Fast Pyrolysis Process Development Unit for Validating Bench Scale Data

Fast pyrolysis bio-oil, char and non-condensable gases were produced from a 8 kg/hr fluidized bed reactor. The bio-oil was collected in a fractionating bio-oil collection system that produced multiple fractions of bio-oil. This bio-oil was fractionated through two separate, but equally important, mechanisms within the collection system. The aerosols and vapors were selectively collected by utilizing laminar flow conditions to prevent aerosol collection and electrostatic precipitators to collect the aerosols. The vapors were successfully collected through a selective condensation process. The combination of these two mechanisms has created the ability to effectively fractionate the bio-oil into distinct fractions with improved characteristics. The fractions of bio-oil each contained different properties. Bio-oil properties that were improved included the energy content, water content, acid content and distribution of certain carbohydrates (levoglucosan and acetic acid). The improved properties that are associated with the fractionated bio-oil could allow bio-oil to be used in new markets, preferably without further upgrading. The decreased water and acid contents in the first four (of five) fractions could allow for easier upgrading of the bio-oil into transportation fuels or other valuable products.

The objective of this study is to investigate the effects of slow and fast pyrolysis on the yields and properties of bio-oils using Macadamia nutshell (MNS) as feedstock. A pilot scale auger pyrolysis reactor which had the facilities of conducting both slow and fast pyrolysis was utilized. The pyrolysis processes were carried out at a temperature of 500 ˚C, the heating rate of 5 ˚C/min, a residence time of 60 mins, and a feedstock particle size of 2 mm. The characterization of feedstock and the produced bio-oils was performed by different techniques like elemental analysis, Gas chromatography-mass spectrometry (GC–MS), and physicochemical properties analysis using appropriate ASTM standards. Proximate and ultimate analysis showed promising prospects of MNS as a feedstock for the pyrolysis process. In the case of slow pyrolysis, the bio-oil yield was found to be 39.7%, whereas the bio-oil yield was 49.5% for the fast pyrolysis process. Significant changes in the peak region of GC–MS were observed for bio-oils produced under two different pyrolysis conditions. It was found from the physicochemical properties analysis that calorific value is higher and water content is lower in the bio-oil produced through fast pyrolysis than the bio-oil produced through slow pyrolysis. Comparison with standard biodiesel properties revealed that produced bio-oils were not suitable for use in engines at this stage. Proper upgradation is required to make it suitable for engine application. Based on these results it can be concluded that the produced bio-oils can be used as fuel in other applications such as in boilers and as additives to produce valuable chemicals.

A novel system of fast pyrolysis and vapour quenching was developed at pilot scale to obtain bio-oil from biomass. The system uses three-stage of interconnected fluidized bed reactors that continuously circulate silica sand from an internal pyrolysis reactor to a second external annular reactor for char burning, which generates most of the heat required by the pyrolysis reactor, and a third sand-preheating reactor that burns non-condensable pyrolysis gas. The hot vapours, after high temperature cleaning, are quenched in a flash cooling system. The process generates up to 62% of bio-oil, 25% of char and 13% of non-condensable gas. The heat requirements for the total system are provided by burning part of the char and non-condensable gases generated in the pyrolysis step and by preheating the fluidizing gas for the pyrolysis reactor.

Energy conversion assessment of vacuum, slow and fast pyrolysis processes for low and high ash paper waste sludge

Assessment of orange peel waste availability in ghana and potential bio-oil yield using fast pyrolysis

With the increasing concern on fossil fuel storage and environmental problems, the utilization of renewable lignocellulosic biomass resources will play an increasing important role in the future. Biomass can be converted to a variety of fuels and chemicals by different technologies, one of them is fast pyrolysis which has received extensive interests in recent years (Bridgwater & Peacocke, 2000; Mohan et al., 2006). Fast pyrolysis of biomass is a thermal decomposition process that occurs in the absence of oxygen, with quickly biomass decomposition and rapid vapor condensation, to convert biomass mainly into a liquid product (know as bio-oil) with the yield as high as 70~80 wt%. The essential principles to obtain high bio-oil yield include moderate pyrolysis temperature (around 500 °C), very high heating rates (103 – 105 °C/s), short vapor residence time (< 2 s) and rapid quenching of pyrolysis vapors. A number of pyrolysis reactors have been developed for the bio-oil production, including bubbling fluidized bed, entrained bed, circulating fluidized bed, rotating cone, screw pyrolysis reactor, vacuum pyrolysis reactor, etc. In recent years, several research institutes (BTG, Dynamotive) have already established demonstration biomass fast pyrolysis plants, suggesting that the fast pyrolysis technique is near commercial. Crude bio-oils, also referred to as biomass pyrolysis liquids, pyrolysis oils, or bio-crude oils, are dark brown, free flowing liquids with an acrid or smoky odor. Chemically, bio-oils are complex mixtures of water and hundreds of organic compounds that belong to acids, aldehydes, ketones, alcohols, esters, anhydrosugars, furans, phenols, guaiacols, syringols, nitrogen compounds, as well as large molecular oligomers (holocellulose-derived anhydrooligosaccharides and lignin-derived oligomers). There are many valuable compounds, and thus, bio-oils have the potential for useful chemicals recovery. However, most of the chemicals are in low contents, making their recovery not only technically difficult but also economically unattractive at present. Therefore, the commercialization of bio-oils for valueadded chemicals requires the production of specific bio-oils with high contents of target products. Selective fast pyrolysis, differed from conventional fast pyrolysis which is usually aimed at the maximum bio-oil yield, is to drive the pyrolysis of biomass towards the products of interest. Since the biomass pyrolytic pathways and the subsequent products are influenced by various factors, and thus, selective fast pyrolysis can be performed in different ways, mostly by catalyst utilization, to (1) maximize the yield of target products and (2) obtain target products with high purity. This manuscript is divided into two sections. The first

