Solid Biomass Research Articles

The controversial role of energy crops in the future German energy system: The trade offs of a phase-out and allocation priorities of the remaining biomass residues

Multiple global crises are adding new elements to the discussion on securing and shaping a resilient, renewable energy system in Germany. Biomass from residues, forest wood and energy crops are major renewable energy contributors in Germany today. The role of energy crops within that system is controversially discussed for a long time and a phase-out from cultivated biomass is again in the focus. But what kind of trade-offs would be connected with such a phase-out and what would be the optimal allocation priorities of the remaining biomass potential? Through a detailed representation of biomass potentials, prices and conversion technologies in an energy system optimisation model, it could be shown in a scenario analysis that a phase-out increases the demand for energy imports by 1400 PJ per year, which is associated with on-costs of €14–25 billion annually in the long term. Finally, the results show that the decision on whether to grow energy crops in the future is directly influencing the future transformation strategy for high-temperature industrial heat applications. Solid biomass is identified as the future cost-optimal solution to fully transform this sector. However, a phase-out of energy crops changes the cost-optimal allocation priorities completely.

Quantitative analysis of biopolymers in lignocellulosic biomass feedstocks via laser-assisted micro-pyrolysis flowing atmospheric-pressure afterglow high-resolution ambient mass spectrometry

Herein, a diode laser-assisted micro-pyrolysis (LAMP) technique coupled with FAPA high resolution mass spectrometry (HRMS) is demonstrated for fast chemical characterization of lignocellulosic biomass feedstocks. The solid lignocellulosic biomass can be analyzed directly with minimal sample preparation. The mass spectra of the pyrolysis products are interpreted with the aid of data visualization tools such as Kendrick mass defect (KMD) plots and van Krevelen plots. Furthermore, quantitation of lignin/cellulose/hemicellulose, sugar contents of glucan/xylan/galactan/arabinan and lignin monomeric unit S/G is achieved with good accuracy and precision, through multivariate analysis methods, including partial least squares regression (PLSR) and support vector regression (SVR).

Development of sulfated polysaccharide‐based film reinforced with seaweed biomass‐derived nanofillers

AbstractCling films and single‐use plastics are difficult to recycle and cause major environmental pollution, leading to an increase in microplastics in nature. To overcome this issue, biodegradable films are being explored more extensively. Seaweed is gaining prominence in the food packaging sector since it is beneficial in all aspects. Two fractions of Indian brown seaweed Sargassum wightii, biopolymer (sulfated polysaccharide [SP]) as base material and nanofillers (cellulose nanocrystals [CNC]) as reinforced filler are employed to develop a sustainable cling film for food packaging. This cellulose filler can be isolated from solid seaweed biomass after the polysaccharide extraction and converted into nanoform using the response surfaces method (RSM) to maximize the yield of CNC. The objective of this research is to construct seaweed‐based biodegradable nanocomposite films and to examine their improved properties. It exhibited a gradual decrease in water absorption and water vapor permeability (WVP), along with better wettability, mechanical, and antioxidant properties, and thermal analysis compared with the control SP film. The degradation rates of the films were analyzed using the soil‐burial method. According to the results obtained, it is suggested that CNC can be utilized as a functional filler to improve the qualities of seaweed‐based cling films.

Kitchen fine particulate matter (PM2.5) concentrations from biomass fuel use in rural households of Northwest Ethiopia.

