(619s) Characterization of Physical Properties of Macroalgal Pyrolysis Products for Process Simulation

Pyrolysis is a thermochemical conversion of carbon based material to lower molecular products. This conversion is performed at elevated temperatures ranging from 450°C to 500°C in the absence of oxygen and the products are solid carbon-rich char, organic liquids called bio-crude, and hydrocarbon gasses. A major goal of pyrolysis in the field of biofuel production is the maximization of bio-crude yield through appropriate optimization of process parameters. Since the number of components in macroalgal bio-crude is vast and mechanisms of product generation and distribution from macroalgal pyrolysis are not very well understood, accurate and representative simulation of such process is challenging.

Nevertheless, this study presents an approach to characterize the liquid product mixture, bio-crude, for simulation of macroalgae pyrolysis using Aspen Plus. Primarily, bio-crude was modeled in order to simulate the conversion accurately and in time efficient manner. Original liquid product mixture contained around 200 compounds (detected experimentally by GC/MS analysis) in water soluble and water non-soluble organic phases. In this study this number was reduced to 21 representative compounds. In its databases Aspen Plus contains information about physical properties of vast number of compounds. Often, simulations of thermochemical conversions of biomaterials require definition of properties for components which are not found in the databases. This study demonstrates the methodology of reducing compositional experimental data based on chemical structure and boiling point range similarities and translating into components which are already contained in the Aspen databases. This is, in essence, a crucial step of simulating a complex thermochemical conversion.