Integrated Biorefinery Research Articles

Apple Pomace Integrated Biorefinery for Biofuels Production: A Techno-Economic and Environmental Sustainability Analysis

The combination of techno-economic process modelling and life cycle assessment is an integrated methodology that addresses quantitative operational data, and evaluates the emissions associated with any process under development. In particular, the valorisation of waste streams within the context of the circular economy could be considered a valid and promising approach, especially regarding techno-economic and environmental indicators. This manuscript aims to evaluate the integral valorisation of apple pomace from the processing industry into bioethanol, and vinasses (a byproduct of the distillation process) into biogas and digestate as biofertiliser. In addition to biogas production, lagooning and composting were considered as strategies for vinasse management. After the conceptual design of the process options was completed, the environmental profile of bioethanol production was estimated across different scenarios. When biogas production was integrated to reduce the biorefinery’s energy demand, the carbon footprint was 1.13 kg CO2eq∙kg−1. This footprint increased to values around four when lagooning and composting were used as vinasse management strategies. Although the economic dimension posed a significant limitation due to high investment costs, the eco-efficiency analysis showed that the scenario of the co-production of bioethanol and biogas is the best alternative. Despite the promising results, further research is needed to explore the recovery of additional co-products to develop a high-potential strategy for apple pomace.

Techno-economic analysis of an integrated biorefinery to convert poplar into jet fuel, xylitol, and formic acid

BackgroundThe overall goal of the present study is to investigate the economics of an integrated biorefinery converting hybrid poplar into jet fuel, xylitol, and formic acid. The process employs a combination of integrated biological, thermochemical, and electrochemical conversion pathways to convert the carbohydrates in poplar into jet fuel, xylitol, and formic acid production. The C5-sugars are converted into xylitol via hydrogenation. The C6-sugars are converted into jet fuel via fermentation into ethanol, followed by dehydration, oligomerization, and hydrogenation into jet fuel. CO2 produced during fermentation is converted into formic acid via electrolysis, thus, avoiding emissions and improving the process’s overall carbon conversion.ResultsThree different biorefinery scales are considered: small, intermediate, and large, assuming feedstock supplies of 150, 250, and 760 dry ktonne of poplar/year, respectively. For the intermediate-scale biorefinery, a minimum jet fuel selling price of $3.13/gallon was obtained at a discount rate of 15%. In a favorable scenario where the xylitol price is 25% higher than its current market value, a jet fuel selling price of $0.64/gallon was obtained. Co-locating the biorefinery with a power plant reduces the jet fuel selling price from $3.13 to $1.03 per gallon.ConclusionA unique integrated biorefinery to produce jet fuel was successfully modeled. Analysis of the biorefinery scales shows that the minimum jet fuel selling price for profitability decreases with increasing biorefinery scale, and for all scales, the biorefinery presents favorable economics, leading to a minimum jet fuel selling price lower than the current price for sustainable aviation fuel (SAF). The amount of xylitol and formic produced in a large-scale facility corresponds to 43% and 25%, respectively, of the global market volume of these products. These volumes will saturate the markets, making them infeasible scenarios. In contrast, the small and intermediate-scale biorefineries have product volumes that would not saturate current markets, does not present a feedstock availability problem, and produce jet fuel at a favorable price given the current SAF policy support. It is shown that the price of co-products greatly influences the minimum selling price of jet fuel, and co-location can further reduce the price of jet fuel.

