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Lignin valorization to chemicals is an important component of creating economically viable biofuels production from lignocellulosic biomass. Any such strategy should aim at producing chemicals used at scales that can appropriately match lignin availability. Herein, a combined pyrolysis and low-pressure hydrodeoxygenation (HDO) process configuration is proposed to achieve total oxygen removal and obtain hydrocarbon (aromatic and alkene) products. This approach is tested for its robustness for lignin feedstocks obtained from a variety of sources and extracted using different procedures. The experimental results demonstrate that regardless of the lignin source, the HDO process using a MoO3 catalyst was able to funnel the complex mixture of pyrolysis vapors to mono-aromatics (17–29 C%), as well as alkenes and alkanes. The formation of char from lignin pyrolysis retains more than 50% of the feed carbon in the pyrolyzer, allowing only a portion of carbon to volatilize and be converted to products. A partial depolymerization technique is employed on one of the lignin samples prior to pyrolysis as an example of how the amount of char can be drastically reduced leading to an increased yield of aromatics (53–55 C%). Techno-economic analysis based on the experimental results suggest significant economic benefit of this strategy compared to using lignin as simply a boiler feed. [ABSTRACT FROM AUTHOR]

This paper describes a novel integrated biorefinery based on fast pyrolysis and subsequent bio-oil upgrading to produce three product portfolios: hydrocarbon biofuels (gasoline and diesel), bio-based products (bioasphalt, calcium acetate, and dextrose), and hydrocarbon chemicals (aromatics, olefins, and fuel oil). Based on the economic assumptions and historical market prices of the products, we calculate internal rates of return ( IRRs) of the biorefinery (2000 dry metric tons per day) over 30 years to evaluate its performance. Given the historical low, average, and high prices of the products, a total of 27 scenarios are explored and the maximum IRR for each scenario is determined. Results indicate that upgrading bio-oil to bio-based products yields the maximum IRR of 67.9% if bio-based products can be marketed at a historical high price level (between $257 and $1491 per metric ton) and an IRR of 42.5% at an average price level (between $240 and $950 per metric ton). Under some market conditions, the biorefinery should produce hydrocarbon chemicals or biofuels to increase the IRR. We also estimate the IRR probability distribution using Monte Carlo simulation by -incorporating distributions of product prices and bio-oil fractions allocated for three product portfolios. Average IRRs of −3.9% for biofuels, 42.7% for bio-based products, and 17.3% for hydrocarbon chemicals are observed with standard deviations of 24.4%, 24.1%, and 6.5%, respectively. The integrated -biorefinery exhibits an IRR distribution of 16.2% ± 16.4% suggesting that the integrated biorefinery could balance the economic disadvantages and benefits from individual product portfolio to achieve profitable IRRs. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Catalytic pyrolysis (CP) of protein-rich biomass such as microalgae is a promising approach to biofuel production. CP of amino acids can help understand the cracking of protein-rich biomass in the presence of zeolite catalysts. In this study, as representatives of aliphatic amino acid and cyclic amino acid, respectively, leucine and proline were pyrolyzed with ZSM-5 catalyst in a Tandem micro-furnace reactor coupled with a MS/FID/TCD. At 650 °C, leucine produced more hydrocarbons (aromatic hydrocarbons of 29.6%, olefins of 34.9% and alkanes of 8.1%) than proline (aromatic hydrocarbons of 25.3%, olefins of 14.0% and alkanes of 5.5%) because its relatively simpler amino structure readily detached as ammonia during CP. However, with an N-cyclic structure, proline produced large quantities of nitrogen-containing heterocyclic compounds that favored coke formation in CP. Accordingly, 28.2% of the nitrogen in proline was retained in the solid residue while most of the nitrogen in leucine was converted into ammonia leaving only 4.3% in the solid residue. In addition, though decarboxylation to carbon dioxide was favored in non-catalytic pyrolysis of leucine and proline, decarbonylation to carbon monoxide became the primary deoxygenation pathway in CP. These results indicate that the chemical structures of amino acids have significant effects on product distributions during CP and N-cyclic amino acid is less favored in CP for production of hydrocarbons and ammonia. [ABSTRACT FROM AUTHOR]

Catalytic fast pyrolysis (CFP) of duckweed is a potential source for biorenewable gasoline and diesel fuel production, but its ability to produce aromatics has not been investigated in detail. In this study, we employed a micro-pyrolyzer coupled with gas chromatograph–mass spectrometer, flame ionization detector, and a thermal conductivity detector to conduct CFP of duckweed ( Lemna minor ) with HZSM-5 catalyst and obtained promising yields of total aromatic hydrocarbon (TAH) and benzene, toluene, and xylene (BTX). In the operating conditions studied, pyrolysis temperatures and catalyst-to-biomass ratios (CBR) had significant effects on product yields and distributions. Duckweed CFP can be optimized to maximize either the TAH yield or the output of the BTX components. Optimal operating conditions were determined based on response surface methodology (RSM) with a 4 × 5 full factorial design (FFD). The RSM predicted optimal TAH and xylene carbon yields to be 27.2 mol% and 6.2 mol% at 736 °C and 662 °C, respectively, with CBR of 16:1. Optimal benzene and toluene carbon yields of 5.5 mol% and 8.0 mol%, respectively, were obtained at 750 °C and CBR of 20:1. [ABSTRACT FROM AUTHOR]

