Feedstock For Synthesis Of Chemicals Research Articles

Plasma Gasification Trasforming Waste Into Energy

Plasma gasification is a cutting-edge technology that transforms various types of waste into clean energy sources. This process involves subjecting waste materials to extremely high temperatures in a controlled environment, breaking them down into their elemental components, and converting them into synthetic gas (syngas) or plasma. The syngas produced can be used as a fuel for electricity generation or as a feedstock for chemical synthesis, while the plasma can be utilized for various industrial applications. This paper explores the principles of plasma gasification, its environmental benefits, technological advancements, and potential challenges.

(Invited) Design of Ceramic Fuel Electrode for Solid Oxide Cells for Direct Oxidation of Hydrocarbon Fuels and for Direct CO2 Electrolysis

Large scale consumption of fossil fuels has led to the rapid increase in the atmospheric CO2 concentration, resulting in very adverse environmental concerns and frequent natural disasters. There is a grand challenge to improve conversion efficiency of fossil fuels and mitigate CO2 emmissions for terrestial applications. To enable long-term manned space exploration, there are critical needs in recycling CO2 to oxygen for life support and in situ generation of propellants using CO2 feedstock for ascent vehicles. Solid oxide cells (SOCs) have a great promise for energy conversion and storage for both terrestrial applications and space explorations. In the fuel cell mode, SOCs can convert chemical energy to electrical energy with high efficiency and fuel flexibility. In the electrolysis mode, SOCs can efficiently utilize CO2 as feedstock for chemical synthesis. The conventional Ni-based fuel electrode is vulnerable to deactivation by carbon build-up (coking) from direct oxidation of hydrocarbon fuels or for direct electrolysis of CO2, and suffers volume instability on redox cycling. This talk will report novel heterogeneous functional materials as SOC fuel electrodes that possess a combined property of good coking resistance and redox cyclability, enabling SOCs to be operated on hydrocarbon fuels for electricity generation in the fuel cell mode and for direct CO2 electrolysis for fuel synthesis in the electrolysis mode.The general philosophy to design novel SOC fuel electrodes is to develop ceramic materials that are redox-stable, possess mixed ionic and electronic mixed conductivity, and have catalytic activities for fuel oxidation and CO2 splitting reaction. Different types of ceramic fuel electrode materials have been explored and characterized as SOC fuel electrodes. The phase formation, redox-stability, electrical conductivity, electrochemical performance, and tolerance to coking and redox-cycling have been systematically evaluated. By judicious design of ceramic-based heterogeneous functional materials, high performance redox-flexible ceramic fuel electrodes can be achieved for direct oxidation of hydrocarbon fuels and for direct CO2 electrolysis. Acknowledgements Financial support from the U.S. Department of Energy (DE-EE0009427), National Science Foundation (DMR–1832809) and NASA EPSCoR (Grant # 80NSSC20M0233) is greatly appreciated.

Hydrogen production from biomass through integration of anaerobic digestion and biogas dry reforming

Hydrogen is a clean fuel for heat and power generation and can serve as a feedstock for chemical synthesis. This study assesses the hydrogen production from biomass (e.g., cow manure) through integrating psychrophilic anaerobic digestion and dry methane reforming. For the first time, a rigorous model is developed for the low-temperature anaerobic digestion process by implementing the complex kinetics of the fermentation bioreactions. The produced biogas from the anaerobic digestion process is fed to the reforming process for hydrogen production. The kinetics of the dry methane reforming and water gas shift reactions over Co-Ni-Al2O3 catalyst are incorporated into the model. Validating the results of the proposed process using experimental data shows <5% relative deviation. The effects of total solids content, organic loading rate, hydraulic retention time, and digestate recirculation fraction on biogas and CH4 yield are investigated. The optimum values of operating parameters in the anaerobic digestion process as well as the dry methane reforming process are obtained. The process is designed to achieve the highest CH4-to-H2 conversion and the lowest energy consumption. A 48.07 kg/h biogas could produce 8.11 kg/h H2. The biomass-to-H2 process offers an energetic efficiency of 72.85%, revealing its superiority to similar processes, such as steam and auto-thermal reforming. The proposed process highlights a high potential for CO2 emission reduction (e.g., 398,736 t/y), compared to the direct biogas combustion for electricity production. Economic analysis shows that the cost of biogas-to-H2 production is 1.39 USD/kg H2 for a plant capacity of 45.5 kg/h H2.

Synthesizing High-Volume Chemicals from CO2 without Direct H2 Input.

Decarbonizing the chemical industry will eventually entail using CO2 as a feedstock for chemical synthesis. However, many chemical syntheses involve CO2 reduction using inputs such as renewable hydrogen. In this review, chemical processes are discussed that use CO2 as an oxidant for upgrading hydrocarbon feedstocks. The captured CO2 is inherently reduced by the hydrocarbon co-reactants without consuming molecular hydrogen or renewable electricity. This CO2 utilization approach can be potentially applied to synthesize eight emission-intensive molecules, including olefins and epoxides. Catalytic systems and reactor concepts are discussed that can overcome practical challenges, such as thermodynamic limitations, over-oxidation, coking, and heat management. Under the best-case scenario, these hydrogen-free CO2 reduction processes have a combined CO2 abatement potential of approximately 1 gigatons per year and avoid the consumption of 1.24 PWh renewable electricity, based on current market demand and supply.

