Carbon offset production flows to regions or industries that have a lower price of carbon—unless carbon can be purchased from that area, which offsets effectively permit, equalizing the price. Carbon offsets may represent six primary categories of greenhouse gases: carbon dioxide (), methane (CH), nitrous oxide (NO), perfluorocarbons (PFCs), hydrofluorocarbons (HFCs), and sulfur hexafluoride (SF). Carbon offsets have several common features: In 2009, 8.2 billion metric tons of carbon dioxide equivalent changed hands worldwide, up 68 per cent from 2008, according to the study by carbon-market research firm Point Carbon, of Washington and Oslo. But at EUR94 billion, or about $135 billion,
Carbon dioxide scrubber of carbon dioxide without expendable products. Regenerable systems allowed a shuttle mission a longer stay in space without having to replenish its sorbent canisters. Older lithium hydroxide (LiOH)-based systems, which are non-regenerable, were replaced by regenerable metal-oxide-based systems. A system based on metal oxide primarily consisted of a metal oxide sorbent canister and a regenerator assembly. It worked by removing carbon dioxide using a sorbent material and then regenerating the sorbent material. The metal-oxide sorbent canister was regenerated by pumping air at approximately through it at a standard flow rate of for 10 hours. Activated carbon can be used as