Assessment Of Raw Material Supply Capability And Energy Potential Of Biomass Resources In China

The current world is confronted with the double pressure of fossil energy depletion and environmental pollutions.Replacing fossil fuels with renewable energy has been an irresistible trend,and biomass energy occupies an important place in renewable energy industry.Raw material supply is the most significant factor that restricts the development of biomass industry in China.Therefore,figuring out the status and distribution characteristics of biomass resources in China is the foundation for developing biomass industry.In our country,a large number of crop stalks,forestry residues,livestock and poultry manure,agricultural products processing residues and organic wastes are produced annually.In addition,there are marginal land resources that can grow energy plants with strong stress resistance.Based on national statistics data in 2015,this study estimated the raw material supply capability and energy potential of agricultural and forestry residues in China.Besides,combining with the population distribution.topography,ecological and environmental protection requirments,the 1 km grid datasets of land use and the net primary productivity(NPP)in 2015 were used in this research,to assess the resource amount of marginal land as well as its energy potential on a national scale.The results of this study are useful to provid a scientific basis for relevant policy-making and industrial distribution of bioenergy industry development in china.The main conclusions are as follows:(1)In China,agricultural and forestry residues can be divided into eight categories,i.e.,crop stalks,agricultural products processing residues,livestock and poultry manure,forestry residues,municipal solid wastes,industrial wastewater and domestic sewage,waste cooking oil and cottonseed oil,of which the resource amount for energy use was estimated at 201 million tons(Mt),51.8 Mt,49.6 Mt,90.5 Mt,5.66 Mt,4.25 Mt,6.12 Mt and 1.49 Mt standard coal equivalence respectively,with a total of 411 Mt standard coal equivalence.(2)The bioenergy potential of agricultural and forestry residues,74,1%(304 Mt standard coal equivalence)was derived from agriculture,22.0%(90.5 Mt standard coal equivalence)from forestry,and 3.90%(16.0 Mt standard coal equivalence)from industrial processing and municipal waste output.The energy potential produced annually of eight main categories,in increasing order,was crop stalks>forestry residues>agricultural products processing residues>livestock and poultry manure>waste cooking oil>municipal solid wastes>industrial wastewater and domestic sewage>cottonseed oil.Although the residue resources have great difference in quantity among the eight main categories,they all have their own characteristics,and each of them can be developed separately.(3)In China,marginal land suitable for bioenergy development includes eleven types,i.e.,shrub land,sparse forest land,sparse grassland,river and canals,shoal land,bottomland,sand land,gobi land,alkaline land,marshland and bare land.Under different screening conditions of biomass threshold and ecological protection standard,the total area of marginal land suitable for growing energy plants was estimated at 90.5-144 million hm2 in 2015.Shrub land,sparse forest land and sparse grassland were the three major components of marginal land whose area for bioenergy production added up to around79.3?100 million hm2,accounting for more than 70%of the total area.(4)The total net primary productivity of the marginal land suitable for energy plants in 2015 was 395 Tg C,which was equal to 895 Mt vegetation biomass and 628 Mt aboveground biomass(dry weight)of the energy plants,respectively.The total bioenergy potential of the marginal land amounted to 345 Mt standard coal equivalence,and among which the bioenergy potential of the aboveground biomass of shrub land and sparse forest land was estimated at 137 and 105 Mt standard coal equivalence respectively,composing 70%of the total bioenergy potential of marginal land.(5)The total bioenergy potential in China was 756 Mt standard coal equivalence,which was equivalent to 1/6 of the national primary energy consumption in 2015.The bioenergy potential of the existing agricultural and forestry residues and the marginal land in the future accounted for 54.3%and 45.7%,respectively.For the short-term development of bioenergy industry,the existing agricultural and forestry residues are the realistic raw materials basis and should be given high priority.At present,the bioenergy industry scale in China is less than 5%of the bioenergy potential of agricultural and forestry residues.It is recommended to give priority to making full use of the biomass resources,including crop stalks burned in fields,livestock and poultry manure,industrial wastewater,municipal solid waste,etc.,which will have a dual effect of energy replacement and enviromental pollution elimination.In addition,from the perspectives of economic feasibility,multiple benefits of environmental protection and energy utilization,and ecological protection,this study reviewed the problems that should be paid attention to when utilizing various biomass resources and put forward several suggestions on the development priority order.