Douglas C. Elliott

Production of Gasoline and Diesel from Biomass via Fast Pyrolysis, Hydrotreating and Hydrocracking: A Design Case

The purpose of this study is to evaluate a processing pathway for converting biomass into infrastructure-compatible hydrocarbon biofuels. This design case investigates production of fast pyrolysis oil from biomass and the upgrading of that bio-oil as a means for generating infrastructure-ready renewable gasoline and diesel fuels. This study has been conducted using the same methodology and underlying basis assumptions as the previous design cases for ethanol. The overall concept and specific processing steps were selected because significant data on this approach exists in the public literature. The analysis evaluates technology that has been demonstrated at the laboratory scale or is in early stages of commercialization. The fast pyrolysis of biomass is already at an early stage of commercialization, while upgrading bio-oil to transportation fuels has only been demonstrated in the laboratory and at small engineering development scale. Advanced methods of pyrolysis, which are under development, are not evaluated in this study. These may be the subject of subsequent analysis by OBP. The plant is designed to use 2000 dry metric tons/day of hybrid poplar wood chips to produce 76 million gallons/year of gasoline and diesel. The processing steps include: 1.Feed drying and size reduction 2.Fast pyrolysis to a highly oxygenated liquid product 3.Hydrotreating of the fast pyrolysis oil to a stable hydrocarbon oil with less than 2% oxygen 4.Hydrocracking of the heavy portion of the stable hydrocarbon oil 5.Distillation of the hydrotreated and hydrocracked oil into gasoline and diesel fuel blendstocks 6. Hydrogen production to support the hydrotreater reactors. The “as received” feedstock to the pyrolysis plant will be “reactor ready.” This development will likely further decrease the cost of producing the fuel. An important sensitivity is the possibility of co-locating the plant with an existing refinery. In this case, the plant consists only of the first three steps: feed prep, fast pyrolysis, and upgrading. Stabilized, upgraded pyrolysis oil is transferred to the refinery for separation and finishing into motor fuels. The off-gas from the hydrotreaters is also transferred to the refinery, and in return the refinery provides lower-cost hydrogen for the hydrotreaters. This reduces the capital investment. Production costs near

Process Design and Economics for the Conversion of Algal Biomass to Hydrocarbons: Whole Algae Hydrothermal Liquefaction and Upgrading

2/gal (in 2007 dollars) and petroleum industry infrastructure-ready products make the production and upgrading of pyrolysis oil to hydrocarbon fuels an economically attractive source of renewable fuels. The study also identifies technical areas where additional research can potentially lead to further cost improvements.

Biomass Direct Liquefaction Options. TechnoEconomic and Life Cycle Assessment

This report provides a preliminary analysis of the costs associated with converting whole wet algal biomass into primarily diesel fuel. Hydrothermal liquefaction converts the whole algae into an oil that is then hydrotreated and distilled. The secondary aqueous product containing significant organic material is converted to a medium btu gas via catalytic hydrothermal gasification.

Low Temperature Gasification of Biomass Under Pressure

The purpose of this work was to assess the competitiveness of two biomass to transportation fuel processing routes, which were under development in Finland, the U.S. and elsewhere. Concepts included fast pyrolysis (FP), and hydrothermal liquefaction (HTL), both followed by hydrodeoxygenation, and final product refining. This work was carried out as a collaboration between VTT (Finland), and PNNL (USA). The public funding agents for the work were Tekes in Finland and the Bioenergy Technologies Office of the U.S. Department of Energy. The effort was proposed as an update of the earlier comparative technoeconomic assessment performed by the IEA Bioenergy Direct Biomass Liquefaction Task in the 1980s. New developments in HTL and the upgrading of the HTL biocrude product triggered the interest in reinvestigating this comparison of these biomass liquefaction processes. In addition, developments in FP bio-oil upgrading had provided additional definition of this process option, which could provide an interesting comparison.

