Evaluate your project

Go through this guide to get a quick evaluation of your biochar project. Start by picking the storyline that fits you best.

Making a flowchart

As you go through this guide, take notes & draft a flowchart of your biochar project using the template & examples below.

Template flowchart for biochar system

Storyline 1 - I have biomass available…

You have access to some biomass resource, and you want to valorise it. Can pyrolysis be an option? What would you use the biochar and other pyrolysis co-products for? Shall you produce biochar yourself or send your biomass somewhere else?

1. Characterising the biomass stream

To characterise the biomass stream, the following questions are relevant:

  • What kind of biomass is available? Is it from one or multiple sources? e.g. straw from field, wood from thining of fruit trees, wood from forest maintenance, rotten silage bales, algae on shores
  • When is the biomass available? e.g. all year long, in fall, harvest harvest
  • How much biomass is produced? e.g. in cubic meters or tonnes, per year or per month
  • How wet is the biomass? e.g. very wet biomass may need pre-drying or a specific pyrolysis technique like hydrothermal carbonisation
  • Where is the biomass located & is it already collected? e.g. wood spread around on land, wood disposed in container
  • Is it already pre-processed? e.g. dried, chipped, sieved
  • Are there any major impurities? e.g. sand in beachcast, plastic & metal in urban waste -

Besides these general considerations, the physical & chemical properties of the biomass may be relevant to investigate. If lab analyses are not already available, one can have a look in databases (https://phyllis.nl/) or the litterature.

Finally, another important aspect is the potential alternative fate of biomass or land (explained here):

  • Would you dedscribe this biomass as being a waste product (secondary) or as primary (i.e. land is dedicated for biomass production)?
  • Current biomass or land fate: what is the current fate of the biomass? Note: there is always a current fate, e.g. left to decay on site (i.e. becomes energy for microorganisms in the soil), sent to a waste management company, used for energy on-site, burnt on site without energy recovery.
  • Possible biomass or land fate: what could be done with the land or biomass? Note: it is good practice to consider several alternative fates. This could be: e.g. mulching, liquid biofuel, combustion for heating.

These alternatives are important when performing environmental comparisons.

2. Is pyrolysis an option?

Regardless of the type of biomass (wood, grass, manure, sludge, algae), a pyrolysis process can be designed. However, other aspects will determine whether you could invest in a pyrolysis reactor yourself, or if a third-party shall do it. Two such criterias are:

  • whether you have a need for the pyrolysis co-products? Since pyrolysis oil and gas are difficult to store, especially in small-scale projects, this is often a limiting factor. If you have an energy need, check out Storyline 2. Otherwise, consider whether another organisation nearby you is better suited to process your biomass or if there is a easily accessible market for pyrolysis co-products.
  • whether the biomass stream identified above will be available for many years to fuel a reactor at your location (secured biomass supply?
  • whether you have a need for biochar? If not, selling your production around you can be an option.

3. Examples

Similar cases that started with a biomass stream at hand:

Storyline 2 - I have an energy need…

You have a need for some energy service, e.g. heating of premises, steam generation, or even biofuel. You want to know whether you should meet that energy need by biomass pyrolysis?

1. Characterising the energy need

To characterise the energy need, the following questions are relevant:

  • What energy product is it? e.g. electricity, transportation fuel, space heating, steam. Note: to date, most commercial pyrolysis plant are designed to generate biochar & heat.
  • How “complex” is the energy system? e.g. is it a small-scale system, where the pyrolysis plant will provide the majority of the demand, or is it a large-scale system, where pyrolysis is only one out of many plants?
  • How does the energy need vary in time, seasons, years? e.g. space heating is needed mostly in winter months, while demand is low in summer
  • In the long term, how is the energy need expected to vary? e.g increase due to expansions planned
  • Quantify the need in terms of energy per year (GJ or kWh per year), but also maximum power required at a given time (kW, peak demand e.g. in winter for heating)

From a systems perspective, it is important to consider current & alternative supply of the energy demand:

  • How is the energy demand met currently?
  • What alternative technologies could supply the same service?