Direct consolidated bioprocessing for d-glucaric acid production from lignocellulose under subcritical water pretreatment

d-glucaric acid production from lignocellulose is a valuable research field, but meets the same challenge as other biorefinery processes that prevents it from commercialization, high production costs. The very path to tackle this is to increase the titer, rate and yield (TRY) of d-glucaric acid production and simplify the process, on which this study focused. Herein we used a novel, clean and environmentally friendly pretreatment, subcritical water pretreatment (SCWP), based on which we compared consolidated bioprocessing (CBP) by the microbial consortium composed of Trichoderma reesei C10 and Saccharomyces cerevisiae LGA-1C3S2 with separated hydrolysis and fermentation (SHF). CBP was found to be advantageous over SHF because of its comparable yield, much more simplified bioprocess and bigger space for cost reduction. Then CBP was upgraded to direct consolidated bioprocessing (dCBP) by adapting the microbial consortium in the raw liquors of SCWP containing inhibitors and toxic chemicals. As a result, more integrated biorefinery processes from corn stover (CS), wheat straw (WS), rice straw (RS) and switchgrass (SG) to d-glucaric acid under SCWP were developed and scaled up from shake flasks to 10 L fermenters, stirred and airlift. The TRYs of d-glucaric acid were improved significantly. The airlift fermenter was preferable for the dCBPs, producing the highest concentrations of d-glucaric acid, which were 10.03 g/L from subcritical water pretreated CS (SWCPCS), 9.53 g/L from SWCPWS, 8.87 g/L from SWCPRS and 10.66 g/L from SWCPSG respectively. Subsequently, the dCBPs were coupled with the downstream separation to establish a closed-circuit circulation and 30 rounds was run successfully. The highly integrated process from lignocellulose to d-glucaric acid with the smallest number of single unit operations was obtained and reported for the first time, providing an important design for biorefinery. This work is of great significance for biomanufacturing d-glucaric acid and other bio-based chemicals.

Techno-Economic Analysis of an Integrated Bio-Refinery for the Production of Biofuels and Value-Added Chemicals from Oil Palm Empty Fruit Bunches

Lignocellulose-rich empty fruit bunches (EFBs) have high potential as feedstock for second-generation biofuel and biochemical production without compromising food security. Nevertheless, the major challenge of valorizing lignocellulose-rich EFB is its high pretreatment cost. In this study, the preliminary techno-economic feasibility of expanding an existing pellet production plant into an integrated bio-refinery plant to produce xylitol and bioethanol was investigated as a strategy to diversify the high production cost and leverage the high selling price of biofuel and biochemicals. The EFB feedstock was split into a pellet production stream and a xylitol and bioethanol production stream. Different economic performance metrics were used to compare the profitability at different splitting ratios of xylitol and bioethanol to pellet production. The analysis showed that an EFB splitting ratio below 40% for pellet production was economically feasible. A sensitivity analysis showed that xylitol price had the most significant impact on the economic performance metrics. Another case study on the coproduction of pellet and xylitol versus that of pellet and bioethanol concluded that cellulosic bioethanol production is yet to be market-ready, requiring a minimum selling price above the current market price to be feasible at 16% of the minimum acceptable return rate.

VIKOR - P-graph Method for Optimal Synthesis of Philippine Agricultural Waste-Based Sustainable Integrated Biorefinery

A sustainable integrated biorefinery (SIBR) is a biomass processing facility that converts agricultural wastes or residues into a wide range of valuable products where both economic sustainability and environmental sustainability are optimized. This work proposed a hybrid method that incorporates Vlsekriterijumska Optimizacija I Kompromisno Resenje (VIKOR), a widely used multi-criteria decision-making (MCDM) tool with the P-graph (process-graph) framework. The proposed VIKOR - P-graph model can (i) generate a set of combinatorically feasible solutions, and (ii) rank the solution sets using VIKOR method, simultaneously in the same P-graph model. In other words, all the drawbacks attributed to the sequential optimization methods can, therefore, be avoided. To demonstrate the effectiveness of the proposed hybrid methodology, a case study in the Philippines is presented in this paper. The hybrid P-graph model generated a total of 7 feasible solutions with different configuration for the SIBR based on the overall profit (i.e., economic goal) and carbon emissions (i.e., environmental goal). Results show that the best compromised solution can be obtained when majority (70 %) of the rice husk is used to produce bioethanol, where the required power is supplied by combusting the remaining rice husk and by importing external power. It offers an hourly profit of 161 $/h with a lower (~38.6 %) carbon emissions as compared to the most profitable option (3.504 tCO2-eq/h). This research is essentially a guide for policymakers to make informed decisions that can maximise the benefits of SIBR on a national scale.

