By Christoph Steitz and Tom Käckenhoff FRANKFURT/DUESSELDORF (Reuters) -Germany’s biggest power producer RWE on Thursday raised its outlook for 2022, citing higher margins in its power generation business and sending its shares to their highest level in nearly 11 years. The group, which is also one of Europe’s largest renewable energy firms, now expects adjusted core earnings (EBITDA) of 3.6 billion to 4 billion euros ($4.1 billion-4.5 billion), up from a previous range of 3.3 billion to 3.6 billion euros. RWE – which makes electricity from solar, wind, water biomass, gas, coal and nuclear ene…