ECONOMIC EVALUATION OF A HYDROTHERMAL LIQUEFACTION PROCESS

Wet waste streams include a wide variety of products such as food processing residues, sewage sludge, but also the organic fraction of municipal solid waste. Hydrothermal liquefaction is a thermochemical conversion in hot compressed water that produces a hydrophobic product. This paper gives presents how hydrothermal liquefaction can produce a biocrude or a heavy fuel oil from blackcurrant pomace, grape marc and sewage sludge. The paper presents experimental results as well as a technical and economic evaluation of the process. The results from hydrothermal liquefaction depend on the resource. Typical biocrude yield is 50% of the dry resource while bio-oil yield can be up to 25%. High ash resources are however less interesting for this technology. The production costs are high compared to their fossil counterparts but gate fees in the order of 50 to 130 € tonne -1 could ensure economic competitiveness compared to fossil fuels.​