Session: 03-11 Hydrogen & Alternative fuels

Paper Number: 101972

101972 - Performance, Emissions, and Decarbonization of an Industrial Gas Turbine Operated With Hydrotreated Vegetable Oil 

Hydrotreated vegetable oil (HVO) has been used extensively as a low-carbon, drop-in replacement biofuel for fossil diesel in the transport sector, particularly in the Nordic and European markets.  However, evidence of the use of HVO in liquid fuel or dual-fuel gas turbine applications is extremely limited.  As part of Uniper’s Making Net Zero Probable project, which aims to decarbonise Uniper’s European power generation fleet by 2035, an open-cycle 63 MW_e Siemens V93.0 gas turbine in Malmö, Sweden was operated with HVO as a replacement for light fuel oil in July 2021.  This gas turbine is part of the emergency reserve in southern Sweden, ensuring security of supply in this key region.  An extensive feasibility study was first undertaken to understand the potential impacts of replacing light fuel oil with HVO in this gas turbine.  This study included an analysis of the fuel and compatibility with the existing diffusion combustion system, flame temperature modelling to predict the expected impact on NO_x emissions and water injection rates, and a detailed hazard identification study for the short-duration trial.  During the two-day demonstration, baseline gas turbine performance and accredited emissions were first measured using the existing light fuel oil.  HVO was then subsequently used to demonstrate its ability to be used across all operating conditions including start-up, synchronisation, ramp to base load, part load, and shut-down.  Accredited emissions of NO_x, CO, SO₂, and dust were measured to allow direct comparison between fuels.  When operating with HVO, all required performance targets were achieved, including an on-load fuel switch from HVO to light fuel oil.  Direct flame imaging through the silo combustor sight-glasses was also used to observe the HVO start-up ignition process and to allow for a flame intensity comparison between fuels.  Comparable NO_x emissions were measured between light fuel oil and HVO operation across all operating conditions.  As a result, no changes to the water injection rate for NO_x control were required when switching fuels, as predicted by the preliminary flame temperature modelling.  Measurable reductions in dust, CO, and SO₂ emissions were observed for HVO as compared with fuel oil for the same power output.  These emissions reductions are respectively attributed to HVO’s low ash and aromatic contents, an increased hydrogen content relative to light fuel oil, and that the fuel is essentially sulphur-free.  HVO also enables significant lifecycle carbon dioxide emissions reductions of over 90% compared with fossil diesel, particularly when the production feedstock comprises of waste vegetable oils and animal fats.  In this trial alone, a CO₂ reduction of approximately 163 tCO₂ was achieved by using HVO. The success of this demonstration provides the necessary support for future site conversion to HVO and has led to subsequent successful HVO demonstrations on other liquid fuel and dual-fuel gas turbines in the Uniper fleet.  Long-duration testing and monitoring is still required to build the evidence base regarding the impact of HVO operation on fuel storage, fuel delivery, and hot gas path components.  To the authors’ knowledge, this trial is the world’s first successful demonstration of HVO use in an industrial gas turbine. 

Presenting Author: Jon Runyon Uniper Technologies Ltd

Presenting Author Biography: Dr. Jon Runyon is a Gas Turbine Combustion Engineer at Uniper Technologies in the United Kingdom. He received his PhD in Mechanical Engineering from the Gas Turbine Research Centre at Cardiff University and his Bachelor's in Mechanical Engineering from the University of Florida. His research areas and interests include the use of hydrogen, ammonia, and biofuels for the decarbonisation of gas turbine power generation.

Authors:

Jon Runyon Uniper Technologies Ltd
Stuart James Uniper Technologies Ltd
Tanmay Kadam Uniper Kraftwerk GmbH
Barak Ofir Sydkraft Thermal Power AB
David Graham Uniper Technologies Ltd