Characterization of Algal and Rice Hull Biochar Derived Via Slow and Flash Pyrolysis

Gasification is one of the most promising new technologies with the capability to thermochemically convert solid, low-value biomass feedstocks into useful combustible syngas products. These syngas products can in turn be used for liquid fuel and chemical synthesis or in turbine combustion cycles for power generation. However, high temperature biomass gasification has received little attention in today’s literature.

The rate-limiting step to the gasification of biomass materials is char-gasification with steam as well as hydrocarbon reforming. Pyrolysis of the feedstock, in which it is converted into solid char and gaseous products dictates not only the residence time of the char and gaseous hydrocarbon species, but also the structure and morphology of the char particles. This process is studied at varying pyrolysis rates and temperatures through which both algae and rice hulls char samples were generated. The char samples underwent a series of tests including size, surface, BET and BJH analyses, through which data about the particles ability to react was collected. Overall, it was found that increased reaction temperature decreased variability in the char products between the two feedstock’s as well as increased parameters such as the pore volume and surface area. It is suspected that an increase in pyrolysis temperature and heating rate increases the reactivity of biochars as well as decreases the necessity for customized gasification processes.

In the future, TGA analyses of the biochar samples will be completed to determine the reactivity of the generated biochars under varied heating conditions.