Hydro-International

Biochar offers many environmental benefits

1
Photo by Oregon Department of Forestry via Flickr.
By Mike Shiralian

Biochar has many applications in helping with climate change, food security, renewable energy and waste management. It is carbon rich charcoal produced through thermal pyrolysis (300oC-700oC) of biomass, under little or zero oxygen conditions. The process also produces a mixture of organic gaseous (syngas) and liquid fraction called “wood vinegar” as byproducts.

Feedstocks to make biochar are abundant and include carbon waste streams from agriculture, forestry, urban sources, farm wastes, livestock remains, human, food and other compostable wastes. These are all low-value materials with limited uses and high disposal costs.

biochar-infograph-showing-feedstocks-and-uses
How biochar is made, its potential feedstocks and many uses. Infograph courtesy of the Alberta Biochar Initiative.

Its tremendous porous and surface structure provides a great habitant for micro-organisms, increases bioavailability, and creates a reservoir for water, nutrients and, in certain applications, pollutants. Using it as a soil additive increases plant growth rates. This, in turn, provides an effective sink for sequestering atmospheric carbon dioxide. Other benefits include:

  • Less risk of reduced crop yield during dry seasons;
  • Reduce the need for chemical fertilizers containing nitrogen and phosphorus;
  • Help retain nitrogen and sulfurs in soil, which also reduces emissions;
  • Facilitate reestablishment of vegetation on sterile ground;
  • Inhibit the growth of molds or mildews;
  • Odour control;
  • Filter out contaminants from shallow soil water;
  • Remove heavy metals and acids from abandoned mine ponds;
  • Bind toxins and prevent their leaching into surface and ground water.

Currently, a variety of biochar derivatives are being produced, with different properties depending on the feedstock, pyrolysis condition, residence time and additives added. Standardization and classification of the various types are required if it is to be marketed for public use.

HALOGEN-Image

Subscribe to our Newsletter!

The latest environmental engineering news direct to your inbox. You can unsubscribe at any time.

Such regulatory initiatives are already underway through many local and international organizations such as the International Biochar Initiative, Biochar Ontario and the Canadian Biochar Initiative. In December 2015, the Canadian federal government approved commercialization of biochar in Alberta, based on a request by the Alberta Biochar Initiative.

Widespread benefits of biochar

Biochar is one of the few climate mitigation and soil enhancement technologies that is relatively inexpensive, widely applicable and quickly scalable. Also, there is a need for small municipalities to recycle their increasing amounts of sewage biosolids and organic wastes in a sustainable way. The technology has advanced so that any municipality could build its own pyrolyzer kiln (or microwave oven) and start converting wastes into biochar.

Mike Shiralian, PhD., is an independent biochar science consultant. This article appears in ES&E Magazine’s June 2016 issue.

 

1 COMMENT

  1. One of the key element of the biochar industrial production and application scenario is the ECONOMY under market competitive conditions, which is not much discussed, if discussed at all, despite over 3500 biochar related publication made past years.

    In Europe the soil improvers are regulated under Member State MS regulations since decades long time and most biochars are soil improvers. However, different MS having different regulations and mandatory Authority permit procedures for soil improvers. The first biochar Authority permit in the EU issued in 2009.
    The MS and the EU having traditionally high environmental standards, and for ex for the priority hazardous substances PAHs 1 mg/kg (PAH16 and in some cases PAH19) applied for soil improvers (biochar) since decades long time. In this context the voluntary biochar certificates having no any technical and legal effects and validity in the EU and the proposed voluntary biochar PAH standards up to 300 mg/kg limits and other very high heavy metal limits are certainly not applicable in the EU.

    Now there is an central EU law harmonization to make one EU28 standard and mandatory biochar legislation, that is interlinked to the Fertilizers Regulation revision (possibly enter in force 2018-2020) where the biochar EU standardization development project REFERTIL (www.refertil.info) contracted by the EU Commission and in 2013 proposed 6 mg/kg PAH level with MS option to apply flexible 1-6 mg/kg limits, plus other reasonably strict limits.

    In the EU 4 biochar permits needed – MANDATORY:
    1. Authority permits for BIOCHAR PRODUCTION over 1 t/y capacity according to the EU/MS regulations.
    2. Authority permits for BIOCHAR APPLICATION over 1 t/y capacity according to the EU/MS regulations.
    3. REACH certificate over 1 t/y capacity (Registration, Evaluation, Authorization and Restriction of Chemicals) EXOTOX investigation, made by GLP – accredited lab.
    4. Extended Producer Responsibility certificate.

    Edward Someus (biochar S&T senior engineer) – biochar@3Ragrocarbon.com

LEAVE A REPLY

Please enter your comment!
Please enter your name here