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31.
32.
When gasified black liquor is used for hydrogen production, significant amounts of biomass must be imported. This paper compares two alternative options for producing hydrogen from biomass: (A) pulp-mill-integrated hydrogen production from gasified back liquor; and (B) stand-alone production of hydrogen from gasified biomass. The comparison assumes that the same amount of biomass that is imported in Alternative A is supplied to a stand-alone hydrogen production plant and that the gasified black liquor in Alternative B is used in a black liquor gasification combined cycle (BLGCC) CHP unit. The comparison is based upon equal amounts of black liquor fed to the gasifier, and identical steam and power requirements for the pulp mill. The two systems are compared on the basis of total CO2 emission consequences, based upon different assumptions for the reference energy system that reflect different societal CO2 emissions reduction target levels. Ambitions targets are expected to lead to a more CO2–lean reference energy system, in which case hydrogen production from gasified black liquor (Alternative A) is best from a CO2 emissions’ perspective, whereas with high CO2 emissions associated with electricity production, hydrogen from gasified biomass and electricity from gasified black liquor (Alternative B) is preferable. 相似文献
33.
Pulp mills use significant amounts of biofuels, both internal and purchased. Biofuels could contribute to reach greenhouse gas emission targets at competitive costs. Implementing process integration measures at a pulp mill in order to achieve pulp production with less use of energy (biofuels) has not only on-site consequences but also off-site consequences, such as substitution of fossil fuels elsewhere by the saved pulp mill biofuels, and less on-site electric power generation. In this paper a method, a linking model, is suggested to analyse pulp mill biofuel saving measures when carbon dioxide (CO2) external costs are internalised. The linking model is based on equilibrium economics and links information from CO2 constrained energy market future scenarios with process integration measures. Pulp mill economics and marginal energy market CO2 response are identified. In an applied study, four process integration measures at a Swedish pulp mill were analysed using five energy market future scenarios emanating from a Nordic energy model. The investigated investment alternatives for biofuel savings all result in positive net annual savings, irrespectively of the scenario used. However, CO2 emissions may increase or decrease depending on the future development of the Nordic energy market. 相似文献
34.
为了分离金川二矿区井下充填管路引流洗管水,避免引流洗管水进入进路对充填体强度带来负面影响,二矿区通过科技攻关,研制应用了矿用充填导水阀,解决了充填过程中引流洗管水进入充填进路的问题,杜绝了接顶充填时的溢流现象,使进路保持完全接顶,保证了充填料浆浓度和充填体强度,降低了污染,节约了充填成本。 相似文献
35.
目的提高果粒饮料的质量监控,改进产品配方,提升饮料的口感。方法采用动态图像法对果粒样品的最大FERET直径进行分析,建立一个粒度粒形与果粒型橙汁饮料口感的关系。结果最大FERET直径大于9 mm的颗粒基本为原始橙粒果肉原料,适当增加该成分对口感的提升有极大帮助。结论对于果粒饮料,动态图像分析法可以给出果粒的原始图形信息,且统计量大,代表性强,对其配方改进及生产质控具有密切的指导意义。 相似文献
36.
基于支持向量机的蒸煮过程卡伯值软测量 总被引:2,自引:0,他引:2
卡伯值是制浆蒸煮过程表征纸浆质量的一个重要质量指标,卡伯值软测量是实现蒸煮过程质量控制的重要途径。支持向量机是一种新型的机器学习方法。该方法采用了结构风险最小化原则,与传统机器学习方法相比,在最小化学习误差的同时可以保证有较小的泛化误差。将支持向量机应用于制浆蒸煮过程卡伯值的软测量建模,取得了比经验模型更好的预测效果。 相似文献
37.
Alkali pretreatment enhances biogas production in the anaerobic digestion of pulp and paper sludge 总被引:3,自引:0,他引:3
The objective of this research was to develop an alkali pretreatment process prior to anaerobic digestion (AD) of pulp and paper sludge (PPS) to improve the methane productivity. Different concentrations of sodium hydroxide solution were used to pretreat PPS, and then followed by AD of PPS and monosodium glutamate waste liquor (MGWL).Laboratory-scale experiments were carried out in completely mixed bioreactors, 1 L capacity with 700 mL worked. Optimal amount of sodium hydroxide for organics solubilization in the step of pretreatment was 8 g NaOH/100 g TSsludge. Under this condition, the PPS flocs structure was well disrupted resulting in the void rate and fiber size decreased after pretreatment, and SCOD increased up to 83% as well as the peak value of VFA concentration attained 1040 mg acetic acid/L during AD. The AD efficiency of PPS with and without pretreatment was evaluated. The highest methane yield under optimal pretreatment condition was 0.32 m3 CH4/kg VSremoval, 183.5% of the control. The results indicated that alkali/NaOH pretreatment could be an effective method for improving methane yield with PPS. 相似文献
38.
A heuristic for design of plantwide control strategies is introduced and applied to the millwide control of a previously presented pulp mill benchmark. Two control strategies (decentralized control and unit-based model predictive control) are compared according to their capacity to reduce the total error and maximize the operating profits. The control strategies are studied through closed-loop simulations of the process including several disturbances and setpoint changes in the digester, oxygen reactor, bleach plant, recausticizing plant and lime kiln. 相似文献
39.
Dushyant Kumar 《分离科学与技术》2020,55(15):2844-2854
ABSTRACT In this study, electrocoagulation (EC) was used to determine the optimum conditions on the basis of maximum chemical oxygen demand (COD) and color removal. At the optimum conditions chlorophenols (CPs), biological oxygen demand and total organic carbon (TOC) were determined. The biodegradability of wastewater was increased significantly with 63% COD, 98% color, 61% TOC and overall 65.51% reductions in CPs. Further, the electro-coagulated sludge was characterized by using different analytical techniques to assist the physicochemical and elemental phases, to find-out better management option, reusability for plant growth and safe disposal. Additionally, aluminum content (70.62%) was successfully recovered from sludge. 相似文献
40.