Blog

US: 877.464.2728
Outside US: 412.344.1870

Acid Gas Removal

When the efficient and effective removal of acid gas is required, APC offers the full range of solutions to address specific application needs. Applications that require acid gas removal systems include industrial boilers, chemical plants, medical and hazardous waste incinerators, sludge incinerators, industrial furnaces, aluminum remelt furnaces, biomass furnaces, kilns, metals finishing, foundries, mining, certain oil and petrochemical applications, power plants, pulp and paper manufacture, recycling operations, wastewater treatment plants, and more.

Regulated Acid Gases and General Control Technologies

Types of acid gas emissions that commonly need to be controlled include emissions of sulfur dioxide and trioxide (SO2 and SO3), hydrogen sulfide (H2S), hydrochloric acid (HCl), hydrogen fluoride (HF), chlorine (Cl2), sulfuric acid mist,nitric acid and phosphoric acid mists, and oxides of nitrogen.

APC has a full range of technologies to remove all of the above contaminants with the exception of nitrogen oxides. APC offers both wet and dry systems to remove acid gases. Wet systems commonly consist of packed bed scrubbers in which water or a scrubbing solution runs countercurrent to the gas stream through a bed of packing material that maximizes the gas-liquid interface, with mist removed at the scrubber gas outlet and the scrubbing liquid recycled to the extent possible. Dry systems typically consist of sorbent injection systems and fabric filters; also, in select cases, a dry media bed can be used to remove select acid gases. Wet systems typically deliver higher acid gas removal efficiencies than dry systems, but can generate a wastewater that needs additional treatment depending on the specific application. Through a partner, APC also offers enhanced wet-dry systems that have the high removal efficiency advantage of a wet process while not generating any wastewater.

GP Series Packed Tower Scrubbers

GP packed tower scrubbers maximize absorption of acid gases and other gas contaminants through use of high-efficiency packing and proven designs, achieving 99%+ acid gas removal efficiency in many applications. APC models the full packed tower design for each application, accounting for all gas conditions and providing removal efficiencies and sizing requirements for all equipment and flows. The composition of outlet gases and any discharged scrubbing liquid are calculated, allowing assessment of any potential wastewater treatment needs. These packed tower scrubbers can be designed as multi-stage units for selective control of multiple gas-phase contaminants. Appropriate materials of construction are used, from various types of FRP to 304 stainless steel to Hastelloy.

Sorbent Injection Systems

APC’s PC Series sorbent injection systems can offer the best combination of performance and cost for applications involving both particulate matter (PM) removal and removal of SO2, HCl, HF, mercury and other gaseous contaminants. Applications for this type of system typically include industrial boilers, incinerators (all types), industrial furnaces, remelt furnaces, kilns, and biomass combustion. APC offers sorbent injection and mixing systems for sorbents such as hydrated lime, trona, sodium bicarbonate, or powdered activated carbon (PAC), into the exhaust gas stream. When PM is co-present with the acid gases and also must be removed, APC sorbent injection systems are typically ideal. Depending on the required acid gas removal efficiencies, exhaust gases may also be treated using a two-stage system, with the PC Series sorbent injection system and baghouse followed by a second-stage, wet GP Series packed tower scrubber as polishing stage to ensure that the required acid gas removal efficiency is achieved.

Media Adsorption Systems

For H2S, Cl2, and HCl removal, APC also offers its adsorption systems that utilize single or multi-bed systems with tailored media to remove the contaminant(s) present with a dry, chemisorption process. This can be a very cost-efficient means to remove acid gases in certain applications, and APC’s extensive experience with fixed-bed media systems allows APC to offer this technology as another option for consideration by the customer.

Finally, APC also offers a unique, low-cost, HX UHF® unit that simultaneously removes particulate, mist, and acid gas in one compact, low-cost unit. This system can be sufficient for certain smaller applications.