Michael Dirk Boot

Eindhoven University of Technology | TUE

There is an environmental concern regarding the use of petroleum-based lubricants, which are generally toxic and nonbiodegradable. Biobased lubricants, such as vegetable oils, are the alternative: they show excellent lubricity, are readily biodegradable and nontoxic. However, a major disadvantage of using vegetable oils in lubricant applications is...

As a hard‐to‐decarbonize sector, the shipping industry is experiencing demands to accelerate the transition from fossil fuels to alternative low‐carbon fuels, to significantly reduce the negative impacts on the environment. Biofuels are regarded as one of the solutions for decarbonization in the marine sector. This paper introduces a lignin‐derived...

We optimized the solvolysis step in methanol for two-step lignin-first upgrading of woody biomass. Birchwood was first converted via sulfuric acid methanolysis to cellulose pulp and a lignin oil intermediate, which comprises a mixture of lignin oligomers and C5 sugars in the methanol solvent. The impact of reaction temperature (140–200 °C), acid lo...

Life‐cycle inventory (LCI) is a fundamental phase in the quantification of the environmental performance of products. However, when it comes to the LCI of a multi‐product system, discussions about the choice of the appropriate methodology to allocate environmental impacts still continue. A further system subdivision and the implementation of a mech...

The thermal profile of solvent liquefaction experiments must be well-controlled to generate data suitable for process scaling and technoeconomic analysis. Acknowledging the differences in small-scale batch systems compared to continuous commercial processes is important. In particular, many experiments have long heating and cooling periods, which i...

A mild thermal solvolysis process using alcohols for the valorization of technical lignin into crude lignin oil (CLO) is presented. The solubilization process results in lower molecular weight lignin fragments (1250-1550 g/mol cf. 2500 g/mol of parent lignin), while rejecting heavy compounds and other solid impurities. The quantitative and qualitat...

Obtaining chemical building blocks from biomass is attractive for meeting sustainability targets. Herein, an effective approach was developed to convert the lignin part of woody biomass into phenol, which is a valuable base chemical. Monomeric alkylmethoxyphenols were obtained from pinewood, rich in guaiacol‐type lignin, through Pt/C‐catalyzed redu...

Lignin is a renewable and abundant source for production of bio-based chemicals and is a valuable alternative to crude oil to obtain aromatic building blocks. It is built from aromatic units with strong chemical linkages, which need to be cleaved to enable the use of the aromatic compounds in industrial applications. In addition to depolymerizing l...

The valorization of lignin in renewable lignocellulosic biomass is an important target in the transition to a more sustainable production of fuels and chemicals. We present here a modification of the “lignin-first” approach that does not hinge on the use of external hydrogen. Instead, we use methanol/water mixtures as a suitable solvent that can be...

With a view to boost practical implementation of lignin conversion technologies, this paper assesses the availability of industrial lignin and evaluates pricing strategies applicable to multi-product biorefineries. The biorefineries, producing either denatured ethanol or sugar hydrolysate as a main product, can yield 43% and 61% of lignin residue (...

Much scientific research has been carried to convert lignin into valuable biobased chemicals or fuels. Most of these studies had the objective to develop active and selective catalysts for effective lignin depolymerization; this with little regard for the parameters that are necessary for later commercialization of these technologies. In this work,...

Lignocellulosic biomass is the only renewable source of carbon for the chemical industry. Alkylmethoxyphenols can be obtained in good yield from woody biomass by reductive fractionation, but these compounds are of limited value for high-value applications. We present a novel approach to convert lignocellulose-derived alkylmethoxyphenols to phenol u...

Soot particle-size profiles of a laminar co-flow diffusion flame were determined using time resolved-laser induced incandescence (TiRe-LII) for various fuels. In the fuel matrix, both the level (0-20 vol.-%) and type (oxygenated vs. non-oxygenated) of aromaticity was varied. Motivation for this study was earlier engine research, which demonstrated...

