1 ton of co. 2. produced for every ton of clinker produced reduction of co. 2 . if amount of clinker produced is less 2 extend cement availability and rely less on foreign cements . 13 . 0.0 0.2 0.4 0.6 0.8 1.0 plant 1 plant 2 plant 3. kg co kg cement. portland cement portlandlimestone cement.