How is Alkatra production where is it used

How is Alkatra production where is it used AlkaTara kya hai aur kyon jaruri hai alkatra Jo Kala ya gehre bhure rang ka hota hai yah ek prakar ka bye product hai jo petroleum ke parishkaran ke dauran utpann hota hai yah petrol ko saaf karne per milta hai junkari liye video dekhiye sony georaphy .com