Scalable Photocatalyst Panels for Photoreforming of Plastic, Biomass and Mixed Waste in Flow

ReWaste4.0 is an innovative and cooperative K-Project in the period 2017–2021. Through ReWaste4.0 the transformation of the non-hazardous mixed municipal and commercial waste treatment industry towards a circular economy has started by investigating and applying the new approaches of the Industry 4.0. Vision of the ReWaste4.0 is, among others, the development of treatment plants for non-hazardous waste into a “Smart Waste Factory” in which a digital communication and interconnection between material quality and machine as well as plant performance is reached. After four years of research and development, various results have been gained and the present review article summarizes, links and discuss the outputs (especially from peer-reviewed papers) of seven sub-projects, in total, within the K-project and discusses the main findings and their relevance and importance for further development of the waste treatment sector. Results are allocated into three areas, namely: contaminants in mixed waste and technical possibilities for their reduction as well as removal; secondary raw and energy materials in mixed waste and digitalization in waste characterization and treatment processes for mixed waste. The research conducted in ReWaste4.0 will be continued in ReWaste F for further development towards a particle-, sensor- and data-based circular economy in the period 2021–2025.

Download Full-text

Characterization of Gas Transport Properties of Compacted Solid Waste Materials

Environments ◽

10.3390/environments8040026 ◽

2021 ◽

Vol 8 (4) ◽

pp. 26

Author(s):

Muhammad Rashid Iqbal ◽

Hiniduma Liyanage Damith Nandika ◽

Yugo Isobe ◽

Ken Kawamoto

Keyword(s):

Hydraulic Conductivity ◽

Solid Waste ◽

Gas Transport ◽

Bottom Ash ◽

Gas Diffusion ◽

Saturated Hydraulic Conductivity ◽

Dry Density ◽

Transport Parameters ◽

Functional Relations ◽

Mixed Waste

Gas transport parameters such as gas diffusivity (Dp/D0), air permeability (ka), and their dependency on void space (air-filled porosity, ε) in a waste body govern convective air and gas diffusion at solid waste dumpsites and surface emission of various gases generated by microbial processes under aerobic and anaerobic decompositions. In this study, Dp/D0(ε) and ka(ε) were measured on dumping solid waste in Japan such as incinerated bottom ash and unburnable mixed waste as well as a buried waste sample (dumped for 20 years). Sieved samples with variable adjusted moistures were compacted by a standard proctor method and used for a series of laboratory tests for measuring compressibility, saturated hydraulic conductivity, and gas transport parameters. Results showed that incinerated bottom ash and unburnable mixed waste did not give the maximum dry density and optimum moisture content. Measured compressibility and saturated hydraulic conductivity of tested samples varied widely depending on the types of materials. Based on the previously proposed Dp/D0(ε) models, the diffusion-based tortuosity (T) was analyzed and unique power functional relations were found in T(ε) and could contribute to evaluating the gas diffusion process in the waste body compacted at different moisture conditions.

Download Full-text

Migration of Sulfur and Nitrogen in the Pyrolysis Products of Waste and Contaminated Plastics

Applied Sciences ◽

10.3390/app11104374 ◽

2021 ◽

Vol 11 (10) ◽

pp. 4374

Author(s):

Waldemar Ścierski

Keyword(s):

Circular Economy ◽

Physicochemical Parameters ◽

Literature Analysis ◽

Waste Plastics ◽

Pyrolysis Process ◽

Pyrolysis Products ◽

Plastics Recycling ◽

A Value ◽

Mixed Waste ◽

Pyrolytic Oil

The most advantageous way of managing plastics, according to circular economy assumptions, is recycling, i.e., reusing them. There are three types of plastics recycling: mechanical, chemical and energy recycling. The products of the pyrolysis process can be used for both chemical and energy recycling. Possibilities of further use of pyrolysis products depend on their physicochemical parameters. Getting to know these parameters was the aim of the research, some of which are presented in this article. The paper presents the research position for conducting the pyrolysis process and discusses the results of research on pyrolysis products of waste plastics. The process was conducted to obtain the temperature of 425 °C in the pyrolytic chamber. Such a value was chosen on the basis of my own previous research and literature analysis. The focus was on the migration of sulfur and nitrogen, as in some processes these substances may pose a certain problem. Studies have shown high possibilities of migration of these elements in products of pyrolysis process. It has been shown that the migration of sulfur is similar in the case of homogeneous and mixed waste plastics—it immobilizes mainly in pyrolytic oil. Different results were obtained for nitrogen. For homogeneous plastics, nitrogen immobilizes mainly in char and oil, whereas for mixed plastics, nitrogen immobilizes in pyrolytic gas.

Download Full-text