Cellulosic Ethanol Plant Research Articles

Technoeconomic analysis of a fungal pretreatment-based cellulosic ethanol production

Cellulosic biomass shows great potential as feedstock for bioethanol production. Despite clear benefits in terms of greenhouse gas mitigation and bioproduct potential, the commercial production of cellulosic ethanol remains economically challenging at the current state of technology. This paper presents a technoeconomic analysis of a fungal pretreatment-based cellulosic ethanol plant with a processing capacity of 2000 tonnes of switchgrass per day. The production process model was designed and simulated using SuperPro Designer. The plant's ethanol yield, capital investment per unit capacity, and unit ethanol production cost were estimated to be 211.90 L/t of switchgrass, $ 3.60/L, and $ 1.44/L of ethanol, respectively. Fungal pretreatment was the major contributor (72%) to the total capital investment, mainly due to the large quantity of equipment required in the process. A positive net present value (NPV) was generated for the baseline model at ethanol selling price of $ 1.50/L, which increased by 5-fold for 80% glucose yield. Glucose yield was the most sensitive to NPV for all the process parameters evaluated.

Dow eyes cellulosic ethylene

Dow is planning to plunge into biobased polyolefin production. The firm, the largest US chemical maker, has agreed to buy ethylene from New Energy Blue, which is planning a cellulosic ethanol plant in Mason City, Iowa. The plant will convert corn stover—the stalks and other leftovers that remain after corn is harvested—into ethanol. It is designed to produce about 75 million L of ethanol per year from 275,000 metric tons of stover. New Energy Blue will convert nearly half of that ethanol into ethylene for Dow, which will use it to make plastics, such as polyethylene for packaging. New Energy Blue unveiled the project in 2021, estimating its cost at $200 million. The company aims to eventually construct four more plants, and Dow will have the option of securing supply from them. New Energy Blue acquired the rights to the technology it is using from the Danish firm Ørsted, which

Valorization of hydrolysis lignin from a spruce-based biorefinery by applying γ-valerolactone treatment

Hydrolysis lignin, i.e., the hydrolysis residue of cellulosic ethanol plants, was extracted with the green solvent γ-valerolactone (GVL). Treatments at 170–210 °C were performed with either non-acidified GVL/water mixtures (NA-GVL) or with mixtures containing sulfuric acid (SA-GVL). SA-GVL treatment at 210 °C resulted in the highest lignin solubilization (64% (w/w) of initial content), and 76% of the solubilized mass was regenerated by water-induced precipitation. Regenerated lignins were characterized through compositional analysis with sulfuric acid, as well as using pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS), high-performance size-exclusion chromatography (HPSEC), solid-state cross-polarization/magic angle spinning 13C nuclear magnetic resonance (CP/MAS 13C NMR) spectroscopy, 1H–13C heteronuclear single-quantum coherence NMR (HSQC NMR), and Fourier-transform infrared (FTIR) spectroscopy. The characterization revealed that the main difference between regenerated lignins was their molecular weight. Molecular weight averages increased with treatment temperature, and they were higher and had broader distribution for SA-GVL lignins than for NA-GVL lignins.

Biomass feeding in cellulosic ethanol projects: An underestimated issue?

Projects unsuitable for specific types of biomass can cause serious flow problems, capable of making the production unfeasible. This paper aims to identify whether there was available technological knowledge proper to design equipment that would guarantee a linear flow feed of biomass as raw material, searching patents applications, that is an efficient tool widely used to analyse technological scenarios. The results showed an increase in the patents number dealing with specific types of biomass as of 2016 – a pick of 14 patent application per year, but still in a very small number if compared to the number of patents applied on biomass in general – a pick of 5.974 patent application per year. Analysing together with problems occurred in cellulosic ethanol plants, these results seem to support the hypothesis that new technological developments will still be needed to allow plants to work efficiently with biomass as feedstock. This study brings a new approach to discussions about the challenges faced by second-generation ethanol plants, both in the search methodology developed for this research and in bringing the theme of biomass feeding and handling to the centre of debates on the next challenges for industrial pants using lignocellulosic biomass as feedstock.