Modeling and simulation of a sawdust mixture-based integrated biorefinery plant producing bioethanol

The design, modeling and simulation of an integrated biorefinery plant assumed to convert different forestry assortments such as sawdust or shavings (sawmill waste) into bioethanol from cellulose and hemicellulose as the main product, and lignin as the most valuable co-product, was carried out. The proposed lignocellulosic ethanol biorefinery plant was simulated with ProSimPlus. The model was based on experimental results and includes an Organosolv pretreatment, enzymatic hydrolysis, fermentation and distillation to obtain bioethanol. The investigated plant size processed 70,088 tons of biomass/year, with a production capacity of 11,650 tons ethanol/year. Ethanol productivity reached 351 L/ton of dry feedstock. Considering water consumption, approximately 4.8 L of water were needed to produce a liter of ethanol. Finally, the energy targeting through conventional pinch analysis lead to 16.4 MW and 16.07 MW of hot and cold utility energy demand for the entire process respectively with the cogeneration of electricity.

Multi-objective optimization of a 1G-2G biorefinery: A tool towards economic and environmental viability

First-generation sugarcane ethanol production is a well-established technology. However, second-generation ethanol is not yet consolidated in industries. Under these circumstances, this work presents a multi-objective optimization of this process focusing on economic and environmental objectives. The impact of the Brazilian decarbonization program on an integrated biorefinery is analyzed, considering a first-generation ethanol conventional autonomous distillery and a second-generation process with hydrothermal pre-treatment, enzymatic hydrolysis and fermentation of the xylose liquor. The economic metric was the Net Present Value and the environmental assessment was based on the plant inventory considering Global Warming Potential. A multi-objective particle swarm optimization algorithm was used, considering the ratio of bagasse diverted to the second-generation process, enzyme loading and solid fraction in the hydrolysis reactor as optimization variables. The carbon credit price was estimated for each point in the Pareto set in order to make the process economically feasible. As the main conclusions, there is a trade-off between economic and environmental targets, indicating that carbon credits may be essential for second-generation ethanol economic feasibility. The optimized integrated biorefinery is able to increase ethanol production by approximately 24% compared to first-generation biorefineries, but an increase in ethanol production higher than 13% would make the process economically unfeasible, while the decarbonization credits are not being commercialized. A price of $ 15.77 for decarbonization credits would make it possible to produce 20% more ethanol, keeping the integrated biorefinery economically feasible.

Impact of co‐product selection on techno‐economic analyses of alternative jet fuel produced with forest harvest residuals

AbstractThis article details techno‐economic analyses for producing alternative jet fuel (AJF) at a greenfield integrated biorefinery (IBR) using softwood forest residues. The scenarios and their corresponding economic outcomes differ based on the co‐product selections. The selected technology to produce AJF uses a mild bisulfite pretreatment process to prepare the feedstock for enzymatic hydrolysis and fermentation to isobutanol, which is then upgraded to hydrocarbon ‘drop‐in’ fuels using an alcohol‐to‐jet process. The hydrocarbons are a combination of jet fuel and aviation gasoline (AvGas). The residuals are used to produce co‐products. Four co‐product scenarios are compared to quantify the impact of co‐product selection on the primary products, jet fuel, and AvGas minimum selling prices (MSPs). For the baseline (BL) scenario, residuals are burned to create steam for conversion to electricity. The excess power generated is sold at a wholesale price to the grid. The total capital investment for an IBR with a forest residue feed rate of 721 k dry metric ton year−1 is 1027 MM US$, and the AJF MSP is 2.07 US$ L−1. The BL scenario is compared with three co‐product selections: 1) liquid calcium lignosulfonate and electricity; 2) activated carbon; and 3) a combination of liquid calcium lignosulfonate and activated carbon. As anticipated, the conversion of residuals into higher value co‐products provides additional revenue to offset the production cost of hydrocarbons. The alternative co‐product scenarios reduced the predicted MSPs; however, the most cost‐competitive model, the scenario where both activated carbon and calcium lignosulfonates are produced, reduced the jet fuel MSP to 1.49 US$ L−1, a 28% reduction. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd

