Catalytic production of low-carbon footprint sustainable natural gas

Natural gas is one of the foremost basic energy sources on earth. Although biological process appears as promising valorization routes to transfer biomass to sustainable methane, the recalcitrance of lignocellulosic biomass is the major limitation for the production of mixing gas to meet the natural gas composition of pipeline transportation. Here we develop a catalytic-drive approach to directly transfer solid biomass to bio-natural gas which can be suitable for the current infrastructure. A catalyst with Ni2Al3 alloy phase enables nearly complete conversion of various agricultural and forestry residues, the total carbon yield of gas products reaches up to 93% after several hours at relative low-temperature (300 degrees Celsius). And the catalyst shows powerful processing capability for the production of natural gas during thirty cycles. A low-carbon footprint is estimated by a preliminary life cycle assessment, especially for the low hydrogen pressure and non-fossil hydrogen, and technical economic analysis predicts that this process is an economically competitive production process.

Pyrolysis of RDF and Catalytic Decomposition of the Produced Tar in a Char Bed Secondary Reactor as an Efficient Source of Syngas

One of the technical limitations of refuse-derived fuel (RDF) pyrolysis is the high content of tar in its gas products. In order to resolve this problem, a two-stage RDF pyrolysis with a catalyst based on char from RDF pyrolysis is proposed. This paper presents the results of municipal waste pyrolysis beginning in an oven heated to 480 °C and ending with catalytic tar cracking carried out in the temperature range from 800 to 1000 °C. Thermal and catalytic pyrolysis with a char catalyst containing a minimum of 6% Fe resulted in increases in the CO and H2 contents in gas products and decreases in CO2 and CH4. At 1000 °C, the mass ratio of gaseous products to liquids was greater than 6. The residence time of the gases in the catalytic zone was about 3–5 s. The reactor was a good source of hydrogen and carbon monoxide.

Assessing the Effects of Logistics Performance on Energy Trade

Logistics has become one of the most important economic sectors. It significantly affects the transport infrastructure and many other sectors that are crucial for the country’s development. It is the factor that also influences trade efficiency. However, the question arises if logistics performance is significant for the trade of critical goods which are energy raw products. The aim of the paper is primarily to investigate the EU energy trade flows in general and to estimate the effect of logistics performance on the international trade of energy raw products. The energy raw products are grouped into solid, liquid, and gaseous products, and separate estimates are made for their export and import. The analysis also differentiates between the trade flows, that is export and import within the EU and trade flows between EU member states and third countries. The empirical model is based on the theory of gravity model extended to include the six subcomponents of the Logistics Performance Index (LPI). The results present that: (1) the standard gravity model variables, such as GDPs of reporter and partner countries and contiguity, are successful in explaining the trade flows of solid and liquid raw energy but in case of gas products, are insignificant; (2) the results indicate that all logistics’ performance subcomponents are highly significant and show positive effects on the export of liquid energy products, while for the solid and gas products, it seems to be insignificant when the energy commodities are more complex and costly to transport and store, and therefore, contiguity, i.e., when countries share a common border, positively affects energy trade.; (3) the EU imports most liquid energy products, but is generally very dependent on energy imports. EU policymakers should strive to either make more use of domestic resources or switch more to renewable energy sources

Modes of Occurrence of Chromium and Their Thermal Stability in Low-Rank Coal Pyrolysis

Chromium (Cr) and the emission of its compounds into the environment have caused long-term environmental contamination. In this study, the modes of occurrence of Cr in low-rank coal and their thermal stability in pyrolysis were investigated by sequential chemical extraction (SCE), single-component samples (SCS) pyrolysis, and thermochemical equilibrium simulation. The results showed that organic matter, aluminosilicate, and carbonate were the dominant modes of occurrence of Cr in low-rank coal. The modes of occurrence and chlorine (Cl) content affected the volatilization of Cr in coal. The characteristic release temperature range of Cr bounded to aluminosilicate was >600 °C and 400–600 °C for Cr bounded to a disulfide. Cr bounded to organic matter almost released completely before 600 °C. Cl enhanced the volatility of Cr and reduced its release temperature in Cr bounded to aluminosilicate. The simulation showed the content of gas products was very low, mainly chlorides. While the content of solid products, sulfides, and oxides, was much higher than gas products, showing their high thermal stability. The sulfides and oxides in chars were closely related to the carbonate and aluminosilicate bound form of Cr. The results of the equilibrium simulation were consistent with the experimental results.

Decomposition characteristics of SF6/N2 gas mixture with local overheating

In recent years, Chinese power enterprises have adopted SF6/N2 to replace SF6 gas in transmission electrical equipment. In this paper, an experimental platform was set up to simulate the local overheating fault of gas insulated electrical equipment. The relationship between the decomposition products of SF6/N2 gas and temperature, experimental time, gas pressure and SF6 content was studied. The results showed that the main products of SF6/N2 gas decomposition were SO2, SO2F2, N2O, C2F6, COS, CS2 and CF4. The content of SO2 increased nonlinearly with the increase of temperature, experimental time, gas pressure and SF6 content. However, the contents of SO2F2, N2O, C2F6, COS, CS2 and CF4 decreased first and remained unchanged with the increase of gas pressure, and increased with the increase of temperature, experimental time and SF6 content. And C element in metal also affected the type and quantity of gas products.

GC investigation of post-irradiation oxidation phenomena on polypropylene

The paper summarizes the results of research on gas products of polypropylene (PP) radiolysis. Particular attention was paid to the phenomena of post-radiation degradation of PP. The protective effect of selected aromatic compounds was investigated. The research was carried out both from the point of view of obtaining radiation-resistant PP varieties and the possibility of accelerating biodegradation phenomena, e.g., PP/cellulose composition. The phenomena of post-radiation chain oxidation of PP were investigated by gas chromatography (GC). The GC in the system used (packed column, thermal conductivity detector, argon – carrier gas) enables the determination of H2, O2, CO, and CH4 in one measurement. The samples were irradiated with electron beams (EBs) accelerated in accelerators: Elektronika 10/10 with a power of 10 kW and energy of 10 MeV and LAE 13/9 with a power of 9 kW and energy up to 13 MeV. In the tests, PP without stabilizing additives (obtained directly from the production line) and non-stabilized styrene were used. Radiolytic efficiency of hydrogen evolution allowed us to estimate the number of originally formed free radicals. The maintenance of the secondary oxidation processes was the loss of oxygen and the formation of oxidation products (CO, CH4). Attention is paid to the protective effect of aromatic compounds (polystyrene (PS), polyethylene terephthalate (PET), anthracene, fluoranthene, acenaphthene, pyrene, naphthalene) both at the stage of hydrogen atom separation and the secondary oxidation process. The examples of post-radiation oxidation of PP irradiated in cryogenic conditions (–196°C) are presented. All used aromatic compounds showed a protective effect in PP radiolysis. We suppose that this phenomenon is responsible for the charge transfer along the polymer chain from the ionization spurs to the aromatic compound. The protective ranges of PS in PP radiolysis were estimated for the variously prepared PP/PS type compositions from 6 mers to 28 mers.