The alkali soil and pollution of SO2 in China were analyzed in this paper. Biomass and coal mixed briquette was suggested to control SO2 emission from domestic coal combustion. The effect of biomass and coal mixed briquette ash on alkali soil modification and yield of crop was discussed. It was concluded that building a production and utilization system of biomass and coal mixed briquette can reduce the difference between city and country in China and partly solve the excess labor force in Chinese countries, which is favorable for even development of China.
We have introduced "heat factor" for the evaluation of the total energy efficiency of cogeneration system in Japan. According to our analysis based on exergy basis, the "heat factor" for Japan is calculated to be 0.24 - 0.28, which is much smaller than the factor for US and Europe, which are 0.5 or higher. This result implicates the difficulty of the use of thermal output of cogeneration in Japan, which has little heat demand compared to the US and Europe. By comparing the adjusted total efficiency of cogeneration with the grid power plant (all average, fossil fuel average, state of art LNG combined cycle), we found that it was inappropriate to regard cogeneration as highly efficient just by the simple total efficiency. The adjusted total efficiency was calculated to be nearly equal or a little higher than the average fossil fired power plant depending on the type of demand, and much smaller than the state of art LNG combined cycle for all demand assumed in our study.
The yield and fuel properties of biodiesel fuel (BDF) produced from animal fats by the existent method from vegetable fats were analyzed. The following results were obtained; (1) Animal fats can yield BDF by the existent method from vegetable fats. However, the cold filter plugging point (CFPP) of BDF from animal fat is higher than that of vegetable fat. (2) CFPP is nearly equal to the value calculated by the solid-liquid equilibrium assuming that methylpalmitate (C16Me) and methylstearate (C18Me) are solid components. It is suggested that decreasing the amount of C16Me and C18Me improves CFPP. (3) The storage stability and combustion property of BDF are improved by increasing the amount of saturated fatty acid methyl ester, on the contrary. (4) Animal fats can produce BDF of suitable properties by controlling the amount of C16Me and C18Me in the appropriate range.