Study type

Economic variables

Main findings

Reference

Biomass availability, energy consumption and biochar production in rural households of Western Kenya

・ on farm assessment of the energy consumption for food preparation, the biomass availability relevant to conventional and pyrolytic cook stoves and the potential biochar generation in rural households of western Kenya

・ biomass availability for pyrolysis varied widely from 0.7 to 12.4 Mg∙ha⁻¹y⁻¹ with an average of 4.3 Mg∙ha⁻¹y⁻¹, across all 50 studied farms

・ the introduction of a first-generation pyrolytic cook stove reduced wood energy consumption by 27% while producing an average of 0.46 Mg∙ha⁻¹y⁻¹ of biochar

[100]

Economics of charcoal production in miombo woodlands of eastern Tanzania: some hidden costs associated with commercialization of the resources

・ assigning monetary values to commercial production of charcoal (using traditional earth kilns) in the miombo woodlands surrounding Kitulanghalo Forest Reserve in eastern Tanzania, through cost-benefit analysis (CBA)

・ the profit from charcoal production is attributable to very low capital outlays, “free” own labor, “free” raw materials, lack of concern about associated external costs and high demand for charcoal

・ when the cost of labor, raw materials and opportunity costs were considered, the NPV value was negative (US $−868 ha⁻¹), indicating that profit realization is accomplished at the expense of other potential uses of the woodlands

・ although commercialization of wood resources provides tangible monetary benefits, it contributes to the resource depletion that threaten their long-term survival

[101]

Techno-economics of rice husk pyrolysis, conversion with catalytic treatment to produce liquid fuel

・ Fluidized Bed Fast Pyrolysis (FBFP) and Fluidised Bed Fast Pyrolysis with Catalytic Treatment (FBFPCT)

・ FBFP was economically better than FBFPCT for the production of primary pyrolysis oil that could be used as boiler fuel oil and for the production of catalytically treated upgraded, liquid-products

・ The FBFP 1000 kg/h plant unit appeared to be economically feasible, with the lowest unit production cost of primary pyrolysis oil

[102]

Technical, economical, and climate-related aspects of biochar

production technologies: A literature review

・ carbonization technologies (pyrolysis, gasification, hydro-thermal carbonization, and flash carbonization)

・ a wide range of data on the costs of char production (between 51 US $ per ton pyrolysis biochar from yard waste and 386 US $ per ton retort charcoal) and on the GHG balance of biochar systems (between 1054 kg CO₂e and +123 kg CO₂e per t dry biomass feedstock) were published

・ more data from pilot projects are needed to improve the evaluation of biochar production technologies

・ additional research on the influence of biochar application on surface albedo, atmospheric soot concentration, and yield responses is necessary to assess the entire climate impact of biochar systems

・ further field trials on the ability of different technologies to produce chars for agricultural soils and carbon sequestration are essential for future technology evaluation

[40]

Life cycle assessment of biochar systems: Estimating the energetic, economic and climate change potential.

・ using life cycle assessment to estimate the energy and climate change impacts and the economics of biochar systems

・ agricultural residues (corn stover), yard waste, and switch grass energy crops were used

・ the economic viability of the pyrolysis-biochar system is largely dependent on the costs of feedstock production, pyrolysis, and the value of C offsets

・ biomass sources that have a need for waste management such as yard waste have the highest potential for economic profitability (+$69 t⁻¹ dry feedstock when CO₂e emission reductions are valued at $80 t⁻¹ CO₂e)

・ the transportation distance for feedstock creates a significant hurdle to the economic profitability of biochar-pyrolysis systems

・ biochar may at present only deliver climate change mitigation benefits and be financially viable as a distributed system using waste biomass

[103]