Viscosity and sulphur content are two important properties of heavy hydrocarbons for downstream processing. Both properties can be significantly reduced in value by processing in subcritical water. Subcritical water has advantages over steam recovery methods in terms of viscosity and sulphur reduction as well as energy consumption. In order to unde...

The main driver to investigate low temperature combustion concepts, such as partially premixed combustion (PPC), is the promise of low particulate matter (PM) and nitric oxide (NOx) emissions. A critical prerequisite for PPC is to temporally isolate the fuel injection and combustion events. In practice, exhaust gas recirculation (EGR) is applied in...

Historically, regulators of diesel emissions have formulated their legislation in gravimetric terms (i.e., in g/km or g/kWh). This quantitative approach, while arguably valid for gaseous emissions such as NOx, does not appreciate the complexity of particulate matter. More recently, much research, along with new legislation, views particulate matter...

A two-step catalytic process for woody biomass fractionation and valorization is presented. Both lignin and carbohydrate are converted to useful chemicals. Oak sawdust is effectively delignified in methanol using different homogeneous acids (sulphuric acid, aluminium triflate, p-methylbenzenesulfonic acid, hydrochloride acid and phosphoric acid) in...

The one-step ethanolysis approach to upgrade lignin to monomeric aromatics using a CuMgAl mixed oxide catalyst is studied in detail. The influence of reaction temperature (200-420°C) on the product distribution is investigated. At low temperature (200-250°C), recondensation is dominant, while char-forming reactions become significant at high reacti...

The objective of this paper is to investigate the anti-knock quality of sugar-derived levulinic esters (methyl levulinate (ML) and ethyl levulinate (EL)) and cyclic ethers (furfuryl ethyl ether (FEE) and ethyl tetrahydrofurfuryl ether (ETE)). To this end, combustion experiments were carried out in both an engine and a constant volume autoignition d...

We determine the chemical changes associated with viscosity reduction when heavy oil is cracked in subcritical water. The viscosity reduction has a temperature threshold for onset of 290 °C—this suggests an enhanced acid cracking regime associated with the maximisation of water dissociation at these conditions aided by the already increased solubil...

The ‘lignin-first’ approach has recently gained attention as an alternative whole biomass pretreatment technology with improved yield and selectivity of aromatics compared with traditional upgrading processes using technical lignins. Metal triflates are effective co-catalysts that considerably speed up the removal of lignin fragments from the whole...

This paper explores the environmental and economic aspects of fast pyrolytic conversion of lignin obtained from 2G ethanol plants, to transport fuels for both the marine and automotive markets. Various scenarios are explored, pertaining to aggregation of lignin from several sites, alternative energy carries to replace lignin, transport modalities a...

At a first glance, ethanol, toluene and methyl tert-butyl ether look nothing alike with respect to their molecular structures. Nevertheless, all share a similarly high octane number. A comprehensive review of the inner workings of such octane boosters has been long overdue, particularly at a time when feedstocks for transport fuels other than crude...

Spark ignition engines typically operate with a fixed air.fuel ratio. This implies that the required air intake is more or less proportional to engine load. Accordingly, at low loads, the engine operates less throttled than it would at full capacity. Throttling is a costly business, however, as the engine has to work hard to breathe in air through...

A catalytic process for the upgrading of woody biomass into mono-aromatics, hemi-cellulose sugars and a solid cellulose-rich carbohydrate residue is presented. Lignin fragments are extracted from the lignocellulosic matrix by cleavage of ester and ether linkages between lignin and carbohydrates by the catalytic action of homogeneous Lewis acid meta...

This paper investigates whether or not two persistent diesel dogmas, namely “the higher the cetane number (CN) the better” and “the lower the aromaticity the better”, still ring true when a compression ignition engine is operated in the low temperature combustion (LTC) regime. The transition from conventional, high temperature combustion (HTC) to L...