Combustion of solid biomass fuels using traditional stoves which is the daily routine for 3 billion people emits various air pollutants including fine particulate matter which is one of the widely recognized risk factors for various cardiorespiratory and other health problems. But, there is only limited evidences of kitchen PM2.5 concentrations in rural Ethiopia. This study is aimed to estimate the 24-h average kitchen area concentrations of PM2.5 and to identify associated factors in rural households of northwest Ethiopia. The average kitchen area PM2.5 concentrations were measured using a low-cost light-scattering Particle and Temperature Sensor Plus (PATS+) for a 24-h sampling period. Data from the PATS+ was downloaded in electronic form for further analysis. Other characteristics were collected using face-to-face interviews. Independent sample t-test and one-way analysis of variance were used to test differences in PM2.5 concentrations between and among various characteristics, respectively. Mixed fuels were the most common cooking biomass fuel. The 24-h average kitchen PM2.5 concentrations was estimated to be 405 μg/m3, ranging from 52 to 965 μg/m3. The average concentrations were 639 vs. 336 μg/m3 (p < 0.001) in the thatched and corrugated iron sheet roof kitchens, respectively. The average concentration was also higher among mixed fuel users at 493 vs. 347 μg/m3 (p = 0.042) compared with firewood users and 493 vs. 233 μg/m3 (p = 0.007) as compared with crop residue fuel users. Statistically significant differences were also observed across starter fuel types 613 vs. 343 μg/m3 (p = 0.016) for kerosene vs. dried leaves and Injera baking events 523 vs. 343 μg/m3 (p < 0.001) for baked vs. not baked events. The average kitchen PM2.5 concentrations in the study area exceeded the world health organization indoor air quality guideline value of 15 μg/m3 which can put pregnant women at greater risk and contribute to poor pregnancy outcomes. Thatched roof kitchen, mixed cooking fuel, kerosene fire starter, and Injera baking events were positively associated with high-level average kitchen PM2.5. concentration. Simple cost-effective interventions like the use of chimney-fitted improved stoves and sensitizing women about factors that aggravate kitchen PM2.5 concentrations could reduce kitchen PM 2.5 levels in the future.

Thermogravimetric and thermovolumetric study of municipal solid waste (MSW) and wood biomass for hydrogen-rich gas production: a case study of Tashkent region.

Application of municipal solid and wood waste, as dominant sources of biomass, could be a promising alternative for producing energy from renewables via thermochemical gasification technology. In this paper, a study of thermogravimetric analysis (TGA) and excurrent gas composition produced by the municipal solid waste (MSW) and wood biomass gasification is presented. Thermogravimetric and heat flow curves for waste samples were performed at the temperature interval of 20-890 °C with a heating rate of 10 °C min-1 under a nitrogen atmosphere. According to thermal analysis data, differential scanning calorimetry (DSC) curves, the degradation stages of waste samples was determined, which correspond to the mono- or bimodal evolution of volatile compounds and the degradation of the resulting carbon residue. The gasification experiments were conducted in a high-pressure quartz reactor at temperatures of 850, 900, and 950 °C, using steam (0.3 g/min) and argon (2 dm3/min) as the gasifying agents. To ascertain the syngas composition, gas chromatography was employed in conjunction with a thermal conductivity detector. Both types of biomass showed remarkably similar syngas compositions. The highest concentration of hydrogen-rich gases was recorded at 950 °C for wood biomass, with 42.9 vol% and 25.2 vol% for hydrogen (H2) and carbon monoxide (CO), and for MSW, with an average 44.2 vol% and 18 vol% for H2 and CO. Higher temperatures improved the syngas composition by promoting endothermic gasification reactions, increasing hydrogen yield while decreasing tar and solid yields. This research helped to comprehend the evolution of the gasification process and the relationship between increased H2 and CO production as the gasification temperature increased.

Regulation Mechanism of Solid Waste on Ash Fusion Characteristics of Sorghum Straw under O2/CO2 Atmosphere

