Optimization of Blended Guava and Fluted Pumpkin Leaves extract as corrosion inhibitor of mild steel in 0.5 m hydrochloric acid

There are many plant extracts that have been studied for possible use as corrosion inhibitors in the oil and gas industries. Hence, this work is focused on optimization of blended Guava and Fluted Pumpkin Leaves extract as corrosion inhibitor of mild steel in HCI using Weight loss method. Response Surface Methodology of Design Expert trial version 12 StatEase was used to design and analyze the result of the 35-run experiments. Three factor-three level was adopted in the design. Time, Temperature and Inhibitor Quantity were the independent variables, while the acid concentration of 0.5M was constant throughout the experiments and Inhibition Efficiencies were measured using IE formula. Intervals of 1 hr, 0.2g, and 10°C were chosen for the immersion time, inhibitor quantity and temperature, respectively. Phytochemical analysis carried out on the Guava and Fluted Pumpkin Leaves shows that each leaf extract contains phytochemicals which are responsible for inhibiting corrosion. Weight loss result shows that the Blended extract reduces the corrosion rate of mild steel in 0.5M HCl. Additionally, 4 experiments for Blended Extract, Fluted Pumpkin, Guava Extract and Industrial Inhibitor were carried out at optimal conditions as predicted by the software at time 4.036 hr, temperature 49.5°C, inhibitor quantity 0.487g and ratio of 59.21GE:FP40.79 Inhibition Efficiencies of the Blended, Fluted Pumpkin, Guava Extracts and Industrial Inhibitor were 93.70%, 78.14%, 63.7% and 95.18%, respectively. The results show that the blended and Industrial Inhibitor compared well with the software predicted IE of 96.085%. Therefore, the blended extract could serve as good substitute to the industrial inhibitor.

PENGARUH PENGASAPAN TERHADAP KEAWETAN KAYU BINTANGUR (Chalophyllum sp.) DAN KAYU MEDANG (Chinnamomum sp) DARI SERANGAN RAYAP TANAH Coptotermes curvignathus Holmgren

Medang wood (Chinnamumum sp) and Bintangur wood (Calophyllum sp) was used for timber construction even they have low quality on the durability. The efforts need to improve their durability, especially against subterranean termites, the most destructive wood organism. One methods of preservation which can improve the durability was fumigation. Fumigation can be processed with traditional methods and modern methods. The aim of the study was to improve the durability of Medang wood (Chinnamumum sp) and Bintangur wood (Calophyllum sp)with modern fumigation methods and evaluation the durability against subterranean termites Coptotermes curvignathus Holmgren. Wood sample was measured 2 cm x 2 cm x 1 cm. The fumigation treatment was conducted with oven. The oven size was 1 m x 1 m x 50 cm. Treatments of fumigation consits of 12 hours and 24 hours. The treatment of evaluation the durability agaisnt termites was conducted for 21 days. The wood sample was put on the bottle and 50 termites consist of 45 workers and 5 soldiers were put in the wood sample. The parameter of indicator was termite’s mortality and wood weight loss. Result of the research showed that average termites mortality was reach 100% at wood sample with fumigation method for 24 hours, and 89.2% for wood sample with fumigation method for 12 hours. Meanwhile in control wood the termite’s mortality only 8.6%. The level of termites mortality with fumigation methods for 24 hours was classified very strong and for fumigation methods for 12 hours was classified as strong. The average wood weight loss was 1.21% - 1.30%. This wood weight loss was classified as very low. From the research it is concluded that fumigation method can increased the durability of wood, both on Medang wood and Bintangur wood against the subterranean termites Coptotermes curvignathus Holmgren. The optimal fumigation methods was on 12 hours, both on Medang wood and Bintangur wood.Keywords: Calophyllum sp, Chinnamumum sp, Coptotermes curvignathus, fumigation, wood preservation

Inhibition Behavior of a Novel Acidification Inhibitor for Steels at High Temperature

The QL-03 corrosion inhibition system is obtained by the compounds of quinoline quaternary ammonium salt，mannich base and synergist. The mechanism of QL-03 with HP13Cr in 20%HCl is investigated by potentiodynamic polarization curves, EIS and weight loss measurements. The results show that the inhibition efficiency towards HP13Cr steel is improved greatly and reaches as high as 90% at 90°C, as a mixed corrosion inhibition system. Cumulating the inhibition efficiency from electrochemical results is more reasonable than weight loss result.