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Production of liquid biogas, LBG, with cryogenic and conventional upgrading technology - Description of systems and evaluations of energy balances

Johansson, Nina (2008)
Environmental and Energy Systems Studies
Abstract
The aim of this master thesis is to evaluate energy balances for the production of liquid biogas, LBG.LBG can be produced in two main ways and these are by means; cryogenic upgrading technology andconventional technologies connected with a small-scale liquefaction plant. A third alternative is to injectbiogas into the gas grid and then liquefy a part-flow at a pressure letdown station.The cryogenic upgrading technology is based on differences in condensation temperature for differentcompounds, and by chilling biogas, impurities and CO2 can be separated from CH4. When using thistechnology also liquid CO2, LCO2, comes as a by-product, which could be used in external applications.With one of the two main ways it takes between 0.8-1.8 kWh/Nm3... (More)
The aim of this master thesis is to evaluate energy balances for the production of liquid biogas, LBG.LBG can be produced in two main ways and these are by means; cryogenic upgrading technology andconventional technologies connected with a small-scale liquefaction plant. A third alternative is to injectbiogas into the gas grid and then liquefy a part-flow at a pressure letdown station.The cryogenic upgrading technology is based on differences in condensation temperature for differentcompounds, and by chilling biogas, impurities and CO2 can be separated from CH4. When using thistechnology also liquid CO2, LCO2, comes as a by-product, which could be used in external applications.With one of the two main ways it takes between 0.8-1.8 kWh/Nm3 clean biogas to produce LBG. If theenergy is expressed in primary energy, this energy consumption corresponds to 12-23 % of the energycontent in the product. The net energy consumption is affected by the disposal of waste heat and use ofLCO2 in external processes while CH4 losses have a small influence.The production of LBG is more energy intensive than the production of compressed biogas but in somesituations the product is more valuable since the biogas becomes available for more customers. (Less)
Please use this url to cite or link to this publication:
author
Johansson, Nina
supervisor
organization
year
type
H3 - Professional qualifications (4 Years - )
subject
keywords
Cryogenic technology, liquid biogas, LBG, energy balance, small-scale liquefaction, LCO2, primary energy
report number
TFEM--08/5032
other publication id
LUTFD2/TFEM--08/5032--SE + (1-92)
language
English
id
4468178
date added to LUP
2014-06-18 13:34:42
date last changed
2014-06-18 13:34:42
@misc{4468178,
  abstract     = {The aim of this master thesis is to evaluate energy balances for the production of liquid biogas, LBG.LBG can be produced in two main ways and these are by means; cryogenic upgrading technology andconventional technologies connected with a small-scale liquefaction plant. A third alternative is to injectbiogas into the gas grid and then liquefy a part-flow at a pressure letdown station.The cryogenic upgrading technology is based on differences in condensation temperature for differentcompounds, and by chilling biogas, impurities and CO2 can be separated from CH4. When using thistechnology also liquid CO2, LCO2, comes as a by-product, which could be used in external applications.With one of the two main ways it takes between 0.8-1.8 kWh/Nm3 clean biogas to produce LBG. If theenergy is expressed in primary energy, this energy consumption corresponds to 12-23 % of the energycontent in the product. The net energy consumption is affected by the disposal of waste heat and use ofLCO2 in external processes while CH4 losses have a small influence.The production of LBG is more energy intensive than the production of compressed biogas but in somesituations the product is more valuable since the biogas becomes available for more customers.},
  author       = {Johansson, Nina},
  keyword      = {Cryogenic technology,liquid biogas,LBG,energy balance,small-scale liquefaction,LCO2,primary energy},
  language     = {eng},
  note         = {Student Paper},
  title        = {Production of liquid biogas, LBG, with cryogenic and conventional upgrading technology - Description of systems and evaluations of energy balances},
  year         = {2008},
}