The Cover picture shows a tandem catalytic process that rapidly separates woody biomass into a narrow stream of lignin-derived alkylmethoxyphenols and cellulose-rich carbohydrates under mild conditions. Metal triflates are identified as a novel class of catalysts effective in the extraction of lignin from the lignocellulosic matrix. The lignin frag...

Invited for this month′s cover is the group of Emiel Hensen at the Eindhoven University of Technology. The image shows how the lignin component can be effectively released from wood and converted into aromatics over a tandem Al-triflate and Pd/C catalyst. The Communication itself is available at 10.1002/cssc.201601252.

Lignin is one of the major components of lignocellulosic biomass, constituting 15-30 % of the weight and approximately 40 % of the energy content depending on the source. Currently the lignin produced in 2G bio-ethanol plants is mainly used for one-site energy production. At Eindhoven University of Technology (Inorganic Material Chemistry group) a...

The performance of spark ignition engines is highly dependent on fuel anti-knock quality, which in turn is governed by autoignition chemistry. In this study, we explore this chemistry for various aromatic oxygenates (i.e., anisole, 4-methyl anisole, 4-propyl anisole, guaiacol, 4-methyl guaiacol, 4-ethyl guaiacol) that can be produced from lignin, a...

Adding value to lignin, the most complex and recalcitrant fraction in lignocellulosic biomass, is highly relevant to costefficient operation of biorefineries. We report the use of homogeneous metal triflates to rapidly release lignin from biomass. Combined with metal-catalyzed hydrogenolysis, the process separates woody biomass into few lignin-deri...

Aromatics suffer from a poor reputation, owing to genuine health concerns in regard to the fuel itself as well as the resulting tailpipe emissions. This has prompted ever more stringent legislation to gradually expel this class of hydrocarbons from gasoline and diesel fuel. Their notoriety notwithstanding, this chapter demonstrates that not all aro...

We investigated the role of Cu-Mg-Al mixed oxides in depolymerization of soda lignin in supercritical ethanol. A series of mixed oxides with varying Cu content and (Cu+Mg)/Al ratio were prepared. The optimum catalyst containing 20 wt % Cu and having a (Cu+Mg)/Al ratio of 4 yielded 36 wt % monomers without formation of char after reaction at 340 °C...

Written by experts in combustion technology, this is a unique and refreshing perspective on the current biofuel discussion, presenting the latest research in this important field. The emphasis throughout this reference is on applications, industrial perspectives and economics, focusing on new classes of biofuels such as butanols, levulinates, benze...

Obtaining renewable fuels and chemicals from lignin presents an important challenge to the use of lignocellulosic biomass in order to meet sustainability and energy goals. We report on a thermocatalytic process for the depolymerization of lignin in supercritical ethanol over a CuMgAlOx catalyst. Ethanol as solvent results in much higher monomer yie...

Oxygenates present in partially hydroprocessed lignocellulosic-biomass pyrolysis oils were examined for their impact on the performance properties of gasoline and diesel. These included: methyltetrahydrofuran, 2,5-dimethylfuran (DMF), 2-hexanone, 4-methylanisole, phenol, p-cresol, 2,4-xylenol, guaiacol, 4-methylguaiacol, 4-methylacetophenone, 4-pro...

Owing to environmental and health concerns, tetraethyl lead was gradually phased out from the early 1970's to mid-1990's in most developed countries. Advances in refining, leading to more aromatics (via reformate) and iso-paraffins such as iso-octane, along with the introduction of (bio) oxygenates such as MTBE, ETBE and ethanol, facilitated the re...

Lignocellulosic biomass consists of (hemi-) cellulose and lignin. Accordingly, an integrated biorefinery will seek to valorize both streams into higher value fuels and chemicals. To this end, this study evaluated the overall combustion performance of both cellulose- and lignin derivatives, namely the high cetane number (CN) di-n-butylether (DnBE) a...

