Biorefinery Developments for Europe. Results of the Integrated Project BIOSYNERGY

Transcription

1 Biorefinery Developments for Europe Results of the Integrated Project BIOSYNERGY A European Integrated Project supported through the Sixth Framework Programme for Research and Technological Development

2 Introduction Introduction to BIOSYNERGY By Hans Reith, ECN, Project Coordinator Objectives and approach Lignocellulosic biomass and residues such as wood, grass and straw are abundant, non-food raw materials for renewable fuels and products. At present however, the use of biomass is still more costly than the use of fossil resources for these applications. Mineral recycling The aim of the Integrated Project (IP) BIOSYNERGY ( ) was to contribute to cost-effective use of biomass through development of integrated, multi-product biorefinery technologies for lignocellulosic biomass, notably straw, for the co-production of transportation fuels, chemicals and materials and combined heat and power (CHP). A strong focus area of the project was the valorisation of by-products (pentoses, lignin) of cellulose ethanol production in order to make the production of this biofuel more competitive. The ambition was to develop synergistic biorefinery concepts, using advanced fractionation and conversion processes and a combination of thermo-chemical and biochemical pathways. biomass BIOENERGY AND BIOPRODUCTS carbon dioxide The approach of the project included: Development of advanced technologies for fractionation of biomass feedstock with a focus on wheat straw, but also including hardwood and softwood and Dried Distillers Grains with Solubles (DDGS) as representatives of major European biomass streams; Development of innovative thermo-chemical conversion technologies and biochemical conversion techniques (enzymatic conversion, fermentation) for the production of intermediate products such as butanol, furfural and phenolic oils from the pentose and lignin fractions; Design and development of conversion processes for synthesizing chemicals and fuels from intermediates including testing of the end products in selected applications; Implementing and demonstrating technologies resulting from the project at pilot scale; Integrating developed technologies in a basic design for an innovative cellulose ethanol based biorefinery plant based on the lignocellulose-tobioethanol BCyL demonstration plant of Abengoa Bioenergy in Salamanca, Spain. Five different cellulose ethanol based biorefinery concepts were modelled and evaluated; Identification of the most promising biorefinery chains for the European Union based on techno-economic criteria including energy efficiency, costs, ecological impacts and socioeconomic aspects; Training and knowledge dissemination through courses, publications, workshops and other activities. Product lines in the Integrated Project BIOSYNERGY The main product lines developed in the Integrated Project BIOSYNERGY are presented in Figure 1. The selection of the products (in addition to cellulose ethanol) was based on the status and outlook of the technology development, potential market volume and value, and industrial interest. All products have sizable projected markets in the order of at least 100,000 ton / yr to several million tons per year worldwide. 2

3 Cellulose Enzymatic Hydrolysis C6 sugars Ethanol Fermentation Acetone + Butanol + Ethanol Xylonic acid Lignocellulosic biomass especially Straw Physical and Chemical Pre-treatment and Fractionation Hemicellulose Chemical Conversion C5 sugars Lignin 2,5-Furan Dicarboxylic Acid (2,5-FDCA) Furfural Chemical Conversion Supercritical Depolymerisation Pentoside Surfactants Enzymatic Conversion Aquathermolysis Phenolics Activated lignins Resins and thermosets Fractionation Pyrolysis and Catalytic Pyrolysis Integration in petrochemical refineries CHP Heat and Power to process Biomass and process residues Figure 1: Product lines developed in the Integrated Project BIOSYNERGY As a first step in the biorefinery, the lignocellulosic feedstock (primarily straw in our project) is fractionated into the three main components cellulose, hemicellulose and lignin via physical/chemical pre-treatment and fractionation. Several fractionation technologies were developed in the project. The main application for cellulose is enzymatic hydrolysis to the C6 sugar glucose followed by ethanol fermentation. Limited work was done on the processing of cellulose via enzymatic hydrolysis. An exception was the conversion of cellulose via glucose to 2,5-Furan Dicarboxylic Acid (2,5-FDCA) as a building block for biopolymers that could form a renewable alternative for fossil based polymers such as PolyEthylene Terephthalate (PET). Most other activities in the project focused on the conversion of the remaining hemicellulose (composed of mainly C5 sugars) and lignin (a random co-polymer consisting of aromatic, phenyl propane units) to value-added products. The upgrading of hemicellulose focused on production of acetone-butanol- ethanol (ABE) and to xylonic acid through development of new fermentation technologies, and on chemical conversion of the C5 sugars to the platform chemical furfural and the synthesis of green pentoside surfactants. A substantial part of the research and development was devoted to lignin upgrading by depolymerization, enzymatic activation and chemical conversion for various applications including phenolics and application in resins for the production of particle boards. Limited work was performed on co-processing of biomass e.g. in the form of pyrolysis oil in existing petrochemical refineries. All the processes investigated were modelled in a comprehensive process synthesis modelling package that included process performance, costs, socioeconomics and environmental criteria in order to aid identification of the most promising processes. The use of residues for CHP generation for internal use and sales was incorporated in the technoeconomic modelling in the project. This brochure presents an overview of the main achievements and highlights of the technology development and design activities from the project as well as some conclusions and perspectives towards future development. More information, publications and reports are available at the project website. BTG Dow ECN JRC-IE TUD WUR-FBR GIG VTT Biorefinery.de Aston ARD IFP JR ABNT Cepsa Chimar CRES Figure 2: BIOSYNERGY Partners (see page 19 for key to abbreviations) 3

