Environmental and energy systems Fossil free tissue drying

Environmental and energy systems Fossil free tissue drying Lars Nilsson Karlstad University One possible industrial application of biomass gasification for the pulp and paper industry

Environmental and energy systems Source: www. skogsindustrierna. org

Environmental and energy systems Tissue products - Toilet paper - Kitchen towels - Napkins - Facials - ……….

Environmental and energy systems Tissue drying process Condensing steam inside the cylinder Impinging hot gases

Environmental and energy systems Research questions Is gasification technology commercially available? Will the need for energy gas increase? Effects of process integration?

Environmental and energy systems Scale of the gasification plant Machine speed Machine width Grammage Press dryness Creping dryness Specific drying energy Impingement drying contribution 1500 m/min 3 m 17 g/m 2 45 % 95 % 3, 0 MJ/kg H 2 O 50 % Gas production roughly 2 MW Go. Bi. Gas 20 MW (demo) and 100 MW (full scale)

Environmental and energy systems Proposed gasification technologies Updraft fixed bed Not OK! Downdraft fixed bed OK!

Environmental and energy systems Proposed gasification technologies (continued) Suspension gasifier OK!

Environmental and energy systems Proposed gasification technologies (continued) Dual bed gasifier OK!

Environmental and energy systems Proposed gasification technologies (continued) Two stage gasifier OK!

Environmental and energy systems Results from tissue drying model Syngas has a lower heating value than LPG. A higher gas flow is needed. This means that more energy is used for heating the energy gas to the working temperature of the hood. A detailed simulation model has revealed that the increased need for energy gas is lower than 3 % for all cases investigated.

Environmental and energy systems Integrated or stand-alone gasification? Today, steam is produced in a bioboiler. Tissue drying is the main steam consumer. Today´s biomass consumption is 2830 kg/h. Today, LPG for tissue drying is bought. When producing the energy gas on-site, excess heat can be used for steam generation.

Environmental and energy systems Base case energy system

Environmental and energy systems Integrated gasification process

Environmental and energy systems Stand-alone gasification process

Environmental and energy systems Increased biomass consumption for replacing the bought LPG

Environmental and energy systems Benefits of process integration Could the bought LPG be replaced with bought ”green” energy gas?

Environmental and energy systems Research questions revisited Gasification technology is commercially available! - What about burners? Need for energy gas only increases marginally. Benefits of process integration are obvious! - Will ”green energy gas” be available?

Environmental and energy systems More details