Syngas Ratio Research Articles

Influence of operating conditions in a continuously stirred tank reactor on the formation of carbon species on alumina supported cobalt Fischer–Tropsch catalysts

The paper focuses on the identification of carbon species using a wide range of ex situ characterization techniques (TPH/MS, TGA-DTA, XPS, TOF-SIMS) in spent 15wt% Co/Al2O3 supported catalysts exposed to different conditions of Fischer–Tropsch synthesis in a continuously stirred tank reactor (CSTR) at 20bar of total pressure, different gas-space velocities and H2/CO ratios. Three types of carbonaceous species were uncovered in the used catalysts: (i) hydrcarbobns (probably wax), (ii) strongly adsorbed hydrocarbons and (iii) amorphous polymeric carbon. The amounts of deposed carbon species strongly depend on the operating conditions. In agreement with the observed slow catalyst deactivation, only very small amounts of strongly adsorbed hydrocarbons and polymeric carbon were observed when the catalyst was exposed to a H2/CO=2 syngas ratio and moderate carbon monoxide conversions. Lower gas space velocity and lower H2/CO ratio in syngas lead to larger amounts of deposed carbon species. Strongly adsorbed hydrocarbons and amorphous polymeric carbon seem to contribute to catalyst deactivation. Cobalt carbide and graphitic carbon were not detected in the used catalysts by ex situ methods.

Sorption-enhanced synthetic natural gas (SNG) production from syngas: A novel process combining CO methanation, water-gas shift, and CO2 capture

Synthetic natural gas (SNG) production from syngas is under investigation again due to the desire for less dependency from imports and the opportunity for increasing coal utilization and reducing greenhouse gas emission. CO methanation is highly exothermic and substantial heat is liberated which can lead to process thermal imbalance and deactivation of the catalyst. As a result, conversion per pass is limited and substantial syngas recycle is employed in conventional processes. Furthermore, the conversion of syngas to SNG is typically performed at moderate temperatures (275–325°C) to ensure high CH4 yields since this reaction is thermodynamically limited. In this study, the effectiveness of a novel integrated process for the SNG production from syngas at high temperature (i.e. 600°C) was investigated. This integrated process consists of combining a CO methanation nickel-based catalyst with a high temperature CO2 capture sorbent in a single reactor. Integration with CO2 separation eliminates the reverse-water-gas shift and the requirement for a separate water-gas shift (WGS) unit. Easing of thermodynamic constraint offers the opportunity of enhancing yield to CH4 at higher operating temperature (500–700°C) which also favors methanation kinetics and improves the overall process efficiency due to exploitation of reaction heat at higher temperatures. Furthermore, simultaneous CO2 capture eliminates greenhouse gas emission. In this work, sorption-enhanced CO methanation was demonstrated using a mixture of a 68% CaO/32% MgAl2O4 sorbent and a CO methanation catalyst (Ni/Al2O3, Ni/MgAl2O4, or Ni/SiC) utilizing a syngas ratio (H2/CO) of 1, gas-hour-space velocity (GHSV) of 22,000h−1, pressure of 1bar and a temperature of 600°C. These conditions resulted in ∼90% yield to methane, which was maintained until the sorbent became saturated with CO2. By contrast, without the use of sorbent, equilibrium yield to methane is only 22%. Cyclic stability of the methanation catalyst and durability of the sorbent were also studied in the multiple carbonation–decarbonation cycle studies proving the potential of this integrated process in a practical application.

등온반응기와 단열반응기 조합으로 구성된 0.25 MW급 메탄합성 파일롯 공정 운전특성

In this study, we analyzed the operational characteristics of a 0.25 MW methanation pilot plant. Isothermal reactor controled the heat released from methanation reaction by saturated water in shell side. Methanation process consisting of isothermal reactor and adiabatic reactor had advantages with no recycle compressor and more less reactors compared with methanation process with only adiabatic reactors. In case that H2/CO ratio of syngas was under 3, carbon deposition occurred on catalyst in tube side of isothermal reactor and the pressure of reactors increased. In case that H2/CO ratio was maintained around

Process efficiency of biofuel production via gasification and Fischer–Tropsch synthesis