4 Work Package 1 Advanced physical/chemical fractionation Work Package Leader: Robert Bakker, WUR-FBR Partners: ABNT, ARD, Biorefinery.de, ECN, TUD and WUR-FBR Advanced physical/ chemical fractionation Introduction The first step in the integrated biorefinery is the fractionation of lignocellulosic biomass feedstock into its constituent elements for further conversion to chemicals, products and energy. The main fractions are hemicellulose sugars, including xylose for further conversion into chemicals, cellulose, a primary source of C6 sugars for fermentation, and lignin, a primary resource for conversion into platform chemicals. The main objective of the fractionation work in BIOSYNERGY was to provide the proof of concept of lignocellulose fractionation in an integrated biorefinery. In the project, five partners developed fractionation techniques and one partner conducted research to improve the enzymatic hydrolysis of lignocellulose-derived carbohydrate polymers. As part of the work, a number of technical benchmarks were defined to compare different fractionation technologies on an equal basis. Processes studied, and main accomplishments Table 1 provides the main characteristics of each fractionation technology developed. A summary of each fractionation technology is given below, along with main accomplishments achieved during the BIOSYNERGY project. Figure 1: Wheat straw pre-treatment at WUR-FBR s laboratory Key FACTS Objectives: The main objective was to provide proofs of concept for lignocellulose fractionation in an integrated biorefinery. During BIOSYNERGY, five fractionation technologies for biomass were developed. Fractionation: is the conversion of lignocellulose into its main elements: hemicellulose, cellulose and lignin. They are used in the biorefinery as the primary source of C5 sugars for chemicals production, C6 sugars for fermentation, and lignin as a resource for platform chemicals. Outcomes: All fractionation technologies developed led to significant fractionation of lignocellulose. Experimental work showed that there are trade-offs in the desired effects of lignocellulosic biomass fractionation. An integrated feedstock conversion end-product approach is needed for further development. Table 1: Overview of fractionation technologies Fractionation technology Lead partner involved Process conditions Solvent used Ethanol-water organosolv Organic acid organosolv Mechanical-alkaline fractionation Mild hemicellulose fractionation HCl-based hydrolysis ECN ARD WUR-FBR TUD Biorefinery.de C, min, 5-30 bar Ethanol-water (acetone-water*) 105 C, atmospheric pressure Acetic acid, formic acid, water* Catalysts used None or H 2 SO 4 * Base for de-acetylisation* C, 1-4h, atmospheric pressure 120 C, 60 min, 5 bar Room temperature Water Water Concentrated HCl NaOH HCl, FeCl 3 * = optional 4

5 Ethanol-water organosolv fractionation is conducted at process temperatures of 160 C or higher and with water and ethanol as solvents. As an alternative to ethanol, acetone can be used. Besides a high enzymatic degradability of the cellulose fraction, the organosolv technology leads to the recovery of a lignin fraction of high purity. During the BIOSYNERGY project, the main process parameters that govern ethanol organosolv fractionation were established, together with the suitability of the organosolv process to other lignocellulosic feedstocks. In addition a conceptual design was completed. Organic acid organosolv process is based on reacting lignocellulosic biomass with a mixture of acetic acid and formic acid at a temperature of 105 C. The organic acid fractionation was shown to extensively hydrolyse hemicellulose into monomeric C5 sugars, and a relatively pure lignin fraction could be recovered after fractionation. Furthermore, the enzymatic degradability of wheat straw cellulose obtained from organic acid organosolv was improved by de-acetylisation of the pulp with a base. The process was also scaled up to the micro-pilot scale. Mechanical/alkaline fractionation is conducted at C at atmospheric pressure, by using sodium hydroxide as a catalyst. This fractionation leads to extensive solubilisation and recovery of lignin, and a cellulose/ hemicellulose fraction that exhibits a high enzymatic degradability. During the project, the effects of processing conditions on chemical composition of fractionated wheat straw were established, along with the yield of products. Furthermore, the properties of lignin that was isolated were studied, and tests on applications for fractionated lignin were conducted. Mild hemicellulose fractionation is directed at selectively removing hemicellulose sugars from lignocellulose, by treating it at 120 C with chloride-based catalysts. The C5 sugars obtained can then be converted to chemicals such as furans. The results obtained indicated that the cellulose obtained from the fractionation remains intact and is free of minerals. However, the enzymatic degradability of the cellulose needs further improvement. HCl-based concentrated acid hydrolysis is a fractionation technique that does not require the use of enzymes. This fractionation technique is conducted at low temperature in a two-step process, and leads to formation of a mixed C5-C6 sugar hydrolysate. The HCl-based fractionation is applicable to all lignocellulosic feedstocks. % Acetone Ethanol; acid catalysed Ethanol organosolv Upscaled process Base case Formic Acid Organic acid organosolv Figure 2: Delignification of wheat straw (% of lignin removed) Extrusion Conical reactor Upscaled process Mechanical alkaline % Acetone Ethanol; acid catalysed Upscaled process Modified organosolv Base case Benchmarks for evaluating fractionation To compare the fractionation technologies, a number of technical benchmarks were defined. These included the extent of delignification of the feedstock, the purity of lignin recovered during fractionation, the extent of hemicellulose hydrolysis, and the enzymatic degradability of the obtained cellulose. Furthermore, the fermentability of glucose obtained from enzymatic hydrolysis of cellulose was evaluated. By conducting experiments on the basis of one feedstock (wheat straw), partners were able to analyze the effect of the various fractionation techniques. Data on delignification (Figure 2) show that highest delignification rates were obtained by ethanol organosolv fractionation, followed by mechanical/alkaline fractionation, and finally organic acid fractionation. Hemicellulose hydrolysis was highest for the mild hemicellulose fractionation process, followed by both ethanol and organic acid organosolv fractionation (Figure 3). Formic acid Organic acid organosolv De-acetylisation Extrusion Conical reactor Upscaled process Mechanical alkaline Mild hemicellulose fract. Hemi fract. Main conclusions Figure 3: Hemicellulose hydrolysis (% of total hemicellulose) All developed fractionation technologies in the BIOSYNERGY project lead to significant fractionation of lignocellulose into its composing elements: hemicellulose, cellulose sugars and lignin. In general, the cellulose obtained from the fractionation exhibits a high enzymatic degradability. There are however differences among fractionation technologies in terms of hemicellulose hydrolysis, lignin yield and purity. Experimental work conducted during the project has shown that there are often trade-offs in the desired effects of lignocellulosic biomass fractionation, and therefore fractionation can only be further developed towards a particular goal. Therefore, the anticipated end-products of the integrated biorefinery will determine how fractionation should be further optimised. 5

