With the Paris Agreement in 2015, the global community committed itself to limit the global warming to 2 °C compared with the pre-industrial level. Hence, the anthropogenic greenhouse gas emissions need to be reduced across all sectors. In Germany, on one hand, this is hitherto mainly achieved by broad deployment of wind turbines and photovoltaic within the energy sector. These technologies in turn lead to an increasing demand for flexible power generation and storage. The industrial sector on the other hand faces the challenge to transform from a linear carbon economy based on fossil resources to a circular carbon economy. The polygeneration concept based on fluidized bed gasification is a promising approach for both a CO₂ lean power production as well as the supply of base chemicals for the chemical industry from fossil resources and biogenic and anthropogenic residues alike. The study at hand presents the conceptual design of a pilot plant for the investigation of the technical and scientific problems to be solved before commercialization of the polygeneration concept. The pilot plant itself is an extension of an existing 500 kWth pilot scale gasifier at the Technical University of Darmstadt. The conceptualization is based on a model of the complete process chain consisting of fluidized bed drying, fluidized bed gasification, catalytic conversions, thermal and chemical separation processes for raw gas cleaning, power production and synthesis of methanol as a base chemical. The relevant research issues are than derived by means of techno-economic assessment of expected operation regimes and transients in commercial scale polygeneration plants. For validation of the design conditions of the pilot scale gas processing, more than 200 operating hours of the pilot scale gasifier have been completed with different feedstocks. Hereby, cold gas efficiencies up to 65 % and carbon conversions up to 95 % were achieved. The techno-economic assessment showed that commercial scale polygeneration plants are able to store up to 58 % of the carbon within the feedstock in the product, without additional use of electrolytic hydrogen. The determined production costs with 145 €/MWh for power and 540 €/t for raw methanol are above the current market price. In the future, increasing prices for CO₂ emissions and more volatile prices for electricity can be expected. These market conditions would make the investigated concept economically feasible. The conceptualized pilot plant includes all critical process steps. The load flexibility of the separation processes and reactors as well as the large scale testing of improved tar removal technologies have been identified as the most pressing questions before commercialization.