Marketing and social effects of industrial scale insect value chains in Europe: case of mealworm for feed in France

Insects are becoming part of the human diet in many regions of the world, either directly or indirectly, as livestock feed. Insects could become a significant feed ingredient if produced at industrial scale, but it is a challenge. Such an emerging sector would result in substantial social effects. One innovation of the DESIRABLE project is exploring potential social consequences induced by industrial scale development of insect production in France for feed, under several production and marketing assumptions. First, this paper explains how the stakeholders and researchers involved in the project built and selected some framework scenarios, which depict upstream (production and meal processing) scenarios. Downstream scenarios were designed based on interviews with specialists in poultry, trout, and feed production markets, that allowed to proposing plausible scenarios for marketing. The potential outlets are more or less narrow market ‘niches’: feed for laying hens to produce organic eggs, or for farmed trout eating insect meal. Second, the method for evaluating social effects linked with the emergence of the new insect’ industry, a social life cycle analysis in four detailed scenarios. The main positive social effects of the four detailed scenarios result from job creation in the insect production sector, while effects on other feed-ingredient suppliers are few. Negative effects result from the allergy risk for employees and potential disturbance to nearby neighbourhoods, but the latter can be easily managed by carefully choosing the locations. In the two scenarios with integrated bio refinery, exists a major risk that could stop the industrial project: activists could use environmental or animal-welfare concerns to oppose the bio refinery, because of agricultural land and water preservation and/or opposition to industrial scale insect production. Nevertheless, insect meal can help preserve fishery resources by providing a constant substitute for fish meal.

Fast pyrolysis of hot-water-extracted and soda-AQ-delignified okra (Abelmoschus esculentus) and miscanthus (miscanthus x giganteus) stalks by Py-GC/MS

The thermochemical behavior of various samples of okra (Abelmoschus esculentus) and miscanthus (Miscanthus x giganteus) stalks (initial, hot-water-extracted, and those from sulfur-free delignification) were studied by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). In all cases, major GC-amenable condensable products were measured semi-quantitatively and classified into several product groups. The formation of these product groups from different feedstock samples with varying mass portions of their structural constituents (carbohydrates and lignin) was investigated at 500 °C and 700 °C with a residence time of 5 s and 20 s. The main product groups were aliphatic compounds, such as lactone, furan, and cyclopentenone derivatives from carbohydrates (mainly hemicelluloses) and aromatic compounds, such as guaiacol, phenol, and syringol derivatives from lignin. Additionally, the formation of aliphatic and aromatic products (e.g., the ratio of aliphatic compounds to aromatic compounds) was found to be characteristically dependent on feedstock composition and pyrolysis conditions. This kind of approach is of practical importance concerning efforts not only to uncover new integrated biorefinery possibilities to manufacture value-added products but also to develop rapid characterization tools for lignocellulosics.

Integration of the biorefinery concept for the development of sustainable processes for pulp and paper industry

This work aims at developing sustainable processes for pulp and paper industry by integration of the biorefinery concept to an existing pulp and paper process. A systematic methodology employing a superstructure-based process synthesis approach is employed with support from computer-aided tools to determine potential pathways for a long-term sustainable growth objective. A superstructure of the multi-product biorefinery process network for the pulp and paper industry is developed. It is divided into three sub-networks, a chemical pulping section, a biochemical production section and a black liquor utilization section. Superstructure optimization is performed with the objective to maximize profit to determine optimal integrated networks for three scenarios. The obtained results provide useful insights for further development of the optimal networks as sustainable integrated biorefinery combined with pulp and paper mills.