6 Work Package 2 Innovative thermo-chemical conversion Work Package Leader: Paul de Wild, ECN Partners: Aston, BTG and ECN Innovative thermo-chemical conversion Introduction WP2 has developed innovative thermo-chemical processing concepts for biomass and residues in a 2nd generation bioethanol refinery based on wheat straw. The main focus was on fast pyrolysis and on a hybrid staged thermo-chemical process consisting of a treatment with hot pressurised water (aquathermolysis) and subsequent pyrolysis of the residue. Target materials and chemicals are biooil, furfural, levoglucosan and phenolic substances. The main residue is biochar. Bio-oil can be used as fuel and as a feedstock for the extraction of valuable substances. Furfural, levoglucosan and phenolic materials are valueadded chemicals that have several applications such as building blocks for biopolymers and phenol substitutes in wood-adhesives. Finally, biochar can be used as fuel or as a low-cost soil improver. The Gas 14% Conditions Char 34% Water 23% Oil 52% Organics 29% work package was conducted by Aston University (UK), Biomass Technology Group (BTG), (the Netherlands) and the Energy research Centre of the Netherlands (ECN) WP leader. Results Aquathermolysis pyrolysis concept Aquathermolysis selectively hydrolyses hemicellulose, dehydrates C5 sugars to furfural and leaches out soluble ash minerals. From the dried hemicellulose-free and ash-free lignocellulose residue, levoglucosan can be produced from the cellulose part by pyrolysis. The residual bio-oil is less acidic and contains less water when compared to regular bio-oil. Yields up to 7 wt% (based on the dry biomass feed) furfural and 11 wt% (based on the dry biomass feed) of levoglucosan have 500 C, 1 atm. 600 grammes silica bed-sand, fed-batch of 50 grammes of lignin fluidization with 20 NL/min preheated Ar (five times the minimum fluidization gas velocity) vapour residence time ~1 sec, solids residence time ~45 min mass balance closure (100+/-5)% Figure 1: Pyrolytic processing of wheat straw derived organosolv lignin by intermediate pyrolysis been obtained. Proof of concept activities for the aquathermolysis step (scale-up from 0.5 L to 20 L (autoclave vessel internal volumes, corresponding to a biomass capacity of (30g 1200g) show comparable results, and techno-economic considerations suggest economic viability of the aquathermolysis-pyrolysis process concept with which the whole biomass can be valorised. Combustion of the methane from the anaerobic digestion of the aquathermolysis filtrate contributes to the overall heat requirements of the process. Methanol 1.1% Acetic acid 0.4% Guaiacols 2.0% Syringols 1.1% Alkylphenols 0.6% Catechols 0.6% Unknowns 3.8% Oligomers 20% GC/MS-FID (Gas Chromatography with Mass Spectrometric and/or Flame Ionisation Detection) Gravimetry Key FACTS Objectives: The objective of Work Package 2 (WP2) is the valorisation of biomass and residues from a wheat straw based 2nd generation bioethanol plant by innovative thermo-chemical processing concepts for value-added chemicals, fuels and materials. The concepts are planned to be self-sustainable with respect to energy demand, environmentally sound and economically efficient. Outcomes: Proof of principle of an aquathermolysis-pyrolysis concept for the production of furfural and levoglucosan from wheat straw and phenolic substances from lignin-enriched residues. Fast pyrolysis of lignocellulose biomass and characterization of the resulting oil. Identification and evaluation of catalysts for improved bio-oil quality. Upgrading of rotating cone fast pyrolysis oil for burner applications and for extraction of a phenolic fraction for use in woodadhesive resins. The aquathermolysis of wheat straw derived Dried Distillers Biomass (DDB)* that contains most of the lignin from the original biomass but only minor amounts of residual carbohydrates, removes most of the residual (hemi)cellulose and ash minerals, after which pyrolysis around 500 C produces a bio-oil that is relatively rich in phenolic compounds. Wheat straw derived organosolv lignin from Work Package 1 could also be converted into a phenolic bio-oil in good yields (>50 wt%) through intermediate pyrolysis (Figure 1). * Dried Distillers Biomass is the dried stillage fermentation residue of cellulose ethanol production from wheat straw 6

7 Catalytic fast pyrolysis Bubbling fluidised bed pyrolysis was used to convert poplar, torrefied poplar, aquathermolysed poplar, spruce, torrefied spruce, wheat straw and aquathermolised wheat straw into bio-oil. Feedstocks and bio-oil were characterised by thermogravimetric analysis (TGA) and analytical pyrolysis (pyrolysis - gas chromatography/ mass spectrometry (Py-GC/ MS). In general, the oil from the pre-treated biomass contains less water and more organics when compared to the oil from the fresh material. Pyrolysis of straw yielded a two-phase oil. Bio-oil upgrading (BTG) All BIOSYNERGY feedstocks (poplar, spruce, barley straw, wheat straw, Dried Distillers Grains with Solubles (DDGS), Dried Distillers Biomass (DDB) can be pyrolysed using rotating cone fast pyrolysis technology at ~500 C. Typical bio-oil yields are wt% with DDB yielding a slightly lower result (43 wt%). The oil quality can be improved by filtration and dewatering (Figure 2). Straw and pre-treated biomass (e.g. torrefied) were difficult to feed to the reactor using conventional feeding technology. Pelletisation or novel feeding systems may offer a solution. A close coupled multiple plug flow reactor for the testing of various catalysts using wheat straw was designed and constructed. The catalysts crack the larger molecules from lignin in order to reduce the average molecular weight of the condensed liquids and thus reduce the viscosity of the final liquid. A complementary objective is the production of lower oxygen content liquids by a combination of cracking and shape selection or re-forming of molecules. Several catalysts have been provided by Cepsa and Saint-Gobain NorPro. Bio-oil filtration unit Bio-oil dewatering Water 100 kg Water phase 160 kg Bio-oil 100 kg Step 1: Water extraction Phase separation Sodium Hydroxide 100 kg [1.0M] Phenolic fraction 115 kg Figure 2: Test rigs for filtration and dewatering of bio-oil (BTG) Organic phase 40 kg Step 2: Alkaline extraction Phase separation Neutrals 25 kg A procedure was developed for the production of bio-oil fractions that are suitable as a substitute for petrochemically derived phenol in conventional phenol/formaldehyde resins (P/F resins). For wheat straw derived oil, the overall product yield from the original bio-oil was lower (~11%) when compared to the 16% for spruce. For the DDGS feedstock the process is not feasible, because the feedstock contains only limited lignin amounts. For wheat straw the process seems feasible, especially after optimisation of the product yield. Figure 3 illustrates the biooil fractionation procedure. Step 3: Distillation Water phase 99 kg Figure 3: Bio-oil fractionation scheme developed by BTG Phenolic fraction 16 kg Figure 4: Operation of the small continuous fluid bed fast pyrolysis reactor at Aston 7

