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Synthesis Gas Production with Gasification Technology from Municipal Solid Waste
Abstract
This study aims to develop, test performance, and evaluate the environmental pollution of garbage fuel with gasification technology. Heat conduction from municipal solid waste (MSW) burning from the gasification process was studied to dispose of solid waste and produce energy for communities. There were four types of solid waste in the total amount of 5 kg (including 0.5 kg of charcoal and firewood, 1.5 kg of paper, 2.0 kg of leaf litter, 0.5 kg of plastic, and 0.5 kg of others) with 2 tested ranges of average humidity: 10–20% and 50–55%. It was found that all waste could be converted for gas production with different gas amounts. From the experiment, dried MSW with 10–15% moisture content produced synthesis gas compositions (mole percent) that were H2, CO2, N2, O2, and CH4 at 1.9–2.4, 1.8–3.2, 56.5–60.2, 3.4–4.6, and 1.2–1.6, respectively. When fuel gas composition at the equivalent ratio between 0.2–0.34 was obtained from the MSW burning test with 10–15% average humidity, MSW burning in various equivalent ratios resulted in different amounts of synthesis gas. In addition, the optimal amounts of CH4 and the heating value of the gas were in the equivalent ratio of 0.28, and the highest production efficiency of synthetic gas (ηg) was 33.46%.
... The conversion of lignocellulosic materials through the conversion of thermochemical methods involves processes, such as pyrolysis, gasification, and combustion. These methods can be tailored to generate heat, electricity, or gaseous and liquid precursors, which can subsequently be upgraded to produce liquid fuels or serve as chemical feedstocks [28], [69]. Thermochemical pathways utilize processes like pyrolysis, gasification, hydrothermal carbonization, and other thermal-based methods. ...
... Presently, pyrolysis is primarily employed by utilizing the obtained oil and char as fuel in stationary ignition operations. However, the advancement of techniques to utilize pyrolysis oil as a transportation fuel is still in progress [69]. Pyrolysis is the thermal decomposition that occurs in an oxygenfree environment or inert atmosphere, as opposed to gasification, which takes place under a temperature range of 450 °C-600 °C [23]. ...
... It can serve as a viable option for vehicle fuel and as a source of electric and heat generation [93]. The raw materials for biogas production are typically derived from biomass, such as lignocellulose, and various types of organic waste, including animal dung and industrial wastewater sludge fermented in aerobic conditions [69]. Moreover, the digestion of oily-biological sludge for biogas production offers a method to mitigate its adverse environmental effects [94]. ...
The sugarcane industry is one of the agricultural sectors for the production of commodity products that can generate sugars along with byproducts such as straw, bagasse, and molasses. When subjected to effective processing, these byproducts of sugarcane cease to be categorized as waste, as they can be converted into resources rich in carbon for use in biorefineries. Numerous conversion technologies consisting of thermochemical, biochemical, and chemical processes of biorefinery are also applied to produce high-value products, either from 1st Generation (molasses feedstock) or through integrated 1 st Generation and 2 nd Generation configurations (molasses and sugarcane lignocellulose feedstock). This review focuses on recent progress in techniques for maximizing the value of sugarcane, encompassing aspects, such as sugarcane processing, pretreatment methods, and the fermentation of sugar derivatives to six value-added products, namely ethanol, xylitol, butanol, polyhydroxyalkanoates, biogas, and nanocellulose. Furthermore, this review encompasses an examination of the economic and environmental repercussions associated with sugarcane biorefinery. It also explores advancements using cutting-edge technology to address obstacles in industrial production.
Large amounts of solid waste have been generated due to the recent acceleration of urbanization and population growth, possessing considerable limitations to waste management systems and infrastructure. This book represents different types of solid wastes collected from domestic/households, agricultural/agro-industrial, and industrial sources. It illustrates the commonly used waste management methods, including physical, chemical, physicochemical, thermal, thermochemical, biological, and biochemical techniques. Information about solid waste management and sustainability is connected to the 17 United Nations’ Sustainable Development Goals (UN SDGs). The barriers, challenges, and opportunities associated with fulfilling the sustainability concept in waste management are defined. The book’s outputs support the involvement of stakeholders, policy-makers, and public and private sectors in maintaining sustainable solid waste management strategies.
