Dissertations and Theses @ UNI


Thesis (UNI Access Only)


Biochar; Pyrolysis--Environmental aspects;


Bio-char is a black solid material resulted from decomposition of biomass. This decomposition can naturally take place through bacterial activities when biomass is embedded in soil for long periods of time. The biomass can be also decomposed by a thermochemical reaction in a low oxygen environment. Such an oxygen inhibited thermochemical reaction is called pyrolysis. When the bio-char derived from pyrolysis is added to soil in a controlled manner, it will increase the crop yield by means of an increase in both soil’s surface area and soil’s total organic carbon.

Bio-char has been conventionally being produced for many years. Most of the conventional methods are ineffective in terms of consistency and quality of product. In many cases the amount of pollution released from the conventional reactors is harmful to the environment. The great deal of attention given to the bio-char in the past decade led into an advancement in the production technologies. However, a few of these advancements are made in portable reactors that can be locally used. This work addresses a design for a low cost and portable bio-char reactor that recirculates and recycles the syngas, which is a source of pollution, generated during pyrolysis. The designed reactor was fabricated and used to make a number of experimental batches of bio-char to benchmark the bio-char quality against those reported within the literature.

The collected data from the experimental batches revealed that a 30 wt% bio-char yield can be achieved by using the designed reactor. In addition, the average carbon content of bio-char derived from the reactor was determined to be 69 wt% when apple tree wood was used as feedstock. By using bio-char carbon content as a measure of quality, the statistical test results also showed that the reactor is capable of producing consistent quality product when apple tree wood was used as feedstock.

Year of Submission


Degree Name

Master of Science


Department of Technology

First Advisor

Julie Zhang

Second Advisor

Catherine Zeman

Date Original


Object Description

1 PDF file (viii, 43 pages)



File Format


Off-Campus Download