A specially designed High Pressure Vessel and Burner and fueling system (called “doped flame”) are presented in this paper. This setup allows for soot measurements in laminar diffusion flames of liquid fuel blends at elevated pressure. Fuels with two typical molecular structures, namely linear and saturated cyclic hydrocarbons, are examined in both...

One-step valorization of soda lignin in supercritical ethanol using a CuMgAlOx catalyst results in high monomer yield (23 wt %) without char formation. Aromatics are the main products. The catalyst combines excellent deoxygenation with low ring-hydrogenation activity. Almost half of the monomer fraction is free from oxygen. Elemental analysis of th...

Invited for this month′s cover is the group of Emiel Hensen at the Eindhoven University of Technology. The image on the right shows how soda lignin is depolymerized and stabilized under supercritical ethanol over a Cu‐containing mixed oxide catalyst. The Full Paper itself is available at 10.1002/cssc.201402094 “Lignin is a hard nut to crack…….” Thi...

The Front Cover image shows a single-step process that effectively depolymerizes lignin in supercritical ethanol using an inexpensive CuMgAlOx catalyst. Ethanol not only acts as a hydrogen-donor solvent but also as a capping agent, which can stabilize the highly reactive phenolic intermediates either by O-alkylation of hydroxyl groups or by C-alkyl...

This research focuses on the effects of an increasing pressure on the soot formation during combustion of vaporized liquid fuel. Therefore soot formation is measured in a laminar diffusion flame, with n-heptane as fuel, over a range of pressures from 1.0 to 3.0 bar. The soot volume fraction in the diffusion flames has been measured using Laser-Indu...

Numerous previous studies have reported that the reduction of emissions by adapting oxygenated bio-fuels chiefly depend on the overall oxygen percentage of the blended oxygenates. However, the effect of molecular structures of the fuels has sometimes only been attributed to differences in auto-ignition quality (i.e. cetane number). In this paper, f...

A Gasoline Compression Ignition combustion strategy was developed and showed its capabilities in the heavy duty single cylinder test-cell, resulting in indicated efficiencies up to 50% and low engine out emissions applying to EU VI and US 10 legislations while the soot remained at a controllable 1.5 FSN. For this concept a single-cylinder CI-engine...

A literature and experimental study was done to create an overview of the behavior of gasoline combusted in a CI-engine. This paper creates a first overview of the work to be done before implementing this Gasoline Compression Ignition concept in a multi-cylinder engine. According to literature the gasoline blend will have advantages over diesel. Fi...

Styrene, or ethylbenzene, is mainly used as a monomer for the production of polymers, most notably Styrofoam. In the synthetis of styrene, the feedstock of benzene and ethylene is converted into aromatic oxygenates such as benzaldehyde, 2-phenyl ethanol and acetophenone. Benzaldehyde and phenyl ethanol are low value side streams, while acetophenone...

In an earlier study, a novel type of diesel fuel injector was proposed. This prototype injects fuel via porous (sintered) micro pores instead of via the conventional 6-8 holes. The micro pores are typically 10-50 micrometer in diameter, versus 120-200 micrometer in the conventional case. The expected advantages of the so-called Porous Fuel Air Mixi...

Mixing is inhibited both by the relatively low volatility of conventional diesel fuel and the short premixing time due to high fuel reactivity (i.e. cetane number (CN)). Consequently, in this research two promising oxygenates which can be produced from 2nd generation biomass -ethanol from cellulose and anisole from lignin - will be blended to gasol...

This paper illustrates the results of an experimental study on the impact of a low cetane number (CN) oxygenated fuel on the combustion process and emissions of a light-duty (LD) single-cylinder research engine. In an earlier study, it was concluded that cyclic oxygenates consistently outperformed their straight and branched counterparts at equal o...