Recently, huge quantities of solid wastes have been produced, owing to the industrialization, urbanization, and exponential population growth patterns. This book succeeded in representing various efficient methods of solid waste management that could sustain a safe and healthy living environment for present and future generations. The given biological-based methods (anaerobic digestion, composting, and vermicomposting) and thermal-related techniques (gasification, pyrolysis, and combustion) could fulfill the targets of the 17 United Nations’ Sustainable Development Goals (UN SDGs) due to pollution reduction, energy generation, and job creation. The book outputs assist citizens, businesses, and government institutions in overcoming the challenges accompanied by the implementation of sustainable solid waste management strategies, including lack of resources, funding, or infrastructure.
Deltas, comprising approximately 5% of the Earth's land surface, occupy a high population density globally. The distribution of population density depends on the geographical location and the countries or regions of Deltas under investigation. Each Delta is unique and influenced by specific hydrological, geological, and environmental conditions. Deltas face the pressing need for effective waste management strategies to mitigate environmental degradation and health risks. This chapter is an introduction to the critical nexus of solid waste management (SWM) and sustainability in Deltas, shedding light on the corresponding challenges and barriers. The chapter’s main findings would strengthen the contribution of stakeholders, policy-makers, and private and public sectors in achieving sustainable SWM strategies.
This paper presents the analysis of properties of bamboo node, as a potential fuel for gasifiers. Both Proximate and Ultimate Analysis are used. The physical properties of bamboo node contain 5.89% moisture, 70.48% volatile matter, 20.73% fixed carbon and 2.9% ash, while its chemical properties consist of H, C, N, O and S of 5.98, 44.76, 0.11, 46.21, and 0.04%, respectively. The higher and lower heating value of 17,417.09 kJ/kg and 16,161 kJ/kg are evaluated. The properties found indicate that the bamboo node has good potential for biomass fuel application. Besides the property analyses, the bamboo node, as a fuel for gasifiers, is tested in the proposed downdraft gasifier (swirl type), which was developed from the conventional downdraft gasifier. The proposed downdraft gasifier (swirl air type) has a cylindrical furnace, 1.35 m. in length. The combustion zone has two walls-the inner wall in a fireproof mortar and the outer layer consists of a steel sheet. It has a thermal capacity of 4.74 kW. The resulted producer gas from the proposed gasifier consists of CO, CH 4 , H 2 , CO 2 , N 2 and O 2 of 30.0837, 0.2933, 25.1701, 17.0366, 23.955, and 3.4613% by volume, respectively, with thermal efficiency of 70.44%, which is 2.99% higher than that of the conventional downdraft gasifier, because the combustion zone of this downdraft gasifier (swirl air type) is designed by using air inlet circular flow as a nozzle-like injection.
Up to 2.4 billion people (approximately 40% of the earth's population) still depend on biomass as their main source of energy and currently, there are a wide variety of stove technologies and designs aimed at providing better cooking experience to end-users. The study design was cross-sectional, and data was collected between November to March of 2019 in the Kasena Nankana Districts. The study conducted 20 in-field uncontrolled cooking tests designed to assess the fuel consumption performance of the Ace stove and the Jumbo stove. Specific Fuel Consumption (SFC), Per Capita Biomass Consumption (PcBC) and Fuel consumption rate were calculated across a variety of meal types using the two stoves. An independent T-test was employed to determine the mean differences. The results showed that the Jumbo stove averaged 1.43±0.23kg of fuel per a cooking event with a per capita annual consumption of 38.06-274.97kg while the Ace stove averaged 0.31±0.04kg per cooking event with a per capita consumption of 14.6-75.65kg. There was a statistically significant difference between the fuel consumption rate per kg of food prepared (p<0.001) between the Ace stove and the Jumbo stove (Figure 1).