A thermodynamic equilibrium model was used to predict the composition of syngas produced by oxygen-blown biomass gasification at different operating conditions. The effects of temperature, pressure, moisture content, steam to biomass ratio and equivalence ratio (ratio of the amount of oxygen that is fed to the gasifier as a fraction of the oxygen required to achieve full combustion) were studied using sugarcane bagasse and pyrolysis slurry derived from sugarcane bagasse as feed. Taking kinetic limitations into account, the optimum operating conditions to maximise gasification efficiency, or to produce the stoichiometric H2/CO syngas ratio of 2, were determined for each feedstock and integrated with a process model for Fischer–Tropsch liquids production. The maximum overall process efficiency of 51%, of which 40% was in the form of Fischer–Tropsch liquids, corresponded with the maximum gasification efficiency of 75%, based on atmospheric gasification of bagasse with 5% moisture at a temperature of 1100K, equivalence ratio of 0.25 and steam to biomass ratio of 0.75. Operating the gasifier at a steam:biomass ratio of 2.25 to yield an equilibrium H2/CO ratio of 2 increased the Fischer–Tropsch liquid yield, while inclusion of a shift reactor downstream from the gasifier had the same effect and was apparently more energy efficient. However, maximising the Fischer–Tropsch liquid yield did not necessarily increase the process thermal efficiencies. It was also observed that the thermal process energy efficiencies previously reported for Fischer–Tropsch synthesis from atmospheric biomass gasification with a shift reactor, could be improved by 10.7% by excluding the shift process, although 5% less liquid fuel energy would be produced.

Modeling Analysis of Shell, Texaco Gasification Technology’s Effects on Water Gas Shift for Fischer-Tropsch Process

This work analyzes different gasification processes affect on WGS process with Excel-Aspen Plus based models.in large scale production. Results show that Shell gasifier can obtain higher (CO + H2)/syngas ratio and higher thermal efficiency but lower H2/CO ratio than Texaco gasifier. However, both of H2/CO ratios are below 1.0 and WGS reaction has to carry out to prepare for the Fischer-Tropsch synthesis. The simulation shows Shell syngas does not offer adequate H2O molecules for WGS shift reaction and it can be supplied by the 5.2MPa steam generated from the boiler of the Shell gasification process. Texaco syngas has sufficient H2O molecules to meet the need of this reaction. The overall thermal efficiency of the Texaco-WGS is lower than that of the Shell-WGS.

Mechanistic Modeling of Cobalt Based Catalyst Sintering in a Fixed Bed Reactor under Different Conditions of Fischer–Tropsch Synthesis

A three-step sintering mechanism is proposed for Co-based catalysts under Fischer–Tropsch reaction conditions. This mechanism includes an intermediate formation of oxide layer on cobalt metal nanoparticles in the presence of water. The partially reversibly oxidized surface accelerates sintering by both reducing the surface energy and enhancing the diffusion rates of cobalt particles. The proposed mechanism is then employed for a fixed-bed unsteady state reactor. The effect of particle growth on the catalytic activity was analyzed within a diverse range of operating conditions (syngas ratio = 1.5–4, water co-feed ratio = 0–6, inert co-feed ratio = 0–6). It is found that, at the same gas space velocity, sintering proceeds faster at higher H2/CO ratios. At the same initial conversion, a low H2/CO syngas ratio increases sintering severity, i.e., catalyst deactivation due to the crystallite growth, as it brings about higher relative water partial pressure. Dilution of syngas with different amounts of inert gas does not affect the cobalt sintering rate. Cobalt sintering proceeds more rapidly if water is co-fed during the reaction.

Sustainable Production of Syngas from Biomass‐Derived Glycerol by Steam Reforming over Highly Stable Ni/SiC

The production of syngas was investigated by steam reforming glycerol over Ni/Al(2)O(3), Ni/CeO(2), and Ni/SiC (which have acidic, basic, and neutral properties) at temperatures below 773 K. The complete and stable conversion of glycerol with a yield (higher than 90 %) of gaseous products (mainly syngas) was achieved over Ni/SiC during a 60 h reaction, whereas the conversion of glycerol continually decreases over Ni/Al(2)O(3) (by 49.8 %) and Ni/CeO(2) (by 77.1 %). The deactivation of Ni/Al(2)O(3) and Ni/CeO(2) is mainly caused by coke deposition because of the C-C cleavage of the byproducts produced by dehydration over acidic sites and condensation over basic sites. Gaseous products with a 1.0-1.9 syngas ratio (H(2)/CO) are produced over Ni/SiC. This ratio is required for the Fischer-Tropsch synthesis. However, a syngas ratio of more than 3.0 was observed over Ni/Al(2)O(3) and Ni/CeO(2) because of the high activity of the water-gas-shift reaction. Any dissociative or associative adsorption of water on Al(2)O(3) and CeO(2) promotes a water-gas-shift reaction and produces a higher syngas ratio. H(2) and CO were mainly produced by decomposition of glycerol through dehydrogenation and decarbonylation over Ni sites. Thus, SiC promotes an intrinsic contribution of nickel (dehydrogenation, and decarbonylation) without any byproducts from the dehydration and condensation.

