From steam engine to gas turbine: time to unleash the potential of bioenergy

Steam engines have been used in many different situations over the past 200 years. When it comes to converting biomass into energy, it has reached its limit, where the cost of producing energy exceeds the value of the final product. In search of a new and profitable alternative for the production of electricity, Phoenix BioPower has developed a revolutionary technology: Biomass Fired Top Cycle.

The great advantage of BTC technology is that it can produce twice the electricity from the same amount of fuel that was previously standard in the market. Efficiency increases to more than 60%, which means that we now have a planned and profitable technology. Power can be produced when it is needed, where it is needed, says Henrik Båge, CEO of Phoenix BioPower AB.

The process at BTC consists mainly of three steps: pressurization, gasification, and gas turbine. In batches, the fuel is pressurized with the help of steam, carbon dioxide, or nitrogen gas and then fed to the carburetor. There, the pressurized fuel is converted into product gas which, after being purified and filtered, is fed into the gas turbine. In the gas turbine combustion chamber, the product gas is burned together with compressed air and steam. Thermal energy from the exhaust gases is recovered in the steam boiler to generate process steam and district heating.

Bioenergy and hydrogen

In 2021, Phoenix BioPower conducted tests to develop a higher cycle gas turbine for bioenergy and hydrogen. Hydrogen has had a major political impact on, among other things, the EU Green Deal in response to how to balance the energy system.

– Conventional gas turbines have enormous problems handling hydrogen. Our combustion technology, after undergoing tests, has proven capable of stable hydrogen burning with extremely low emissions of harmful nitrogen dioxide, says Henrik Båge.

Fuel logistics in focus

The application of this technology on a large scale requires careful work with fuel logistics. When 20-30 tonnes of fuel are to be transported to a plant every hour, a challenge arises in certain markets or areas. In Sweden, however, there are already examples of successful fuel logistics. Värtanverket in Stockholm and Igelstaverket in Södertälje are two of them.

-These two are, from an international perspective, large cogeneration plants that are fed with biofuels, says Henrik Båge. At the same time, there are examples of installations many times larger in Europe.

Carbon capture

To achieve the established climate targets, the production of renewable electricity is required to increase by approximately 1,000 TWh per year. But to reach the climate goal of 1.5 ° C in temperature rise, it is not enough just to reduce carbon dioxide emissions, we must also actively reduce the amount of carbon dioxide in the atmosphere, as indicated in the report of the 2019 IPCC. With the help of negative flue gas carbon dioxide technology and therefore long-term negative emissions are created.

-There are two techniques for this; One is to capture carbon dioxide from the flue gas that arises during combustion (so-called afterburning). The second technology involves entering and dividing the gas so that it can separate, capture, and store carbon dioxide. Captured carbon dioxide is purified and concentrated and then stored in places where it does not cause harm or can be used to replace the carbon dioxide produced by fossils. With Phoenix BioPower’s BTC technology, negative emissions can be achieved much more cost-effectively and energy-efficiently than conventional bioenergy can handle, says Henrik Båge.

Pilot plant in operation 2024

In 2020, Phoenix BioPower started the project to establish a pilot plant where the principle of the system for BTC technology can be tested and validated on an industrial scale through a comprehensive feasibility study of what is required technical, budgetary and in time. to carry out such a project. Preparatory testing and development will continue through 2021/22.

-Part of the preparations for the pilot plant consists of the Scarlett test bed, which is scheduled to be commissioned in 2022 at the Phoenix BioPower facility in Stockholm. The test bed will be a way to develop the technology in conditions similar to those of BTC. Here, gasification, gas purification and combustion can be integrated and observe how conditions change with different fuels. This platform will be the first “flame fuel” platform based on the principles of BTC.

We are actively working to take the next step towards a pilot plant. With a fuel output of 3-5 MW and a pressure of 35-40 bar, the pilot plant will be unique in the world. The goal is for the plant to be operational by 2024, concludes Henrik Båge.