8 Work Package 3 Advanced biochemical conversion Work Package Leader: Frédéric Monot, IFP Partners: GIG, IFP, VTT and WUR-FBR Advanced biochemical conversion This Work Package focuses on the development of advanced biochemical processes for conversion of sugars and lignin into value-added products or intermediates. Acetone-butanol-ethanol (ABE) production ABE fermentation is carried out by bacteria belonging to the Clostridium genus, such as C. acetobutylicum or C. beijerinckii. The capability of these strains to convert both C5 and C6 sugars to ABE was fruitfully exploited in BIOSYNERGY by investigating their suitability to produce ABE on fractions of lignocellulosic raw materials. An example is the production of around 18 g/l ABE from the hemicellulose hydrolysates obtained after steam explosion in diluted acid of wheat straw (Figure 1). The main difficulty was the presence of compounds that are toxic to the micro-organism. Another interesting substrate for ABE production is Dried Distillers Grains with Solubles (DDGS), a residue of ethanol production from wheat or corn grains. DDGS can be a good source of nutrients for ABE fermentation of poor substrates such as cellulosic and hemicellulosic hydrolysates, and after alkaline hydrolysis, they could also be efficiently converted to ABE. Because the maximum ABE concentration that Clostridium strains can tolerate is typically around 2%, distillation is a high energy separation method and alternative separation technologies are worth investigation. One of the technologies considered in BIOSYNERGY was pervaporation which can be coupled with fermentation to remove the inhibiting ABE mixture. Numerous membranes were screened and a fold increase in concentration could be achieved at 37 C with an ABE flux of 0.2 l m -2 h -1 using ABE aqueous solutions. Coupling ABE fermentation and pervaporation was also carried out (Figure 2) and the ABE flux through the membrane module was two times lower than expected, resulting in slow removal of the solvents. Although solvent inhibition still occurred in the bioreactor, the ABE fermentation coupled to pervaporation did not show operational difficulties, and the data obtained was used for the modelling and evaluation of a fermentation process with in-situ product removal. The other separation technology tested was based on rotating disc contactors (RDC). This exploited the synergy from integrating the reaction and separation processes within a twin (double rotor) system of rotating disc units (Figure 3). The rotation of the discs results in continuous transport of the fermentation products as a liquid film from the liquid at the bottom of the reactor to the gas space at the top. The fermentation products are transferred by gas convection to the liquid film on the rotating absorbing disc and collected in the liquid at the bottom. The design has been confirmed as a competitive solution for ethanol, acetone and butanol removal from aqueous solutions. Key FACTS Objectives: The aim of Work Package 3 (WP3) is to develop biochemical conversion routes to use fractions from the initial transformation steps of lignocellulosic feedstocks. Outcomes: Acetonebutanol-ethanol (ABE) could be efficiently produced from hemicellulosic hydrolysates of wheat straw and from Dried Distillers Grains with Solubles (DDGS) by fermentation. Pervaporation and rotating disc contactors are possible alternative techniques for acetone-butanol removal instead of distillation. The capacity to biologically convert xylose to xylonic acid was assessed on mixtures of glucose and xylose, and on acid-hydrolyzed DDGS or pentose-rich wheat straw hydrolysate. The enzymatic lignin modification was found highly dependent on the origin of the lignin used. Residual Glucose (g/l) Residual Xylose (g/l) Total solvents (g/l) Total acids (g/l) Residual glucose or xylose (g/l) ,00 15,00 10,00 5,00 0, Time (h) Acids or Solvents (g/l) Figure 1: Fermentation time course of Clostridium beijerinckii NCIB8052 on a wheat straw hemicellulose hydrolysate supplemented with Gapes nutrients. Figure 2: Pervaporation system used for on-line coupling with ABE fermentation. 8

9 Xylonic acid production from xylose Xylonic acid can be used as i) chelator, dispersant, clarifying agent, ii) antibiotic, health enhancer, iii) polyamide or hydrogel modifier, or iv) 1,2,4-butanetriol precursor. However, there is no bulk commercial production of xylonic acid. The capacity to biologically convert xylose to xylonic acid was assessed in batch and continuous cultures on mixtures of glucose (or galactose) and xylose, and on acid-hydrolyzed DDGS or on pentose-rich wheat straw hydrolysate. The toxicity of the different hydrolysates varies and the sensitivity to the toxic compounds is dependent on the microorganism used ˈ 5ˈ Various parameters were determined including product concentration, productivity, selectivity in order to compare performances of the different systems selected: bacteria (Gluconobacter oxydans), filamentous fungi (Aspergillus niger) and engineered yeast strains (e.g. Saccharomyces cerevisiae). See Table 1. Xylonate was produced at high yields and rates, especially using Gluconobacter oxydans (Figure 4). However, production of xylonate by recombinant yeast has been improved more than ten-fold through genetic engineering, making this system also very interesting ˈ 6ˈ 7ˈ Lignin to functional derivatives 3 3ˈ In BIOSYNERGY, a procedure for the production of lignin nanoparticles has been defined and lignin nanoparticles have been prepared on a laboratory scale and characterised by microscopic analyses. 2 In addition, the enzymatic lignin modification by Trametes hirsuta laccase was investigated. The reactivity was highly dependent on the lignin used. The potential processes that would produce lignins to be used as raw materials for the preparation of functional lignin derivatives have been identified. Modified lignin polymers have been prepared on laboratory scale using laccase and they have been thoroughly characterised using several chemical and spectroscopic methods. It was shown that laccase could have a polymerisation effect. Such derivatives have been characterised, prepared at a kg scale and sent to partners in order to test potential applications (see section on Work Package 4). Figure 3: Twin rotating disc contactors containing an emission disc (blue) and a capture disc (red) separated by a gas phase 50 Table 1: Organisms used for xylonate production 40 Organism Bacteria Fungi Benefits/disadvantages High rates and titres Complex nutrients needed for inoculum High sensitivity to inhibitors in hydrolysates Acidic by-products Low rates and titres Co-substrate needed Xylonate (gl -1 ) G. oxydans S. cerevisiae A. niger Yeast High titres Few by-products High potential for improvements High tolerance to inhibitors in hydrolysates Co-substrates needed to maintain biomass Time (h) Figure 4: Production of xylonate from xylose by three different micro-organisms. Cells were incubated in bioreactors at ph 5.5 (G.oxydans & S. cerevisiae) or in CaCO3 buffered flasks (A. niger) at 30 C 9

