Search

Techno-economic analysis of hydrothermal carbonization of pulp mill biosludge, TAPPI Journal March 2023

ABSTRACT: For many mills, the biosludge from wastewater treatment is difficult to recycle or dispose of. This makes it a challenging side stream and an important issue for chemical pulping. It often ends up being burned in the recovery or biomass boiler, although the moisture and non-process element (NPE) contents make it a problematic fuel. Biosludge has proven resistant to attempts to reduce its moisture. When incinerated in the biomass boiler, the heat from dry matter combustion is often insufficient to yield positive net heat. Mixing the sludge with black liquor in the evaporator plant for incineration in the recovery boiler is more energy efficient, but is still an additional load on the evaporator plant, as well as introducing NPEs to the liquor. In this study, treating the biosludge by hydrother-mal carbonization (HTC), a mild thermochemical conversion technology, is investigated. The HTC process has some notable advantages for biosludge treatment; taking place in water, it is well suited for sludge, and the hydrochar product is much easier to dewater than untreated sludge. In this study, two HTC plant designs are simulated using IPSEpro process simulation software, followed by economic analysis. Low temperature levels are used to minimize investment costs and steam consumption. The results show that if the sludge is incinerated in a biomass boiler, payback periods could be short at likely electricity prices. The HTC treatment before mixing the sludge with black liquor in the evaporator plant is profitable only if the freed evaporator capacity can be used to increase the firing liquor dry solids content.

Meeting the Future Through Knowledge Sharing and Connection, Paper360º March/April 2023

Woodland Pulp: Local Leadership, Global Competitiveness, Paper360º May/June 2023

Reducing Energy Consumption with Enzymatic Treatment, Paper360º May/June 2023

Artificial Biofilms and Slimicide Efficacy, 1997 Biological Sciences Symposium Proceedings

Artificial Biofilms and Slimicide Efficacy, 1997 Biological Sciences Symposium Proceedings

Resistance to Industrial Microbicides - A Review and Ecological Perspective, 1997 Biological Sciences Symposium Proceedings

Resistance to Industrial Microbicides - A Review and Ecological Perspective, 1997 Biological Sciences Symposium Proceedings

Impact of Water Reuse on Papermachine Microorganisms, 1997 Biological Sciences Symposium Proceedings

Impact of Water Reuse on Papermachine Microorganisms, 1997 Biological Sciences Symposium Proceedings

Effect of Cartapip 97 Pretreatment on the Kraft Pulping of Radiata Pine, 1997 Biological Sciences Symposium Proceedings

Effect of Cartapip 97 Pretreatment on the Kraft Pulping of Radiata Pine, 1997 Biological Sciences Symposium Proceedings

Industrial Production of Enzyme Treated Kraft Pulp from Radiata Pine, 1997 Biological Sciences Symposioum Proceedings

Industrial Production of Enzyme Treated Kraft Pulp from Radiata Pine, 1997 Biological Sciences Symposioum Proceedings

Isolation, Expression and Characterization of Family 10 and 11 Xylanases from an Extremely Thermophilic Bacterium, Dictyoglomus Thermophilum Strain..., 1997 Biological Sciences Symposium Proceedings

Isolation, Expression and Characterization of Family 10 and 11 Xylanases from an Extremely Thermophilic Bacterium, Dictyoglomus Thermophilum Strain..., 1997 Biological Sciences Symposium Proceedings