Integrating low steam demand CO shift process to coal based polygeneration energy systems: Process design and analysis

Coal based polygeneration, a technology that couples power generation and chemical production, is a promising solution to the challenges of fossil fuel depletion and greenhouse gas emissions. Carbon monoxide shift process is a key unit in polygeneration, which adjusts hydrogen and CO ratio according to the requirements of downstream processes. Usually steam is added to shift the gas composition extensively, which contributes considerably to the energy efficiency penalty.This paper presents a polygeneration system with a low steam demand CO shift process, based on a recently developed catalyst QDB-04. Compared with a conventional CO shift, the proposed process is characterized by a low steam to CO ratio in the feeding syngas, and the steam required for the CO shift can be significantly reduced. A model of the proposed CO shift process was developed and its performance was compared with a conventional CO shift. Key system parameters were chosen to integrate the low steam CO shift process in a methanol/power polygeneration system. Based on flowsheet simulation, an energy assessment was performed to compare the proposed polygeneration system with a conventional one. Results show that the polygeneration with the low steam CO shift process has considerable energy savings over the conventional scheme.

High-temperature entrained flow gasification of biomass

Biomass (wood and straw) gasification has been studied in a laboratory scale atmospheric pressure entrained flow reactor. Effects of reaction temperature, steam/carbon molar ratio, excess air ratio, and biomass type on the solid, liquid and gas products were investigated. The biomass was completely converted at all investigated operating conditions and the syngas contained nearly no tar but some soot at the highest applied reaction temperature of 1350°C. With a rise of reaction temperature from 1000°C to 1350°C, the yield of producer gas (defined as the sum of H2, CO, CO2 and hydrocarbons up to C3 species) increased dramatically by 72%. The H2/CO molar ratio in syngas was close to 1 at reaction temperature above 1200°C with steam addition. Higher temperature was beneficial to lower the amount of tar while the soot yield showed a peak of 56.7g/kg fuel at 1200°C. With steam addition, the producer gas yield and in particular the H2 yield increased gradually, while the CO yield decreased slowly. The molar ratio of H2/CO was equal to 1 with the largest supplied amount of steam addition (H2O/C=1). Steam addition gave an obvious reduction in the soot yield, but it was not possible to completely avoid soot. Increasing excess air ratio from 0.25 to 0.50 gave no significant change in the producer gas yield, but the yields of H2, CO, and soot decreased, the CO2 yield increased, and the molar ratio of H2/CO decreased. Moreover, wood and straw gasification provided similar product compositions. At 1350°C and with steam addition, the syngas composition is close to equilibrium as verified by calculation.

Effect of H2:CO ratio in syngas on the performance of a dual fuel diesel engine operation

Syngas, an environment friendly alternative gaseous fuel for internal combustion engine operations, consists mainly of carbon monoxide and hydrogen. In this paper, at different loads, the effect of syngas on the performance, combustion and emission characteristics of a diesel engine was studied. For this purpose, three different volumetric compositions of syngas fuels were examined in the diesel engine under dual fuel modes. The syngas with 100% H2 compositions showed an improved engine performance, but, at the expense of higher NOx emissions for an increase in load. The NOx emissions reduced when 25% and 50% CO were added in the 100% H2 composition syngas. At the best efficiency loading point of 80%, the maximum diesel replacement was found as 72.3% for 100% H2 syngas mode. At same engine load, the thermal efficiency was found to be 16.1% for 50% H2 syngas. It increased to 18.3% and 19.8% when H2 content was increased to 75% and 100%, respectively. At higher loads, the 50% and 75% H2 content syngas modes showed a good competitive performance to that of 100% H2 mode. The higher CO and HC emission levels were recorded for 25 and 50% CO fraction syngas fuels due to their CO content in the fuel compositions. At part-loads (20% and 40% loads), all the tested ranges of syngas modes resulted in a poor performance including higher emission levels.