Techno-economic assessment of poly-generation pathways of bioethanol and lignin-based products

In this study, two fermentation-pyrolysis pathways for cellulosic ethanol production were established to improve the economy of cellulosic ethanol plants by lignin-rich residue pyrolysis. Techno-economic assessment (TEA) was conducted for both novel pathways compared with conventional fermentation-combustion pathway based on biomass Arundo donax. Pathway simulation showed that compared with the fermentation-combustion pathway, fermentation-pyrolysis pathway produced extra bio-char and hydrocarbon fuels except 256,000 m3 of ethanol each year. Economic analysis showed that the Minimum Ethanol Selling Price (MESP) of fermentation-combustion pathway was 1.623$/gal. The MESP of fermentation-pyrolysis A pathway and fermentation-pyrolysis B pathway was 1.673$/gal and 1.494$/gal respectively. The MESP of fermentation-pyrolysis B pathway indicated a potential process of lignin pyrolysis applied in cellulosic ethanol plants in the future. Sensitivity analysis indicated that price change of A. donax and plant scale both have a great impact on the MESP.

Clariant completes cellulosic ethanol plant

Clariant has completed a plant in Romania that will use its Sunliquid technology to convert about 250,000 metric tons (t) per year of straw into 50,000 t of ethanol. Clariant says such cellulosic ethanol can play a role in lowering greenhouse gas emissions in the transportation sector. Clariant says it has sold five licenses to the technology in Europe and China. DuPont and at least two other firms built cellulosic ethanol plants in the US that are no longer running.

Construction on cellulosic ethanol plant in Romania continues.

Construction on cellulosic ethanol plant in Romania continues.

Lignin valorization beyond energy use: has lignin's time finally come?

AbstractAccording to an old proverb, ‘you can make anything out of lignin, except money’. The complexity of lignin's structure and many inferior characteristics of lignin, such as its insolubility in organic solvent and poor reactivity related to it large molecular weight, have posed significant challenges to lignin valorization. Driven mainly by the commercial availability of large amounts of kraft lignin and hydrolysis lignin in kraft pulp mills and cellulosic ethanol plants, there is a pressing need to valorize lignin for high‐value chemical and material products for better overall profitability for the plants, and for the emerging bioeconomy. To this end, we have developed, over 10 years and in several publications, an engineering approach to lignin valorization. This perspective paper provides an overview of this process and concretizes the research achieved in support of lignin valorization. In the method presented, lignin is first de‐polymerized into de‐polymerized lignin (DL) at a high yield and with a tunable Mw (weight average molecular weight). The DL is then utilized as a mixture (no separation needed) to substitute directly petroleum‐based phenol (up to 75% substitution), polyols (up to 50% substitution), and bis‐phenol A (100 substitution) in preparation of bio‐based phenolic resins, polyurethane foams, and epoxy resins. The DL products were also used to replace petroleum‐based antioxidants resulting in enhanced thermo‐oxidative and thermal stability of polyethylene in the synthesis of bio‐based resins / plastic composites. This approach has demonstrated both technical and economic feasibility, generating a payback period of approximately 3 years for a commercial capacity of 40 000 t/y. Thus, Lignin valorization beyond energy use can be profitable, and the old proverb may prove wrong. Lignin's time might have finally come! © 2020 Society of Industrial Chemistry and John Wiley & Sons Ltd

Production of cellulases and xylanases by Humicola grisea var. thermoidea and application in sugarcane bagasse arabinoxylan hydrolysis