This study provides the optimum equivalence ratio of biomass gasification process based on thermodynamic equilibrium model. There are two cases of chemical equilibrium in a gasification process. The first being with excess carbon present in the gasification process while the second one possess excess gasifying agent with all the carbon completely gasified. The simulation results clearly show that under the certain conditions, there must exist a case between these two cases where the carbon is completely gasified without any excess gasifying agent or carbon. This point has been determined from the cross over point between CO2 and CO. Moreover, the results show that at higher gasifying agent temperatures the trend of CO increases more sharply than that at lower gasifying agent temperatures and vice versa for CO2. The optimum equivalence ratio becomes less fuel rich with increase in gasification temperatures. At atmospheric pressures the optimum equivalence ratio was found to be 3.0 for gasification temperatures in the range of 600-900K, while it was 2.0 for gasification temperatures of 1000-1500K and 1.5 for gasification temperatures of 1600-2500K.
Ten different types of biomass served as fuel to generate electricity using a pilot-scale downdraft biomass gasification power plant. The gasifier temperature profile, along with the syngas quality and performance were determined for varying flow rates. It was found that temperature
profiles depended on syngas flow rate and type of biomass feedstock and can be divided into three groups. An increase in syngas flow rate from 105 to 211 m3 h–1 (across all biomass types) was found to have little effect on gas composition, causing calorific values
peaking between 4.2 and 5.6 MJ (Nm)–3. Maximum electrical power output of each tested biomass feedstocks was observed at the highest syngas flow rate, ranging from 47 to 63 kW with specific biomass consumption below 2.0 kg kW–1 h–1. Among
them, gasification efficiency exceeding 70% was achieved from Eucalyptus and corncob, and Giant Leucaena. Engine-generator set efficiency and electrical efficiency ranged from 11.0 to 25.8% and from 6.3 to 18.6%, respectively. Overall, biomasses varying widely in their properties showed
a strong potential for electricity generation using downdraft gasification technology.
Prominent among problems of developing nations are access to affordable and reliable energy as well as clean and livable environment. The abovementioned points coincide with the sustainable development goals 7 (SDG 7) and 11 (SDG 11) of the United Nations (UN), respectively. Adopting waste-to-energy system could leverage on the possibility of reducing the adverse environmental impact occasioned by waste generation and ensuring production of renewable and sustainable energy while achieving circular economy. A review of most commonly used technologies for solid waste management worldwide, such as incineration, pyrolysis, gasification, anaerobic digestion, and landfilling with gas recovery in order to achieve waste-to-energy nexus is presented. A brief discussion on the economic, environmental and social impact as well as the implementation levels, some challenges and possible solutions to the implementation of the mentioned technologies for both developed and developing countries are included. This paper also addresses waste-to-energy (WtE) as a contributor to achieving sustainable development. It is evident from this paper that the waste stream of developing countries contained 50-56% food and garden wastes making anaerobic digestion technology more appropriate for treatment. Incineration is widely adopted in developed countries with more than 1,700 incineration plants operational worldwide. This paper offers to add to the pool of literature while helping researchers and decision-makers to make an informed decision on the feasibility of WtE as a pathway for sustainable waste management and renewable energy generation.
The production of hydrogen-rich syngas from municipal solid waste (MSW) by pyrolysis/gasification is one of the most promising waste-to-energy pathways for realizing a circular bioeconomy. This mini-review provides an overview of current research and development efforts in the field, focusing on the development of syngas upgrades and novel gasification processes with the ultimate goal of making MSW gasification a sustainable and affordable route for the final disposal of MSW. A graphical assessment protocol is proposed to support comprehension of the main reactions that are involved in MSW gasification. MSW gasification studies will be reviewed and its prospects considered to provide a reference for future work.