Fischer–Tropsch synthesis in milli-fixed bed reactor: Comparison with centimetric fixed bed and slurry stirred tank reactors

This paper presents a comparative study of Fischer–Tropsch synthesis in single channel milli-fixed bed, conventional centimetric fixed bed and slurry stirred tank reactors. In the three reactors, the catalytic measurements were carried out with the same conventional platinum-promoted alumina supported cobalt catalyst at 493 K and 20 bar using a stoichiometric syngas ratio (H 2/CO = 2). The single channel milli-fixed bed reactor displays a higher initial Fischer–Tropsch reaction rate than the conventional centimetric fixed bed reactor. This effect was assigned to a better temperature control and less significant catalyst deactivation during the startup of the single channel milli-fixed bed reactor. The slurry stirred tank reactor shows much lower hydrocarbon productivity than the milli- and centimetric fixed bed reactors, which is probably due to incomplete catalyst reduction. A considerable catalyst deactivation due to the uncontrolled temperature hike can occur during the reactor startup in the conventional centimetric fixed bed reactor. The slurry stirred tank and milli-fixed bed reactors show similar apparent deactivation behavior.

Hydrogen and syngas yield from residual branches of oil palm tree using steam gasification

Wastes produced during oil palm production from agro-industries have great potential as a source of renewable energy in agriculturally rich countries, such as Thailand and Malaysia. Clean chemical energy recovery from oil palm residual branches via steam gasification is investigated here. A semi-batch reactor was used to investigate the gasification of palm trunk wastes at different reactor temperatures in the range of 600 to 1000°C. The steam flow rate was fixed at 3.10g/min. Characteristics and overall yield of syngas properties are presented and discussed. Results show that gasification temperature slightly affects the overall syngas yield. However, the chemical composition of the syngas varied tremendously with the reactor temperature. Consequently, the syngas heating value and ratio of energy yield to energy consumed were found to be strongly dependent on the reactor temperature. Both the heating value and energy yield ratio increased with increase in reactor temperature. Gasification duration and the steam to solid fuel ratio indicate that reaction rate becomes progressively slower at reactor temperatures of less than 700°C. The results reveal that steam gasification of oil palm residues should not be carried out at reactor temperatures lower than 700°C, since a large amount of steam is consumed per unit mass of the sample in order to gasify the residual char.

Co-liquefaction of lignite and sawdust under syngas

Individual and co-liquefaction of lignite and sawdust (CLLS) under syngas was performed in an autoclave and the effects of temperature, initial syngas pressure, reaction time and ratio of solvent to coal and biomass on the product distribution of CLLS were studied. Sawdust is easier to be liquefied than lignite and the addition of sawdust promotes the liquefaction of lignite. There is some positive synergetic effect during CLLS. In the range of the experimental conditions investigated, the oil yield of CLLS increases with the increase of temperature, reaction time (10–30 min) and the ratio of the solvent to the feedstock (0–3), but varies little with the increase of initial syngas pressure. Accordingly, the total conversion, the yield of preasphaltene and asphaltene (PA + A) and gas, changes by the difference in operation conditions of liquefaction. The gas products are mainly CO and CO 2 with a few C 1–C 4 components. The syngas can replace the pure hydrogen during CLLS. The optimized operation conditions in the present work for CLLS are as follows: syngas, temperature 360 °C, initial cold pressure 3.5 MPa, reaction time 30 min, the ratio of solvent to coal and sawdust 3:1. Water gas shift reaction occurs between CO in the syngas and H 2O from coal and sawdust moisture during the co-liquefaction, producing the active hydrogen which increases the conversion of liquefaction and decreases the hydrogen consumption.