10 HO HO Work Package 4 Innovative chemical conversion and synthesis Work Package Leader: Boris Estrine, ARD Partners: ARD, Biorefinery.de, Chimar, Dow, GIG, TUD and WUR-FBR Innovative chemical conversion and synthesis This Work Package has developed several promising chemical conversion technologies for the valorization of C5 and C6 sugars, lignin and thermo-chemically derived intermediates. The main outcomes are summarized below: Lignin depolymerisation Organosolv lignin from hardwood and straw has been depolymerised in super critical carbon dioxide. The use of various co-solvents has been studied and phenolic fractions were produced with about 10% identified monomeric aromatics. Furfural production The synthesis of furfural from D-xylose was studied and new insight developed in the formation chemistry of furfural 1. These results, together with a new economical process concept design, resulted in a patent application filed in Hydroxymethylfurfural (HMF) production from glucose Partners developed new process conditions to obtain isolated yields higher than 90% from D-glucose obtained from cellulose. Furan Dicarboxylic Acid (FDCA) production from HMF Key FACTS Objectives: To analyze and develop various promising chemical conversion technologies for the valorization of C5 and C6 sugars, lignin and thermo-chemically derived intermediates. Outcomes: Production and characterization of platform chemicals: Furfural, Hydroxymethylfurfural (HMF) and lignin phenolic fractions. Products from platform chemicals (reaction and process design): production of 2,5-Furan Dicarboxylic Acid (FDCA) from HMF. Production of materials and polymers using products obtained from platform chemicals (phenolic resins produced with lignin and wood pyrolysis phenolic fraction). Applications testing on wood composites and market validation. Valorization of pentoses into surfactants. The mechanism of FDCA formation has been studied in detail and some results of this study have been protected by a patent application 2. Production of 100g samples of FDCA of resin grade quality (>99.9%) have been made for use in polymer activities. Cellulose Glucose Fructose H O O HMF O HO O FDCA O Figure 1: Complete chemical route for FDCA production Figure 2: Production of particle boards with lignin based resins 1 Gianluca Marcotullio and Wiebren De Jong; Chloride ions enhance furfural formation from D-xylose in dilute aqueous acidic solutions; Green Chem., 2010, 12, (DOI: /B927424C), Paper. 2 Frits van de Klis, Daan van Es, Jacco van Haveren; Succinic Acid from Biomass, EP ,

11 Production of polymers and materials from FDCA and lignin (or lignin fractions) and application testing and market validation FDCA reactivity and quality have been established through the preparation of polyesters at 100 grams scale. There is very little published data available on mechanical and chemical properties of FDCA based polyesters at this scale. The second topic is the use of lignin or lignin fractions from straw and phenolic fraction from wood pyrolysis in the production of phenol-formaldehyde thermosetting resins. Phenolic fractions obtained by pyrolysis of wood, and lignin from wheat straw obtained by organic acid fractionation process enabled the production of resins with a phenol substitution level of up to 50 wt%. Particle boards and plywood panels (complying with the required performance of the relative European standards) were produced using resins at a phenol substitution of up to 30%. % Yields 100,0 90,0 80,0 70,0 60,0 50,0 40,0 30,0 20,0 10,0 0,0 Xylose Syrup HO Wheat O Bran Straw OH Starch Hemicelluloses Hemicelluloses ROH 1 H+ H 2 O H Hydrolysis Hydrolysis D-Glucose L-Arabinose D-Xylose L-Arabinose D-Xylose C5 surfactants Figure 3: New approach developed by Agro-industrie Recherches et Développements (ARD) for new agro-surfactants Butyl Pentosides Isoamyl Pentosides Decyl Pentosides ( ) Valorization of pentoses into surfactants The use of C5 sugars obtained from steam explosion or from organic acid fractionation processes as new raw materials for surfactant production has been investigated. The use of FDCA as co-catalyst in glycosylation reaction has also been studied so as to optimize yields and colour of surfactants. This technology has been successfully scaled up on a 63 litre reactor (Work Package 7), where high isolated yields were obtained (over 90%). O O DP O This confirmed the possibility to reach the targeted price of 1.5 /kg. The surfactants produced at pilot scale were successfully tested in standard application tests for the detergent market. A new application was developed for amyl pentosides which were successfully used in the preparation of wetting agents for the impregnation of papers used in the wood-based panels industry 3. Their benchmarking with other totally petrochemical wetting agents, both in laboratory and pilot scale, proved their superior performance. AVIDEL Syrup ABNT PWS Syrup Figure 4: Production of surfactants from pentoses at pilot scale at ARD s facilities 3 E. Papadopoulou, A. Hatjiissaak, B. Estrine, S. Marinkovic; Novel use of biomass derived alkyl-xylosides in wetting agent for paper impregnation suitable for the wood-based industry. European Journal of Wood and Wood products 2010, manuscript in press approved for publication. 11

