Evaluation of Small-Scale Gasification for CHP for Wood from Salvage Logging in the Czech Republic

This study focused on small gasification units for combined heat and power generation (CHP) up to 200 kW of electric power, which can use wood from salvage logging, and assessed the current feasibility of running commercially available units in the conditions of the Czech Republic. In total, the technical and economic parameters of 21 gasification units from ten major international producers were compiled. One of the most important parameters assessed was the net calorific value, which in the analysed samples of spruce wood was determined at 18.37 MJ kg−1 on a dry basis. This complies to the requirements for fuel quality for these units. The economic profitability was determined for three investment variants with electric power of 10, 100, and 200 kWel in an operating mode of constant power at 20 and 30 wt.% input moisture level of the wood. Economic analysis showed that smaller alternatives with an output of 10 and 100 kWel produce economic losses. On the other hand, the 200-kWel alternative produced operating profit and positive cash flow at both fuel moisture levels in the first year of operation. The evaluation of individual alternatives using dynamic investment evaluation methods also showed that only the alternative with an output of 200 kWel with both fuel moistures was able to produce a positive net present value.