Co-combustion of solid waste and biomass can alleviate biomass ash-related problems. To investigate the effects of solid waste on the ash fusion characteristics of biomass and its variation mechanisms under an oxidation atmosphere, an X-ray diffraction, thermogravimetric analyzer (TG), scanning electron microscope (SEM), and FactSage calculation were used to examine the ash fusion behaviors of sorghum straw (SS) with the addition of textile dyeing sludge (TDS) or chicken manure (CM). The ash fusion temperature (AFT) of SS increased gradually with the TDS ash addition; with CM ash addition, the AFT of SS mixtures increased rapidly (0–20%), decreased slightly (20–30%), and finally increased slowly (30–60%). The generations of high melting point (MP) minerals (e.g., KAlSi2O6, Fe2O3, and Fe3O4) led to an increase in the AFT of TDS-SS mixtures. The K+ in silicate was gradually replaced by Mg2+ or Ca2+, which caused the generations of high-MP minerals (e.g., Ca3MgSi2O8, Ca2MgSi2O7, and CaMgSiO4). The TG analysis showed that the additions of TDS or CM ash slowed down the weight loss of SS mixed ash due to the formation of high-MP minerals. The SEM and FactSage calculations were also explained with the AFT change and their variation mechanisms. The result provided effective references for the AFT regulation during the co-combustion of biomass and solid waste.

On the Feasibility of Building Mini-Thermal Power Plant Using Local Fuels in the Conditions of the Republic of Belarus. Part 1. State of Use of Local Fuels in Heat Supply Systems

As part of ensuring the country's energy security and pursuing a policy of decarbonization of the economy in the Republic of Belarus, the maximum use of its own fuel and energy resources (FER) is expected. However, the question of choosing the type of heat source in centralized heat supply systems when using local fuels (LF) remains open. The commissioning of the Belarusian Nuclear Power Plant and the relatively high specific cost of electricity generating capacities using local fuels tip the scales to the use of boiler houses as heat sources. However, world experience in the development and application of heating, as the most energy-efficient solution in the field of heat supply, requires a more thorough study of this problem. The paper presents an overview of the use of local fuels in Belarus and a number of European countries with developed centralized heat supply. Based on the analysis of open source data, the paper provides information on the state of use of local fuels in district heating systems of the Republic of Belarus and a number of European countries that have experience in the widespread use of solid biomass and where it constitutes a significant share in the structure of thermal and electrical energy production in relation to other fuel and energy resources. The main aspects of the energy programs of a number of European countries with the largest share of thermal and electrical energy generation using local fuels are presented. It has been revealed that the energy program of Finland is of the greatest interest for Belarus, where the share of nuclear energy in the structure of electrical energy production, just like in the Republic of Belarus, is approaching to 40 % and the energy strategy assumes an increase in the share of thermal power plants using local fuels in the structure of heat and electricity generation.

Investigation and Optimization of Co-Combustion Efficiency of Food Waste Biochar and Coal

Among the alternative recycling methods for food waste, its utilization as a renewable biomass resource has demonstrated great potential. This study presents empirical findings pertaining to the cofiring of solid biomass fuel and coal for power generation. Various co-combustion ratios involving food waste biochar (FWB) and coal (100:0, 85:15, 90:10, 95:5, and 0:100) were tested to optimize combustion efficiency, monitor the emissions of NOX, CO, and unburned carbon (UBC), assess ash deposition tendencies, and evaluate grindability. Two types of FWB and sewage sludge were selected as biomass fuels. The results demonstrated that co-combustion involving FWB reduced NOX and UBC emissions compared to coal combustion alone. In particular, the 10% FWB_A blend exhibited the best combustion efficiency. Notably, FWB demonstrated lower tendencies for ash deposition. The ash fusion characteristics were monitored via thermomechanical analysis (TMA), and the corresponding shrinkage levels were measured. Furthermore, FWB exhibited superior grindability compared to both coal and sewage sludge, reducing power consumption during fuel preparation. This study suggests that FWB is a valuable co-combustion resource in coal-fired power plants, thereby facilitating the efficient recycling of food waste while concurrently advancing clean energy generation. Nevertheless, further research is required to validate its practical applicability and promote its use as a renewable resource.