12 Work Package 5 Conceptual design of an integrated biorefinery Work Package Leader: Reyes Capote, ABNT Partners: ABNT, Aston and ECN Conceptual design of an integrated biorefinery Based on an existing biomass-to-ethanol demonstration facility A biorefinery is a further stage in the development of technologies based on biomass, since it makes possible an optimal combination of chemical, biochemical and thermo-chemical processes to produce a wide range of products using a broad range of feedstocks, while taking advantage of synergies between the processes involved. The conceptual design of an innovative biorefinery that integrates the most promising technologies under study within BIOSYNERGY is pursued in this work package. Starting point: Abengoa Bioenergy BCyL demonstration plant As part of its research and development activities, Abengoa Bioenergy designed and constructed the first precommercial facility in the world for the demonstration of ethanol production from lignocellulosic biomass. The BCyL biomass plant, which has an input capacity of 70 dry tonnes of biomass per day, is located next to a 195 million litres ethanol per year grain facility and produces 5 million litres of ethanol per year. The plant has been running for more than one year, accumulating more than 4000 hours operation. The successful operation of BCyL has made possible the demonstration of ethanol production from agricultural residues with acceptable yields, as well as the production of samples for experimentation within the project. The conceptual design of the proposed integrated biorefinery takes the process design of the BCyL biomass plant as a starting point. Key FACTS Objective: To devise a conceptual design of an innovative biorefinery plant based on the existing bioethanol site owned by Abengoa (BCyL), Spain by integrating advanced chemical, biochemical and/or thermo-chemical conversion processes for the production of a wide range of bioproducts. Outcomes: A selection of interesting products for coproduction with ethanol has been identified and evaluated. A conceptual design of a multiproduct biorefinery scheme has been produced at commercial scale that improves the base case in terms of economics. Wheat straw Storage and preparation Catalyst Pre-treatment Steam Enzymes Enzymatic hydrolysis and fermentation Yeast Distillation Ethanol Figure 1: BCyL demonstration plant The process taking place in BCyL is depicted in Figure 2. The biomass feedstock is first milled and cleaned in the preparation stage and then pre-treated to make sugars accessible to the enzymes that will hydrolyze cellulose into its composing sugars. These are further converted by yeast into ethanol and CO 2. Ethanol is then recovered by distillation, where a solid residue (stillage) is obtained as a co-product. Co-product Figure 2: Process block diagram of the BCyL demonstration plant 12

13 Concept approach Based on the current status of the enzymatic hydrolysis (EH) technology, work is being carried out to optimize the separation and valorisation of C5 sugars from hemicellulose and lignin. C5 sugars may be converted, for example, into furfural or sugarbased surfactants, via chemical synthesis, or fermented into a mixture of acetone, butanol and ethanol. Lignin may be thermochemically converted into heat for the main process, or used as phenol substitute in the resins production industry. The integration of these technologies has been evaluated in terms of economic performance in Work Package 5. To this aim, a set of process combinations (biorefinery concepts), all of them connected to the BCyL plant, has been defined. BCyL Plant (Starting point) Base Case Commercial scale Biomass fractionation C5 sugars fermentation Lignin valorization for burning On-site enzyme production Figure 3: Overview of concepts under study in Work Package 5 Biorefinery Concepts 100% Ethanol Biorefinery Ethanol, Furfural and Phenols Ethanol, Surfactants and Resins Ethanol, Acetone, Butanol and Resins Combination of bioand thermo-chemical conversion processes G&C as energy surplus for EH Some process streams from EH as feedstock for G&C Combination of a number of conversion processes in an integrated way Selection: -- Technologies being developed within the biosynergy -- Technical feasibility has been proved by means of experimentation -- Products selected are marketable Overview of concepts studied in Work Package 5 In total, five biorefinery scenarios have been proposed: Base case: The base case is an upgraded version of BCyL that includes commercial scale biomass fractionation, C5 sugars fermentation into ethanol, on-site enzyme production and lignin valorization by burning; 100% ethanol biorefinery: A combination of the base case with the thermo-chemical process for biomass conversion into ethanol by gasification and synthesis (G&C) is proposed. In this case, the gasification and synthesis stage acts as an energy surplus for the enzymatic hydrolysis process, while the solid residue from the biochemical process may be used as feedstock for gasification and synthesis stage; Ethanol, furfural and phenols integrated production; Ethanol, surfactants and resins integrated production; Ethanol, acetone, butanol and resins integrated production. A selection of all the biorefinery concepts was made taking into account the market and price of products, their connection to the base case and the results of technical and economic feasibility studies carried out in other work packages. Procedure For each concept, an Aspen Plus based simulation model has been developed using BCyL design specifications and operating parameters as well as experimental data obtained by project members involved in selected technologies. From the simulation model, mass and energy balances were obtained, which made possible cost calculations for economic analysis. Finally the concepts were compared. CONCEPT Conceptual Design Process Simulation Mass and Energy Balances Energy Integration Economic Analysis Comparison of Different Process Scenarios Figure 4: Methodology for design and analysis of biorefinery schemes Conclusions From the work conducted in Work Package 5, it has been concluded that valorization of biomass fractions is necessary to make the lignocellulosic biomass-to-ethanol process competitive. Results of the comparative analysis demonstrated that the biorefinery business may be considered as a way to improve the economic performance of the biomassto-ethanol process in the long term while taking advantage of synergies between technologies. However, there is still uncertainty based on the current status of technology and future prices of bio-based products. In any case, further research and development is required for commercial implementation of these concepts. 13