Humicola grisea var. thermoidea is a deuteromycete that secretes a large spectrum of hydrolytic enzymes when grown on lignocellulosic residues. Agricultural residues are rich in lignocellulosic material and can be used as an alternate source for the production of different value-added products. The fungus was grown on sugarcane bagasse (SCB), wheat brain (WB), rice straw (RS) and corn cob (CC) as carbon source. The major endoxylanase, cellobiohydrolase, arabinofuranosidase and avicelase activities were observed when the fungus had grown on WB, while the major endoglucanase, FPAse and β-xylosidase activities on SCB. Secreted proteins by H. grisea upon growth on WB (HgWB) and SCB (HgSCB) by 144 h were analyzed by SDS/PAGE and Zymogram. The results suggested that HgWB and HgSCB presented a different pool of cellulases and xylanases. Cellulases and xylanases are used in enzyme cocktail to cellulose hydrolysis in cellulosic ethanol plants from SCB, hemicelluloses currently represents the largest polysaccharide fraction wasted in these plants. H. grisea enzymes (HgWB and HgSCB) and recombinant hemicellulases (endoxylanase GH11 – HXYN2, β-xylosidase – HXYLA and arabinofuranosidase ABF3) were employed to design hemicellulases cocktail which were employed to recovery arabinoxylan (AX) from steam explosion sugarcane bagasse (seSCB). The hydrolysis of seSCB with hemicellulases cocktail proved to be efficient and the release of reducing sugars (RS) from AX arriving at 91% conversion and the highest hydrolysis yields were obtained when using 4.200 U g−1 (Units per gram substrate) of HXYN2, 10 U g−1 of HXYLA and 4 U g−1 of ABF3. After AX hydrolysis, the solid fraction containing cellulose was hydrolyzed with commercial cellulases and presented 28% increase in hydrolysis yield (glucose production) comparing to seSCB hydrolysis without enzymatic pre-treatment. A scanning electron microscope (SEM) was an important tool to observe the modifications in seSCB after steam explosion treatment and hydrolysis. SEM images revealed that steam explosion caused considerable damage to the fibers, such as the relaxation, fragmentation and peeling of the superficial layers of the cellulose and after enzymatic hydrolysis can be observed a greater number of cracks and more brittle in the structure. The results demonstrated that enzymatic pre-treatment with hemicellulases cocktail allowed recovery of pentoses from AX which can be converted in diverse products and improved glucose production from cellulose fraction.

Cellulosic Ethanol from Sugarcane Straw: a Discussion Based on Industrial Experience in the Northeast of Brazil

Second-generation technology (2G) is currently the industrial route that is being developed with the potential to meet the demand for biofuels and bioproducts. The technology studied in the present work is based on the non-food processing of sugarcane straw, which is unlike the bagasse processing route (a lignocellulosic residue) that is commonly used in boilers for steam and electricity generation. In the last years, cellulosic ethanol plants worldwide include the utilisation of corn stover, sugarcane bagasse, wood waste and plant residues. Therefore, a communication based on industrial aspects using sugarcane straw is important in order to expand the knowledge regarding this promising technology. The main objective of this work included listing the results obtained in a cellulosic-ethanol production industry using sugarcane straw, located in the Northeast region of Brazil and taking into account the efficiency of pre-treatment, enzymatic hydrolysis and fermentation processes and comparing these results with data found in the literature regarding studies with similar efficiency. It was possible to observe that the production of ethanol from sugarcane straw at an industrial scale achieved a productivity of 200 l of ethanol per tonne of biomass, exhibiting 90, 70 and 85% of pre-treatment, hydrolysis and fermentation efficiency, respectively.

Lignin from energy plant (Arundo donax): Pyrolysis kinetics, mechanism and pathway evaluation

Pyrolysis of lignin was conducted and main decomposition temperature range was 250–500 °C and the maximum mass loss of lignin occurred at 300–350 °C (10–20 °C/min). Activation energy was ranged from 166 to 182 kJ/mol and lnA was ranged from 35 to 40. All fitting peaks described by mechanism function of random nucleation followed by growth. There was apparent infrared spectroscopy absorbance at 3565, 2950, 2367, 2182, 1775, and 1103 cm−1 because of vibrations of functional group in H2O, CH4, CO2, CO, CO and O-containing compounds. Main composition of bio-oil was phenols and main carbon distribution was ranged from C5 to C8. Ratio of p-hydroxyphenyl, guaiacyl and syringyl structures in bio-oil varied with pyrolysis temperature. Main pyrolysis mechanism of lignin was cracking of typical structure into phenols, cracking of carboxyl groups in side chains to form CO2 and carbonization of aromatic structure to biochar. Lignin showed higher biochar yield (up to 47.46%) and biochar from lignin pyrolysis have high carbon and low ash content. Comparing with direct pyrolysis, fermentation-pyrolysis pathway produced extra high-value products of ethanol (16.70%) and CO2 (8.5%). It indicated a potential and high-value pathway of lignin produced in cellulosic ethanol plants.

