Life of energy infrastructures such as power generation plants and petroleum refineries is more than 40 years, and it takes long time for changing over technology generations. For studying the future energy infrastructure, it is required to consider several aspects: change of supply conditions of primary energies, change of energy conversion technologies and change of demand side of secondary energies. According to the energy outlook of Japan, dependency on petroleum will be reduced while requirement for electricity will be increased. Availability of light crude oil will become tight while demand for lighter products will increase relatively with less demand for heavier products. This means it is crucial to adopt some technologies for processing heavy bottoms. We constructed an integrated model including grid power generation system and petroleum refining system to study the change of energy conversion sectors. It is a multi-period linear programming model covering 2000 to 2050. Gasification technologies, such as Resid IGCC and Gasification Hydrogen Unit, are introduced as bottom processing technologies in addition to conventional thermal and hydro cracking. We found following results: (1) Using only heaviest crude oil, lighter products can be supplied by cracking facilities, while residues are fed to power generation then exported to power grid. (2) Potential of electricity generated by Resid IGCC is about 5% of total Japanese power demand, with generation capacity 7GW. (3) Hydrogen unit is also converted from conventional steam reformer using light feed stocks to gasification hydrogen unit using thermal cracked residues.
In this study, 13 types of sewage energy system are evaluated by using inventory analysis. Evaluation indexes are energy balance, greenhouse gas emission, and economic efficiency. The main equipment of those energy systems are three types of incineration, three types of solid fuel, two types of pyrolysis gasification, and five types of digestion. The range of evaluation is from sewage sludge to power generation. Inputs of those energy systems are electricity, city gas, light oil, and wood biomass, and outputs are production of electricity, CO2 gas, and N2O gas. The results from the viewpoint of energy balance show that only the systems with gasification furnace produce larger electricity generation than total consumption. The results about the greenhouse gas emission show that the lowest gas emission system is the system with solid fuel produced by drying. N2O gas emitted by solid fuel is lower than the others. The results about the economic efficiency show that the lowest cost system is the systems with solid fuel because the construction cost that holds most of total cost is much lower than the other systems.
The present study aims to compile an extended input-output table to analyze employment effects of the introduction of solar photovoltaic (PV) and wind power generation technologies. Based on 2005 input-output table for Japan, the extended input-output table is constructed by creating new sectors related to the two above generation technologies and adding direct employment requirements in all the sectors. The extended input-output table allows for estimating direct and indirect employment required over the life cycle (manufacturing, construction, and operation & maintenance) of PV and wind power generation technologies. Using the extended table, life cycle employments induced by the introduction of PV and wind power generation technologies are estimated to be 2.8 and 0.69 person/GWh, respectively. Also, about 30% and 35% of life cycle employments for PV and wind power are roughly generated overseas, respectively.
Rice straw was treated using hot compressed water with or without phosphoric acid for enzymatic saccharification. The yields of xylose and glucose obtained from the treatment of the rice straw using hot compressed water without phosphoric acid were low. However, when 0.7% phosphoric acid solution was added to hot compressed water, the yield of xylose increased remarkably, and the highest yield (71%) was obtained at 160°C. Furthermore, the yield of glucose from the treated rice straw by enzymatic saccharification using an enzyme cocktail with a cellulase loading of 2 FPU/g- rice straw was 86%. It clarified that the hot compressed water treatment with phosphoric acid was effective in lowering the enzyme loading compared with the original hot compressed water treatment.
The structure of asphaltene is an important factor in the reactivity of heavy hydrocarbons, with. elemental analysis and nuclear magnetic resonance (NMR) spectrometry commonly used to evaluate its structure. However, such analyses can be limited by small sample amounts. In particular, 13C-NMR for the determination of carbon aromaticity (fa) requires about 100 mg of asphaltene, whereas elemental analysis and 1H-NMR need only 10 mg or less. In addition, 13C-NMR has the disadvantage of a long time. To avoid these drawbacks, we used a statistical estimation method to determine the fa of the pentane-insoluble and hepane-soluble fraction (C5AS) based on the results of elemental analysis and 1H-NMR analysis using 29 worldwide vacuum resides. Results showed that the fa was estimated within an error of 0.03 using H/C, N/C and S/C atomic ratios obtained by an elemental analysis, and hydrogen distribution obtained by 1H-NMR. The difference between the observed and estimated number of aromatic rings per unit structure was expected to be within 1. This method can estimate the fa for C5AS using a sample of only 20-30 mg, and the structural analysis is more accurate than that without fa value.