Temperature resolved release of inorganic compounds from biomass

The release of inorganic compounds during the thermal conversion of solid biomass can cause severe operational problems in thermal power plants. To effectively reduce fine particle emissions and depositions, it is important to understand the release of problematic elements into the gas phase.This study presents a temperature-resolved analysis of the release of potassium, sodium, chlorine, sulfur, phosphorus, calcium, and magnesium from ten biomass samples. Conventional woody biofuels, alternative woody biofuels, and stalk-like biomass are analyzed in an electrothermal vaporization unit (ETV) which is connected directly to an inductively coupled plasma optical emission spectrometer (ICP-OES). The suppression of secondary gas-phase reactions in the given setup enables the isolated observation of each individual species’ release pattern. The results from this experimental setup are compared to a range of release patterns found in the literature, with a particular focus on potassium. For the high heating rates applied in this setup, the potassium release starts at around 700 °C, with the majority being release between 1000 °C and 1400 °C. Since hardly any potassium is released together with chlorine and sulfur, the majority of it is released as KOH or elemental potassium. Overall, this work presents reproducible temperature-resolved release patterns of inorganic elements from various biogenic feedstocks in an inert atmosphere.

Corn biochar influences yield attributes of two varieties of chili (Capsicum annuum) in the coastal region

A solid biomass pyrolysis byproduct is biochar. The most important uses of this carbon-rich, porous substance are soil enhancement, remediation, and pollution management. Biochar improves soil fertility, water retention, and fertilizer efficiency. Biochar stores plant nutrients, reduces salinity and drought, and neutralizes soil acidity. This component is environmentally favorable. It reduces chemical fertilizer and irrigation as well as lowers farmer costs. Green chili benefits greatly from organic fertilizer. Biochar must pay more attention to this economically valued crop despite its importance. Under a randomized complete block design (RCBD) with 3 replications, a field experiment determined the best dose to boost chili plant yield. Thus, to determine how two green chili varieties—Bangladeshi local hybrid 'Anal 1701 DG F1' (V1) and Indian hybrid 'Bijlee Plus F1' (V2)—react to different corn biochar doses. The treatments included T1 (Control), T2 (0.1kg/m2), T3 (0.3kg/m2), T4 (0.5kg/m2), and T5 (0.7kg/m2). Using biochar significantly (*p&lt;0.05) increased yield characteristics. Bijlee plus F1 had the highest yield and yield-related parameters above Anal 1701 DG F1. The combination of treatments and varieties yielded the maximum (2.40 ton/ha) in T5V2, while the lowest (0.3134 ton/ha) was in T1V1. Most yield-related characteristics (fruit number per plant, single fruit weight, mature chili length, diameter, and total yield) were achieved from T5 treatment and T5V2 interaction. Corn biochar performed well on green chili varieties and yield-related parameters. The investigation proposed using Bijlee plus F1 variety and 0.7kg/m2 corn biochar (T5) dose to maximize chili production. This is an excellent recommendation for the farmers of coastal areas.

Lung Function Impairment Among Women Cooking with Biomass Fuels Compared to LPG Fuel in Rural Tamil Nadu

Background: Women in developing countries are exposed to household air pollution from traditional cook a stove, which causes a huge burden of morbidity. This study aims to examine the impact of cooking fuel use on lung function changes among women in rural Tamil Nadu, India. Methods: Between 2012 and 2014, 565 adult women (237 using solid biomass fuel and 328 using clean fuel for cooking) participated in this cross-sectional study. Basic demographic and socioeconomic characteristics and exposure related information such as fuel type, kitchen type, type of house, and other potential sources of particulates inside the house, such as cigarettes; incense, and mosquito coils, were collected using questionnaires. A pulmonary function test assessment was done for all participants using a KOKO spirometer following the standard protocols. Results: Pulmonary function was significantly (p &lt; 0.05) lower in rural women using biomass fuel for cooking. Women in the biomass group had FVC 2.45 (0.58), FEV1 1.99 (0.49), and PEFR 5.31 (1.54), while women in the LPG group had FVC 2.63 (0.48), FEV1 2.19 (0.42), and PEFR 5.81 (1.38). Conclusion: This cross-sectional study found that the reduction in the pulmonary function parameters was considerably higher among women using biomass for cooking compared to women using liquefied petroleum gas for cooking in rural Tamil Nadu. Objective measurements by spirometry from this study can help physicians and health policy makers develop measures for better prevention and management of respiratory diseases among rural women in Tamil Nadu, southern India.