Life‐cycle analysis of integrated biorefineries with co‐production of biofuels and bio‐based chemicals: co‐product handling methods and implications

AbstractNew integrated biorefinery (IBR) concepts are being investigated to co‐produce hydrocarbon fuels and high‐value bio‐based chemicals to improve the economic viability of IBRs, to enhance biomass resource utilization efficiencies, and to maximize potential greenhouse gas (GHG) emission reductions. Unlike fuel‐only biorefineries, IBRs may co‐produce a significant amount of bio‐based chemicals, whose emission implications for specific biorefinery products and the biorefinery as a whole need to be evaluated. We discuss this in principle and apply three sets of co‐product handling methods to conduct life‐cycle analysis (LCA) of modeled IBRs with co‐production of two bioproduct examples – succinic acid and adipic acid – alongside a renewable diesel blendstock fuel product. The LCA results for the specific co‐product handling methods that were examined shed light on potential artifacts of product‐specific LCA with selected co‐product methods. We discuss the advantages and limitations of each method and conclude that (i) a system‐level or ‘black‐box’ LCA allocation method is too simplistic to reflect appropriately the GHG burdens of distinctly different processing trains for fuels and chemicals in the IBR context, and (ii) the displacement method is the only co‐product handling method that accounts fully for the emission effects of both the fuel product and the non‐fuel bio‐based co‐products in the IBRs within the context of the existing fuel‐focused GHG regulatory framework. Alternatively, biorefinery system‐level LCA combines benefits of individual products to offer a complete picture. This system‐level LCA approach offers a holistic LCA without somewhat arbitrary decisions either on an allocation basis or by the selection of an evaluation metric based on specific products. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.

Production of 2-methylfuran from biomass through an integrated biorefinery approach

Herein we present a high yield 2-methylfuran production process with the required features to be implemented in a future integrated biorefinery. The strategy is based on the right solvent selection, 2-methyltetrahydrofuran, which i) can be used to extract the reactant, furfural, from the aqueous solution obtained after corncob biomass hydrolysis; ii) allows for highly selective 2-methylfuran production form furfural with up to 80% yields and iii) presents suitable biofuel properties in the gasoline range. Using this innovative approach, two energy intensive separation steps are avoided: the initial furfural purification and the final solvent/product complete separation. Further benefits of this process arise from the developed low-cost, selective, and reusable Cu-Co/γ-Al2O3 catalyst.

Hydrothermal Extraction of Microalgae Fatty Acid Influences Hydrochar Phytotoxicity

Hydrothermal carbonization (HTC) of microalgae biomass for the production of triacylglycerides is a potentially valuable enabling technology for a waste water treatment-based integrated biorefinery. Here, HTC was used to treat Phaeodactylum tricornutum lipid-rich biomass producing a solid hydrochar from the surface of which adsorbed lipids were removed by hexane extraction following filtration of the solid hydrochar from the process liquid product. Approximately 7% of the input biomass was recovered and transesterified for qualitative and quantitative GCMS analysis for fatty acid methyl esters. Transesterifiable lipids accounted for 94% of the material recovered by solvent extraction. Of the transesterified fatty acids (FA) analysed, the majority was monounsaturated (40.4%) and saturated (37%) C-16 FA. Other FA detected included saturated and monounsaturated C-18 (7.7% and 1.9%) and saturated C-14 (5.3%) and C-25 (1.5%). Thermal analysis (TGA/DSC) of the hydrochar in air showed calorific values of 10.6 MJ kg-1 (delipidated hydrochar) and 3.1 MJ kg-1 (non-delipidated hydrochar) with the latter exhibiting the presence of volatalisable components. Germination trials were conducted to assess the potential phytotoxic effects of these hydrochars. Delipidated hydrochar showed a germination index of 73% suggesting the presence of some phytotoxicity. Non-delipidated hydrochar showed high germination index results of 102% (unground) and 126 % (ground). Taken together with the observation of reduced root hair proliferation in these two test conditions, this suggests the operation of a second phytotoxic effect that is removed by delipidation.

