Contribution Of Biomass-Based Liquid Fuel To Chinese Oil Security

Energy resources are the precondition for human civilization.Energy security is the guarantee of energy supply that is needed by the economic development and social progress over a country or a region.Because of the high energy content and liquid property,oil takes a more important position in all fossil fuels.Besides supply security,oil security all considers price risks.There have been three oil crises in the world history.Oil crisis caused negative impacts to the world economy,especially for those countries with higher dependence on imported oil. There is no oil crises caused by supply intermission in the new century,but the price of crude oil in the world oil market is ascending continuously.In 2006,the price of crude once reached a peak of 78 US dollars per barrel.The fundamental reason of the existence of international oil security is the great difference of geographic distribution of oil resources and consumption.In the remaining proven oil reserves in 2005,61.9%is located in Middle East.The oil production in the region is 31%of the total oil production in the world.However,the top 8 countries in oil consumption are USA,China,Japan, Russia,Germany,India,Korea,and Canada,7 of 8 countries are net oil import countries,except Russia.Because the asymmetric distribution of oil resource and consumption is the existing fact, the problem of oil security will exist as long as oil is still the main source of liquid fuel.China became the net oil import country in 1993,and amount of imported oil are increasing year after year.In 2006,the total amount of imported crude oil is 145 Mt,with expenditure of more than 66.4 billion US dollars.In the same year,China imports 36.38 Mt of oil products, with expenditure of 15.55 billion US dollars.The dependence on imported oil is over 40%.Many approaches can be applied to mitigate the oil security problem,including establishment of strategic oil reserve,ensuring oil import,increasing domestic oil production,disseminating energy-saving technologies and equipment,and developing biomass-based liquid fuel.All of these approaches have their own advantages and disadvantages,and none of them can solve the problem of oil security independently.Development of biomass-based liquid fuels is the certain approach to substitute oil and to guarantee the oil security.At present,the biomass-based liquid fuels are mostly fuel ethanol and bio-diesel. Technology of fuel ethanol production from saccharine material such as starch is already mature. The technology of fuel ethanol production from cellulose(straw)still has some obstacles to overcome,e.g.difficulties in pre-treatment of raw material,problem of pentose fermentation,high cost of cellulose enzyme,etc.Technologies of bio-diesel production are basically mature. However,the chemical method has such disadvantages as complicated procedure,high energy consumption,dark color of product,high cost,and pollutant disposal.Biological enzyme method has such disadvantages as long reaction time,high cost of biological enzyme,and short life of enzyme.Material production is the key to development of biomass-based liquid fuels.Because the food security is more important than energy security,and plantation field per capita is much less than the world average,China will have to select non-food crop and trees to be the material for developing biomass-based liquid fuels.For China,the ideal materials for fuel ethanol production are sweet sorghum stem,cassava,and sweet potato;and for bio-diesel rape seed and woody plant such as Jatropha curcas.Production of these materials does not engross the plantation field for food crops,and fuel ethanol or bio-diesel production rate per unit area is relatively high.Currently,the annual production of fuel ethanol is 1.02 Mt,with material of food crops such as maize and wheat;the production of bio-diesel is small,with material of wasted animal or plant. grease.Even if all the major agricultural products in 2005 were used to produce liquid fuel,the substitution for oil would still much less than the oil consumption in the same year.On any piece of land,the production of biomass-based liquid fuel is positively relative to the available land area and fuel ethanol or bio-diesel production rate per unit area.The fuel ethanol or bio-diesel production rate per unit area is positively relative to the material yield and saccharine content or oil content of material.In China,the land resources that can be used to produce material for liquid fuels are:plantation field of sorghum and maize that can be substituted by sweet sorghum,winter idle field in South China,sloping landthat is needed to convert into forest, oil plant forestry land,and in-support plantation land.Based on the quantity and quality of these land resources,the maximum of possible production of biomass-based liquid fuel is 220 Mt, which can substitute crude oil of 270 Mt,less than the oil consumption in 2005.Therefore, development of biomass-based liquid fuel is one of the good approaches to solve the problem of oil security in China,but because of the restriction of land resource,bare dependence on biomass-base liquid fuel can not solve the problem.In terms of substitution effect and the ratio of gasoline and diesel consumption,China should vigorously develop bio-diesel rather than fuel ethanol.However,the materials for fuel ethanol production are agricultural crops,while the materials for fuel ethanol production are oil wood plants,of which the cost and harvest difficulties are higher than crops.These difficulties must be fully considered in the process of developing bio-diesel in order to realize the coordinated development between different products of biomass-based liquid fuel.At the initial phase of biomass-based liquid fuel development in China,the government must give great supports to the new industry.Laws and regulations should clearly prescribe:reform and perfect the administration system,establish efficient leading and management system;strictly enforce the responsibilities invested by the laws,establish the subsidy and other financial incentive mechanism as soon as possible;encourage the research and development of technology and engineering;constitute laws or regulations to ensure the biological energy development in line with the targets of food security and environment security,encourage the plantation of energy corps and plants on the condition of no confliction with food crop production;establish the laws or regulations to enable qualified biomass-based liquid fuels to freely enter the fuel distribution system.In addition,China should carry out a national survey on material for biomass-based liquid fuel as soon as possible,and formulate the regional development planning.China should also recognize the importance of experiment and demonstration of biomass-base liquid fuel project.