2. What biomass source and biochar use?


Based on the characterised energy need:

  • how much biomass is needed?
  • is the biomass available locally?
  • is it possible to secure its affordable supply in the long-term? (check also Storyline 1)


Will the expected production be used directly, and for what application? If so, what biochar properties are needed & what potential environmental benefits could be obtained?Alternatively, biochar or excess biochar can be sold to a wholesaler. (check also Storyline 3)

3. Examples

Similar cases that started with an energy need:

  • Lindeborg’s farm: check out our case study. Other farms in Sweden have made a similar choice (Hjelsäter Egendom). Biochar production is constrained by the heat demand, varying with seasons. Biochar is used on the farms, and excess is sold to other actors.

Storyline 3 - I want biochar in my products…

You are developing and selling some kind of material product. You would like to consider whether biochar could be a component of your next product?

1. Identifying tangible benefits for your products

The main driver for including some biochar in your product formulation should be to create a product i) with specific desired properties and ii) an improved environmental performance relative to alternative equivalent products.

Ideally, the main driver should not be to sequester carbon nor to “offset” the greenhouse gas emissions of the product via the biochar carbon sink – this should be seen as a secondary effect.

i) Properties of your product that biochar could affect

You can think in terms of:

  • Physico-chemical: bulk density, porosity, nutrient content, ash content, water holding capacity, nutrient holding capacity, sorption, adsorption, surface area, colour, odour, particle size, sieving profile, pH, elemental content

  • Mechanical properties: elasticity, tensile strength, elongation, hardness and fatigue

  • Biological properties: habitat, enhanced or inhibition of activity

What implications does this have on the type of biochar you will use?

ii) Improved environmental performance

Improved environmental performance of a product is always relative to one or multiple references (see our explanation on the relativeness of effects here).

The first step here is to consider what alternative products can serve as a benchmark. This can be a product without biochar, whether it is the current generation of a product you are selling, or another version under development. It can also be a product with another type of biochar, as biochars do not have the same properties.

Environmental effects can be of several types:

  • Change in technosphere inputs: product manufacturing uses different materials or different amounts, e.g. biochar-compost blend replacing peat substrate, lower fertiliser requirement

  • Change in biosphere exchanges: direct environmental emissions are different, e.g. biological processeses affected, water filtering function

  • Change in technosphere outputs: more service is delivered by a unit of product, e.g. increased product lifetime or durability, higher product efficiency

You can read more about biochar effect identification in our dedicated paper (Azzi et al. 2021)

2. Producing or buying biochar?

At first, we recommend buying biochar. It is usually easier, allows for development & testing of biochar-products. However, you should pay attention to what kind of biochar you get, in relation to the material properties you need (identified above) & the transparency of the supplier regarding biomass sourcing, production process conditions, and certifications.

3. Examples

Similar cases that started with adding biochar to the formulation of a product:

  • VegTech AB: this company produces green roofs, some of which include biochar in their formulation. In 2020, the company aquired a pyrolysis unit to heat its facilities & produce biochar for its sedum green roofs.
  • Soil manufacturers (e.g. Bara Mineraler AB, Hasselfors Garden AB, Rölunda Produkter AB): several soil manufacturers in Sweden offer soil blends with biochar; however, most do not produce biochar themselves, but buy it from other producers.

Storyline 4 - I am an investor or decision-maker…

You have heard about biochar, and you would like to invest or support a biochar project. Alternatively, you are a decision-maker or a consultant, and you have to decide whether or not to proceed with a biochar project?

Ideally, you could have a look at our overall biochar system description over here & its different modules.

Then, by scanning the above 3 storylines, you could get to understand the perspectives arising from different needs & resources available.

Finally, we recommend making a flowchart using the template provided at the top of the page.