14 Work Package 6 Biorefinery design, analysis and optimization Work Package Leader: Tony Bridgwater, Aston University Partners: Aston, CRES, ECN, IFP, JR and JRC Integral biomass to products chain design, analysis and optimization The BIOSYNERGY project required the development of a methodology for the generation and evaluation of new process chains for converting biomass into valuable products that properly considers performance, cost, environment, socio-economics and other factors that influence the commercial viability of a process. The aim was to consider the full range of process and product opportunities to allow both their short term and long term evaluation and also the identification of the most promising biorefinery concepts. The methodology developed was based on the principles of process synthesis which had the advantage of a defined and transparent methodology with a rigorous and consistent set of rules which could be readily re-examined and modified if circumstances changed. This satisfied the requirement for consistency in structure and use, particularly for multiple analyses. It was important that analyses could be quickly and easily carried out to consider, for example, different scales, configurations and product portfolios. One of the additional objectives was to provide some clear directions for research and policies in the short, medium and long term as well as to identify the most interesting opportunities for industry to enable the development of a robust bio-based industrial sector. The work flow is shown in Figure 1. In the course of the development of the methodology, it became clear that a process model that allowed users the opportunity to create their own process route and define their own products would create a unique resource for the members of the consortium to evaluate their own defined processes and products. The methodology included process chain generation, process modelling and subsequent evaluation of results in order to compare alternative process routes. A modular structure was chosen to give greater flexibility allowing the user to generate a large number of different biorefinery configurations. Each module represented a processing step and fully described that process step in terms of mass and energy balances and cost estimations. Key FACTS Objectives: To identify the most promising biorefinery chains through process synthesis, and to evaluate the potential of integrated biorefinery concepts for a bio-based economy. Outcome: The most promising biorefinery chains were identified through construction of a novel comprehensive process model. This was used to derive a full set of performance indicators for each possibility which included efficiency, performance, capital cost, product cost, environmental impacts and socio-economics. These were combined to provide an overall process performance score using the technique of Multiple Criteria Decision Analysis (MCDA). Information requirements Feedstocks Products Pre-treatment Conversion Refining Heat & power Data Process Outcomes Characteristics Prices Performance Costs Environment Environment sub-model Final Model for biorefinery concepts Socio-economic sub-model Review Evaluation of 27 biorefinery concepts by Performance, Economics, Environment, Social, MCDA Process synthesis model A user interface was created so that the model could be used by members of the project. The user interface allowed the user to specify feedstock, key variables and preferred technology combinations. It was possible for the user to mix and match process modules (see Figure 2) based on inbuilt logic rules. Figure 1: Schematic diagram of work flow 14

15 Pre-treatment F1 Fractionation C6 H1 Enzymatic Hydrolysis + Fermentation to Ethanol H2 FDCA Production H3 Fermentation to ABE A1 Reception Storage Handling B1 Steam Explosion B2 Avidel B3 Organosolv B4 Mechanical/Alkaline B5 Concentrated HCL T3 Aquathermolysis The outputs were the identification of the most promising biorefinery chains with a full set of performance indicators for each possibility which included efficiency, performance, capital cost, product cost, environmental impacts and socio-economics. These could be combined to provide an overall process performance score using the technique of Multiple Criteria Decision Analysis (MCDA). K1 Enzymatic Hydrolysis + Fermentation to Ethanol K2 ABE Fermentation L1 Lignin Pyrolysis L2 Lignin Gasification + D1 Drying Gas Cleaning U1 Heat and Power L3 Lignin Combustion L4 Lignin Direct Resin Substitution Synthesis P1 P2 P3 P4 P5 T1 T2 C5 Fermentation to Ethanol Fermentation to ABE Furfural Production Surfactant Production Xylonic Acid C5 + C6 Lignin Thermo-chemical Gasification + Gas Cleaning Fast Pyrolysis S1 S2 S3 S4 Ethanol Synthesis Hydrocarbon Synthesis Hydrotreating Bio-oil Phenolic Fractionation R1 R2 R3 R4 R5 Refining Ethanol Distillation ABE Pervaporation Mixed Alcohols Distillation Furfural Distillation Hydrocarbon Refining One of the advantages of this approach to process definition and evaluation was that it was based on a set of defined rules or relationships. These were transparent and could be readily changed by the users or project team to reflect changing scenarios such as feedstock or product prices, crude oil prices, new technology developments, new processes etc. This will enable the final model to be updated and can thus be maintained as a valuable procedure for evaluation of new opportunities. Figure 2: Mix and match process module Table 1: Most promising biorefinery concepts identified Feed Pre-treatment C5 C6 Lignin Straw Fluidised bed Bio-oil fast pyrolysis Straw Steam explosion Xylonic acid Ethanol Dry lignin product Straw Conc. HCL pre-treatment Table 2: Least promising biorefinery concepts identified Furfural Ethanol Dry lignin product Feed Pre-treatment C5 C6 Lignin Softwood AVIDEL Furfural Ethanol Bio-oil phenolic fractionation Straw Fast pyrolysis Bio-oil gasification mixed alcohol synthesis Straw AVIDEL Furfural Ethanol Bio-oil phenolic fractionation Results 27 complete biorefinery chains were chosen by the partners and evaluated in detail, although it is possible with the methodology to consider many more, and over 3500 combinations are possible. The most promising biorefineries (Table 1) were identified as those that: produce specialty chemicals in addition to ethanol; utilise all fractions of the biomass producing only value added products. It should be noted that a market analysis was not included in the evaluation so it did not take into account whether there would be a market for bio-oil and lignin. The least promising biorefineries were identified as those with: no profit and low conversion efficiencies; high heat and power demand. Heat/power provision becomes expensive and biomass requirement too high. Table 2 details the least promising biorefinery concepts. 15

16 Highlights and perspectives Highlights and perspectives for further development By Hans Reith, ECN, Project Coordinator, and Tony Bridgwater, Aston University The project results provide a strong basis for valorization of hemicellulose and lignin in cellulose ethanol based biorefineries and other biorefinery concepts. The activities and results from the technical work packages have been thoroughly described previously and the key outcomes are summarised below. Significant progress was made in WP1 in the area of lignocellulose pre-treatment/fractionation which is a critical and costly step in a biorefinery. Five pre-treatment technologies were optimized for wheat straw and compared by technical benchmarking. All technologies lead to significant fractionation of lignocellulose into its components cellulose, hemicellulose and lignin for further processing. Due to a trade-off between desired effects, there is no single optimum technology. Fractionation should be developed for a specific combination of feedstock and products and optimized towards this goal. 16