Inorganic element transfer from biomass to fast pyrolysis oil: Review and experiments

Miscanthus×giganteus was subjected to pre-treatment with deionised water, hydrochloric acid or Triton X-100 surfactant, and subsequently fast pyrolysed in a fluidised bed reactor at 535°C to obtain bio-oil. Triton X-100 surfactant was identified as a promising pre-treatment medium for removal of inorganic matter because its physicochemical nature was expected to mobilise inorganic matter in the biomass matrix. The influence of different concentrations of Triton X-100 pre-treatment solutions on the quality of bio-oil produced from fast pyrolysis was studied, as defined by a single phase bio-oil, viscosity index and water content index. The highest concentration of Triton X-100 surfactant produced the best quality bio-oil with high organic yield and low reaction water content. The calculated viscosity index from the accelerated ageing test showed that bio-oil stability improved as the concentration of Triton X-100 increased.

Development of a generalized numerical framework for simulating biomass fast pyrolysis in fluidized-bed reactors

This laboratory analytical procedure covers the accelerated aging of fast pyrolysis bio-oils. Bio-oils undergo reactions that result in physical and chemical changes over time . These changes typically result in an increase in molecular weight, decrease in some functional groups such as carbonyls, and an increase in viscosity; additionally, the aging process often leads to phase separation. Studies have shown that accelerated aging of bio-oils using this method closely mimics room temperature aging for long periods of time (over 3 years). This procedure has been developed for the accelerated aging of fast pyrolysis bio-oils only. Fast pyrolysis bio-oils are more reactive than other bio-oils (e.g., catalytic fast pyrolysis) and undergo aging much more rapidly. Therefore, this procedure should only be used for fast pyrolysis bio-oil samples.

We can prevent climate change by reducing greenhouse gas (GHG) emissions caused by fossil fuel usage through introducing alternative fuels such as bio-oil. The fast pyrolysis process used for wood materials has recently gained substantial attention as an approach to produce bio-oil worldwide and in Korea as well. Bio-oil from fast pyrolysis contains highly oxygenated compounds and phenolics, thereby requiring upgrading processes, such as deoxygenation and condensation, for high-end use. To determine an efficient upgrading method for fast pyrolysis bio-oil (FPBO), one needs to elucidate its composition and classify it into chemical groups. We analyzed the composition of fractionized FPBO toward high-end use. FPBO was separated into two layers by adding distilled water: (a) the water-soluble phase, and (b) the oil phase, whereas liquid-liquid extraction and multi-step separation were applied for fractionization, respectively. The fractions were obtained, and their chemical groups were analyzed by gas chromatography time-of-flight mass spectrometry (GC×GC-TOF/MS). The water phase was separated into two fractions and classified into the main chemical groups of phenolics (9%) and heterocyclics (31%). The oil phase, which was separated into four fractions, was classified into the main chemical groups of phenolics (32%) and heterocyclics (23%). Our findings can help to upgrade products for high-end use.

A CFD model for biomass fast pyrolysis in fluidized-bed reactors

This paper provides a review of pyrolysis technologies, focusing on reactor designs and companies commercializing these technologies. The renewed interest in pyrolysis is driven by the potential to convert lignocellulosic materials into bio-oil and biochar and the use of these intermediates for the production of biofuels, biochemicals, and engineered biochars for environmental services. This review presents slow, intermediate, fast, and microwave pyrolysis as complementary technologies that share some commonalities in their designs. While slow pyrolysis technologies (traditional carbonization kilns) use wood trunks to produce char chunks for cooking, fast pyrolysis systems process small particles to maximize bio-oil yield. The realization of the environmental issues associated with the use of carbonization technologies and the technical difficulties of operating fast pyrolysis reactors using sand as the heating medium and large volumes of carrier gas, as well as the problems with refining the resulting hi...

Spray combustion properties of fast pyrolysis bio-oil produced from rice husk

Effects of warm water washing on the fast pyrolysis of Arundo Donax