Integration of bioproducts and pulp production in a BCTMP mill

漂白化学热磨机械浆（BCTMP）作为一种提高产品性能的经济有效的方法，已越来越多地用于纸张中。加拿大生产的BCTMP占世界市场的70%以上，其中大部分出口到欧洲和亚洲。然而，加拿大BCTMP生产商目前正面临来自世界低成本生产商的激烈竞争，需要开发新技术以增加收入和/或降低生产成本，以保持竞争力。用于生物产品的半纤维素的预提取可以为BCTMP工厂提供额外的收入。来自硬木BCTMP米尔斯厂的提取流可以富含半纤维素，因此提供了在制造纸浆之前预提取并将这些提取物转化为增值生物产品的机会。BCTMP工艺的化学预处理阶段可以很容易地用作预提取阶段，而无需大量的资本投资。作者等人的早期研究表明，在常规BCTMP工艺之前进行酸预提取可以通过显著降低精炼能量来降低生产成本。纸浆的松厚度和表面性能不受影响，但白度和强度降低。因此，需要研究在预提取阶段期间使提取效率最大化同时使亮度和强度损失最小化的方法。对于BCTMP工艺，尚未研究预提取中各种化学品的提取效率和对纸浆性质的影响。还存在挑战，例如如何从稀释流中浓缩/分离/纯化半纤维素。目前的计划解决了这些需求，旨在为加拿大BCTMP公司开发和实施新技术/生物产品，从而通过提供新的收入和降低生产成本来提高其竞争力。从这项研究中获得的也可以应用到热磨机械浆厂米尔斯，正面临着一个显着的纸张广告的需求下降。

Bleached chemi-thermomechanical pulp (BCTMP) has been increasingly used in papers as a cost-effective way to improve product performance. Canada produces over 70% of the world's market BCTMP and most of them are exported to Europe and Asia. However, the Canadian BCTMP producers are now facing strong competition from low-cost producers in the world and need to develop new technologies to increase their revenue and/or reduce production cost in order to stay competitive. Pre-extraction of hemicelluloses for bioproducts may provide additional revenue to a BCTMP mill. The extracted flows from hardwood BCTMP mills can be rich in hemicelluloses, thereofre, providing opportunities to pre-extract and convert these extracts into value-added bioproducts before making pulp. The chemical pre-treatment stage of a BCTMP process can easily be served as the pre-extraction stage without major capital investment. Earlier studies by the author et al. have shown that acid pre-extraction before the normal BCTMP process can reduce production cost by significantly reducing the refining energy. Pulp bulk and surface properties are not affected but brightness and strength are reduced. Therefore, work is required to investigate ways to maximize the extraction efficiency while minimizing the loss of brightness and strength during the pre-extraction stage. The extraction efficiency and impact on pulp properties with various chemicals in pre-extraction have not been studied for a BCTMP process. There are also challenges such as how to concentrate/separate/purify the hemicelluloses from the dilute stream. The present program addresses these needs and will aim to develop and implement new technologies/bioproducts for the Canadian BCTMP companies, therefore, increasing their competitiveness by providing new revenues and reducing production cost. What acquired from this study could also be applied to the thermomechanical pulp mills that are facing a significant downturn of the demand for paper advertising.