An Integrated Biorefinery Framework for the Coproduction of Biofuels and Chemicals: Experimental Analysis, Detailed Modelling, Optimization and Life Cycle Analysis

In this work, a novel integrated biorefinery framework is introduced. A ?cradle to grave? analysis is developed by adding novel steps into a basic biodiesel process involving the valorization of waste streams to value-added chemicals. Insights are given towards a new bioconversion route of glycerol to succinic acid. An unstructured model of batch experiments at different conditions is constructed. Experimental results at the bench scale are used to estimate kinetic parameters and to validate model predictions. The developed model is used in optimization studies to compute the best initial conditions for batch as well as the optimal feeding profiles for fed-batch processes to maximize succinic acid productivity. Finally, the above process is incorporated into a biorefinery scheme. Simulation and optimization in conjunction with life cycle analysis (LCA) is performed to simultaneously improve its sustainability and its economics.

Conceptual design of sustainable integrated microalgae biorefineries: Parametric analysis of energy use, greenhouse gas emissions and techno-economics

This study covers four main aspects of the conceptual design of sustainable integrated microalgae-based biorefineries using flue gas from CO2-intensive industries (i.e. 100% CO2): i) screening of technologies (4 options for cultivation, 3 for culture dewatering, 3 for cell disruption, 4 for lipids extraction & purification, and 4 for fractions upgrading); ii) analysis of processing variables (parametric study of the main cultivation conditions affecting the global performance of the biorefinery systems); iii) combination of final products (10 biorefinery configurations are generated from the combination of 9 final products); and iv) assessment of sustainability criteria (i.e., non-renewable energy use (NREU), greenhouse gas (GHG) emissions and economics). The used approach compares processing options and operation conditions to identify those combinations of production processes that minimize NREU and GHG emissions. In a second step, 10 integrated biorefinery concepts are selected and compared with respect to their environmental and economic performances. The impacts of choosing different microalgae species, locations, and nutrient sources were also studied as part of the scenario analysis. The results showed that the biorefinery systems with the best economic and environmental performances are those where microalgae oil-free cake is used as nutrient for substitution of animal feed and where lipids are used for substitution of vegetable oils. The worst economic and environmental performances of biorefineries were obtained when microalgae oil-free cake is anaerobically digested to biogas and lipids are converted to either biodiesel or green diesel. Regarding the cultivation technologies for the biorefinery systems with the best performance, favorable environmental results were obtained for flat panel photobioreactors (FPPBRs), followed by open ponds (OPs), vertical photobioreactors (VPBRs) and horizontal photobioreactors (HPBRs). In contrast, the best economic results were found for FPPBRs followed by VPBRs, HPBRs and OPs.

Novel Methodology for the Synthesis of Optimal Biochemicals in Integrated Biorefineries via Inverse Design Techniques

The recent developments of process synthesis and design for integrated biorefineries have significantly increased the potential of biomass to generate sustainable renewable energy as an alternative source for fossil fuels. In addition, biomass can be converted into various value-added products (e.g., biochemicals, biomaterials, biosolvents, etc.). To ensure the sustainable production of energy and value-added products, biomass is converted into commodities and specialty products in an integrated biorefinery. However, due to the increase in the number of potential products, new reactions, and technologies, determining of optimum products and processing routes in an integrated biorefinery has become more challenging. Therefore, it is essential to develop a systematic approach to address the above-mentioned issues. In this work, a novel two-stage optimization approach has been developed to design optimal biochemical products and synthesize optimum biomass conversion pathways in an integrated biorefinery. In the presented approach, optimal biochemical products that meet the customer requirements are first determined via signature based molecular design techniques. In addition, optimum conversion pathways that convert biomass into the biochemical products which are identified in the previous step can be determined via a superstructural mathematical optimization approach. A case study of biobased fuel production from palm-based biomass is solved to illustrate the proposed approach.