Pairing combustion experiments and thermogravimetric analysis to uncover timescales controlling cellulose ignition and burnout in a Hencken burner

Solid biomass fuels are potential components of several industrial and power-generation decarbonization pathways. Despite considerable literature that documents the fuel properties of lignocellulosic biomass, the fundamental combustion characteristics of biomass constituents are not well understood. We tackle this knowledge gap by analyzing the combustion properties of cellulose (a key biomass component) in a Hencken burner across various temperature and oxygen mole fractions of the oxidizer gases. Combustion data are compared with results from thermogravimetric analysis (TGA) and scaling analyses to reveal two rate-controlling timescales in the ignition of cellulose: devolatilization time and volatile ignition delay time. TGA shows that the devolatilization time is only a function of temperature and occurs on a considerably shorter timescale than oxidation. Hencken burner experiments show that ignition delay time is highly sensitive to temperature; at very low levels of oxygen in the oxidizer gas (mole fractions of 0.01–0.04), the ignition delay time is sensitive to oxygen mole fraction, but this sensitivity disappears at higher oxygen levels. Burnout time is the least sensitive parameter investigated. The combination of experiments and chemical kinetic simulations begins to explain the ignition behavior of the volatiles from cellulose decomposition and lays groundwork for future research to address uncertainties in quantifying the kinetics of cellulose ignition. Finally, this combined combustion-fuel science study raises serious doubts about the use of combustion indices and TGA-calculated properties to predict the true combustion behavior of biomass.

A Review of Biomass Thermal Analysis, Kinetics and Product Distribution for Combustion Modeling: From the Micro to Macro Perspective

Driven by its accessibility, extensive availability, and growing environmental consciousness, solid biomass has emerged as a viable alternative to enhance the diversity of renewable energy sources for electricity generation. To understand the phenomena involved in solid biomass conversion, it is necessary not only to understand the stages of the biomass combustion process but also to understand specifically the kinetics of the reaction and the release of the volatiles. The present work presents an overview of the existing literature on several topics related to the biomass combustion process, its characterization, as well as strategies to develop simple and effective models to describe biomass conversion with a view to the future development of numerical simulation models. Since the focus of most of the investigations is the development of a numerical model, a summary and identification of the different model assumptions and problems involved in thermal analysis experiments are presented. This literature review establishes the significance and credibility of the research, providing the main concepts and assumptions with a critique on their validity. Hence, this work provides specific contributions from a multi-scale perspective which can further be extended to provide insights into the design and optimization of biomass combustion technologies, such as boilers and furnaces.

Coproduction of Phase-Separated Carotenoids and β-Farnesene as a Yeast Biomass Valorization Strategy.

Valorization, the process whereby waste materials are converted into more valuable products, is rarely practiced in industrial fermentation. We developed a model valorization system whereby Saccharomyces cerevisiae that had previously been engineered to produce high concentrations (>100 g/L) of extracellular β-farnesene was further engineered to simultaneously produce intracellular carotenoids, both products being isoprenoids. Thus, a single fermentation generates two valuable products, namely, β-farnesene in the liquid phase and carotenoids in the solid biomass phase. Initial attempts to produce high levels of canthaxanthin (a ketocarotenoid used extensively in animal feed) in a β-farnesene production strain negatively impacted both biomass growth and β-farnesene production. A refined approach used a promoter titration strategy to reduce β-carotene production to a level that had minimal impact on growth and β-farnesene production in fed-batch fermentations and then engineered the resulting strain to produce canthaxanthin. Further optimization of canthaxanthin coproduction used a bioprospecting approach to identify ketolase enzymes that maximized conversion of β-carotene to canthaxanthin. Finally, we demonstrated that β-carotene is not present in the extracellular β-farnesene at a significant concentration and that which is present can be removed by a simple distillation, indicating that β-farnesene (the primary fermentation product) purity is unaffected by coproduction of carotenoids.

