DIAGNÓSTICO CLIENTES

several technical and institutional

challenges.

gasifier technology cannot meet large-scale power generation applications). In Jiangsu, a 4-MW entrained flow biomass gasification power plant has also been operating for several years. Crop straw gasification for electricity generation has good economic, environmental, and social effectiveness, because it provides clean electricity, utilizes agricultural waste, and can help increase farmer income (Table 3.11). However, there are a number of obstacles to expanding the use of this technology.

Most significantly, the electricity generated is difficult to sell to the grid because (i) the utility company may not be interested in such a small amount of electricity, and (ii) the inclusion of required grid protection and safety equipment are not economical at small plants. In addition, the

gas produced contains tar, ash, and alkaline metals that must be removed to safe levels before the gas can be burned in a gas engine or gas turbine for power generation. Doing so at low cost has been difficult.

Biofuels

Interest in biofuels as a substitute to fossil fuels will continue to increase because of concerns over the environment, energy security, and climate change. However, development of this industry must be carefully considered, as the recent food-versus-fuel debate has shown, and the full life-cycle of biofuel benefits must be considered. Marginal lands, including desolated hills and slopes, river-basin flood areas and winter idle lands, will be the most suitable for growing energy crops.

Table 3.11: Scoring for Crop Straw Gasification

Criteria Score Comments

Technical Evaluation ★★★

The volumetric heat content of the producer gas will vary depending on the gasifier design and the amount of air used in the gasification process. The gas produced in the gasifier contains tar, ash, and alkaline metals that can be difficult to remove at a low cost.

Economic Assessmenta _★★★★

It provides a reasonable FIRR, because of the subsidy provided under the Renewable Energy Law. A sample power plant for 6-MW crop straw gasi- fication entails an initial investment of CNY39,039,000 and payment of CNY7,800,000 in annual operation and maintenance costs, while resulting in annual benefit of CNY17,820,000, so the FIRR is 21% and EIRR is 29%. Environmental Impact ★★★ The environmental impact is similar to that of electricity generated by direct

straw combustion.

Social Impact ★★★★ The social impact is similar to that of electricity generated by direct straw combustion.

Comprehensive Result ★★★

a _{The data used for evaluation of this power generation option came from the 4-MW crop straw gasification project in Xinghua, Jiangsu} Province surveyed by Jia Xiaoli (consultant of biomass power generation of the TA team) in 2007.

EIRR = economic internal rate of return, FIRR = financial internal rate of return.

Table 3.12: Cost–Benefit Analysis for Crop Straw Gasification

Number of Plants Initial Investment (CNY) Annual O&M Cost (CNY) Annual Economic Benefit (CNY) Net Benefit (CNY) EIRR (%) FIRR (%) Benefit– Cost Ratio Payback Period (years) 6 39,039,000 7,800,000 17,820,000 13,839,068 29 21 1.80 2.8

EIRR = economic internal rate of return, FIRR = financial internal rate of return, O&M = operation and maintenance. Source: ADB. 2008. Preparing National Strategy for Rural Biomass Renewable Energy Development. Manila.

Technologies for bioethanol and biodiesel are in the test phase or just entering commercialization; their industrialization is expected within the next 5–10 years. Other biofuel technologies, such as fast pyrolysis oils, biomass-based Fischer-Tropsch synthesis gas, and biohydrogen production face technology and cost barriers.

The TA study considered the potential of energy crops for bioethanol and biodiesel production. It did not, however, study forestry resources (e.g., oil seed trees) as another potential resource for biofuels.

Bioethanol. After years of trials in selected

provinces, the government has begun pouring huge investments into ethanol. The country produced 1.02 million tons of bioethanol from stored corn stocks and other raw materials in 2005. The ethanol is added to petrol at a ratio of 1:10 for automobiles.25 _{The government estimates that by}

2010, ethanol-mix petrol will account for half of the country’s petrol consumption.

Large firms have announced ambitious plans for bioenergy investments. China National Petroleum

Corporation signed an agreement with the government of Sichuan Province in southwest PRC to develop facilities to produce 600,000 tons of automotive-grade ethanol from sweet potatoes annually and 100,000 tons of biodiesel from the seeds of the jatropha curcas tree. China National Cereals, Oils and Foodstuffs Corporation said in October 2007 it would invest CNY1 billion to build a major ethanol plant in the Guangxi region, also in southwest PRC. The plant, with a capacity of 400,000 tons, will lift 1.1 million farmers out of poverty by growing cassava as the raw material for the plant, said Yue Guojun, head of the

corporation’s bio-chemical and bioenergy division.26

ADB’s assessment noted that the three main feedstocks for bioethanol production—sweet sorghum, cassava, and sugarcane—have good environmental, economic, and social effectiveness, although each raises concerns regarding impacts on the efficient use of rural land, structuring of energy plantations, and equity of farmer income and employment. Important differences in their relative cost-effectiveness stem from regional factors, such as climate and water availability, feedstock costs, and by-product values.

The highest score went to sweet sorghum, as it has higher economic and financial returns than the other two crops. Ethanol production from sweet sorghum is best suited to the northeastern and northwestern regions, the middle and lower reaches of the Yellow River, and the Qinghai-Xizang tableland.

The assessment gives sugarcane ethanol a

moderate priority because of its attractive regional potential. Production is best suited to southern and tropical regions, such as Guangdong, Guangxi, Hainan, and Yunnan. The government should support enterprises using sugarcane for ethanol by offering modest subsidies according to the environmental and social benefits generated in the process.

25 _{Xinhua News Agency. 2006. China to Provide Subsidies to Bio-Energy Sector. Beijing Pioneer Technology Co. Ltd. 1 December.}

Available: http://210.51.191.165/show.php?contentid=20866

26 _Ibid.

ADB’s assessment noted that the