Towards integrated biorefinery from dried distillers grains: Selective extraction of pentoses using dilute acid hydrolysis

The abundant availability and high level of hemicellulose content make dried distillers grains (DDG) an attractive feedstock for production of pentoses (C5) and conversion of C5 to bioproducts. One target of this work was to produce a C5 extract (hydrolyzate) with high yield and purity with a low concentration of C5 degradation products. A high selectivity towards pentoses was achieved using dilute acid hydrolysis of DDG in a percolation reactor with liquid recirculation. Pretreatment of starting material using screening and ultrasonication resulted in fractional increase of the pentose yield by 42%. A 94% yield of pentoses on the DDG (280.9 g kg−1) was obtained. Selective extraction of individual pentoses has been achieved by using a 2-stage hydrolysis process, resulting in arabinose-rich (arabinose 81.5%) and xylose-rich (xylose 85.2%) streams. A broader impact of this work is towards an Integrated Bio-Refinery based on DDG – for production of biofuels, biochemical intermediates, and other bioproducts.

Characterization of trace contaminants in syngas from the thermochemical conversion of biomass

Sampling and analysis procedures are described that have been developed and validated for the detailed characterization of trace organic and inorganic contaminants in purified syngas generated from an integrated biorefinery (IBR). A dynamic dilution sampling system was employed to minimize the potential loss of polar organic and particulate species during the sampling of the syngas. Sample collection media included a combination of filters, adsorbent cartridges, and evacuated canisters. Results were generated for up to 165 syngas contaminants generated from the conversion of rice hull and wood chip feedstocks over a 3-day test period from a pilot IBR having a biomass conversion capability of 10 to15 dry tons per day. Special emphasis was placed on the characterization of trace sulfur species (H2S, SO2, and inorganic sulfates), nitrogen species (NH3, HNO3, NO2, and inorganic nitrates), chlorine species (HCl and inorganic chlorides), tars (organic particulates), and inorganic particulate matter (elemental species) since these materials are known contaminants that can adversely affect catalysts used in subsequent conversion of syngas to fuels. The dynamic dilution sampling system was shown to reliably collect trace contaminants in the syngas, collected both before and after the IBR syngas purification system. The detection limits for most chemical species were found to be in the low ppb range. The total average concentrations of all particulate contaminants using filter sampling media were in good agreement with PM2.5 measurements using a real-time particulate monitoring instrument. It was found that the purified syngas contained very low levels of contaminants, and that the syngas from this biorefinery would be suitable for subsequent catalytic conversion to liquid fuels over extended periods of biorefinery operation.

Simultaneous Process Synthesis, Heat and Power Integration in a Sustainable Integrated Biorefinery

An integrated biorefinery is a processing facility that converts biomass feedstocks into a wide range of value added products (e.g., biofuels, specialty chemicals) via multiple technologies. To synthesize a sustainable integrated biorefinery, consumption of energy within such biorefinery should be self-sustained. The performances of integrated biorefinery can be improved via simultaneous process synthesis, heat and power integration. Due to the complexity of the process synthesis and integration problem, there is a need for a systematic approach to address the problem. In this work, the modular optimization approach, which breaks a large optimization problem into small models, is adapted to solve the complex problem. This allows engineers to ‘zoom in’ on specific key process units in a smaller model. Based on the proposed approach, selection of the optimum process alternatives/technologies and products, as well as integration of heat and power between process units, can be performed simultaneously. To illustrate the capability of proposed approach, two case studies are solved.