Utilization of greenhouse gases through carbon dioxide reforming of methane over Ni–Co/MgO–ZrO2: Preparation, characterization and activity studies

MgO–ZrO2 mesoporous support (Zr/Mg molar ratio=9) impregnated with 6wt% Ni, 6wt% Co and 3wt% of both Ni and Co were prepared using a novel surfactant assisted-impregnation method. Carbon dioxide reforming of methane using these catalysts was studied in a quartz tube microreactor at a CH4/CO2 feed ratio of 1, 750°C, 1atm with a gas hourly space velocity of 125,000mL/g/h. Based on reactant's conversion and syngas production, the bimetallic catalyst was the most suitable catalyst for the reaction. The catalyst exhibited high and constant activity during 40h reaction time with methane and carbon dioxide conversions of 80% and 84%, respectively with a syngas ratio close to unity without significant deactivation as compared to the respective monometallic catalysts. For longer time on stream, the catalyst showed constant activity up to 60h after which it gradually decreased. The bimetallic catalyst also exhibited excellent regenerability by restoring its initial catalytic activity after 1h of regeneration in air. The catalysts were also characterized by XRD, XPS, N2-physisorption, H2-chemisorption, TGA-DTA, HRTEM, H2-TPR, TPH and SEM. The high performance of the bimetallic catalyst was due to the stabilization of t-phase in zirconia, better metal dispersion, small metal particle size and synergetic effect between Ni and Co particles. The XPS results showed that bimetallic catalyst had the ability to hinder metal oxidation and exhibited presence of higher surface basicity which were responsible to maintain the stability of the catalyst.

High temperature steam gasification of wastewater sludge

High temperature steam gasification is one of the most promising, viable, effective and efficient technology for clean conversion of wastes to energy with minimal or negligible environmental impact. Gasification can add value by transforming the waste to low or medium heating value fuel which can be used as a source of clean energy or co-fired with other fuels in current power systems. Wastewater sludge is a good source of sustainable fuel after fuel reforming with steam gasification. The use of steam is shown to provide value added characteristics to the sewage sludge with increased hydrogen content as well total energy. Results obtained on the syngas properties from sewage sludge are presented here at various steam to carbon ratios at a reactor temperature of 1173 K. Effect of steam to carbon ratio on syngas properties are evaluated with specific focus on the amounts of syngas yield, syngas composition, hydrogen yield, energy yield, and apparent thermal efficiency. The apparent thermal efficiency is similar to cold gas efficiency used in industry and was determined from the ratio of energy in syngas to energy in the solid sewage sludge feedstock. A laboratory scale semi-batch type gasifier was used to determine the evolutionary behavior of the syngas properties using calibrated experiments and diagnostic facilities. Results showed an optimum steam to carbon ratio of 5.62 for the range of conditions examined here for syngas yield, hydrogen yield, energy yield and energy ratio of syngas to sewage sludge fuel. The results show that steam gasification provided 25% increase in energy yield as compared to pyrolysis at the same temperature.

Thermodynamic study of combining chemical looping combustion and combined reforming of propane

Existing energy generation technologies emit CO 2 gas and are posing a serious problem of global warming and climate change. The thermodynamic feasibility of a new process scheme combining chemical looping combustion (CLC) and combined reforming (CR) of propane (LPG) is studied in this paper. The study of CLC of propane with CaSO 4 as oxygen carrier shows thermodynamic feasibility in temperature range (400–782.95 °C) at 1 bar pressure. The CO 2 generated in the CLC can be used for combined reforming of propane in an autothermal way within the temperature range (400–1000 °C) at 1 bar pressure to generate syngas of ratio 3.0 (above 600 °C) which is extremely desirable for petrochemical manufacture. The process scheme generates (a) huge thermal energy in CLC that can be used for various processes, (b) pure N 2 and syngas rich streams can be used for petrochemical manufacture and (c) takes care of the expensive CO 2 separation from flue gas stream and CO 2 sequestration. The thermoneutral temperature (TNP) of 702.12 °C yielding maximum syngas of 5.98 mol per mole propane fed, of syngas ratio 1.73 with negligible methane and carbon formation was identified as the best condition for the CR reactor operation. The process can be used for different fuels and oxygen carriers.