Exploring hostel kitchen waste as feedstock for bioethanol and biogas production in a biorefinery setup

Waste to wealth is today’s need, as waste generation has become humongous challenge for mankind now. In the present study kitchen waste from the Institute, hostel mess is used as raw material for ethanol, biogas, and manure production in a bio-refinery system. In the first step of the biorefinery the kitchen waste, which contains approximately 35% carbohydrates, was pretreated with 0.5 % H2SO4 to release sugars required for fermentation and 3.6 mg/ml of reducing sugars, and 0.46 mg/ml of pentose sugar. Enzymatic hydrolysis of the un-hydrolyzed biomass remnant after acid pretreatment at 30 °C with crude amylase (enzyme activity: 45.36 U/min/ml) obtained from Aspergillus niger followed by hydrolysis at 55 °C with crude cellulase (enzyme activity: 36.25 U/min/ml) and xylanase activity (activity: 11.25 U/min/ml) obtained from Trichoderma reesei produced 1.64 mg/ml and 1.66 mg/ml hexose and pentose sugar, respectively. Fermentation of the hydrolysate with S. cerevisiae and Pistia stipitis produced a 2.43% (v/v) ethanol yield. Anaerobic digestion of the unutilized solid biomass produced 270 ml/Kg biogas and 63.35 gm/Kg dry soil nutrient enhancer. The study suggested that the kitchen waste-based economically viable bio-refinery setup can be developed for the eco-friendly management and production of various valuable products from kitchen waste.

Interlaboratory study: Testing reproducibility of solid biofuels component identification using reflected light microscopy

Considering global market trends and concerns about climate change and sustainability, increased biomass use for energy is expected to continue. As more diverse materials are being utilized to manufacture solid biomass fuels, it is critical to implement quality assessment methods to analyze these fuels thoroughly. One such method is reflected light microscopy (RLM), which has the potential to complement and enhance current standard testing, leading to improving fuel quality assessment and, ultimately, preventing avoidable air pollution.An interlaboratory study (ILS) was conducted to test the reproducibility of biomass fuels component identification using a reflected light microscopy technique. The exercise was conducted on thirty photomicrographs showing biomass and various undesired components (like plastics or mineral matter), which were purposely added (by the ILS organizers) to contaminate wood pellets and charcoal-based grilling fuels.Forty-six participants had various levels of difficulty identifying the marked components, and as a result, the percentage of correct answers ranged from 52.2 to 94.4%. Among the most difficult components to distinguish were petroleum products and inorganic matter. Various reasons led to the misidentification, including insufficient morphological descriptions of the components provided to participants, ambiguities of the nomenclature, limitations of the analytical and exercise method, and insufficient experience of the participants.Overall, the results indicate that RLM has the potential to enhance the quality assessment of biomass fuels. However, they also demonstrate that the petrographic classification used in this exercise requires further refinement before it can be standardized. While a new simplified classification of solid biomass fuels components was created as an outcome of this study, future research is necessary to refine the nomenclature, develop a microscopic morphological description of the components, and verify the accuracy of component identification with a follow-up ILS.

Conversion of solid wastes and natural biomass for deciphering the valorization of biochar in pollution abatement: A review on the thermo-chemical processes

