(411d) Study of Lignocellulosic Biomass Pretreatment and Its Effect On Product Distribution Using Fast Pyrolysis
Study of Lignocellulosic Biomass pretreatment and its effect on product distribution using Fast Pyrolysis
Rene Garrido, Joseph Reckamp, Lindsay Peterson, Maria Nydia Ruiz-Felix, and Justinus A. Satrio
Department of Chemical Engineering, Villanova University
800 East Lancaster Avenue, Villanova, PA 19041
Energy based in biomass is a source of renewable energy from organic and inorganic matter formed in a biological or mechanical process. Although fossil fuels, such as petroleum, oil and coal, have their foundation in ancient biomass, they have been “out” of the carbon cycle for a long time. Their combustion consequently disturbs the carbon dioxide content in the atmosphere.
Lignocellulosic biomass can be classified as natural (without human intervention), residual (by-product of waste generated by agricultural activities, forestry, and industry wood processing), and energy-based crops (for the production of biofuels); it is the only carbon-containing renewable energy source.
The complex structure of lignocellulosic biomass has been extensively studied and poses highly valuable carbohydrates (cellulose and hemicelluloses) and lignin, whereas there is a substantial challenge to the large-scale biomass utilization. The carbohydrate polymers are strongly bound to the lignin, which makes the separation process technically difficult.
While it is scientifically viable to exploit lignocellulosic materials and organic wastes into energy, chemicals and fuels, it is far from an economic process and the cost needs to be lowered. It also must be demonstrated that a commercial scale biomass utilization process is environmentally sound, and there is a need to find an inexpensive and widely available lignocellulosic source of biomass
This study investigates common Reed Grass (Phragmites Australis), Paper Mill Sludge (PMS), and Pinewood as an example of different sources of lignocellulosic biomass. It was found that, even though they all have a high probability for bio-oil conversion its high moisture content and, in some cases, a high ash content in feedstock results in a low yield and quality of the bio-oil. The removal of these recalcitrant is a key element to make a more desirable feedstock for biomass conversion. This investigation has revealed that using torrefaction and hydrolysis as pretreatments before pyrolysis shows an interesting switch in the kinetics reaction of all feedstocks producing predominantly levoglucosenone as one of the main products of pyrolysis.
Analytical pyrolysis combined with gas chromatography and mass spectrometry (Py-GCMS) is used to study the chemical composition of volatile products from previously hydrolyzed and torrefied biomass. Effects of the severity of hydrolysis (0 – 20% H3PO4 solutions) pre-treatment and torrefaction temperatures on the chemical composition and yield distribution of the fast pyrolysis products were evaluated and it was possible to determine the best pretreatment condition combinations for each feedstock. The chemical composition study of pyrolyzed biomass would then aid in the understanding of the chemistry behind the different compounds to further enhance the process of upgrading bio-crude oil. By this, ground work is laid as a preliminary attempt to understand how different feedstocks can be used for biomass conversion.