Experimental Demonstration and Validation of Hydrogen Production Based on Gasification of Lignocellulosic Feedstock

The worldwide production of hydrogen in 2010 was estimated to be approximately 50 Mt/a, mostly based on fossil fuels. By using lignocellulosic feedstock, an environmentally friendly hydrogen production route can be established. A flow sheet simulation for a biomass based hydrogen production plant was published in a previous work. The plant layout consisted of a dual fluidized bed gasifier including a gas cooler and a dust filter. Subsequently, a water gas shift plant was installed to enhance the hydrogen yield and a biodiesel scrubber was used to remove tars and water from the syngas. CO$_{2}$ was removed and the gas was compressed to separate hydrogen in a pressure swing adsorption. A steam reformer was used to reform the hydrocarbon-rich tail gas of the pressure swing adsorption and increase the hydrogen yield. Based on this work, a research facility was erected and the results were validated. These results were used to upscale the research plant to a 10 MW fuel feed scale. A validation of the system showed a chemical efficiency of the system of 60% and an overall efficiency of 55%, which indicates the high potential of this technology

Developing an adsorption-based gas cleaning system for a dual fluidized bed gasification process

Biomass can make a major contribution to a renewable future economy. If biomass is gasified a wide variety of products (e.g.: bulk chemicals, hydrogen, methane, alcohols, diesel) can be produced. In each of these processes gas cleaning is a crucial factor. Impurities in the gas can cause catalyst poisoning, pipe plugging, unstable or poisoned end products or harm the environment. Especially aromatic compounds (e.g.: benzene, naphthalene, pyrene) have a huge impact regarding a stable operation of a syngas process. A removal of these compounds can be accomplished either with wet, dry or hot gas cleaning methods. Wet gas cleaning methods tend to produce huge amounts of waste water which needs to be treated separately. Hot gas cleaning methods provide a clean gas, but are often cost intensive due to their high operating temperatures and catalysts used in the system. Another approach is dry or semi dry gas cleaning methods including absorption and adsorption on solid matter. In this work special focus will be laid on adsorption based gas cleaning for syngas applications. Adsorption and desorption test runs were carried out under laboratory conditions using a model gas with aromatic impurities. Adsorption isotherms as well as dynamics were measured with a multi compound model gas. Based on these results a temperature swing adsorption process was designed and tested under laboratory conditions, showing the possibility of replacing the conventional wet gas cleaning by a semi-dry gas cleaning approach.Austrian Research Promotion Agency1841951

Experimental Demonstration and Validation of Hydrogen Production Based on Gasification of Lignocellulosic Feedstock

The worldwide production of hydrogen in 2010 was estimated to be approximately 50 Mt/a, mostly based on fossil fuels. By using lignocellulosic feedstock, an environmentally friendly hydrogen production route can be established. A flow sheet simulation for a biomass based hydrogen production plant was published in a previous work. The plant layout consisted of a dual fluidized bed gasifier including a gas cooler and a dust filter. Subsequently, a water gas shift plant was installed to enhance the hydrogen yield and a biodiesel scrubber was used to remove tars and water from the syngas. CO2 was removed and the gas was compressed to separate hydrogen in a pressure swing adsorption. A steam reformer was used to reform the hydrocarbon-rich tail gas of the pressure swing adsorption and increase the hydrogen yield. Based on this work, a research facility was erected and the results were validated. These results were used to upscale the research plant to a 10 MW fuel feed scale. A validation of the system showed a chemical efficiency of the system of 60% and an overall efficiency of 55%, which indicates the high potential of this technology