What is still Limiting the Deployment of Cellulosic Ethanol? Analysis of the Current Status of the Sector

Ethanol production from cellulosic material is considered one of the most promising options for future biofuel production contributing to both the energy diversification and decarbonization of the transport sector, especially where electricity is not a viable option (e.g., aviation). Compared to conventional (or first generation) ethanol production from food and feed crops (mainly sugar and starch based crops), cellulosic (or second generation) ethanol provides better performance in terms of greenhouse gas (GHG) emissions savings and low risk of direct and indirect land-use change. However, despite the policy support (in terms of targets) and significant R&D funding in the last decade (both in EU and outside the EU), cellulosic ethanol production appears to be still limited. The paper provides a comprehensive overview of the status of cellulosic ethanol production in EU and outside EU, reviewing available literature and highlighting technical and non-technical barriers that still limit its production at commercial scale. The review shows that the cellulosic ethanol sector appears to be still stagnating, characterized by technical difficulties as well as high production costs. Competitiveness issues, against standard starch based ethanol, are evident considering many commercial scale cellulosic ethanol plants appear to be currently in idle or on-hold states.

Constructing super large scale cellulosic ethanol plant by decentralizing dry acid pretreatment technology into biomass collection depots

Commercial cellulosic ethanol plants require mature and year-round biomass feedstock supply. Decentralizing pretreatment operation from central ethanol plant into local regional biomass collection depots provides an important solution to reach this goal. In this study, we introduced a newly established pretreatment technology, dry acid pretreatment, into the decentralized pretreatment operation by its advantages on zero wastewater generation and high volumetric density. Collection radius of crop residues feedstock is extended to nearly 100 km by decentralizing dry acid pretreatment, and biorefinery scale for cellulosic ethanol production is increased to the scale of modern petroleum refining factories in the densified agricultural regions in China and USA with the minimum ethanol selling price of below $2/gal. The technology overcomes the barrier of cellulosic ethanol cost increase with increasing biomass collection range, and provides a methodology for optimal supply method of large biorefinery plants in agricultural countries.

DowDuPont CEO favors short-term R&D

DowDuPont CEO Ed Breen says he prefers small, short-term R&D projects that quickly yield marketable products to moonshots that are risky and more expensive. Breen took over as DuPont CEO in November 2015 and quickly inked an agreement to merge with Dow Chemical. At the Bernstein Strategic Decisions Conference in New York City on May 31, Breen discussed his company’s R&D strategy. Breen said that he scaled back ambitious projects as soon as he was in charge at DuPont. “When I got to the company, we killed almost all of what I’d call the moonshot projects,” he said. “And, by the way, the moonshots cost the most money. I didn’t feel comfortable with most of them.” He cited DuPont’s $200 million cellulosic ethanol plant in Nevada, Iowa, as an example. The plant, meant to process agricultural residues from local farmers, opened in October 2015. The company closed the plant last

Clariant to build cellulosic ethanol plant in Romania

Clariant to build cellulosic ethanol plant in Romania

DuPont seeks to sell cellulosic ethanol plant

It’s one step forward and two steps back for the cellulosic ethanol business. As Clariant pushes ahead with plans to make ethanol from agricultural waste in Europe, two other chemical firms—DuPont and Beta Renewables—are pulling back from the technology. On Oct. 31, Clariant announced plans to build a cellulosic ethanol plant in Romania based on its Sunliquid process. The Swiss specialty chemical company said the plant will be a flagship facility intended to demonstrate the technology’s competitiveness and support a licensing strategy. That was pretty much DuPont’s plan when it decided to build a cellulosic ethanol facility in Nevada, Iowa. The plant, which opened in October 2015 at a cost of more than $200 million, was intended to be the first of a string of facilities that would use DuPont enzymes and yeast to turn corn cobs, stems, and leaves into ethanol. But on Nov. 2, the same day that

Clariant to make cellulosic ethanol

Clariant plans to build a commercial-scale cellulosic ethanol plant in southwestern Romania. The facility will use agricultural residues such as wheat straw to make 50,000 metric tons per year of the biofuel. Clariant says it’s building a flagship site intended to confirm that its Sunliquid enzyme and fermentation technology is competitive and sustainable. In September, the company signed a license agreement to allow Enviral to produce cellulosic ethanol in Slovakia.

