TY - JOUR
T1 - A comparison of two low grade heat recovery options
AU - Walsh, C.
AU - Thornley, P.
N1 - © 2013, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
PY - 2013/5/2
Y1 - 2013/5/2
N2 - Low grade heat (LGH) recovery is one way of increasing industrial energy efficiency and reducing associated greenhouse gas emissions. The organic Rankine cycle (ORC) and condensing boiler are two options that can be used to recover low grade heat (<250 °C). This paper assesses the lifecycle greenhouse gas reduction impacts and discounted payback periods associated with both technologies. Generation of electricity through the operation of the ORC saves approximately 11 kt of CO2 annually, but the high carbon intensity of the coking process means this has a negligible influence (<1%) on the overall process lifecycle impacts. However, if the electricity generated offsets the external purchasing of electricity this results in favourable economic payback periods of between 3 and 6 years. The operation of a condensing boiler within a woodchip boiler reduces the fuel required to achieve an increased thermal output. The thermal efficiency gains reduce the lifecycle impacts by between 11 and 21%, and reflect payback periods as low as 1.5–2 years, depending on the condenser type and wood supply chain. The two case studies are used to highlight the difficulty in identifying LGH recovery solutions that satisfy multiple environmental, economic and wider objectives.
AB - Low grade heat (LGH) recovery is one way of increasing industrial energy efficiency and reducing associated greenhouse gas emissions. The organic Rankine cycle (ORC) and condensing boiler are two options that can be used to recover low grade heat (<250 °C). This paper assesses the lifecycle greenhouse gas reduction impacts and discounted payback periods associated with both technologies. Generation of electricity through the operation of the ORC saves approximately 11 kt of CO2 annually, but the high carbon intensity of the coking process means this has a negligible influence (<1%) on the overall process lifecycle impacts. However, if the electricity generated offsets the external purchasing of electricity this results in favourable economic payback periods of between 3 and 6 years. The operation of a condensing boiler within a woodchip boiler reduces the fuel required to achieve an increased thermal output. The thermal efficiency gains reduce the lifecycle impacts by between 11 and 21%, and reflect payback periods as low as 1.5–2 years, depending on the condenser type and wood supply chain. The two case studies are used to highlight the difficulty in identifying LGH recovery solutions that satisfy multiple environmental, economic and wider objectives.
UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84877866187&partnerID=MN8TOARS
UR - https://www.sciencedirect.com/science/article/pii/S1359431112002785?via%3Dihub
U2 - 10.1016/j.applthermaleng.2012.04.035
DO - 10.1016/j.applthermaleng.2012.04.035
M3 - Article
SN - 1359-4311
VL - 53
SP - 210
EP - 216
JO - Applied Thermal Engineering
JF - Applied Thermal Engineering
IS - 2
ER -