Global Exhaust Gas Purifiers Market By Type (General Filter Type Exhaust Gas Purifier , Initiative Regeneration Type Exhaust Gas Purifier , Passive Regeneration Type Exhaust Gas Purifier , Fuel Injection Type Exhaust Gas Purifier , and Microwave Regeneration Type Exhaust Gas Purifier), By Application (Power Generation , Chemical , Cement & Printing , and Iron and Steel), By Region, and Key Companies - Industry Segment Outlook, Market Assessment, Competition Scenario, Trends and Forecast 2020-2029