A prefeasibility study of integrating WoodRoll gasification technology into Ovako Steel and HEAB replacing fosssil fuels in Hofors

Abstract

Biomass gasification is considered a key technology in reaching targets for renewable energy and CO2 emissions reduction. This thesis studies the feasibility of a new technology of biomass gasification called WoodRoll for the production of Syngas with the aim to replace fossil fuels in the furnaces of the steel company OVAKO in Hofors. This research attempts to study the techno-economic viability of WoodRoll technology integration with the district heating company HEAB, creating a synergy between the companies and WoodRoll technology. Moreover, a theoretically study of the environmental impact, concerning greenhouse effect and pollutants it is also carried out. In the future scenario HEAB, as an energy supplier will be the gasification plant owner supplying with Syngas 5% cheaper than the fuels that they use today to Ovako. Three different scenarios have been studied varying the capacity of the gasification plant. The scenarios are 5MW, 10MW and 15MW capacity. The study show that the system is technically viable being possible to create a synergy between the three process improving efficiency and decreasing cost and CO2 emissions. The results from the economic study show that biomass gasification using WoodRoll technology is a highly interesting investment option for HEAB. From Ovako side, the project is very interesting too since the company can have a combustible 5% cheaper than the fuels used today without doing any investment. In 5MW scenario, 40GWh per year are converted in Ovako from oil to Syngas. With an investment for HEAB of 9.8 mSEK, profits were a Net Present Value of 6.3mSEK with 7.8 years of payback period. In 10MW scenario 80GWh were replaced. In this scenario, required investment was 146 mSEK with a NPV of 32.5 mSEK . Payback in this case was 6.3 years. The most profitable scenario was the case of 15M. With an investment of 188 mSEK the profits of the project were 60mSEK with a payback period of 5.8 years. In the three cases, especially in 15MW case, sensitivity study of the system show that it is very robust to changes in biomass cost and Syngas price. This parameters have a big impact on the profits but a big margin until becomes unfeasible. From Ovako side, savings for the fuel conversion were 1.2; 2.4 and 3.6mSEK for the 5, 10 and 15MW respectively. Reduction of CO2 emissions was 11, 20 and 30 thousands of CO2 tons for the three scenarios allowing the company to sell CO2 allowances and having an extra profit of 3, 6 and 8mSEK per year in the 5, 10 and 15MW scenario respectively.