In theory, biodiesel should be carbon neutral (whether it is in practice is not so clear). So in an arid country like Iraq you will either - need a large amount of water to irrigate all the plants you make the biodiesel from - or you import it. The impacts on the country are wildly different.
Technically, using biodiesel instead of fossil based diesel will contribute to reduction in GHG provided biodiesel production can be argued to carbon neutral. However, knowing the condition of Iraq, I think such a question should be addressed on a lower priority.
With reference to researches that were carry out in the field of biodiesel, it can not replaced completely petroleum based diesel but can be blended with it at difference proportion for the purpose of research and for better performance in diesel engine puting into consideration specific fuel consumption and emitted gases