Municipal solid waste (MSW) of Urmia University student dormitories was utilized to trigger a co-generation system. The combined heat and power system consisted of a gasifier, a micro gas turbine, an organic Rankine cycle, a heat exchanger, and a domestic heat recovery. The system performance was validated by comparing the results with experimental results available in the literature. Air, steam, and oxygen were considered as different gasification mediums. Hydrogen content in the case of the steam medium was higher at all gasification temperatures and low moisture contents. However, hydrogen content of the system based oxygen medium was higher at high moisture contents. The system performances from power generation and hot water flow rate viewpoints were assessed versus the MSW flow rate, gasification temperature, pressure ratio, and turbine inlet temperature. Taguchi approach was employed to optimize the generated power in air, steam, and oxygen medium cases. The optimum conditions were the same for all cases. The optimum powers were 281.1 kW, 279.4 kW, and 266.9 kW for the system based steam, air, and oxygen gasifying agents, respectively.
To realize highly efficient and environmentally friendly utilization of municipal solid waste (MSW) and iron ore, we proposed a novel method for combining MSW pyrolysis and iron ore reduction. The effects of two iron-based additives (iron ore and iron oxide) on the pyrolysis characteristics of MSW were first investigated by using TGA, and the kinetic results illustrated that the average activation energy of MSW pyrolysis was 180.32 kJ/mol. By adding iron ore and iron oxide, the activation energy decreased to 151.76 and 150.18 kJ/mol, respectively. Then, the product yield and product composition of MSW were analyzed by a fixed-bed reactor, GC-MS and GC. The fixed-bed reactor experiments of MSW pyrolysis indicated that the iron ore and iron oxide acted as catalysts to change the yield and composition of pyrolysis gas and tar, thereby promoting thermal cracking of MSW and showing a high conversion rate for MSW pyrolysis (55.81 and 55.05%). The GC-MS and GC analyses demonstrated that the two additives could significantly reduce the heteroatomic compounds of pyrolysis tar and increase H2, CO and CO2 production. Furthermore, the reduction of iron ore and the catalytic mechanism were analyzed by H2-TPR, XPS and BET. The H2-TPR results showed that compared with the peak of iron oxide, the characteristic peaks of iron ore shifted to a high temperature due to being suppressed by minerals in the iron ore. XPS suggested that the MSW volatiles led to an increase in the binding energy of Fe 2p3/2 and Fe 2p1/2 and a decrease in the binding energy of O 1s during the reduction of iron ore. BET analysis indicated that the high activity of the catalyst might be attributed to its high surface area.
The aim of the paper is to provide thermodynamic evaluations for the production of synthetic natural gas from biomasses in order to determine parameters such as purity and productivity obtained with different configurations process.
Analysis results showed that, fixed biomethane productivity, with a single stage of methanation, the use of a water gas shift reactor (WGS) prior to the methanation stage, may contribute to increase of purity in methane, although modest, increasing from 65% to 80 vol.% The final effect is the increase of the heating value of SNG from 23 to 26 MJ/Nm3.
Numerical results showed that with a single stage methanation for SNG production, in isothermal conditions, it is possible to obtain a productivity of about 0.30 Nm3biomethane/Nm3syngas with a purity of 80 vol.% but with different complications for the process, such as introduction of WGS stage and/or double CO2 adsorption stage.
Other evaluations are proposed in the paper in order to improve the performance of the process, such as the use of isothermal reactor although more difficult to manage compared to the pseudo adiabatic configuration plant.
Using isothermal configuration it is possible to have higher conversion levels with smaller dimensions plant and therefore it may be an alternative to conventional systems at the end to create demo as driving force for technological development.
