Turbomachinery in Biofuel Production Doctoral student : Martin Görling gorling@kth.se Supervisors: Prof Mats Westermark (EP) Prof Krister Sjöström, Prof Sven Järås (KT)

The main objectives of the project are :   To perform a techno-economic feasibility study of the integration of turbo-machinery into different promising bio-fuel production processes. To improve the technological knowledge in the field of turbo-machinery and bio-fuel production

Biofuels First Generation Vegetable oil-esters or biodiesel Ethanol from fermentation of agriculture and waste products Second Generation Gasification of non-food crops and cellulosic biomass Third Generation Hydrogen used in fuel cells Algae

Biofuels Biomass Process Fuel Cellulosic & Lignin Hydrogen Gasification FT-Diesel Sugar Fermentation Methanol &DME Fermentable Ethanol Digestion Oilseed Biogas Extraction Waste RME

Methanol production

Methanol production

Methane is an excellant raw material for methanol and the reaction is Methanol synthesis from methane CH4 + ½ O2  CH3OH + reaction heat Energy: 802,3 + 0  676 (84%) + 126 (16%) kJ/mol Theoretically about 84% of the LHV of methane can be recovered as methanol In practice about 75% is recovered as methanol. This is a good recovery! Methane is an excellant raw material for methanol and the reaction is rather reversible The reaction heat (~300C) is used for steam injection (~50 bar) and for distillation of the product. The use of steam turbines are rare.

About 60% of the biomass energy can be recovered as methanol. Methanol synthesis from biomass 2,7 CH1,5 O0,6 + 1,4 O2  CH3OH + reaction heat + 1,7CO2 Energy: 1127 + 0  676 (=60%) + 450 kJ/mol MeOH About 60% of the biomass energy can be recovered as methanol. The remaining 40% is transformed to heat. Biomass requires heating to be gasified before the methanisation reactor Alternatives for gasifiers: Oxygen addition to gasifier (see above) Hydrogen addition to gasifier (high carbon recovery,) Indirect gasification with hot sand (no oxygen plant) The reaction heat (~300C) is used for steam injection (~50 bar) and for distillation of the product. Recovery of additional heat from gasifier may be used in steam turbines.

Methanol plant size Average plant: 1100t/d Mega plant: 5000t/d ≈ 10,1 TWh/y MeOH ≈ 1150 MW MeOH Fuel demand: ≈13 TWh Natural gas ≈17 TWh Biomass ≈ 2,2 TWh/y MeOH ≈ 255 MW MeOH Fuel demand: ≈3 TWh Natural gas ≈3,7 TWh Biomass Dilemma between steam production and Methanol efficiency

Production process Pre-treatment Gasification Gas clean-up Gas conditioning Fuel synthesis Fuel + off-gas

Gasification Kanske ska bort men lite intro till förgasare Agent Oxygen Steam Hydrogen Techniques Fluidized bed Indirect Kanske ska bort men lite intro till förgasare

Fluidized bed Pressure: 1 – 40 bar Gasification agent Air Oxygen Hydrogen No scale up limit

Indirect gasification Small scale Atmospheric pressure Syngas content High methane Low nitrogen chalmers

Methane synthesis from biomass Oxygen gasification: 2,7 CH1,5 O0,6 + 1,4 O2  CH4 + reaction heat + 1,7CO2 Energy: 1127 + 0  676 (=60%) + 450 kJ/mol MeOH Oxygen addition to gasifier (storage of CO2 requires oxygen plant) Suitable for carbon capture and storage Hydrogasification: CH1,5 O0,6 + 1,85 H2  CH4 + reaction heat + 0,6H2O Energy: 420 + 448  676 (=78%) + 192 kJ/mol MeOH Hydrogen addition to gasifier requires hydrogen but gives high carbon recovery Suitable for use of wind energy in the transport sector

SNG production Internal power prod. 5MW

Available steam: 33MW

Turbomachinery in biofuel production Large amounts of excess heat Minimize steam consumption Indirect/hydrogen gasification Humidification steam turbine power production is a given complement in biofuel production systems Steam turbines

Turbomachinery in biofuel production Gas turbines – syngas combustion Optimized for natural gas. Problems with syngas combustion in modern low NOx burners. Limited resources of biomass, scale problems. Hybrid combined cycle Input -Natural gas for gas turbine -Biomass for fuel and heat (excess heat from fuel prod.) Output -Biofuel -Electricity -Heat