Thermodynamic analysis of dry autothermal reforming of glycerol

Dry autothermal reforming of glycerol uses a combination of dry (CO 2) reforming and partial oxidation reactions to produce syngas rich product stream. Thermodynamic equilibrium data for dry autothermal reforming of glycerol was generated for temperature range 600–1000 K, 1 bar pressure, OCGR [feed O 2/C (C of glycerol only) ratio] 0.1 to 0.5 and CGR [feed CO 2/glycerol ratio] 1 to 5 and analyzed. The objective of the paper is to identify the thermodynamic domain of the process operation, study the variation of product distribution pattern and describe the optimum conditions to maximize yield of the desired product and minimize the undesired product formation. Higher OCGR and higher CGR yielded a syngas ratio (∼ 1), with lower carbon and methane formation, while lower CGR and lower OCGR yielded good hydrogen and total hydrogen, with low water and CO 2 production. The best thermoneutral condition for DATR of glycerol operation was seen at a temperature of 926.31 K at 1 bar pressure, OCGR = 0.3 and CGR = 1 that gave 2.67 mol of hydrogen, 4.8 mol of total hydrogen with negligible methane and carbon formations.

Numerical simulation of syngas combustion with a multi-spark ignition system in a diesel engine adapted to work at the Otto cycle

This work focuses on the construction of a 2D dynamic model, taking into consideration the turbulent flux combustion reactions of syngas inside a combustion chamber and its displacement through the cylinder of a diesel engine model OM 447 LA converted to Otto cycle operation. The engine has a multi-spark ignition system. The geometry of both the chamber and cylinder is symmetric to a radius of 0.064 m and to a length of 0.17595 m. The simulation is carried out on only half of the system, with a premixed supply of the syngas and air. The supply temperature of the mixture is 336 K. The supply relation air/syngas ratio is 1.1:1, and the supply pressure of the mixture is 1 bar. The gaseous phase is modeled as a multi-component mixture comprised of carbon monoxide (CO), hydrogen (H 2), methane (CH 4), nitrogen (N 2), carbon dioxide (CO 2) and oxygen (O 2). The study describes a Computational Fluid Dynamic (CFD) numerical model, in which the conservation of matter, motion and energy equations are solved; in addition, sub-models are used to represent the turbulence intensity and the multiple reactions. The model predicts the profiles of syngas speed, temperature, chemical composition, pressure, and turbulence intensity for the gases when the working parameters and the supply characteristics are modified (air–syngas ratio, initial temperature of the mixture, initial pressure, compression ratio, and engine speed). The equation formulation is elliptic staggered. The result is a simple nonlinear map that resolves combustion time sequences using the commercial code CFD in PHOENICS.

E204 STUDY ABOUT HYDROGEN ADDITION ON GASOLINE SPARK IGNITION ENGINE : FLAMMABILITY OF MIXTURE CONTAINING SYNGAS AND GASOLINE IN SPARK IGNITION ENGINE(Diesel Engine)

Flammability of mixture containing syngas and gasoline in spark ignition engine is discussed as a part of feasibility study of new proposed gasoline engine system, which consists of two engines. In the engine system, the syngas is partial burnt gasoline, and the reactor is one of the spark ignition engines. The syngas is supplied to another engine. The ratio of syngas against mixture was about 34 %. Therefore it was thought that the syngas was burnt in another engine. Lower heating value of the mixture containing syngas, gasoline and air is quite low, comparing with same volume of stoichiometric mixture not containing syngas. The system was proposed to improve thermal efficiency of partial load condition. Experimental data shows the possibility that the system reduces throttle loss. In addition, process of gasoline gasification in spark ignition engine is also effective to improve thermal efficiency.

Performance Analysis of a New Biomass-Based Polygeneration System for Power and Methanol

A new kind of biomass-based polygeneration system for the production of power and methanol is proposed in this paper. The most attractive feature of this proposed system is the elimination of shift process and the adoption of the partial recycling of unreacted synthesis gas (syngas). In this study, the thermodynamic performance of the system is examined and is then compared to those of two biomass-based reference individual systems, including the individual biomass to methanol system with the shift process (B-MS) and the biomass integrated gasification combined cycle (BIGCC). The influence of the recycling ratio of unreacted syngas (Ru), which determines the exergy ratio of the chemical product to power (γ), is also investigated. This paper further discusses a synergetic viewpoint of chemical conversion and energy utilization, with and without shift reaction and different treatments of unreacted syngas. Results show that the new polygeneration system can reduce energy consumption by as much as 10% compared with the reference individual systems. Moreover, the proposed polygeneration system is expected to realize the synergetic combination of chemical conversion and efficient utilization of bio-energy; hence, offering a possibility of developing new technologies for biomass-based systems.