Production from waste biomass for green and sustainable future

The current industrial production has issues in terms of sustainability. Production facilities use fossil resources for chemicals, fuels and energy. However, fossils are being depleted while energy demand is increasing. Moreover, fossil-based production cause environmental problems including global warming and air pollution through carbon emissions and other pollutants. Consequently, renewable sources has increasingly become important. Among renewables, biomass is the most abundant renewable source and a raw material for chemical production as well as energy. To sum up, biomass has the potential to replace fossil-based resources: as a renewable source, with no net carbon emission, less ash content and air pollution impact.

The objectives of my research are to develop a biomass conversion process as the enabler of sustainable biorefinery.

Biomass conversion and sustainable biorefinery

The target of biomass processing would be sustainable production without the need of fossils. Furthermore, biomass is already involved in various sectors (e.g., agriculture and forestry) of which the wastes/byproducts can be utilized for further production. The sustainable biorefinery should fulfil the criteria listed below:

• no compromise with critical needs, such as food and animal feed
• the regeneration of biomass and biodiversity
• minimum environmental impacts
• the ability to adapt the variations in quality and quantity of biomass feedstock
• the ability to adapt the changes in market demand

Regarding the feedstock, biomass processing is classified as 1^st generation and 2^nd generation. The 1^st generation refers to using the edible biomass as the feedstock, such as corn crops and vegetable oils. However, this competes with the food sector. Consequently, the 2^nd generation processing has potential for sustainable biorefinery, i.e. processing the non-edible biomass sources and waste/by-product streams. However, this requires advanced conversion processes, and the current biomass conversion processes have high operation costs and operational concerns.

Even though biomass processing is not economically feasible now, there are potential improvements on this aspect. Various wastes and by-products can be processed together. Therefore, collecting wastes from various biomass sites would enable larger capacity conversion processes and provide additional revenue to all the biomass sites. This concept can potentially make the biorefinery sector competitive with petroleum refinery. Therefore, the current investigations include the whole supply chain: transporting waste/byproduct biomass from field to conversion plants, the chemical conversion of biomass and finally transport of the products to the demand sites. The figure below shows the sectoral integration formulated in this research as the supply chain structure, with the concept of converting wastes from various sectors together in the regional conversion plants.

The biomass conversion processes are still the heart of a supply chain network. Considering the criteria of sustainable biorefinery, the conversion process should have the features of being:

• multi-feed-multi-product process
• flexibility in terms of the products and the amounts
• processing wide spectrum of feedstock from various sectors
• techno-economically suitable regarding biomass properties

My research scope and outcomes

The purpose of my research is to develop a biomass conversion process with the above-mentioned features. The process is selected in accordance with the feedstock and target products together.

The figure below shows the process development approach and the scope. The aim is to develop the blue box in the right-side: a novel hydrothermal conversion process. The process is considered as the regional conversion process of the sectoral integration structure. My research focuses on lignocellulosic biomass (e.g., wood, straw, black liquor); nevertheless, the findings can partly be applied to other feedstock types as well. The products in the scope include lignin, syngas and bio-oil. Lignin has various applications in high technology materials and chemical industry as shown in the figure below, thus potentially replacing fossil-based sources in those applications. Syngas can be used to produce fuels, chemicals or energy. Bio-oil is used as a liquid biofuel after upgrading.

During my research, I have been collaborating with colleagues in Aalto University and Åbo Akademi. I also participated scientific conferences that provided remarkable overview to the field and networking. I aim to continue further developments in the biomass field.

Karhan Özdenkçi is the doctoral candidate in Plant Design Research Group in Aalto University. He has B. Sc. degree in Chemical Engineering from Izmir Institute of Technology (Turkey) and M. Sc. degree in Process Systems Engineering from Aalto University. His current research subject is hydrothermal conversion of biomass into valuable chemical and energy. He is also a referee for scientific journals: Energy Conversion and Management, Cellulose Chemistry and Technology, Environmental Technology, and Applied Energies.