IEA Technoeconomic Analysis of the Thermochemical Conversion of Biomass to Gasoline by the NREL Process

Previous studies of the influence of catalysts on the thermal gasification of biomass have shown that alkali carbonates are among the most active catalysts for the gasification of biomass with steam.1–3 Most of these studies have investigated gasification at temperatures above 550 °C and have concentrated on gasification of the char formed after initial volatilization. When considering single reactor production of high-Btu gas from biomass, or any other organic substrate, one is faced with the contrasting reaction conditions favoring gasification and methane formation. The basic dilemma is the choice between a high temperature, low pressure reaction system which favors the breakdown of biomass to gases, and a low temperature, high pressure system which favors methane formation. In this article, we report laboratory investigations of the influence of sodium carbonate in the presence of a supported nickel metal catalyst with the intent of maximizing methane production from biomass at low temperature in a pressurized gasification system.

Catalytic Hydrothermal Gasification of Lignin-Rich Biorefinery Residues and Algae Final Report

The Liquefaction Group of the lEA Biomass Agreement has carefully studied and analyzed a thermochemical conversion process under development at the National Renewable Energy Laboratory (NREL, formerly the Solar Energy Research Institute). This process converts biomass to an aromatic gasoline product. Biomass is subjected to very rapid pyrolysis in a vortex reactor to maximize the formation of oil vapors. After the char is removed from the process stream, the oil vapors are immediately sent to a catalytic cracking reactor with ZSM-5 zeolite catalyst to form a mixture of aromatic gasoline and gaseous olefins. Subsequent processing recovers byproduct gaseous olefms and converts them to aromatic gasoline. The small amount of toxic benzene formed as an intermediate compound is alkylated to extinction to form relatively benign compounds with a higher octane, such as cumene. The narrow boiling range desired for tomorrow’s reformulated gasolines is maintained by recycling both the volatile light ends and the difficult-to-bum heavy ends to extinction. A gasoline with a very high blending octane is the primary product. It is expected that this product will command a premium price. The process features state-of-the-art energy-saving and waste-management techniques. Using a consistent and well documented approach, the technoeconomics of this process were determined for both a “present” case and a “potential” case. The difference between the product costs for these two cases serves as an incentive for further research and development (R&D).

Analysis and Comparison of Products from Wood Liquefaction

This report describes the results of the work performed by PNNL using feedstock materials provided by the National Renewable Energy Laboratory, KL Energy and Lignol lignocellulosic ethanol pilot plants. Test results with algae feedstocks provided by Genifuel, which provided in-kind cost share to the project, are also included. The work conducted during this project involved developing and demonstrating on the bench-scale process technology at PNNL for catalytic hydrothermal gasification of lignin-rich biorefinery residues and algae. A technoeconomic assessment evaluated the use of the technology for energy recovery in a lignocellulosic ethanol plant.

Analysis of chemical intermediates from low-temperature steam gasification of biomass

This paper describes the results of the analytical effort dealing with the products from the United States Department of Energy, Biomass Liquefaction Experimental Facility at Albany, Oregon. This facility, which was operated under contract to DOE by Wheelabrator Cleanfuel produced approximately 80 barrels of wood-derived oil in the period from August 1979 to March 1981.1,2 The oil was produced by two variations of the basic CO-steam process.3 One variation, the PERC process, involved recycle of a portion of the product so that a wood-flour-in-oil slurry system was used. The other variation, the LBL process, was a once-through process wherein the wood was prehydrolyzed and then processed in a water slurry mode. Both variations operated at about 340 °C and 3000 psig with aqueous sodium carbonate as the catalyst and CO/H2 as the cover gas. Both processes were tested in a number of reactor configurations. The actual plant operation time is therefore broken into a number of test runs; products from runs 7 through 12 will be discussed in this paper. A detailed description of the equipment configuration and processing conditions for each test run is given in refs 1 and 2.

Whole Algae Hydrothermal Liquefaction: 2014 State of Technology

Abstract A reactor system was developed to study the process of lignin and biomass gasification at low temperatures (100 °C to 350 °C) and high pressure (up to 375 atm). The reactor allowed for withdrawal of samples from either the top or bottom of the reaction environment throughout the period of the experiment while maintaining the reaction temperature and pressure. An analytical method was developed for separating and standardizing the initial decomposition products formed during steam-alkali gasification of kraft pine lignin and Douglas fir wood flour.

Chemical processing in high-pressure aqueous environments. 2. Development of catalysts for gasification

This report describes the base case yields and operating conditions for converting whole microalgae via hydrothermal liquefaction and upgrading to liquid fuels. This serves as the basis against which future technical improvements will be measured.