Exergoeconomic assessment of CHP-integrated biomass upgrading

Techno-economic Assessment of Integrated Hydrothermal Liquefaction and Combined Heat and Power Production from Lignocellulose Residues

“…However, a recent study for a hydrothermal carbonization plant (where solid fuel is the primary product) showed both thermal and economic benefits from co-location and integration with a wood-fired CHP plant [28]. Similar observation was re-iterated for the utilization of the char by-product from the pyrolysis process as well [29]. In our HTL-CHP integration concept, the HTL process acts as a direct production unit for Biocrude from the forest residue feedstock as well as a mean of densifying the organic by-products for direct utilization in a CHP unit, connected to the national power grid and local District Heating Networks (DHN).…”

“…The operational assumption here, a Circulating Fluidized Bed (CFB) operates as a char combustor for the HTL solid yield. The selection of the CFB configuration is based on similar synergies to those associated with biomass pre-treatment systems integrated with CFB boiler systems [29]. The extracted sand (as fluidizing medium) from the CFB acts as a heat transfer medium for auxiliary pre-heaters adapted in the HTL system, as is the configuration in case 7, similar configurations have been adapted in literature [46].…”

“…The heat exchanger design arrangement and the mass flow of the SC, simulated as a variable for each case, control the flue gas outlet to the stack between 170-180 °C at full load conditions. This is to maintain part-load operation temperature at a minimum of 120 °C [29] (part load operation is not modelled in this study). Another set design consideration is the multi-stage turbine system, where the high-pressure turbine (No.…”

“…The combined heat and power simulation model on Aspen Plus ® The employed SC for CHP production is based on a reference base case for biomass-fueled power plants, reported in earlier work in our research group [29]. The CHP plant includes 15 main components, shown in Figure 3.…”

“…The total number of 47 variables of the model represented the product yield in molar basis for each compound shown in Table 2, the specific phase yields, and the maximized objective variable, feedstock conversion to products (organics + solid + gases). The modelling approach was developed earlier in our research group at Aalto University [35] and has been applied successfully and reported in literature for various biomass thermochemical processes such as pyrolysis and torrefaction [29].…”