Although pyrolysis of carbohydrate-rich biomass should theoretically yield large amounts of sugar, the presence of alkali and alkaline earth metals (AAEMs) in most biomass prevents this from happening. Even in small amounts, AAEM strongly catalyzes the fragmentation of holocellulose to light oxygenates compared to the thermally-induced breaking of glycosidic bonds that yield anhydrosugars. The concept of AAEM passivation, by which the catalytic activity of AAEMs can be suppressed to enhance thermal depolymerization of lignocellulose to sugars, has been previously established at the microgram scale using batch reactors. The feasibility of increasing sugar yield via AAEM passivation has not been previously demonstrated at the kilogram scale in a continuous flow reactor. The goal of this research is to demonstrate the enhanced production of sugars from AAEM passivated feedstocks in a continuous auger pyrolyzer at the kilogram scale. Alkali and alkaline earth metal passivation prior to pyrolysis increased total sugars from red oak by 105% compared to conventional pyrolysis, increasing from 7.8 wt% to 15.9 wt% of feedstock. Light oxygenates and non-condensable gases (NCGs) simultaneously decreased 45%, from 27.1 wt% to 14.7 wt% of feedstock as a result of AAEM passivation. Similarly, AAEM passivation of switchgrass increased total sugars by 259%, from 4.5 wt% to 16.2 wt% of feedstock, while the light oxygenates and NCGs decreased by 48%, from 20.0 wt% to 10.5 wt% of feedstock. An undesirable outcome of AAEM passivation was an increase in char production, increasing by 65% and 30% for pyrolysis of red oak and switchgrass, respectively. Loss of lignin-derived phenolic compounds from the bio-oil can explain 67% and 38% of the increase in char for red oak and switchgrass, respectively. The remaining 33% char increase for red oak (3.1 wt% char) and 62% char increase for switchgrass (4.0 wt% char) appear to be from carbonization of sugars released during pyrolysis of acid-infused biomass. [ABSTRACT FROM AUTHOR]

Highlights: [•] The study develops a techno-economic analysis of microalgae remnant pyrolysis biofuels. [•] It compares partial mechanical drying and thermal drying scenarios with subsequent energy flow analyses. [•] It finds that microalgae remnant biofuel could vary in price between $1.49 and $1.80perliter. [•] Sensitivity analyses show strong influence of fuel yields, feedstock prices, and capital costs. [Copyright &y& Elsevier]

Abstract: This techno-economic study examines fast pyrolysis of corn stover to bio-oil with subsequent upgrading of the bio-oil to naphtha and diesel range fuels. Two 2000 dry tonne per day scenarios are developed: the first scenario separates a fraction of the bio-oil to generate hydrogen on-site for fuel upgrading, while the second scenario relies on merchant hydrogen. The modeling effort resulted in liquid fuel production rates of 134 and 220 million liters per year for the hydrogen production and purchase scenarios, respectively. Capital costs for these plants are $287 and $200 million. Fuel product value estimates are $3.09 and $2.11 per gallon of gasoline equivalent ($0.82 and $0.56 per liter). While calculated costs of this biofuel are competitive with other kinds of alternative fuels, further research is required to better determine the effect of feedstock properties and process conditions on the ultimate yield of liquid fuel from bio-oil. Pioneer plant analysis estimates capital costs to be $911 and $585 million for construction of a first-of-a-kind fast pyrolysis and upgrading biorefinery with product values of $6.55 and $3.41 per gge ($1.73 and $0.90 per liter). [ABSTRACT FROM AUTHOR]

This study evaluated the impact of biomass properties on the pyrolysis product yields, economic and environmental performance for the pyrolysis-biochar-bioenergy platform. We developed and applied a fast pyrolysis, feedstock-sensitive, regression-based chemical process model to 346 different feedstocks, which were grouped into five types: woody, stalk/cob/ear, grass/plant, organic residue/product and husk/shell/pit. The results show that biomass ash content of 0.3–7.7 wt% increases biochar yield from 0.13 to 0.16 kg/kg of biomass, and decreases biofuel yields from 87.3 to 40.7 gallons per tonne. Higher O/C ratio (0.88–1.12) in biomass decreases biochar yield and increases biofuel yields within the same ash content level. Higher ash content of biomass increases minimum fuel selling price (MFSP), while higher O/C ratio of biomass decreases MFSP within the same ash content level. The impact of ash and O/C ratio of biomass on GHG emissions are not consistent for all feedstocks. [ABSTRACT FROM AUTHOR]

Abstract: This analysis compares capital and operating cost for six near-term biomass-to-liquid fuels technology scenarios representing three conversion platforms: pyrolysis, gasification, and biochemical. These analyses employed similar assumptions to allow comparisons among the results. Most prominently, the feedstock is assumed to be corn stover and plant capacity was 2000tonne/day for each plant. There are large differences in the total capital investments required among the three platforms. The stand-alone biomass-to-liquid fuel plants are expected to produce fuels with a product value in the range of $2.00–5.50per gallon ($0.53–1.45per liter) gasoline equivalent, with pyrolysis the lowest and biochemical the highest. These relatively high product values are driven primarily by an assumed feedstock cost of $75per dry ton and the cost of capital for the plants. Pioneer plant analysis, which takes into account increased capital costs and decreased plant performance associated with first-of-a-kind plants, increases estimated product values to $2.00–12.00per gallon ($0.53–3.17per liter) gasoline equivalent. [ABSTRACT FROM AUTHOR]