17 In the area of thermo-chemical conversion in WP2, one of the highlights is the development of a two-stage process consisting of a hot pressurised water treatment ( aquathermolysis ) and subsequent pyrolysis. Products include chemicals furfural, levoglucosan and phenolics, as well as gases and biochar for various applications. Good progress was also achieved in the field of catalytic fast pyrolysis and upgrading of the fuel quality of fast pyrolysis oil via dewatering and filtration. A major highlight is the development of a procedure to produce phenolics enriched bio-oil fractions for application in resins. In fermentation research in WP3, ABE (acetone-butanol-ethanol) could be efficiently produced from hemicellulose hydrolysate from wheat straw. Membrane pervaporation and rotating disk contactors were shown to offer a realistic alternative to distillation for removal of acetone and butanol. Much improved product yields were achieved in the bioconversion of xylose to xylonic acid. A procedure for the production of lignin nanoparticles has been developed and work on enzymatic modification of lignin by laccases showed a useful activating and polymerisation effect. Major highlights were achieved in the development of reaction chemistries and process designs for a number of platform chemicals and products in WP4. Simplified, efficient processes with much improved yields were developed for the production of polymer grade Furan Dicarboxylic Acid (2,5-FDCA) (>99.9% purity) from cellulose with glucose and Hydroxymethylfurfural (HMF) as intermediates. 2,5-FDCA was successfully polymerised to colourless polymer powders or transparent fibres that can replace the polymer PolyEthylene Terephthalate (PET). Excellent results were achieved for conversion of xylose to the platform chemical furfural with much improved product yields. A novel process for production of furfural has been designed and patented with an energy consumption reduction of 85-95% compared with the current process. A major highlight is the development of two new processes for the production of alkyl polypentosides from pentose streams. The first process uses unpurified pentose streams from acid organosolv pre-treatment or steam explosion of wheat straw for the production of short tail, green surfactants (C4 and C5) with high yields and significant cost savings. This process was successfully scaled up. The second process uses direct conversion of wheat straw to pentoside surfactants with high yield at low cost. Phenolic oils for resins and other applications were successfully produced from lignin via supercritical depolymerisation. Promising results were obtained for direct application of acid organosolv derived lignin in phenyl/ formaldehyde resins for particle boards. Up to 30 wt% phenol substitution was shown to be possible at the required quality standards. 17

18 Highlights and perspectives The project results were integrated in WP5 with the conceptual design of an innovative biorefinery by scale-up and expansion of the Abengoa BCyL cellulose ethanol demonstration plant design with sections for upgrading of pentoses and lignin. Five different cellulose ethanol based biorefineries were modelled and their economic performance compared. The main conclusion is that the biorefinery approach indeed increases the competitiveness of the biomassto-ethanol process in the long term and the valorization of side streams is necessary to make the whole process competitive. Another highlight is the development of a robust modelling tool in WP6 for generating and comparing biorefinery process chains via Multi Criteria Decision Analysis (MCDA) using technical, economic, environmental and socio-economic data. In the project the model was used to evaluate and rank 27 biorefinery chains, although the model can be used to evaluate more than 3500 different processes in five EU countries. One of the conclusions is that the most promising biorefineries are those where specialty chemicals are produced in addition to ethanol using simple processing routes and all fractions of the biomass are used producing only value added products. Outcomes The results of the technology development, training and dissemination all contribute towards meeting the European Commission programme goals in the field of renewable energy. They also help to understand the role that biorefineries can play in a future bio-based economy by providing technical, economic, socio-economic and ecological perspectives of integrated refinery processes for co-production of chemicals, transportation fuels and energy from biomass. Important and valuable information has been gained about the most promising technologies and co-products for a cellulose ethanol based biorefinery and the optimum integration of processes. In particular the results show that lignin upgrading to chemicals has a major impact on the profitability of a lignocellulose biorefinery. The designs generated for ethanol based biorefinery processes, in which residues are upgraded to added-value products, will accelerate implementation of this process into the commercial market, contributing to meeting the policy goals for the use of second generation biofuels in the transportation sector. The project results provide real evidence of new opportunities for demonstration and commercial scale biorefineries as well as identifying important new areas that require development. In this manner the project outcome will have a significant impact on the development of biorefineries in the European Union and the creation of a sustainable and profitable biobased economy. 18

19 The consortium The BIOSYNERGY project ( ) was performed by 17 partners with complementary expertise in the field of biorefinery from industry, universities and research institutes from 9 EU countries listed below. The project was coordinated by the Energy research Centre of the Netherlands (ECN). Abengoa Bioenergía Nuevas Tecnologías (ABNT) Spain Agro Industrie Recherches et Développements (ARD) France Aston University (Aston) United Kingdom BTG Biomass Technology Group (BTG) Netherlands Biorefinery.de (Biorefinery.de) Germany Centre for Renewable Energy Sources and Saving (CRES) Greece Chimar Hellas S.A. (Chimar) Greece Compañía Española de Petróleos (CEPSA) Spain Delft University of Technology (TUD) Netherlands Dow Benelux B.V. (Dow) Netherlands Energy research Centre of the Netherlands (ECN) Netherlands Główny Instytut Górnictwa (GIG) Poland Institute for Energy Joint Research Centre, European Commission (JRC-IE) the Netherlands IFP Energies nouvelles (IFP) France Joanneum Research Forschungsgesellschaft m.b.h. (JR) Austria VTT Technical Research Centre of Finland (VTT) Finland WUR Food and Biobased Research (WUR-FBR) Netherlands The project budget was 13.4 million Euros, supported via a grant of up to 7 million Euros by the European Commission through its Sixth Framework Programme under contract number (SES 6). The project was performed from 1st January 2007 until 31st December

20 The BIOSYNERGY project was supported by the European Commission through the Sixth Framework Programme for Research and Technological Development ( ) under contract number (SES 6). The project addressed Thematic Priority Sustainable development, global change and ecosystems. It started on the 1st of January 2007 and had a duration of 48 months. Project Coordinator: ECN, Hans Reith, , reith@ecn.nl Assistant Project Coordinator: Wageningen UR Food & Biobased Research, René van Ree, , rene.vanree@wur.nl European Commission Project Officers: Silvia Ferratini, , silvia.ferratini@ec.europa.eu Philippe Schild, , philippe.schild@ec.europa.eu Designed by Glued Limited. Disclaimer. This publication was edited and produced by the Bioenergy Research Group, Aston University, UK on behalf of the BIOSYNERGY consortium. Any opinions or material contained within are those of the contributors and do not necessarily reflect any views or policies of the European Commission, Aston University or any other organisation. This literature is printed on 100% recycled paper.