This overview addresses the formation of solid trash and the various forms of waste from a variety of industries, which environmentalists have embraced. The paper investigates the negative effects on the environment caused by unsustainable management of municipal solid trash as well as the opportunities presented by the formal system. This examination looks at the origins of solid waste as well as the typical treatment methods. Pyrolysis methods, feedstock pyrolysis, and lignocellulosic biomass pyrolysis were highlighted. Explain in detail the various thermochemical processes that take place during the pyrolysis of biomass. Due to its carbon content, low cost, accessibility, ubiquitousness, renewable nature, and environmental friendliness, biomass waste is a unique biochar precursor. This study looks at the different types of biomass waste that are available for treating wastewater. This study discussed a wide variety of reactors. Adsorption is the standard method that is used the most frequently to remove hazardous organic, dye, and inorganic pollutants from wastewater. These pollutants cause damage to the environment and water supplies, thus it is important to remove them. Adsorption is both simple and inexpensive to utilize. Temperature-dependent conversions explain the kinetic theories of biomaterial biochemical degradation. This article presents a review that explains how pyrolytic breakdown char materials can be used to reduce pollution and improve environmental management.

Simulations of biomass compression-screw feeding using a compressible non-Newtonian constitutive model

There is global interest in the conversion of biomass into sustainable low-carbon-footprint fuels and chemicals as an alternative to non-renewable fossil feedstocks. Feeding biomass solids into pressurized reactors is one of the key steps in biomass conversion. Predicting mechanical failure and energy requirements for this step helps avoid upstream processing bottlenecks and enables efficient operation of a biorefinery. In this work, we developed a predictive computational model for biomass screw feeders that capture the highly viscous, non-Newtonian and compressible behavior of biomass slurries. Biomass compressible behavior is formulated by an equation of state and the non-Newtonian rheology is represented by a density-dependent viscosity model. Experimental data from two compression screw-feeder systems are presented as a validation for our model. Our model successfully predicted the location of the compressed biomass “plug”, biomass flow rate, and the required torque at different operating conditions for the experimental conditions studied in this work.

Air quality—climate forcing double whammy from domestic firelighters

Renewable biomass plays a crucial role in transitioning toward climate-friendly heating sources; however, not without its collateral damage in terms of the disproportionately high effects on local air quality. The associated proliferation of residential heating appliances around the world, including developed regions like Europe, where an estimated 70 million are housed, does not appear to be abating. Here, we identify super self-concentrating ambient pollution events whereby solid-fuel residential heating haze is infused with a hitherto unaccounted for firelighter smoke that contributes additional adsorbing black carbon. This black carbon-organic aerosol combination results in a strong positive radiative forcing (up to 149 W m−2) and alters the boundary layer thermodynamics sufficiently so as to further suppress pollutant dilution and dispersion leading to extraordinary high submicron particulate matter (PM1: 166 µg m−3). Unfortunately, there is no silver lining in this cloud until the promotion of solid biomass fires with firelighters for ignition is replaced by a co-benefit policy.

Sustainable H2 production/separation by integration of solid oxide electrolyzer, biomass gasifier and H2 separation membrane: A techno-economic/environmental evaluation and multi-objective optimization

Hydrogen as a clean fuel can simultaneously respond to the challenges of energy shortage and environmental issues, provided that it is produced in a clean and cheap way. In this research, a hydrogen production system based on the combination of a solid oxide electrolyzer with a gasifier and a hydrogen separation membrane has been studied from a techno-economic outlook. In order to achieve a proper approximation of the levelized cost of hydrogen (LCOH), an elaborated economic analysis has been performed considering all aspects, where the life of the hydrogen separation membrane (HSM) and the solid oxide electrolyzer (SOE) has been taken into account. Finally, the minimization of the levelized cost of hydrogen and the levelized carbon dioxide emission (LCE) was carried out through multi-objective optimization. The cost of selling hydrogen was determined according to the various payback times. According to the conducted optimization, it is possible to obtain the minimum levelized cost of hydrogen of 3.63 $/kg. This condition leads to the levelized emission of 10.17 kg CO2/kg H2. Also, the system has the ability to bear levelized CO2 emissions up to 2.92 kg CO2/kg H2, so that the levelized cost of H2 production is 6.45 $/kg. In the four optimal conditions obtained from the optimization, considering the payback time of 5 years, the cost of selling the produced H2 can be 3.64 $/kg, 6.45 $/kg, 5.98 $/kg, and 5.29 $/kg.