Catalytic tar conversion and the prospective use of iron-based catalyst in the future development of biomass gasification: a review

Biomass is a promising renewable energy source which is available globally, mostly in developing countries where access to clean and affordable energy is a critical problem. Biomass gasification is an interesting technology that can convert biomasses to a more versatile fuel known as syngas, the energy which can substitute conventional fossil fuels in the future. Syngas can amenably be combusted to produce power and heat as well as a feedstock for synthesis of chemicals and other fuels. The biomass gasification is facing severe operational challenges, one of the problems being tar formation and its removal techniques. Tar condenses at reduced temperature, thus causing blockage in the downstream equipment such as compressors and engines. Many studies have considered syngas cleaning by physical removal and thermal cracking unsuitable as they need downstream processing of scrub liquor and utilizes a part of the produced gas in maintaining the thermal cracking temperature, respectively. The utilization of catalysts has been an interesting focus; however, it has not yet been fruitful as many of the developed catalysts deactivate rapidly, and they are expensive or toxic. The motives of the current study are to review tar formation characteristics and trends on catalytic conversion. In addition, the study elucidates the fascinating behaviour of metallic and oxides of the iron-based catalyst under different syngas composition (oxidizing and reducing environments). The behaviours of the iron-based catalyst indicate its fundamental role in developing a catalyst for tar cracking with respect to less toxic, inexpensive, abundant, and regenerable alternatives.

One-pot process converts CO2 from air into methanol

Capturing carbon dioxide from ambient air and converting it into methanol—an alternative transportation fuel and feedstock for chemical synthesis—is one way to help keep rising levels of greenhouse...

The coupling of carbon dioxide with ethene to produce acrylic acid sodium salt in one pot by using Ni(II) and Pd(II)-phosphine complexes as precatalysts

Abstract The use of CO2 as a feedstock for chemical synthesis is considered as a viable alternative option to some traditional processes. One of the most interesting challenge for the industry is represented by the CO2 coupling with olefins to produce acrylate. Only recently, with the choice of suitable ligands and the use of a sacrificial base, a selective catalytic reaction was established by using Ni(0)-based complexes. The one-pot reaction, which leads to the highest TON (107 mol/mol Ni, in 20 h) reported so far, was successfully developed starting from Ni(0)-based precursors in the presence of disphosphine ligands, a large excess of base and of finely powdered zinc. In the present paper, we carried out the catalytic synthesis of sodium acrylate from CO2 and ethene, in one-pot, by using Ni(II)-chloride and Pd(II)-chloride phosphine-complexes as precatalyst. The reaction occurs under basic conditions and without adding any external reductants. The Ni(II) complexes lead to higher TON than the respective Pd(II) precursors and the best results are obtained by using diphosphines having high bite angles. Such catalysis is favored by aprotic and polar solvents in which a TON of 290 mol/mol Ni is reached by using the [NiCl2(dppp)] precursor in DMSO. Furthermore the TON could be increased by increasing the temperature, the base concentration and by using diphosphine ligands having high bite angle.

Investigating forward osmosis process for simultaneous preparation of brown coal slurry and wastewater reclamation

The feasibility of using the forward osmosis (FO) process involving brown coal as draw agent to reclaim clean water from dye wastewater is evaluated in this study. It is found that brown coal not only has enough driving force for drawing water from dye wastewater but also can be reconstituted during the FO process, thus resulting in directly usable coal water slurry after appropriate FO time as an energy source equivalent to fossil oil or feedstock for chemical synthesis via gasification. In the FO process, water-drawing effect can significantly enhance the slurryability of brown coal via weakening the moisture holding capacity, decreasing the porosity and achieving the favorable particle size distribution due to the improved grindability. A possible tri-factor water-drawing and reconstitution mechanism of brown coal during the FO process is proposed to explain the effects of FO process on the properties of brown coal. The results indicate that the FO process promises to be a low-cost green process for simultaneous wastewater treatment and preparation of coal water slurry for environmental protection and energy production.

Recent advances in the catalytic conversion of CO2 to value added compunds

CO2 is a major greenhouse gas, and it can also be used as a chemical feedstock for synthesis of chemicals and fuels by passing the petrochemical source. Herein, we present the recent progress of our research work in the catalytic conversion of CO2 to chemicals, with particular attention paid to catalytic reactivity and reaction mechanism. We also give the recommendations regarding the challenges and potential directions of the future research in this field.

Synthesis Gas as a Source of Fuels and Chemicals: C-1 Chemistry

This chapter is concerned with the present and future uses of synthesis gas as a source of fuels and chemicals. Synthesis gas, a mixture of hydrogen and carbon monoxide in various ratios, is important both as a fuel and as a feedstock for chemical synthesis. Fully developed processes are available for producing it from natural gas, petroleum, petroleum derivatives, and coal. Synthesis gas, in fact, can be made from almost any organic material, including biomass and organic wastes, and increasingly diverse raw materials may find use in the future. The composition of the raw synthesis gas produced can vary widely, depending on the process technology and the quality of the raw materials (especially their hydrogen-to-carbon ratios and their reactivities).