In this paper, the soot-NOx trade-off and fuel efficiency of various aromatic oxygenates is investigated in a modern DAF heavy-duty diesel engine. All oxygenates were blended to diesel fuel such that the blend oxygen concentration was 2.59 wt.-%. The oxygenates in question, anisole, benzyl alcohol and 2-phenyl ethanol, have similar heating values a...

An experimental analysis was executed on a NA (Natural Aspirated) 4-stroke gasoline engine to investigate the potential of exhaust waste energy recovery using power turbine technology for light duty application. Restrictions with decreasing diameter were mounted in the exhaust to simulate different vane positions of a VGT (Variable Geometry Turbine...

An optimization at the lower off-design mass-flow range of the radial-inflow variable geometry turbine is required for future turbine applications. One of these applications is using this type of turbine as the throttling apparatus for a spark ignition engine to recover energy which is wasted by the conventional throttle. A wide operating mass-flow...

It is well known that the addition of gaseous fuels to the intake manifold of diesel engines can have significant benefits in terms of both reducing emissions of hazardous gases and soot and improving fuel economy. Particularly, the addition of LPG has been investigated in numerous studies. Drawbacks, however, of such dual fuel strategies can be fo...

The relation between ignition delay and flame lift-off length (based on OH* chemiluminescence) has been studied in an optically accessible heavy-duty diesel engine. Soot production has been studied as well, using both exhaust soot data and high-speed imaging of the in-cylinder natural luminosity. Since the luminosity is estimated to scale with T13...

High-speed imaging, spectroscopy and thermodynamical characterization are applied to an optically accessible, heavy-duty diesel engine in order to compare sooting and chemiluminescence behaviour of bio-derived, oxygenated fuels and various reference fuels. The fuels concerned include the bio-derived fuels Jatropha oil (pure), Jatropha-methylester (...

Early Direct Injection Premixed Charge Compression Ignition (EDI PCCI) is a widely researched combustion concept, which promises soot and CO 2 emission levels of a spark-ignition (SI) and compression-ignition (CI) engine, respectively. Application of this concept to a conventional CI engine using a conventional CI fuel faces a number of challenges....

Combustion behavior of various oxygenated fuels has been studied in a DAF heavy-duty (HD) direct-injection (DI) diesel engine. From these fuels, it is well-known that they lead to lower particle (PM) emissions; however, for a given fuel oxygen mass fraction, there are significant differences in PM reduction. Although this can be traced back to the...

Different strategies are being investigated towards reducing engine-out emission levels of soot and NOx of modern Diesel engines. A fuel-based strategy currently under investigation, entails the use of low cetane number (CN; i.e. low reactive) oxygenates. Previous research has shown that low CN oxygenates (e.g. cyclohexanone, X1), compared to their...

High-speed imaging and thermodynamical characterization are applied to an optically accessible, heavy-duty diesel engine in order to compare soot incandescence and NO emission behaviour of four bioderived fuels: rapeseed-methylester, Jatropha oil (pure), Jatropha-methylester and a 50/50 blend of cyclohexanone with a Fischer-Tropsch synthetic fuel....

This paper reports on a study of a large number of blends of a low-sulfur EN-590 type diesel fuel respectively of a Swedish Class 1 fuel and of a synthetic diesel with different types of oxygenates. Oxygen mass fraction of the blends varied between 0 and 15 %. For comparison, the fuel matrix was extended with non-oxygenated blends including a diese...

Homogeneous Charge Compression Ignition (HCCI) is a promising new engine concept. Its successful introduction, however, hinges on the ability of overcoming several complications. One of these, wall-wetting (i.e. collision and subsequent adhesion of fuel droplets with and to the cold combustion chamber walls), is the result of injecting high-boiling...

The possibility to reduce soot emissions by means of injecting diesel fuel through a porous injector is investigated. From literature it is known that better oxygen entrainment into the fuel spray leads to lower soot emissions. By selection of porous material properties and geometry, the spray is tunable such that a maximum of air, present in the c...