Large-Scale Pyrolysis Oil Production: A Technology Assessment and Economic Analysis

Abstract

Executive SummaryPyrolysis is one of a number of possible paths for converting biomass to higher value products. As such, this technology can play a role in a biorefinery model to expand the suite of product options available from biomass. The intent of this report is to provide the reader with a broad perspective of pyrolysis technology as it relates to converting biomass substrates to a liquid "bio oil" product, and a detailed technical and economic assessment of a fast pyrolysis plant producing 16 tonne/day of bio-oil.The international research community has developed a considerable body of knowledge on the topic over the last twenty-five years. The first part of this report attempts to synthesize much of this information into the relevant issues that are important to advancing pyrolysis technology to commercialization. The most relevant topics fall under the following categories: 1) Technical requirements for converting biomass to high yields of liquid bio-oil 2) Reactor designs capable of meeting technical requirements 3) Bio-oil stability issues and recent findings that address the problem 4) Product specifications and standards that need to be established 5) Applications for using bio-oil in existing or modified end use devices 6) Environmental, safety, and health issues For the bio-oil plant technical and economic analysis, the process is based on fast pyrolysis, which is composed of five major processing areas: feed handling and drying, pyrolysis, char combustion, product recovery, and steam generation. An ASPEN model was developed to simulate the operation of the bio-oil production plant. Based on a 550 tonne/day biomass (wood chips, 50% by mass water content) feed, the cost of the bio-oil for a fully equity financed plant and 10% internal rate of return is $7.62/GJ on a lower heating value (LHV) basis.

An economic analysis of mobile pyrolysis for northern New Mexico forests.

“…However, they require energy to fluidize the system or provide cyclonic motion and tend to result in large amounts of char and ash fines comingled with the product stream. Mineral content of the pyrolysis oils is believed to relate to the stability of the product (Ringer et al, 2006). This is typically mitigated with cyclonic separators at the exit of the furnace, requiring additional energy, yet still allowing some particle pass-through.…”

“…The experimental section to this report focuses on the prospects for the gases based on analysis of a bench-scale system. The end use of the liquids is not well studied, although it is suggested that the oils can substitute for fuel oils, be upgraded to petroleum equivalent fuels, or be used as tars in asphalt (see for example Czernik andBridgwater, 2004 andRinger et al, 2006 who review end uses of the product). Solids are essentially charcoal-like material.…”

“…However, pyrolysis has not been examined for portable application at the scales presently considered and using the design principles presented in this study. Ringer et al (2006) provide extensive background on technology and economic issues relating to large-scale pyrolysis oil production. They do a fairly comprehensive review of past and existing work on the topic, including health effect issues and cradle-to-grave analysis of issues.…”

“…It yields a variable product (Oasmaa et al, 2009;Ringer et al, 2006;Bahng et al, 2009) with a range of properties that depend on the process and the material of origin.…”

Novel Method for the Determination of Water Content and Higher Heating Value of Pyrolysis Oil

“…Currently, its application for electricity generation is still in an infant stage. In the areas of internal combustion engines and aeroderivative turbines, quality issues remain a challenge (Ringer et al 2006). This may be overcome through deoxygenation of most of the chemical species present in the oil.…”