助制定解决技术障碍的研究战略。将生产和验证生物炼制单元操作模型和基于纸浆厂的生物炼制的独特过程模拟软件。

The Kraft process produces wood pulp for the manufacture of high quality printing papers, tissue papers and packaging material. It is an attractive candidate for partial conversion to biorefinery while maintaining the manufacturing of its traditional core products. The premise of the forest biorefinery is that some of the organic constituents of the wood which are by-products of the chemical pulping step dissolved in the spent liquor may be used for greater advantage than being burnt on-site to recover their beating value as is currently done; they could be used as feedstock for the manufacture of a broad variety of products which have a significant market value. However, the conversion of a Kraft mill to a biorefinery will profoundly modify its capacity for sustainable energy production. This project proposes to develop a methodology and criteria to evaluate the techno-economic feasibility of biorefinery options for Canadian Kraft mills. Starting from the base-case of highly integrated and energy efficient Kraft mills, we will apply state-of-the-art simulation techniques and systems engineering tools to examine the effects of key biorefinery technologies on the energy balance and operating cost of the process. They are, lignin precipitation, hemicelluloses extraction and biomass gasification. A new methodology for advanced energy efficiency analysis will be developed and applied to the study. It will take into account the factors that affect energy consumption individually and in conjunction: internal energy recovery, use of steam injection and mixing, water systems closure, heat and power production and the incorporation of energy upgrading technologies (co- and tri-generation, absorption heat pumps). Economic viability will be assessed by a new thermo-economic analysis method. The impacts of biorefining technologies on the process air emissions will be determined. The major outcome of this project will be guidelines that can be applied to examine the feasibility of proposed biorefinery concepts, guide investments in these technologies and help develop research strategies that address technical impediments. Models of biorefinery unit operations and a unique process simulation software for pulp mill-based biorefineries will be produced and validated.