Techno-Economics of Biocarbon Production Processes under Norwegian Conditions

Abstract

This work deals with techno-economic analysis studies in the context of production of 8 various grade biocarbon for utilization as reducing agents in metallurgical industries. A 9 detailed process design was developed for wood handling, debarking, chipping, drying, 10 carbonization, and combined heat and power production using Aspen Plus for 10 ton per 11 day (TPD) biocarbon output. A Fortran based user defined function was developed for the 12 carbonization process by considering pressure, temperature and particle size effects using a 13 Box -Behnken approach. The empirical correlation indicates a strong influence of 14 temperature as well as a significant influence of pressure and particle size on the biocarbon 15 yield and its fixed carbon content. Fixed carbon content increases with temperature, pressure 16 and particle size. Mass and energy balance results from Aspen Plus provided necessary 17 results for cost parametrization considering three influencing parameters; temperature, 18 pressure and plant scale on the equipment costs, operating expenses and production cost of 19 biocarbon. Four scenarios are compared i.e. logwood supply, woodchips supply, co-20 production of biooil and replacing the carbonization agent from nitrogen to air. The results 21 indicate that logwood supply is more economical than supplying woodchips to the plant 22 gate. Economic benefits in terms of cost is ~5% (at 1 bar and 450-500ºC, 55-60 TPD) and 23 ~4% (at 10 bar, 450-500ºC, 55-60 TPD). Co-production of biooil decreased the production 24 cost of biocarbon ($/GJ) by 40-44% (at 1 bar, 450-500ºC, 40-60 TPD) and 30-36% (at 10 25 bar, 450-500ºC, 40-60 TPD), respectively. Finally, the economic return based on IRR 26 suggests that highest IRR is achieved for scenario C, where biooil is a co-product, it is due 27

Pyrolysis Kinetics of Hydrochars Produced from Brewer’s Spent Grains

“…Mochidzuki et al [30] reported that there is an internal structural change (strong cross-linking and aromatization of the structure) due to the higher carbonization degree (above 700 • C), which results in a reduction of the porosity and increasing electrical conductivity. These chars were carbon-rich materials which have the potential for use as carbon electrodes [31] or as reductant in metallurgical (e.g., silicon and ferrosilicon) industry [32].…”

Investigating the Potential for Increased Energy Utilisation and Reduced CO2 Emissions at Mo Industrial Park

“…The modelling framework and assumptions made regarding biocarbon production was to a large extent based on the work by Olszewski et al [42]. They present a techno economical evaluation of biocarbon production processes, with focus on Norwegian conditions and conclude that there are economic benefits by supplying logwood rather than wood chips to the end user of biocarbon.…”

“…Replacement of fossil carbon (typically coal, char or coke) with more CO 2 -neutral biocarbon (charcoal and some woodchips) has been an important research area over the last decades [42,51]. Local production of biocarbon from virgin biomass offers several obvious integration opportunities in terms of energy recovery.…”

Biochar as a Multifunctional Component of the Environment—A Review

“…One of the main applications of biochar is its use as a renewable fuel [71][72][73]. Carbonization products can be incinerated or co-incinerated in combined heat and power plants and power plants.…”