The ArrowBio Process for Unsorted Municipal Solid Waste

Intoduction

The ArrowBio process is an integrated solution that receives Municipal Solid Waste (whether pre-sorted or unsorted) as an input, eliminating the need for prior separation or classification of mixed waste.

This waste is delivered by trucks and dumped into a pit, where it will be managed, in order for bulky items to be removed, and the waste bags will be opened.

* to read explanation about ArrowBio process, click on different sections on the diagram.

Arrowbio Process Basic principles Treatment of Inorganic Materials Treatment of Organic Material The Biological Reactors Output

Basic principles

The preliminary dry waste preparation and separation stage is based on the principle that the most of the biodegradable organic materials are smaller, thus can be separated with the waste’s liquids by a trommel. The larger elements will go through, and they contain more cardboard, paper, and plastics, which can be separated manually, and are more volume related than weight related.

The preliminary liquid-based waste preparation and separation stage is based on the principle that inorganic materials, such as metals and glass, have a specific weight that is greater than water, while plastics and biodegradable organic matter have a specific weight that is equal to or less than water. The larger materials will enter the Primary vat, while the smaller materials will go to the Secondary vat.

Treatment of Inorganic Materials

The heavy components that sunk to the bottom and were subsequently separated from the organic stream include ferrous metals, non-ferrous metals, glass and other inert materials.

These materials travel down a processing line, where they are separated by a number of methods, including a magnetic force, an eddy current and manual means. The remaining materials are returned to the dissolving tank and proceed to the light materials process.

Treatment of Organic Material

The light organic waste, already separated from the heavy components, is transported through a conveyor into a trammel, where strong water streams wash the materials and they enter a rough screen where the smaller elements go through the holes to a hydro-crushing unit. The large items proceed to a sorting conveyor, where the PET and HDPE are screened out manually, the metals are taken with a magnet, and the film plastic is blown out by using an air sifter. The rest of the materials enter into a rough shredder and then to the hydro-crusher.

The biodegradable material enters the filtering systems. Here, the residual contaminations are filtered out, and the grit, sand, broken glass, and small metal elements, are screened out using a settling vat. Larger elements go through a secondary air sifter and then return for a second cycle in the system, or out to be landfilled. The remaining energy rich organic watery solution, is sent to the biological reactors to yield fertilizer, water and biogas.

The Biological Reactors

In the biological reactors section the fluid undergoes another two processes, both of which are orchestrated by naturally occurring microorganisms.

In the first bioreactor tank, acidogenic fermentation transforms complex organic material into simpler organic acids and fatty acids. This acid rich organic matter is then heated up to 36-40 degrees Celsius, and transported to the Methanogenic Fermentation reactor, for anaerobic degradation of the organic materials and the generation of clean fertilizer, water and biogas.

The Biogas is used for energetic needs and for heating the Methanogenic tank.

Output

The anaerobic digestion process generates fertilizer, water, and Biogas containing up to 75% pure methane.

The Biogas is stored in inflatable buffer tanks. It can be sold as clean green energy for transportation and power plants - a substantially less polluting alternative to fossil fuels.