Over the course of time, a broad range of feedstock has been tested in the several reference plants. On commercial scale, HTW has shown excellent results with MSW, RDF, Wood and Lignite.
Refuse derived fuel - RDF, covers a wide range of waste materials which have been processed to fulfill guideline, regulatory or industry specifications mainly to achieve a high calorific value. Waste derived fuels include residues from municipal solid waste (MSW) recycling, industrial/trade waste, sewage sludge, industrial hazardous waste, biomass waste, etc. A variety of materials can be processed and turned into Refuse Derived Fuel, meaning that this practice poses environmental benefits. Typically, the waste material is processed to remove the recyclable fraction (e.g. metals), the inert fractions (such as glass) and separate if it is possible the fine wet organic fraction (e.g. food and garden waste) containing high moisture and high ash material before being pulverized. The medium fraction, consisting of paper, card, wood, plastic and textiles is dried and pelletized into dense RDF. As a result, RDF has, on average, higher heating value, lower ash content, and a lower bulk density compared to untreated waste. Gasification of RDF has been proven and applied on commercial scale. The main benefit offered by RDF-gasification technologies is the combination of high fuel flexibility, high power production efficiency and good environmental performance. This provides plant operators with more options when sourcing fuels and more electricity production, both improving plant profitability. Turning waste into clean gas also gives the option to replace fossil fuels with RDF in existing plants. RDF is currently being incinerated for the production of power, but more legislation comes in place to reduce waste material to be used for incineration and landfilling, and more recycling and reuse. Gasification of RDF and MSW therefore gives opportunities for the the production of fuels and chemicals.
Municipal Solid Waste - MSW, also called garbage or trash, is nonhazardous disposable materials generated by households, institutions, industries, agriculture, and sewage. It is made up of waste, organics, and recyclable materials, with the municipality overseeing its disposal. Typically, municipal solid waste is collected, separated and sent to either a landfill or municipal recycling center for processing. There is an increasing demand for replacing primary resources in manufacturing and fossil fuels in energy production with competitive and renewable alternatives. At the same time, many countries still landfill the majority of their municipal solid waste (MSW), inflicting critical environmental challenges and wasting a valuable resource. Waste is not only a problem to get rid of, but a source of valuable raw materials and competitive alternative to fossil fuels. As more legislation comes in place to reduce waste material to be used for incineration and landfilling, and more recycling and reuse, Gasification of MSW gives opportunities for the the production of fuels and chemicals. The gasification of MSW has been proven and applied on larger scale. By adopting an integrated solution for waste management and energy production, such as using MSW as a feedstock for gasification, a municipality can reduce the environmental impact of waste and increase its revenues from recycling and energy sales.
Wood waste and wood pellets are one of the largest internationally traded solid biomass commodities used specifically for energy purposes. Gasification is possible for a broad range of woody biomass, including Wood chips, B-wood waste and pellets. While the handling of wood pellets requires care, the advantages over other types of solid biomass such as wood chips or agricultural residues are their storability and relative easy handling. Wood pellets also have a low moisture content and relatively high energy density (about 17.5 GJLHV/tonne), motivating properties for long-distance transport. The use of wood pellets, replacing fossil based feedstocks, also leads to the reduction of greenhouse gas (GHG) emissions and therefore contributes to an objective set by the EU Directive: 40% greenhouse gas reductions by 2030 compared to 1990.