Nutrient Recovery from Algae Using Mild Oxidative Treatment and Ion Exchange.

Valorization of algal biomass to fuels and chemicals frequently requires pretreatment to lyse cells and extract lipids, leaving behind an extracted solid residue as an underutilized intermediate. Mild oxidative treatment (MOT) is a promising route to simultaneously convert nitrogen contained in these residues to easily recyclable ammonium and to convert carbon in the same fraction to biofuel precursor carboxylates. We show that for a algae under certain oxidation conditions, nearly all the nitrogen in the residues can be converted to ammonium and recovered by cation exchange, while up to ∼20% of the carbon can be converted to short chain carboxylates.

From Biomass to Fuel Blendstocks via Catalytic Fast Pyrolysis and Hydrotreating: An Evaluation of Carbon Efficiency and Fuel Properties for Three Pathways.

Biomass was upgraded to fuel blendstocks via catalytic fast pyrolysis (CFP) followed by hydrotreating using three approaches: ex situ CFP with a zeolite catalyst (HZSM-5), ex situ CFP with a hydrodeoxygenation catalyst (Pt/TiO) and cofed hydrogen, and in situ CFP with a low-cost mixed metal oxide catalyst (red mud). Each approach was evaluated using a common pine feedstock and the same hydrotreating procedure. The oxygen contents in the CFP oils ranged from 17 to 28 wt % on a dry basis, and the carbon efficiencies for the CFP processes were in the range of 28-38%.

Screening and evaluation of biomass upgrading strategies for sustainable transportation fuel production with biomass-derived volatile fatty acids.

Biomass conversion to fuels and chemicals is crucial to decarbonization, but choosing an advantageous upgrading pathway out of many options is challenging. Rigorously evaluating all candidate pathways (process simulation, product property testing) requires a prohibitive amount of research effort; even simple upgrading schemes have hundreds of possible permutations. We present a method enabling high-throughput screening by approximating upgrading unit operations and drop-in compatibility of products (, fuel properties) and apply it to volatile fatty acid (VFA) conversion to liquid transportation fuels via a MATLAB script, VFA Upgrading to Liquid Transportation fUels Refinery Estimation (VULTURE).

Online Biogenic Carbon Analysis Enables Refineries to Reduce Carbon Footprint during Coprocessing Biomass- and Petroleum-Derived Liquids.

To mitigate green-house gas (GHG) emissions, governments around the world are enacting legislation to reduce carbon intensity in transportation fuels. Coprocessing biomass and petroleum-derived liquids in existing refineries is a near-term, cost-effective approach for introducing renewable carbon in fuels and enabling refineries to meet regulatory mandates. However, coprocessing biomass-derived liquids in refineries results in variable degrees of biogenic carbon incorporation, necessitating accurate quantification to verify compliance with mandates.

Performance-advantaged ether diesel bioblendstock production by a priori design.

Lignocellulosic biomass offers a renewable carbon source which can be anaerobically digested to produce short-chain carboxylic acids. Here, we assess fuel properties of oxygenates accessible from catalytic upgrading of these acids a priori for their potential to serve as diesel bioblendstocks. Ethers derived from C and C carboxylic acids are identified as advantaged fuel candidates with significantly improved ignition quality (>56% cetane number increase) and reduced sooting (>86% yield sooting index reduction) when compared to commercial petrodiesel.

A High Throughput Ambient Mass Spectrometric Approach to Species Identification and Classification from Chemical Fingerprint Signatures.

A high throughput method for species identification and classification through chemometric processing of direct analysis in real time (DART) mass spectrometry-derived fingerprint signatures has been developed. The method entails introduction of samples to the open air space between the DART ion source and the mass spectrometer inlet, with the entire observed mass spectral fingerprint subjected to unsupervised hierarchical clustering processing. A range of both polar and non-polar chemotypes are instantaneously detected.

Impact of higher alcohols blended in gasoline on light-duty vehicle exhaust emissions.

Certification gasoline was splash blended with alcohols to produce four blends: ethanol (16 vol%), n-butanol (17 vol%), i-butanol (21 vol%), and an i-butanol (12 vol%)/ethanol (7 vol%) mixture; these fuels were tested in a 2009 Honda Odyssey (a Tier 2 Bin 5 vehicle) over triplicate LA92 cycles. Emissions of oxides of nitrogen, carbon monoxide, non-methane organic gases (NMOG), unburned alcohols, carbonyls, and C1-C8 hydrocarbons (particularly 1,3-butadiene and benzene) were determined. Large, statistically significant fuel effects on regulated emissions were a 29% reduction in CO from E16 and a 60% increase in formaldehyde emissions from i-butanol, compared to certification gasoline.