The goal of biofuel production is to partially replace fossil fuels in energy generation and transport. For the evaluation of biofuel production processes different criteria are applied and usually they include costs, efficiency aspects and emissions. However, evaluation of the energy efficiency of biofuels production is difficult since no general standard method exists for that. This paper compares three different assessment methods of energy efficiency both qualitatively and quantitatively. The methods are: thermal efficiency, exergy analysis and primary energy analysis. The feasibility of the methods is tested on a Bio-SNG (synthetic natural gas) production process which was modelled in AspenPlus and MS Excel. The results show that the exergy analysis seems to be advantageous when it comes to detailed (sub-) process analysis whereas the primary energy analysis offers the advantage of showing how the system is influencing the global primary energy resources. The results obtained by the thermal efficiency analysis do not add any new information to the results obtained by exergy and primary energy analyses. Exergy and primary energy analyses should be the preferred means for process assessment. Especially a combination of the two methods could offer the chance to develop a more holistic energy efficiency indicator.
A mathematical model for the entire length of a downdraft gasifier was developed using thermochemical principles to derive energy and mass conversion equations. Analysis of heat transfer (conduction, convection and radiation) and chemical kinetic technique were applied to predict the temperature profile, feedstock consumption rate (FCR) and reaction equivalence ratio (RER). The model will be useful for designing gasifiers, estimating output gas composition and gas production rate (GPR). Implicit finite difference method solved the equations on the considered reactor length (50 cm) and diameter (20 cm). Conversion criteria for calculation of temperature and feedstock consumption rate were 1 × 10−6 °C and 1 × 10−6 kg/h, respectively. Experimental validation showed that model outputs fitted well with experimental data. Maximum deviation between model and experimental data of temperature, FCR and RER were 52 °C at combustion temperature 663 °C, 0.7 kg/h at the rate 8.1 kg/h and 0.03 at the RER 0.42, respectively. Experimental uncertainty of temperature, FCR and RER were 24.4 °C, 0.71 kg/h and 0.04, respectively, on confidence level of 95%.
Biomass downdraft reactors, coupled with reciprocating internal combustion engines (RICEs), are a viable technology for small scale heat and power generation. This paper contains information gathered from a review of published papers on the effects of the particle size and the moisture content of biomass feedstock and the air/fuel equivalence ratio used in the gasification process with regard to the quality of the producer gas. Additionally, data on the parameters of producer gas, such as its energy density, flame speed, knock tendency, auto-ignition delay period and the typical spark ignition timing, are systematised. Finally, information on the typical performance of various diesel and spark ignition RICEs fuelled with producer gas is presented.
The paper proposes a critical assessment of municipal solid waste gasification today, starting from basic aspects of the process (process types and steps, operating and performance parameters) and arriving to a comparative analysis of the reactors (fixed bed, fluidized bed, entrained bed, vertical shaft, moving grate furnace, rotary kiln, plasma reactor) as well as of the possible plant configurations (heat gasifier and power gasifier) and the environmental performances of the main commercially available gasifiers for municipal solid wastes. The analysis indicates that gasification is a technically viable option for the solid waste conversion, including residual waste from separate collection of municipal solid waste. It is able to meet existing emission limits and can have a remarkable effect on reduction of landfill disposal option.
The characteristics of biomass air-steam gasification in a fluidized bed are studied in this paper. A series of experiments have been performed to investigate the effects of reactor temperature, steam to biomass ratio (S/B), equivalence ratio (ER) and biomass particle size on gas composition, gas yield, steam decomposition, low heating value (LHV) and carbon conversion efficiency. Over the ranges of the experimental conditions used, the fuel gas yield varied between 1.43 and 2.57 Nm3/kg biomass and the LHV of the fuel gas was between 6741 and 9143 kJ/Nm3. The results showed that higher temperature contributed to more hydrogen production, but too high a temperature lowered gas heating value. The LHV of fuel gas decreased with ER. Compared with biomass air gasification, the introduction of steam improved gas quality. However, excessive steam would lower gasification temperature and so degrade fuel gas quality. It was also shown that a smaller particle was more favorable for higher gas LHV and yield.