Chemical looping ammonia synthesis based on the self-carried active N and Al from aluminum dross as low-cost nitrogen carrier.

Ammonia (NH), as a hydrogen energy carrier, is advantageous for mitigating energy consumption and carbon emission; however, the current Haber process for NH synthesis requires harsh conditions with a low conversion rate. To address these challenges, chemical looping ammonia synthesis (CLAS) has been proposed for utilizing aluminum dross (AD)-a hazardous waste containing sufficient active Al and N as a nitrogen carrier-involving carbon conversion without emissions. AD samples were employed to investigate the performance of CLAS, and the evolution of nitrogen carrier.

Dual mechanisms in hydrogen reduction of copper oxide: surface reaction and subsurface oxygen atom transfer.

The study of the reduction of copper oxide (CuO) by hydrogen (H) is helpful in elucidating the reduction mechanism of oxygen carriers. In this study, the reduction mechanism of CuO by H and the process of oxygen atom transfer were investigated through the density functional theory (DFT) method and thermodynamic calculation. DFT calculation results showed that during the reaction between H and the surface of CuO, Cu underwent a Cu → Cu → Cu transformation, the Cu-O bond (-IpCOHP = 2.

Numerical Simulation of an Improved Updraft Biomass Gasifier Based on Aspen Plus.

In this paper, numerical investigation and optimization is conducted upon an improved updraft gasifier which is expected to overcome the weakness of conventional updraft gasifier. The comprehensive Aspen Plus model of the improved updraft gasifier is based on the RYield and RCSTR reactor. The tar prediction model is constructed, and the yield of tar is determined by the volatile of biomass and gasification temperature.

Syngas production and gas-N evolution over heterogeneously doped La-Fe-O perovskite-type oxygen carriers in chemical looping gasification of microalgae.

Chemical looping gasification (CLG) is a promising technology for syngas production with low pollutant emission. In this study, doped La-Fe-O perovskites including LaFeO (LF), LaFeNiO (LN5F5) and LaBaFeO (L3B7F) were developed for microalgae CLG. The as-prepared perovskites exhibited an outstanding performance in syngas production with accumulative syngas yield > 33 mol/kg.

Simulation and Optimization of a Multistage Interconnected Fluidized Bed Reactor for Coal Chemical Looping Combustion.

This work established a three-dimensional model of a chemical looping system with multistage reactors coupled with hydrodynamics and chemical reactions. The thermal characteristics in the chemical looping combustion (CLC) system were simulated using coal as fuel and hematite as an oxygen carrier (OC). Some significant aspects, including gas composition, particle residence time, backmixing rate, wall erosion, carbon capture rate, etc.

The behavior of organic sulfur species in fuel during chemical looping gasification.

Uncoupling chemical looping gasification (CLG), the organic sulfur evolution was simulated and explored qualitatively and quantitatively using typical sulfur compounds on TG-MS and temperature-programmed fixed bed. The HS radical in the reductive atmosphere easier converted to HS and COS. HO activated the evolution of S which was stably bonded to carbon, and H generated from gasification and oxidation of reductive Fe by HO contributed to the release of sulfur.

Synergistic effects of lanthanum ferrite perovskite and hydrogen to promote ammonia production during microalgae catalytic pyrolysis process.

Ammonia (NH) production from nitrogen-enriched renewable resources pyrolysis is a green, clean, and sustainable technology. In this paper, lanthanum ferrite perovskite (LaFeO) and hydrogen (H) atmosphere were combined to enhance NH production during microalgae pyrolysis. The catalytic pyrolysis of microalgae pyrolysis was carried out in a fixed bed reactor.

Characteristic Evaluation and Process Simulation of CuFeO as Oxygen Carriers in Coal Chemical Looping Gasification.

Chemical looping gasification (CLG) has been described as an innovative and low-cost gasification technology to convert carbonaceous fuels into synthesis gases. Oxygen carrier (OC) is the key to resolve the contradiction between rapid carbon conversion and appropriate partial oxidation of coal. At present, the solid fuel conversion in the CLG process is limited by an iron-based OC, and a copper-based carrier has difficulty in maintaining the reduction atmosphere.