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Emission Control

Pyrolisis, Incineration and Gasification

Thermal decomposition processes (TD Processes), such as Pyrolisis, Incineration and Gasification are increasingly related with carbon capture, originated from several sources, from RDF to Biomass. CO2 is not solid and thereby it is impossible for it to be captured or filtered. However, several technologies are emerging for the conversion of biomass to fuels and thereby storing CO2 on a solid form.
Bioenergy with carbon capture and storage (so called BECCS) is the process of using biomass, such as trees, crops, or residues, for energy production through these TD processes involving very low O2, while capturing the carbon in a solid form (dust) before it is released into the atmosphere. BECCS is assumed to have a prominent role in many integrated assessment models of climate change, mainly due to its presumed low cost in the future. It is considered as the most fundamental Carbon Reduction Pillar by the Intergovernmental Panel on Climate Change (IPCC).
Dedusting after these high temperature processes has always been a very good application for cyclones since these can separate particulate matter (PM) from very hot air streams with reduced pressure drop, negligible downtime and low CAPEX and OPEX.

Furthermore, the CO2 in the flue gases can also be captured by several alternative means such as by the injection of solid sorbents e.g. hydrated lime, or calcium oxide (CaO). The product of the reaction from CO2 and CaO, known as “carbonation”, is solid Calcium Carbonate (CaCO3) and cyclones are ideal to capture it. In more recently developed processes such as Calcium Looping the calcium oxide is regenerated and can be used repeatedly in a closed loop.

For these very high temperature exhaust streams (>600ºC ) the general arrangement of the plants include cyclones and/or heat ceramic filters followed by heat exchangers, after which traditional bag filters or scrubbers are used as end stage dedusters.
The primary high temperature separator, typically a cyclone, needs to reduce ash and char as much as possible, which is often a byproduct (biochar). A good efficiency is important for the product yield and to diminish concentration of solids to end stage dedusters, avoiding plugging of scrubbers and damaging of filters. Ceramic filters are an option but have a considerable pressure drop, typically up to 300mm w.g., gradually increasing due to clogging of the pores. The long-term durability and cracking risk (mainly during cleaning) of the elements are also critical.
At low temperatures, traditional bag filters imply the frequent change of bags and often disturb the continuity of syngas production with the need to clean the filtering elements. Bag filters have operation costs and imply production downtime.

Client's needs include an efficient and robust high temperature pre-separator and a very high efficient final stage dedusting system upstream of the engine with low OPEX.
ACS solutions include hot cyclones to be placed immediately after the gasifier and high efficiency cyclones as alternative to scrubbers and bag filters, whenever there is low particulate concentration in the gas streams.
Please see our case studies for several specific industrial segments.