A corn-stover harvest scheduling problem arising in cellulosic ethanol production

In this paper, we address a corn-stover harvest scheduling problem (CSHSP) that arises when a cellulosic ethanol plant contracts with farmers to harvest corn stover after the grain harvest has been completed. The plant contracts a fleet of harvesting crews, which must be assigned by the plant scheduler to harvest fields as they are called in by the farmers over the harvest season. First, we study the static CSHSP, in which the call in times for the fields are assumed known at the beginning of the season, and propose a mathematical programming-based approach that we show to generate solutions with an average optimality gap of only 6.1% for real-life-inspired instances. We also consider the dynamic CSHSP, in which the call in times are not known at the beginning of the harvest season and the requests arrive randomly over time. The method that we develop for the solution of this problem incurs costs that are about 4.8% higher, on average, than those incurred for the static case. These results exhibit the proposed approach to be robust for use by a plant scheduler in his/her efforts to optimize harvest scheduling as the actual season unfolds. Our proposed approach can also effectively deal with uncertainties encountered in a commercial harvest.

Large‐scale commercial production of cellulosic ethanol from agricultural residues: A case study of wheat straw in the Canadian Prairies

AbstractThis paper provides a business case for a large‐scale wheat‐straw‐based cellulosic ethanol plant in the Canadian Prairies. Feedstock availability and costs were quantified for 11 locations representing the region’s agroecological soil zones. The economic feasibility of the cellulosic ethanol plant was evaluated using SuperPro Designer® based on simultaneous saccharification and cofermentation process. Total capital investment is approximately $90–$200 million for corresponding plant with capacities of 69–208 million liters annum‐1. The lowest operating costs are associated with high volume biomass locations such as Yorkton, Lanigan, and Weyburn. A range of discount rates (7–15%), ethanol selling price ($1.00–$1.70 L‐1), and feedstock cost ($35–70 tonne‐1) was used to assess the sensitivity of plant profitability (NPV) to changes in these parameters. Average total cost of ethanol production decreased with increasing plant size, from $0.90 L‐1 in a small ethanol plant to $0.66 L‐1 for plant capacity higher than 125 million L. The sensitivity analysis showed better economies of scale for larger plants, with marginal costs and average cost curves suggesting that Canadian Prairies could support a cellulosic ethanol plant capacity of 250 million L annum‐1 at a single location. Yorkton, Melfort, Weyburn, Prince Albert, and Lanigan generate positive NPV over a wider range of annual plant capacities (138–208 million L). Swift Current, Rosetown, and Kindersley have the lowest NPV, associated with their low straw density and correspondingly higher transportation costs. © 2017 Her Majesty the Queen in Right of Canada Biofuels, Bioproducts and Biorefining © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd

“Even our Dairy Queen shut down”: Risk and resilience in bioenergy development in forest-dependent communities in the US South

Wood-based bioenergy in the US South is a key element in a sociotechnical imaginary that brings together rural development, energy independence, and environmental sustainability; it is also a key element in another imaginary in which powerful interest groups from the private sector and government collude in ways that enrich them regardless of success of the endeavor, while simultaneously posing risks to the host community. We contend that bioenergy development can introduce new risks for local communities that are often overlooked in imaginaries promulgating bioenergy as a driver of community resilience. Based on ethnographic research in Soperton, Georgia, site of the failed Range Fuels cellulosic ethanol plant and current LanzaTech experimental plant, we show how various aspects of these imaginaries merge, overlap, and compete as different actors experience the opening—and sometimes closure—of these facilities in rural communities that are often economically depressed, politically conservative, and deeply rooted in forestry both economically and culturally.