Sieving

Technology
Technology details
Name:	Sieving
Category:	Pre-processing (Separation technologies), Post-processing (Separation technologies)
Feedstock:	all solid materials
Product:	separated products

Sieving is a simple technique for separating particles of different sizes. Sieving has been around since the time of the ancient Egyptians and can be considered the backbone of particle size technology.  Sieving’s continuing popularity is due to the technique’s fundamentally simple principle and methodology, historical reference, and cost effectiveness. Several instrument components involved in a sieve analysis can be quality controlled, making the technique applicable to various industries including pharmaceutical, industrial, agricultural, and chemical. In food industries sieves (often vibrating) are used to prevent the contamination of the product by foreign bodies. The main method is separation of product(s) into different fractions according to the particle size. Particles with a size bigger than the mesh of the used sieve will be withheld and smaller particles will fall through.

Feedstock

Sieving process

Origin and composition

The sieving method is used to separate different components from a solid mixture via separating particles of different sizes. The feedstock composition therefore is a mixture of materials of different particle size e.g. coming from a sizing pro-treatment or a drying process.

Pre-treatment

For sieving no specific pre-treatment is needed since it is used to separate different fraction within a process chain. Sometimes it is combined with other separation technologies or the particle mixtures need to be dry.

Process and technologies

While sieving may appear rudimentary compared to more modern instrumental particle sizing techniques, it still requires several important considerations to obtain the best repeatable and precise results.  Several factors must be considered when developing a robust sieving method or performing a routine quality analysis. Sample size, sieving duration, controlled agitation parameters and end point determination are all critical method variables which need to be addressed.

Sieve analysis

Sieving analysis

A sieve analysis (or gradation test) is a practice to assess the particle size distribution (also called gradation) of a granular material by allowing the material to pass through a series of sieves of progressively smaller mesh size and weighing the amount of material that is stopped by each sieve as a fraction of the whole mass.

Several mechanisms are used to disperse the sample and transport it through the screens (i.e. vibration, air entrainment or flowing liquid).  While considered relatively low resolution, sieving’s practical applications lend itself well to quality control specifications.

Products

Post-treatment

The post-treatment of the different products are depending on the next steps within the production chain.

Technology providers

ABC

Particle classification, sieving provider

General information
Company:
Country:
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Technology and process details
Technology name:		Technology category:	Pre-processing (Separation technologies), Post-processing (Separation technologies)
TRL:		Capacity:	kg·h-1
Pore size:	µm	Sieve material:
Sieve type:		Surface area:	m2
		Other:
Feedstock and product details
Feedstock:		Product:

describe the company, here is an example

ABC was founded in 20... 12 by KNN and Syncom, in collaboration with the university of Groningen, Netherlands. The company is a technology provider developing chemical recycling technologies for different feedstocks including non-food bio- and plastics waste. In 2018 a pilot plant with the capability to process biomass and plastic waste was set up at the Zernike Advanced Processing (ZAP) Facility. The company is now focused on setting up their first commercial plant with a capacity of 20,000 to 30,000 tonnes. The investing phase B was recently completed, with the last investment phase in 2019 the financial requirements are fulfilled to complete the commercialisation activities to build the plant which is expected for 2023.

describe their technology, here is an example

The technology is based on an Integrated Cascading Catalytic Pyrolysis (ICCP) process, being able to produce aromatics including benzene, toluene, and xylene (BTX) as well as light olefins from low grade biomass and plastics waste. This technology utilises catalytic cracking in a two-step process at temperatures between 450- 850 °C. In the first step the feedstock material is vaporised via thermal cracking. The pyrolysis vapours are then directly passed into a second reactor in which they are converted into aromatics by utilising a zeolite catalyst which can be continuously regenerated. Finally, the products are separated from the gas via condensation. An ex situ approach of catalytic conversion has several advantages such as the protection of the catalyst from deactivation/degradation expanding its lifetime, a greater variety of feedstock, and a precise adjustment of process conditions (e.g. temperature, catalyst design, and Weight Hourly Space Velocity (WHSV) in each step for improved yields. In current pilot plant with 10 kg h-1 feed capacity for either waste plastics or biomass, final design details are established, which will be include in the running engineering activities for the commercial plant.

Open access pilot and demo facility providers

Pilots4U Database

Patents

Currently no patents have been identified.

References

• Sieving in Wikipedia
• Sieve analysis